GrTessellator.cpp revision 70f5251cc59191040a14cd0f1567aa2129e1f7c6
1e9709e831954c3427d5cb839e84221a177bfedebethannicholas/* 2e9709e831954c3427d5cb839e84221a177bfedebethannicholas * Copyright 2015 Google Inc. 3e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 4e9709e831954c3427d5cb839e84221a177bfedebethannicholas * Use of this source code is governed by a BSD-style license that can be 5e9709e831954c3427d5cb839e84221a177bfedebethannicholas * found in the LICENSE file. 6e9709e831954c3427d5cb839e84221a177bfedebethannicholas */ 7e9709e831954c3427d5cb839e84221a177bfedebethannicholas 8e9709e831954c3427d5cb839e84221a177bfedebethannicholas#include "GrTessellator.h" 9e9709e831954c3427d5cb839e84221a177bfedebethannicholas 10e9709e831954c3427d5cb839e84221a177bfedebethannicholas#include "GrPathUtils.h" 11e9709e831954c3427d5cb839e84221a177bfedebethannicholas 126599efffeef3168dfc68dca99c30454c5c23b859senorblanco#include "SkChunkAlloc.h" 136599efffeef3168dfc68dca99c30454c5c23b859senorblanco#include "SkGeometry.h" 146599efffeef3168dfc68dca99c30454c5c23b859senorblanco#include "SkPath.h" 15e9709e831954c3427d5cb839e84221a177bfedebethannicholas 16e9709e831954c3427d5cb839e84221a177bfedebethannicholas#include <stdio.h> 17e9709e831954c3427d5cb839e84221a177bfedebethannicholas 18e9709e831954c3427d5cb839e84221a177bfedebethannicholas/* 19e9709e831954c3427d5cb839e84221a177bfedebethannicholas * There are six stages to the algorithm: 20e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 21e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 1) Linearize the path contours into piecewise linear segments (path_to_contours()). 22e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 2) Build a mesh of edges connecting the vertices (build_edges()). 23e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 3) Sort the vertices in Y (and secondarily in X) (merge_sort()). 24e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 4) Simplify the mesh by inserting new vertices at intersecting edges (simplify()). 25e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 5) Tessellate the simplified mesh into monotone polygons (tessellate()). 26e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 6) Triangulate the monotone polygons directly into a vertex buffer (polys_to_triangles()). 27e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 28e9709e831954c3427d5cb839e84221a177bfedebethannicholas * The vertex sorting in step (3) is a merge sort, since it plays well with the linked list 29e9709e831954c3427d5cb839e84221a177bfedebethannicholas * of vertices (and the necessity of inserting new vertices on intersection). 30e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 31e9709e831954c3427d5cb839e84221a177bfedebethannicholas * Stages (4) and (5) use an active edge list, which a list of all edges for which the 32e9709e831954c3427d5cb839e84221a177bfedebethannicholas * sweep line has crossed the top vertex, but not the bottom vertex. It's sorted 33e9709e831954c3427d5cb839e84221a177bfedebethannicholas * left-to-right based on the point where both edges are active (when both top vertices 34e9709e831954c3427d5cb839e84221a177bfedebethannicholas * have been seen, so the "lower" top vertex of the two). If the top vertices are equal 35e9709e831954c3427d5cb839e84221a177bfedebethannicholas * (shared), it's sorted based on the last point where both edges are active, so the 36e9709e831954c3427d5cb839e84221a177bfedebethannicholas * "upper" bottom vertex. 37e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 38e9709e831954c3427d5cb839e84221a177bfedebethannicholas * The most complex step is the simplification (4). It's based on the Bentley-Ottman 39e9709e831954c3427d5cb839e84221a177bfedebethannicholas * line-sweep algorithm, but due to floating point inaccuracy, the intersection points are 40e9709e831954c3427d5cb839e84221a177bfedebethannicholas * not exact and may violate the mesh topology or active edge list ordering. We 41e9709e831954c3427d5cb839e84221a177bfedebethannicholas * accommodate this by adjusting the topology of the mesh and AEL to match the intersection 42e9709e831954c3427d5cb839e84221a177bfedebethannicholas * points. This occurs in three ways: 43e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 44e9709e831954c3427d5cb839e84221a177bfedebethannicholas * A) Intersections may cause a shortened edge to no longer be ordered with respect to its 45e9709e831954c3427d5cb839e84221a177bfedebethannicholas * neighbouring edges at the top or bottom vertex. This is handled by merging the 46e9709e831954c3427d5cb839e84221a177bfedebethannicholas * edges (merge_collinear_edges()). 47e9709e831954c3427d5cb839e84221a177bfedebethannicholas * B) Intersections may cause an edge to violate the left-to-right ordering of the 48e9709e831954c3427d5cb839e84221a177bfedebethannicholas * active edge list. This is handled by splitting the neighbour edge on the 49e9709e831954c3427d5cb839e84221a177bfedebethannicholas * intersected vertex (cleanup_active_edges()). 50e9709e831954c3427d5cb839e84221a177bfedebethannicholas * C) Shortening an edge may cause an active edge to become inactive or an inactive edge 51e9709e831954c3427d5cb839e84221a177bfedebethannicholas * to become active. This is handled by removing or inserting the edge in the active 52e9709e831954c3427d5cb839e84221a177bfedebethannicholas * edge list (fix_active_state()). 53e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 54e9709e831954c3427d5cb839e84221a177bfedebethannicholas * The tessellation steps (5) and (6) are based on "Triangulating Simple Polygons and 55e9709e831954c3427d5cb839e84221a177bfedebethannicholas * Equivalent Problems" (Fournier and Montuno); also a line-sweep algorithm. Note that it 56e9709e831954c3427d5cb839e84221a177bfedebethannicholas * currently uses a linked list for the active edge list, rather than a 2-3 tree as the 57e9709e831954c3427d5cb839e84221a177bfedebethannicholas * paper describes. The 2-3 tree gives O(lg N) lookups, but insertion and removal also 58e9709e831954c3427d5cb839e84221a177bfedebethannicholas * become O(lg N). In all the test cases, it was found that the cost of frequent O(lg N) 59e9709e831954c3427d5cb839e84221a177bfedebethannicholas * insertions and removals was greater than the cost of infrequent O(N) lookups with the 60e9709e831954c3427d5cb839e84221a177bfedebethannicholas * linked list implementation. With the latter, all removals are O(1), and most insertions 61e9709e831954c3427d5cb839e84221a177bfedebethannicholas * are O(1), since we know the adjacent edge in the active edge list based on the topology. 62e9709e831954c3427d5cb839e84221a177bfedebethannicholas * Only type 2 vertices (see paper) require the O(N) lookups, and these are much less 63e9709e831954c3427d5cb839e84221a177bfedebethannicholas * frequent. There may be other data structures worth investigating, however. 64e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 65e9709e831954c3427d5cb839e84221a177bfedebethannicholas * Note that the orientation of the line sweep algorithms is determined by the aspect ratio of the 66e9709e831954c3427d5cb839e84221a177bfedebethannicholas * path bounds. When the path is taller than it is wide, we sort vertices based on increasing Y 67e9709e831954c3427d5cb839e84221a177bfedebethannicholas * coordinate, and secondarily by increasing X coordinate. When the path is wider than it is tall, 68e9709e831954c3427d5cb839e84221a177bfedebethannicholas * we sort by increasing X coordinate, but secondarily by *decreasing* Y coordinate. This is so 69e9709e831954c3427d5cb839e84221a177bfedebethannicholas * that the "left" and "right" orientation in the code remains correct (edges to the left are 70e9709e831954c3427d5cb839e84221a177bfedebethannicholas * increasing in Y; edges to the right are decreasing in Y). That is, the setting rotates 90 71e9709e831954c3427d5cb839e84221a177bfedebethannicholas * degrees counterclockwise, rather that transposing. 72e9709e831954c3427d5cb839e84221a177bfedebethannicholas */ 73e9709e831954c3427d5cb839e84221a177bfedebethannicholas 74e9709e831954c3427d5cb839e84221a177bfedebethannicholas#define LOGGING_ENABLED 0 75e9709e831954c3427d5cb839e84221a177bfedebethannicholas 76e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 77e9709e831954c3427d5cb839e84221a177bfedebethannicholas#define LOG printf 78e9709e831954c3427d5cb839e84221a177bfedebethannicholas#else 79e9709e831954c3427d5cb839e84221a177bfedebethannicholas#define LOG(...) 80e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 81e9709e831954c3427d5cb839e84221a177bfedebethannicholas 82e9709e831954c3427d5cb839e84221a177bfedebethannicholas#define ALLOC_NEW(Type, args, alloc) new (alloc.allocThrow(sizeof(Type))) Type args 83e9709e831954c3427d5cb839e84221a177bfedebethannicholas 84e9709e831954c3427d5cb839e84221a177bfedebethannicholasnamespace { 85e9709e831954c3427d5cb839e84221a177bfedebethannicholas 86e9709e831954c3427d5cb839e84221a177bfedebethannicholasstruct Vertex; 87e9709e831954c3427d5cb839e84221a177bfedebethannicholasstruct Edge; 88e9709e831954c3427d5cb839e84221a177bfedebethannicholasstruct Poly; 89e9709e831954c3427d5cb839e84221a177bfedebethannicholas 90e9709e831954c3427d5cb839e84221a177bfedebethannicholastemplate <class T, T* T::*Prev, T* T::*Next> 91e6eaa320e8dac34396dc364aa0863574d7b5291csenorblancovoid list_insert(T* t, T* prev, T* next, T** head, T** tail) { 92e9709e831954c3427d5cb839e84221a177bfedebethannicholas t->*Prev = prev; 93e9709e831954c3427d5cb839e84221a177bfedebethannicholas t->*Next = next; 94e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (prev) { 95e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->*Next = t; 96e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (head) { 97e9709e831954c3427d5cb839e84221a177bfedebethannicholas *head = t; 98e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 99e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (next) { 100e9709e831954c3427d5cb839e84221a177bfedebethannicholas next->*Prev = t; 101e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (tail) { 102e9709e831954c3427d5cb839e84221a177bfedebethannicholas *tail = t; 103e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 104e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 105e9709e831954c3427d5cb839e84221a177bfedebethannicholas 106e9709e831954c3427d5cb839e84221a177bfedebethannicholastemplate <class T, T* T::*Prev, T* T::*Next> 107e6eaa320e8dac34396dc364aa0863574d7b5291csenorblancovoid list_remove(T* t, T** head, T** tail) { 108e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (t->*Prev) { 109e9709e831954c3427d5cb839e84221a177bfedebethannicholas t->*Prev->*Next = t->*Next; 110e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (head) { 111e9709e831954c3427d5cb839e84221a177bfedebethannicholas *head = t->*Next; 112e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 113e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (t->*Next) { 114e9709e831954c3427d5cb839e84221a177bfedebethannicholas t->*Next->*Prev = t->*Prev; 115e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (tail) { 116e9709e831954c3427d5cb839e84221a177bfedebethannicholas *tail = t->*Prev; 117e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 118e9709e831954c3427d5cb839e84221a177bfedebethannicholas t->*Prev = t->*Next = nullptr; 119e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 120e9709e831954c3427d5cb839e84221a177bfedebethannicholas 121e9709e831954c3427d5cb839e84221a177bfedebethannicholas/** 122e9709e831954c3427d5cb839e84221a177bfedebethannicholas * Vertices are used in three ways: first, the path contours are converted into a 123e9709e831954c3427d5cb839e84221a177bfedebethannicholas * circularly-linked list of Vertices for each contour. After edge construction, the same Vertices 124e9709e831954c3427d5cb839e84221a177bfedebethannicholas * are re-ordered by the merge sort according to the sweep_lt comparator (usually, increasing 125e9709e831954c3427d5cb839e84221a177bfedebethannicholas * in Y) using the same fPrev/fNext pointers that were used for the contours, to avoid 126e9709e831954c3427d5cb839e84221a177bfedebethannicholas * reallocation. Finally, MonotonePolys are built containing a circularly-linked list of 127e9709e831954c3427d5cb839e84221a177bfedebethannicholas * Vertices. (Currently, those Vertices are newly-allocated for the MonotonePolys, since 128e9709e831954c3427d5cb839e84221a177bfedebethannicholas * an individual Vertex from the path mesh may belong to multiple 129e9709e831954c3427d5cb839e84221a177bfedebethannicholas * MonotonePolys, so the original Vertices cannot be re-used. 130e9709e831954c3427d5cb839e84221a177bfedebethannicholas */ 131e9709e831954c3427d5cb839e84221a177bfedebethannicholas 132e9709e831954c3427d5cb839e84221a177bfedebethannicholasstruct Vertex { 133e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex(const SkPoint& point) 134e9709e831954c3427d5cb839e84221a177bfedebethannicholas : fPoint(point), fPrev(nullptr), fNext(nullptr) 135e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fFirstEdgeAbove(nullptr), fLastEdgeAbove(nullptr) 136e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fFirstEdgeBelow(nullptr), fLastEdgeBelow(nullptr) 137e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fProcessed(false) 138e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 139e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fID (-1.0f) 140e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 141e9709e831954c3427d5cb839e84221a177bfedebethannicholas {} 142e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint fPoint; // Vertex position 143e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* fPrev; // Linked list of contours, then Y-sorted vertices. 144e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* fNext; // " 145e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fFirstEdgeAbove; // Linked list of edges above this vertex. 146e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fLastEdgeAbove; // " 147e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fFirstEdgeBelow; // Linked list of edges below this vertex. 148e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fLastEdgeBelow; // " 149e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool fProcessed; // Has this vertex been seen in simplify()? 150e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 151e9709e831954c3427d5cb839e84221a177bfedebethannicholas float fID; // Identifier used for logging. 152e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 153e9709e831954c3427d5cb839e84221a177bfedebethannicholas}; 154e9709e831954c3427d5cb839e84221a177bfedebethannicholas 155e9709e831954c3427d5cb839e84221a177bfedebethannicholas/***************************************************************************************/ 156e9709e831954c3427d5cb839e84221a177bfedebethannicholas 157e9709e831954c3427d5cb839e84221a177bfedebethannicholastypedef bool (*CompareFunc)(const SkPoint& a, const SkPoint& b); 158e9709e831954c3427d5cb839e84221a177bfedebethannicholas 159e9709e831954c3427d5cb839e84221a177bfedebethannicholasstruct Comparator { 160e9709e831954c3427d5cb839e84221a177bfedebethannicholas CompareFunc sweep_lt; 161e9709e831954c3427d5cb839e84221a177bfedebethannicholas CompareFunc sweep_gt; 162e9709e831954c3427d5cb839e84221a177bfedebethannicholas}; 163e9709e831954c3427d5cb839e84221a177bfedebethannicholas 164e9709e831954c3427d5cb839e84221a177bfedebethannicholasbool sweep_lt_horiz(const SkPoint& a, const SkPoint& b) { 165e9709e831954c3427d5cb839e84221a177bfedebethannicholas return a.fX == b.fX ? a.fY > b.fY : a.fX < b.fX; 166e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 167e9709e831954c3427d5cb839e84221a177bfedebethannicholas 168e9709e831954c3427d5cb839e84221a177bfedebethannicholasbool sweep_lt_vert(const SkPoint& a, const SkPoint& b) { 169e9709e831954c3427d5cb839e84221a177bfedebethannicholas return a.fY == b.fY ? a.fX < b.fX : a.fY < b.fY; 170e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 171e9709e831954c3427d5cb839e84221a177bfedebethannicholas 172e9709e831954c3427d5cb839e84221a177bfedebethannicholasbool sweep_gt_horiz(const SkPoint& a, const SkPoint& b) { 173e9709e831954c3427d5cb839e84221a177bfedebethannicholas return a.fX == b.fX ? a.fY < b.fY : a.fX > b.fX; 174e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 175e9709e831954c3427d5cb839e84221a177bfedebethannicholas 176e9709e831954c3427d5cb839e84221a177bfedebethannicholasbool sweep_gt_vert(const SkPoint& a, const SkPoint& b) { 177e9709e831954c3427d5cb839e84221a177bfedebethannicholas return a.fY == b.fY ? a.fX > b.fX : a.fY > b.fY; 178e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 179e9709e831954c3427d5cb839e84221a177bfedebethannicholas 180e9709e831954c3427d5cb839e84221a177bfedebethannicholasinline SkPoint* emit_vertex(Vertex* v, SkPoint* data) { 181e9709e831954c3427d5cb839e84221a177bfedebethannicholas *data++ = v->fPoint; 182e9709e831954c3427d5cb839e84221a177bfedebethannicholas return data; 183e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 184e9709e831954c3427d5cb839e84221a177bfedebethannicholas 185e9709e831954c3427d5cb839e84221a177bfedebethannicholasSkPoint* emit_triangle(Vertex* v0, Vertex* v1, Vertex* v2, SkPoint* data) { 186e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if WIREFRAME 187e9709e831954c3427d5cb839e84221a177bfedebethannicholas data = emit_vertex(v0, data); 188e9709e831954c3427d5cb839e84221a177bfedebethannicholas data = emit_vertex(v1, data); 189e9709e831954c3427d5cb839e84221a177bfedebethannicholas data = emit_vertex(v1, data); 190e9709e831954c3427d5cb839e84221a177bfedebethannicholas data = emit_vertex(v2, data); 191e9709e831954c3427d5cb839e84221a177bfedebethannicholas data = emit_vertex(v2, data); 192e9709e831954c3427d5cb839e84221a177bfedebethannicholas data = emit_vertex(v0, data); 193e9709e831954c3427d5cb839e84221a177bfedebethannicholas#else 194e9709e831954c3427d5cb839e84221a177bfedebethannicholas data = emit_vertex(v0, data); 195e9709e831954c3427d5cb839e84221a177bfedebethannicholas data = emit_vertex(v1, data); 196e9709e831954c3427d5cb839e84221a177bfedebethannicholas data = emit_vertex(v2, data); 197e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 198e9709e831954c3427d5cb839e84221a177bfedebethannicholas return data; 199e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 200e9709e831954c3427d5cb839e84221a177bfedebethannicholas 201e9709e831954c3427d5cb839e84221a177bfedebethannicholasstruct EdgeList { 202e9709e831954c3427d5cb839e84221a177bfedebethannicholas EdgeList() : fHead(nullptr), fTail(nullptr) {} 203e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fHead; 204e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fTail; 205e9709e831954c3427d5cb839e84221a177bfedebethannicholas}; 206e9709e831954c3427d5cb839e84221a177bfedebethannicholas 207e6eaa320e8dac34396dc364aa0863574d7b5291csenorblancostruct VertexList { 208e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco VertexList() : fHead(nullptr), fTail(nullptr) {} 209e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco Vertex* fHead; 210e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco Vertex* fTail; 211e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco void insert(Vertex* v, Vertex* prev, Vertex* next) { 212e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_insert<Vertex, &Vertex::fPrev, &Vertex::fNext>(v, prev, next, &fHead, &fTail); 213e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco } 214e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco void append(Vertex* v) { 215e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco insert(v, fTail, nullptr); 216e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco } 217e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco void prepend(Vertex* v) { 218e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco insert(v, nullptr, fHead); 219e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco } 220e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco}; 221e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco 222e9709e831954c3427d5cb839e84221a177bfedebethannicholas/** 223e9709e831954c3427d5cb839e84221a177bfedebethannicholas * An Edge joins a top Vertex to a bottom Vertex. Edge ordering for the list of "edges above" and 224e9709e831954c3427d5cb839e84221a177bfedebethannicholas * "edge below" a vertex as well as for the active edge list is handled by isLeftOf()/isRightOf(). 225e9709e831954c3427d5cb839e84221a177bfedebethannicholas * Note that an Edge will give occasionally dist() != 0 for its own endpoints (because floating 226e9709e831954c3427d5cb839e84221a177bfedebethannicholas * point). For speed, that case is only tested by the callers which require it (e.g., 227e9709e831954c3427d5cb839e84221a177bfedebethannicholas * cleanup_active_edges()). Edges also handle checking for intersection with other edges. 228e9709e831954c3427d5cb839e84221a177bfedebethannicholas * Currently, this converts the edges to the parametric form, in order to avoid doing a division 229e9709e831954c3427d5cb839e84221a177bfedebethannicholas * until an intersection has been confirmed. This is slightly slower in the "found" case, but 230e9709e831954c3427d5cb839e84221a177bfedebethannicholas * a lot faster in the "not found" case. 231e9709e831954c3427d5cb839e84221a177bfedebethannicholas * 232e9709e831954c3427d5cb839e84221a177bfedebethannicholas * The coefficients of the line equation stored in double precision to avoid catastrphic 233e9709e831954c3427d5cb839e84221a177bfedebethannicholas * cancellation in the isLeftOf() and isRightOf() checks. Using doubles ensures that the result is 234e9709e831954c3427d5cb839e84221a177bfedebethannicholas * correct in float, since it's a polynomial of degree 2. The intersect() function, being 235e9709e831954c3427d5cb839e84221a177bfedebethannicholas * degree 5, is still subject to catastrophic cancellation. We deal with that by assuming its 236e9709e831954c3427d5cb839e84221a177bfedebethannicholas * output may be incorrect, and adjusting the mesh topology to match (see comment at the top of 237e9709e831954c3427d5cb839e84221a177bfedebethannicholas * this file). 238e9709e831954c3427d5cb839e84221a177bfedebethannicholas */ 239e9709e831954c3427d5cb839e84221a177bfedebethannicholas 240e9709e831954c3427d5cb839e84221a177bfedebethannicholasstruct Edge { 241e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge(Vertex* top, Vertex* bottom, int winding) 242e9709e831954c3427d5cb839e84221a177bfedebethannicholas : fWinding(winding) 243e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fTop(top) 244e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fBottom(bottom) 245e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fLeft(nullptr) 246e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fRight(nullptr) 247e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fPrevEdgeAbove(nullptr) 248e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fNextEdgeAbove(nullptr) 249e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fPrevEdgeBelow(nullptr) 250e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fNextEdgeBelow(nullptr) 251e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fLeftPoly(nullptr) 252531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco , fRightPoly(nullptr) 253531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco , fLeftPolyPrev(nullptr) 254531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco , fLeftPolyNext(nullptr) 255531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco , fRightPolyPrev(nullptr) 25670f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco , fRightPolyNext(nullptr) 25770f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco , fUsedInLeftPoly(false) 25870f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco , fUsedInRightPoly(false) { 259e9709e831954c3427d5cb839e84221a177bfedebethannicholas recompute(); 260e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 261e9709e831954c3427d5cb839e84221a177bfedebethannicholas int fWinding; // 1 == edge goes downward; -1 = edge goes upward. 262e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* fTop; // The top vertex in vertex-sort-order (sweep_lt). 263e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* fBottom; // The bottom vertex in vertex-sort-order. 264e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fLeft; // The linked list of edges in the active edge list. 265e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fRight; // " 266e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fPrevEdgeAbove; // The linked list of edges in the bottom Vertex's "edges above". 267e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fNextEdgeAbove; // " 268e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fPrevEdgeBelow; // The linked list of edges in the top Vertex's "edges below". 269e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fNextEdgeBelow; // " 270e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* fLeftPoly; // The Poly to the left of this edge, if any. 271e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* fRightPoly; // The Poly to the right of this edge, if any. 272531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* fLeftPolyPrev; 273531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* fLeftPolyNext; 274531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* fRightPolyPrev; 275531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* fRightPolyNext; 27670f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco bool fUsedInLeftPoly; 27770f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco bool fUsedInRightPoly; 278e9709e831954c3427d5cb839e84221a177bfedebethannicholas double fDX; // The line equation for this edge, in implicit form. 279e9709e831954c3427d5cb839e84221a177bfedebethannicholas double fDY; // fDY * x + fDX * y + fC = 0, for point (x, y) on the line. 280e9709e831954c3427d5cb839e84221a177bfedebethannicholas double fC; 281e9709e831954c3427d5cb839e84221a177bfedebethannicholas double dist(const SkPoint& p) const { 282e9709e831954c3427d5cb839e84221a177bfedebethannicholas return fDY * p.fX - fDX * p.fY + fC; 283e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 284e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool isRightOf(Vertex* v) const { 285e9709e831954c3427d5cb839e84221a177bfedebethannicholas return dist(v->fPoint) < 0.0; 286e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 287e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool isLeftOf(Vertex* v) const { 288e9709e831954c3427d5cb839e84221a177bfedebethannicholas return dist(v->fPoint) > 0.0; 289e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 290e9709e831954c3427d5cb839e84221a177bfedebethannicholas void recompute() { 291e9709e831954c3427d5cb839e84221a177bfedebethannicholas fDX = static_cast<double>(fBottom->fPoint.fX) - fTop->fPoint.fX; 292e9709e831954c3427d5cb839e84221a177bfedebethannicholas fDY = static_cast<double>(fBottom->fPoint.fY) - fTop->fPoint.fY; 293e9709e831954c3427d5cb839e84221a177bfedebethannicholas fC = static_cast<double>(fTop->fPoint.fY) * fBottom->fPoint.fX - 294e9709e831954c3427d5cb839e84221a177bfedebethannicholas static_cast<double>(fTop->fPoint.fX) * fBottom->fPoint.fY; 295e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 296e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool intersect(const Edge& other, SkPoint* p) { 297e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("intersecting %g -> %g with %g -> %g\n", 298e9709e831954c3427d5cb839e84221a177bfedebethannicholas fTop->fID, fBottom->fID, 299e9709e831954c3427d5cb839e84221a177bfedebethannicholas other.fTop->fID, other.fBottom->fID); 300e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (fTop == other.fTop || fBottom == other.fBottom) { 301e9709e831954c3427d5cb839e84221a177bfedebethannicholas return false; 302e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 303e9709e831954c3427d5cb839e84221a177bfedebethannicholas double denom = fDX * other.fDY - fDY * other.fDX; 304e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (denom == 0.0) { 305e9709e831954c3427d5cb839e84221a177bfedebethannicholas return false; 306e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 307e9709e831954c3427d5cb839e84221a177bfedebethannicholas double dx = static_cast<double>(fTop->fPoint.fX) - other.fTop->fPoint.fX; 308e9709e831954c3427d5cb839e84221a177bfedebethannicholas double dy = static_cast<double>(fTop->fPoint.fY) - other.fTop->fPoint.fY; 309e9709e831954c3427d5cb839e84221a177bfedebethannicholas double sNumer = dy * other.fDX - dx * other.fDY; 310e9709e831954c3427d5cb839e84221a177bfedebethannicholas double tNumer = dy * fDX - dx * fDY; 311e9709e831954c3427d5cb839e84221a177bfedebethannicholas // If (sNumer / denom) or (tNumer / denom) is not in [0..1], exit early. 312e9709e831954c3427d5cb839e84221a177bfedebethannicholas // This saves us doing the divide below unless absolutely necessary. 313e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (denom > 0.0 ? (sNumer < 0.0 || sNumer > denom || tNumer < 0.0 || tNumer > denom) 314e9709e831954c3427d5cb839e84221a177bfedebethannicholas : (sNumer > 0.0 || sNumer < denom || tNumer > 0.0 || tNumer < denom)) { 315e9709e831954c3427d5cb839e84221a177bfedebethannicholas return false; 316e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 317e9709e831954c3427d5cb839e84221a177bfedebethannicholas double s = sNumer / denom; 318e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(s >= 0.0 && s <= 1.0); 319e9709e831954c3427d5cb839e84221a177bfedebethannicholas p->fX = SkDoubleToScalar(fTop->fPoint.fX + s * fDX); 320e9709e831954c3427d5cb839e84221a177bfedebethannicholas p->fY = SkDoubleToScalar(fTop->fPoint.fY + s * fDY); 321e9709e831954c3427d5cb839e84221a177bfedebethannicholas return true; 322e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 323e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool isActive(EdgeList* activeEdges) const { 324e9709e831954c3427d5cb839e84221a177bfedebethannicholas return activeEdges && (fLeft || fRight || activeEdges->fHead == this); 325e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 326e9709e831954c3427d5cb839e84221a177bfedebethannicholas}; 327e9709e831954c3427d5cb839e84221a177bfedebethannicholas 328e9709e831954c3427d5cb839e84221a177bfedebethannicholas/***************************************************************************************/ 329e9709e831954c3427d5cb839e84221a177bfedebethannicholas 330e9709e831954c3427d5cb839e84221a177bfedebethannicholasstruct Poly { 331531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Poly(Vertex* v, int winding) 332531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco : fFirstVertex(v) 333531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco , fWinding(winding) 334e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fHead(nullptr) 335e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fTail(nullptr) 336e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fNext(nullptr) 337e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fPartner(nullptr) 338e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fCount(0) 339e9709e831954c3427d5cb839e84221a177bfedebethannicholas { 340e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 341e9709e831954c3427d5cb839e84221a177bfedebethannicholas static int gID = 0; 342e9709e831954c3427d5cb839e84221a177bfedebethannicholas fID = gID++; 343e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("*** created Poly %d\n", fID); 344e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 345e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 346531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco typedef enum { kLeft_Side, kRight_Side } Side; 347e9709e831954c3427d5cb839e84221a177bfedebethannicholas struct MonotonePoly { 348531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco MonotonePoly(Edge* edge, Side side) 349531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco : fSide(side) 350531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco , fFirstEdge(nullptr) 351531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco , fLastEdge(nullptr) 352e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fPrev(nullptr) 353531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco , fNext(nullptr) { 354531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco this->addEdge(edge); 355531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } 356e9709e831954c3427d5cb839e84221a177bfedebethannicholas Side fSide; 357531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* fFirstEdge; 358531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* fLastEdge; 359e9709e831954c3427d5cb839e84221a177bfedebethannicholas MonotonePoly* fPrev; 360e9709e831954c3427d5cb839e84221a177bfedebethannicholas MonotonePoly* fNext; 361531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco void addEdge(Edge* edge) { 362e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco if (fSide == kRight_Side) { 36370f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco if (edge->fUsedInRightPoly) { 36470f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco return; 36570f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco } 366531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco list_insert<Edge, &Edge::fRightPolyPrev, &Edge::fRightPolyNext>( 367531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco edge, fLastEdge, nullptr, &fFirstEdge, &fLastEdge); 36870f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco edge->fUsedInRightPoly = true; 369e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 37070f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco if (edge->fUsedInLeftPoly) { 37170f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco return; 37270f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco } 373531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco list_insert<Edge, &Edge::fLeftPolyPrev, &Edge::fLeftPolyNext>( 374531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco edge, fLastEdge, nullptr, &fFirstEdge, &fLastEdge); 37570f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco edge->fUsedInLeftPoly = true; 376e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 377e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 378e9709e831954c3427d5cb839e84221a177bfedebethannicholas 379e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint* emit(SkPoint* data) { 380531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* e = fFirstEdge; 381531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco e->fTop->fPrev = e->fTop->fNext = nullptr; 382531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco VertexList vertices; 383531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco vertices.append(e->fTop); 384531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco while (e != nullptr) { 385531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco e->fBottom->fPrev = e->fBottom->fNext = nullptr; 386531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco if (kRight_Side == fSide) { 387531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco vertices.append(e->fBottom); 388531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco e = e->fRightPolyNext; 389531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } else { 390531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco vertices.prepend(e->fBottom); 391531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco e = e->fLeftPolyNext; 392531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } 393531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } 394531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Vertex* first = vertices.fHead; 395e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* v = first->fNext; 396531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco while (v != vertices.fTail) { 397e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(v && v->fPrev && v->fNext); 398e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* prev = v->fPrev; 399e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* curr = v; 400e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* next = v->fNext; 401e9709e831954c3427d5cb839e84221a177bfedebethannicholas double ax = static_cast<double>(curr->fPoint.fX) - prev->fPoint.fX; 402e9709e831954c3427d5cb839e84221a177bfedebethannicholas double ay = static_cast<double>(curr->fPoint.fY) - prev->fPoint.fY; 403e9709e831954c3427d5cb839e84221a177bfedebethannicholas double bx = static_cast<double>(next->fPoint.fX) - curr->fPoint.fX; 404e9709e831954c3427d5cb839e84221a177bfedebethannicholas double by = static_cast<double>(next->fPoint.fY) - curr->fPoint.fY; 405e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (ax * by - ay * bx >= 0.0) { 406e9709e831954c3427d5cb839e84221a177bfedebethannicholas data = emit_triangle(prev, curr, next, data); 407e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fPrev->fNext = v->fNext; 408e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fNext->fPrev = v->fPrev; 409e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fPrev == first) { 410e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = v->fNext; 411e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 412e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = v->fPrev; 413e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 414e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 415e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = v->fNext; 416e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 417e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 418e9709e831954c3427d5cb839e84221a177bfedebethannicholas return data; 419e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 420e9709e831954c3427d5cb839e84221a177bfedebethannicholas }; 421531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Poly* addEdge(Edge* e, Side side, SkChunkAlloc& alloc) { 42270f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco LOG("addEdge (%g -> %g) to poly %d, %s side\n", 42370f5251cc59191040a14cd0f1567aa2129e1f7c6senorblanco e->fTop->fID, e->fBottom->fID, fID, side == kLeft_Side ? "left" : "right"); 424e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* partner = fPartner; 425e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* poly = this; 426e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (partner) { 427e9709e831954c3427d5cb839e84221a177bfedebethannicholas fPartner = partner->fPartner = nullptr; 428e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 429531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco if (!fTail) { 430531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fHead = fTail = ALLOC_NEW(MonotonePoly, (e, side), alloc); 431531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fCount += 2; 43293e3fff79eaaa86bc2fb740a42111a074ccc73absenorblanco } else if (e->fBottom == fTail->fLastEdge->fBottom) { 43393e3fff79eaaa86bc2fb740a42111a074ccc73absenorblanco return poly; 434531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } else if (side == fTail->fSide) { 435531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fTail->addEdge(e); 436531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fCount++; 437531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } else { 438531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco e = ALLOC_NEW(Edge, (fTail->fLastEdge->fBottom, e->fBottom, 1), alloc); 439531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fTail->addEdge(e); 440531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fCount++; 441e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (partner) { 442531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco partner->addEdge(e, side, alloc); 443e9709e831954c3427d5cb839e84221a177bfedebethannicholas poly = partner; 444e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 445531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco MonotonePoly* m = ALLOC_NEW(MonotonePoly, (e, side), alloc); 446531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco m->fPrev = fTail; 447531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fTail->fNext = m; 448531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fTail = m; 449e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 450e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 451e9709e831954c3427d5cb839e84221a177bfedebethannicholas return poly; 452e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 453e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint* emit(SkPoint *data) { 454e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (fCount < 3) { 455e9709e831954c3427d5cb839e84221a177bfedebethannicholas return data; 456e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 457e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("emit() %d, size %d\n", fID, fCount); 458e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (MonotonePoly* m = fHead; m != nullptr; m = m->fNext) { 459e9709e831954c3427d5cb839e84221a177bfedebethannicholas data = m->emit(data); 460e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 461e9709e831954c3427d5cb839e84221a177bfedebethannicholas return data; 462e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 463531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Vertex* lastVertex() const { return fTail ? fTail->fLastEdge->fBottom : fFirstVertex; } 464531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Vertex* fFirstVertex; 465e9709e831954c3427d5cb839e84221a177bfedebethannicholas int fWinding; 466e9709e831954c3427d5cb839e84221a177bfedebethannicholas MonotonePoly* fHead; 467e9709e831954c3427d5cb839e84221a177bfedebethannicholas MonotonePoly* fTail; 468e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* fNext; 469e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* fPartner; 470e9709e831954c3427d5cb839e84221a177bfedebethannicholas int fCount; 471e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 472e9709e831954c3427d5cb839e84221a177bfedebethannicholas int fID; 473e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 474e9709e831954c3427d5cb839e84221a177bfedebethannicholas}; 475e9709e831954c3427d5cb839e84221a177bfedebethannicholas 476e9709e831954c3427d5cb839e84221a177bfedebethannicholas/***************************************************************************************/ 477e9709e831954c3427d5cb839e84221a177bfedebethannicholas 478e9709e831954c3427d5cb839e84221a177bfedebethannicholasbool coincident(const SkPoint& a, const SkPoint& b) { 479e9709e831954c3427d5cb839e84221a177bfedebethannicholas return a == b; 480e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 481e9709e831954c3427d5cb839e84221a177bfedebethannicholas 482e9709e831954c3427d5cb839e84221a177bfedebethannicholasPoly* new_poly(Poly** head, Vertex* v, int winding, SkChunkAlloc& alloc) { 483531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Poly* poly = ALLOC_NEW(Poly, (v, winding), alloc); 484e9709e831954c3427d5cb839e84221a177bfedebethannicholas poly->fNext = *head; 485e9709e831954c3427d5cb839e84221a177bfedebethannicholas *head = poly; 486e9709e831954c3427d5cb839e84221a177bfedebethannicholas return poly; 487e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 488e9709e831954c3427d5cb839e84221a177bfedebethannicholas 489e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* append_point_to_contour(const SkPoint& p, Vertex* prev, Vertex** head, 490e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc& alloc) { 491e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* v = ALLOC_NEW(Vertex, (p), alloc); 492e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 493e9709e831954c3427d5cb839e84221a177bfedebethannicholas static float gID = 0.0f; 494e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fID = gID++; 495e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 496e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (prev) { 497e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = v; 498e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fPrev = prev; 499e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 500e9709e831954c3427d5cb839e84221a177bfedebethannicholas *head = v; 501e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 502e9709e831954c3427d5cb839e84221a177bfedebethannicholas return v; 503e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 504e9709e831954c3427d5cb839e84221a177bfedebethannicholas 505e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* generate_quadratic_points(const SkPoint& p0, 506e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint& p1, 507e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint& p2, 508e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar tolSqd, 509e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* prev, 510e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex** head, 511e9709e831954c3427d5cb839e84221a177bfedebethannicholas int pointsLeft, 512e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc& alloc) { 513e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar d = p1.distanceToLineSegmentBetweenSqd(p0, p2); 514e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (pointsLeft < 2 || d < tolSqd || !SkScalarIsFinite(d)) { 515e9709e831954c3427d5cb839e84221a177bfedebethannicholas return append_point_to_contour(p2, prev, head, alloc); 516e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 517e9709e831954c3427d5cb839e84221a177bfedebethannicholas 518e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint q[] = { 519e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(p0.fX, p1.fX), SkScalarAve(p0.fY, p1.fY) }, 520e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(p1.fX, p2.fX), SkScalarAve(p1.fY, p2.fY) }, 521e9709e831954c3427d5cb839e84221a177bfedebethannicholas }; 522e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint r = { SkScalarAve(q[0].fX, q[1].fX), SkScalarAve(q[0].fY, q[1].fY) }; 523e9709e831954c3427d5cb839e84221a177bfedebethannicholas 524e9709e831954c3427d5cb839e84221a177bfedebethannicholas pointsLeft >>= 1; 525e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_quadratic_points(p0, q[0], r, tolSqd, prev, head, pointsLeft, alloc); 526e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_quadratic_points(r, q[1], p2, tolSqd, prev, head, pointsLeft, alloc); 527e9709e831954c3427d5cb839e84221a177bfedebethannicholas return prev; 528e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 529e9709e831954c3427d5cb839e84221a177bfedebethannicholas 530e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* generate_cubic_points(const SkPoint& p0, 531e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint& p1, 532e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint& p2, 533e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint& p3, 534e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar tolSqd, 535e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* prev, 536e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex** head, 537e9709e831954c3427d5cb839e84221a177bfedebethannicholas int pointsLeft, 538e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc& alloc) { 539e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar d1 = p1.distanceToLineSegmentBetweenSqd(p0, p3); 540e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar d2 = p2.distanceToLineSegmentBetweenSqd(p0, p3); 541e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (pointsLeft < 2 || (d1 < tolSqd && d2 < tolSqd) || 542e9709e831954c3427d5cb839e84221a177bfedebethannicholas !SkScalarIsFinite(d1) || !SkScalarIsFinite(d2)) { 543e9709e831954c3427d5cb839e84221a177bfedebethannicholas return append_point_to_contour(p3, prev, head, alloc); 544e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 545e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint q[] = { 546e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(p0.fX, p1.fX), SkScalarAve(p0.fY, p1.fY) }, 547e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(p1.fX, p2.fX), SkScalarAve(p1.fY, p2.fY) }, 548e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(p2.fX, p3.fX), SkScalarAve(p2.fY, p3.fY) } 549e9709e831954c3427d5cb839e84221a177bfedebethannicholas }; 550e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint r[] = { 551e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(q[0].fX, q[1].fX), SkScalarAve(q[0].fY, q[1].fY) }, 552e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(q[1].fX, q[2].fX), SkScalarAve(q[1].fY, q[2].fY) } 553e9709e831954c3427d5cb839e84221a177bfedebethannicholas }; 554e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint s = { SkScalarAve(r[0].fX, r[1].fX), SkScalarAve(r[0].fY, r[1].fY) }; 555e9709e831954c3427d5cb839e84221a177bfedebethannicholas pointsLeft >>= 1; 556e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_cubic_points(p0, q[0], r[0], s, tolSqd, prev, head, pointsLeft, alloc); 557e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_cubic_points(s, r[1], q[2], p3, tolSqd, prev, head, pointsLeft, alloc); 558e9709e831954c3427d5cb839e84221a177bfedebethannicholas return prev; 559e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 560e9709e831954c3427d5cb839e84221a177bfedebethannicholas 561e9709e831954c3427d5cb839e84221a177bfedebethannicholas// Stage 1: convert the input path to a set of linear contours (linked list of Vertices). 562e9709e831954c3427d5cb839e84221a177bfedebethannicholas 563e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid path_to_contours(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds, 564e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex** contours, SkChunkAlloc& alloc, bool *isLinear) { 565e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar toleranceSqd = tolerance * tolerance; 566e9709e831954c3427d5cb839e84221a177bfedebethannicholas 567e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint pts[4]; 568e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool done = false; 569e9709e831954c3427d5cb839e84221a177bfedebethannicholas *isLinear = true; 570e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPath::Iter iter(path, false); 571e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* prev = nullptr; 572e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* head = nullptr; 573e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (path.isInverseFillType()) { 574e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint quad[4]; 575e9709e831954c3427d5cb839e84221a177bfedebethannicholas clipBounds.toQuad(quad); 576e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (int i = 3; i >= 0; i--) { 577e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = append_point_to_contour(quad[i], prev, &head, alloc); 578e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 579e9709e831954c3427d5cb839e84221a177bfedebethannicholas head->fPrev = prev; 580e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = head; 581e9709e831954c3427d5cb839e84221a177bfedebethannicholas *contours++ = head; 582e9709e831954c3427d5cb839e84221a177bfedebethannicholas head = prev = nullptr; 583e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 584e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkAutoConicToQuads converter; 585e9709e831954c3427d5cb839e84221a177bfedebethannicholas while (!done) { 586e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPath::Verb verb = iter.next(pts); 587e9709e831954c3427d5cb839e84221a177bfedebethannicholas switch (verb) { 588e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kConic_Verb: { 589e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar weight = iter.conicWeight(); 590e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint* quadPts = converter.computeQuads(pts, weight, toleranceSqd); 591e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (int i = 0; i < converter.countQuads(); ++i) { 592e9709e831954c3427d5cb839e84221a177bfedebethannicholas int pointsLeft = GrPathUtils::quadraticPointCount(quadPts, tolerance); 593e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_quadratic_points(quadPts[0], quadPts[1], quadPts[2], 594e9709e831954c3427d5cb839e84221a177bfedebethannicholas toleranceSqd, prev, &head, pointsLeft, alloc); 595e9709e831954c3427d5cb839e84221a177bfedebethannicholas quadPts += 2; 596e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 597e9709e831954c3427d5cb839e84221a177bfedebethannicholas *isLinear = false; 598e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 599e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 600e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kMove_Verb: 601e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (head) { 602e9709e831954c3427d5cb839e84221a177bfedebethannicholas head->fPrev = prev; 603e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = head; 604e9709e831954c3427d5cb839e84221a177bfedebethannicholas *contours++ = head; 605e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 606e9709e831954c3427d5cb839e84221a177bfedebethannicholas head = prev = nullptr; 607e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = append_point_to_contour(pts[0], prev, &head, alloc); 608e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 609e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kLine_Verb: { 610e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = append_point_to_contour(pts[1], prev, &head, alloc); 611e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 612e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 613e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kQuad_Verb: { 614e9709e831954c3427d5cb839e84221a177bfedebethannicholas int pointsLeft = GrPathUtils::quadraticPointCount(pts, tolerance); 615e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_quadratic_points(pts[0], pts[1], pts[2], toleranceSqd, prev, 616e9709e831954c3427d5cb839e84221a177bfedebethannicholas &head, pointsLeft, alloc); 617e9709e831954c3427d5cb839e84221a177bfedebethannicholas *isLinear = false; 618e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 619e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 620e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kCubic_Verb: { 621e9709e831954c3427d5cb839e84221a177bfedebethannicholas int pointsLeft = GrPathUtils::cubicPointCount(pts, tolerance); 622e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_cubic_points(pts[0], pts[1], pts[2], pts[3], 623e9709e831954c3427d5cb839e84221a177bfedebethannicholas toleranceSqd, prev, &head, pointsLeft, alloc); 624e9709e831954c3427d5cb839e84221a177bfedebethannicholas *isLinear = false; 625e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 626e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 627e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kClose_Verb: 628e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (head) { 629e9709e831954c3427d5cb839e84221a177bfedebethannicholas head->fPrev = prev; 630e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = head; 631e9709e831954c3427d5cb839e84221a177bfedebethannicholas *contours++ = head; 632e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 633e9709e831954c3427d5cb839e84221a177bfedebethannicholas head = prev = nullptr; 634e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 635e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kDone_Verb: 636e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (head) { 637e9709e831954c3427d5cb839e84221a177bfedebethannicholas head->fPrev = prev; 638e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = head; 639e9709e831954c3427d5cb839e84221a177bfedebethannicholas *contours++ = head; 640e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 641e9709e831954c3427d5cb839e84221a177bfedebethannicholas done = true; 642e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 643e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 644e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 645e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 646e9709e831954c3427d5cb839e84221a177bfedebethannicholas 647e9709e831954c3427d5cb839e84221a177bfedebethannicholasinline bool apply_fill_type(SkPath::FillType fillType, int winding) { 648e9709e831954c3427d5cb839e84221a177bfedebethannicholas switch (fillType) { 649e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kWinding_FillType: 650e9709e831954c3427d5cb839e84221a177bfedebethannicholas return winding != 0; 651e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kEvenOdd_FillType: 652e9709e831954c3427d5cb839e84221a177bfedebethannicholas return (winding & 1) != 0; 653e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kInverseWinding_FillType: 654e9709e831954c3427d5cb839e84221a177bfedebethannicholas return winding == 1; 655e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kInverseEvenOdd_FillType: 656e9709e831954c3427d5cb839e84221a177bfedebethannicholas return (winding & 1) == 1; 657e9709e831954c3427d5cb839e84221a177bfedebethannicholas default: 658e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(false); 659e9709e831954c3427d5cb839e84221a177bfedebethannicholas return false; 660e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 661e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 662e9709e831954c3427d5cb839e84221a177bfedebethannicholas 663e9709e831954c3427d5cb839e84221a177bfedebethannicholasEdge* new_edge(Vertex* prev, Vertex* next, SkChunkAlloc& alloc, Comparator& c) { 664e9709e831954c3427d5cb839e84221a177bfedebethannicholas int winding = c.sweep_lt(prev->fPoint, next->fPoint) ? 1 : -1; 665e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* top = winding < 0 ? next : prev; 666e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* bottom = winding < 0 ? prev : next; 667e9709e831954c3427d5cb839e84221a177bfedebethannicholas return ALLOC_NEW(Edge, (top, bottom, winding), alloc); 668e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 669e9709e831954c3427d5cb839e84221a177bfedebethannicholas 670e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid remove_edge(Edge* edge, EdgeList* edges) { 671e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("removing edge %g -> %g\n", edge->fTop->fID, edge->fBottom->fID); 672e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(edge->isActive(edges)); 673e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_remove<Edge, &Edge::fLeft, &Edge::fRight>(edge, &edges->fHead, &edges->fTail); 674e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 675e9709e831954c3427d5cb839e84221a177bfedebethannicholas 676e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid insert_edge(Edge* edge, Edge* prev, EdgeList* edges) { 677e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("inserting edge %g -> %g\n", edge->fTop->fID, edge->fBottom->fID); 678e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(!edge->isActive(edges)); 679e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next = prev ? prev->fRight : edges->fHead; 680e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_insert<Edge, &Edge::fLeft, &Edge::fRight>(edge, prev, next, &edges->fHead, &edges->fTail); 681e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 682e9709e831954c3427d5cb839e84221a177bfedebethannicholas 683e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid find_enclosing_edges(Vertex* v, EdgeList* edges, Edge** left, Edge** right) { 684e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fFirstEdgeAbove) { 685e9709e831954c3427d5cb839e84221a177bfedebethannicholas *left = v->fFirstEdgeAbove->fLeft; 686e9709e831954c3427d5cb839e84221a177bfedebethannicholas *right = v->fLastEdgeAbove->fRight; 687e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 688e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 689e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next = nullptr; 690e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* prev; 691e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (prev = edges->fTail; prev != nullptr; prev = prev->fLeft) { 692e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (prev->isLeftOf(v)) { 693e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 694e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 695e9709e831954c3427d5cb839e84221a177bfedebethannicholas next = prev; 696e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 697e9709e831954c3427d5cb839e84221a177bfedebethannicholas *left = prev; 698e9709e831954c3427d5cb839e84221a177bfedebethannicholas *right = next; 699e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 700e9709e831954c3427d5cb839e84221a177bfedebethannicholas 701e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid find_enclosing_edges(Edge* edge, EdgeList* edges, Comparator& c, Edge** left, Edge** right) { 702e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* prev = nullptr; 703e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next; 704e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (next = edges->fHead; next != nullptr; next = next->fRight) { 705e9709e831954c3427d5cb839e84221a177bfedebethannicholas if ((c.sweep_gt(edge->fTop->fPoint, next->fTop->fPoint) && next->isRightOf(edge->fTop)) || 706e9709e831954c3427d5cb839e84221a177bfedebethannicholas (c.sweep_gt(next->fTop->fPoint, edge->fTop->fPoint) && edge->isLeftOf(next->fTop)) || 707e9709e831954c3427d5cb839e84221a177bfedebethannicholas (c.sweep_lt(edge->fBottom->fPoint, next->fBottom->fPoint) && 708e9709e831954c3427d5cb839e84221a177bfedebethannicholas next->isRightOf(edge->fBottom)) || 709e9709e831954c3427d5cb839e84221a177bfedebethannicholas (c.sweep_lt(next->fBottom->fPoint, edge->fBottom->fPoint) && 710e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->isLeftOf(next->fBottom))) { 711e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 712e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 713e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = next; 714e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 715e9709e831954c3427d5cb839e84221a177bfedebethannicholas *left = prev; 716e9709e831954c3427d5cb839e84221a177bfedebethannicholas *right = next; 717e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 718e9709e831954c3427d5cb839e84221a177bfedebethannicholas 719e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid fix_active_state(Edge* edge, EdgeList* activeEdges, Comparator& c) { 720e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->isActive(activeEdges)) { 721e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fBottom->fProcessed || !edge->fTop->fProcessed) { 722e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge(edge, activeEdges); 723e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 724e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (edge->fTop->fProcessed && !edge->fBottom->fProcessed) { 725e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* left; 726e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* right; 727e9709e831954c3427d5cb839e84221a177bfedebethannicholas find_enclosing_edges(edge, activeEdges, c, &left, &right); 728e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge(edge, left, activeEdges); 729e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 730e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 731e9709e831954c3427d5cb839e84221a177bfedebethannicholas 732e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid insert_edge_above(Edge* edge, Vertex* v, Comparator& c) { 733e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fTop->fPoint == edge->fBottom->fPoint || 734e9709e831954c3427d5cb839e84221a177bfedebethannicholas c.sweep_gt(edge->fTop->fPoint, edge->fBottom->fPoint)) { 735e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 736e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 737e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("insert edge (%g -> %g) above vertex %g\n", edge->fTop->fID, edge->fBottom->fID, v->fID); 738e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* prev = nullptr; 739e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next; 740e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (next = v->fFirstEdgeAbove; next; next = next->fNextEdgeAbove) { 741e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (next->isRightOf(edge->fTop)) { 742e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 743e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 744e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = next; 745e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 746e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_insert<Edge, &Edge::fPrevEdgeAbove, &Edge::fNextEdgeAbove>( 747e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge, prev, next, &v->fFirstEdgeAbove, &v->fLastEdgeAbove); 748e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 749e9709e831954c3427d5cb839e84221a177bfedebethannicholas 750e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid insert_edge_below(Edge* edge, Vertex* v, Comparator& c) { 751e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fTop->fPoint == edge->fBottom->fPoint || 752e9709e831954c3427d5cb839e84221a177bfedebethannicholas c.sweep_gt(edge->fTop->fPoint, edge->fBottom->fPoint)) { 753e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 754e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 755e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("insert edge (%g -> %g) below vertex %g\n", edge->fTop->fID, edge->fBottom->fID, v->fID); 756e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* prev = nullptr; 757e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next; 758e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (next = v->fFirstEdgeBelow; next; next = next->fNextEdgeBelow) { 759e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (next->isRightOf(edge->fBottom)) { 760e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 761e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 762e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = next; 763e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 764e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_insert<Edge, &Edge::fPrevEdgeBelow, &Edge::fNextEdgeBelow>( 765e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge, prev, next, &v->fFirstEdgeBelow, &v->fLastEdgeBelow); 766e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 767e9709e831954c3427d5cb839e84221a177bfedebethannicholas 768e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid remove_edge_above(Edge* edge) { 769e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("removing edge (%g -> %g) above vertex %g\n", edge->fTop->fID, edge->fBottom->fID, 770e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fBottom->fID); 771e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_remove<Edge, &Edge::fPrevEdgeAbove, &Edge::fNextEdgeAbove>( 772e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge, &edge->fBottom->fFirstEdgeAbove, &edge->fBottom->fLastEdgeAbove); 773e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 774e9709e831954c3427d5cb839e84221a177bfedebethannicholas 775e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid remove_edge_below(Edge* edge) { 776e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("removing edge (%g -> %g) below vertex %g\n", edge->fTop->fID, edge->fBottom->fID, 777e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fTop->fID); 778e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_remove<Edge, &Edge::fPrevEdgeBelow, &Edge::fNextEdgeBelow>( 779e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge, &edge->fTop->fFirstEdgeBelow, &edge->fTop->fLastEdgeBelow); 780e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 781e9709e831954c3427d5cb839e84221a177bfedebethannicholas 782e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid erase_edge_if_zero_winding(Edge* edge, EdgeList* edges) { 783e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fWinding != 0) { 784e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 785e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 786e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("erasing edge (%g -> %g)\n", edge->fTop->fID, edge->fBottom->fID); 787e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge_above(edge); 788e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge_below(edge); 789e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->isActive(edges)) { 790e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge(edge, edges); 791e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 792e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 793e9709e831954c3427d5cb839e84221a177bfedebethannicholas 794e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_collinear_edges(Edge* edge, EdgeList* activeEdges, Comparator& c); 795e9709e831954c3427d5cb839e84221a177bfedebethannicholas 796e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid set_top(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c) { 797e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge_below(edge); 798e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fTop = v; 799e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->recompute(); 800e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_below(edge, v, c); 801e9709e831954c3427d5cb839e84221a177bfedebethannicholas fix_active_state(edge, activeEdges, c); 802e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_collinear_edges(edge, activeEdges, c); 803e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 804e9709e831954c3427d5cb839e84221a177bfedebethannicholas 805e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid set_bottom(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c) { 806e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge_above(edge); 807e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fBottom = v; 808e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->recompute(); 809e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_above(edge, v, c); 810e9709e831954c3427d5cb839e84221a177bfedebethannicholas fix_active_state(edge, activeEdges, c); 811e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_collinear_edges(edge, activeEdges, c); 812e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 813e9709e831954c3427d5cb839e84221a177bfedebethannicholas 814e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_edges_above(Edge* edge, Edge* other, EdgeList* activeEdges, Comparator& c) { 815e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (coincident(edge->fTop->fPoint, other->fTop->fPoint)) { 816e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("merging coincident above edges (%g, %g) -> (%g, %g)\n", 817e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fTop->fPoint.fX, edge->fTop->fPoint.fY, 818e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fBottom->fPoint.fX, edge->fBottom->fPoint.fY); 819e9709e831954c3427d5cb839e84221a177bfedebethannicholas other->fWinding += edge->fWinding; 820e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(other, activeEdges); 821e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fWinding = 0; 822e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(edge, activeEdges); 823e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_lt(edge->fTop->fPoint, other->fTop->fPoint)) { 824e9709e831954c3427d5cb839e84221a177bfedebethannicholas other->fWinding += edge->fWinding; 825e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(other, activeEdges); 826e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_bottom(edge, other->fTop, activeEdges, c); 827e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 828e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fWinding += other->fWinding; 829e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(edge, activeEdges); 830e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_bottom(other, edge->fTop, activeEdges, c); 831e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 832e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 833e9709e831954c3427d5cb839e84221a177bfedebethannicholas 834e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_edges_below(Edge* edge, Edge* other, EdgeList* activeEdges, Comparator& c) { 835e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (coincident(edge->fBottom->fPoint, other->fBottom->fPoint)) { 836e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("merging coincident below edges (%g, %g) -> (%g, %g)\n", 837e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fTop->fPoint.fX, edge->fTop->fPoint.fY, 838e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fBottom->fPoint.fX, edge->fBottom->fPoint.fY); 839e9709e831954c3427d5cb839e84221a177bfedebethannicholas other->fWinding += edge->fWinding; 840e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(other, activeEdges); 841e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fWinding = 0; 842e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(edge, activeEdges); 843e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_lt(edge->fBottom->fPoint, other->fBottom->fPoint)) { 844e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fWinding += other->fWinding; 845e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(edge, activeEdges); 846e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_top(other, edge->fBottom, activeEdges, c); 847e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 848e9709e831954c3427d5cb839e84221a177bfedebethannicholas other->fWinding += edge->fWinding; 849e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(other, activeEdges); 850e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_top(edge, other->fBottom, activeEdges, c); 851e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 852e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 853e9709e831954c3427d5cb839e84221a177bfedebethannicholas 854e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_collinear_edges(Edge* edge, EdgeList* activeEdges, Comparator& c) { 855e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fPrevEdgeAbove && (edge->fTop == edge->fPrevEdgeAbove->fTop || 856e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->fPrevEdgeAbove->isLeftOf(edge->fTop))) { 857e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_edges_above(edge, edge->fPrevEdgeAbove, activeEdges, c); 858e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (edge->fNextEdgeAbove && (edge->fTop == edge->fNextEdgeAbove->fTop || 859e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->isLeftOf(edge->fNextEdgeAbove->fTop))) { 860e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_edges_above(edge, edge->fNextEdgeAbove, activeEdges, c); 861e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 862e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fPrevEdgeBelow && (edge->fBottom == edge->fPrevEdgeBelow->fBottom || 863e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->fPrevEdgeBelow->isLeftOf(edge->fBottom))) { 864e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_edges_below(edge, edge->fPrevEdgeBelow, activeEdges, c); 865e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (edge->fNextEdgeBelow && (edge->fBottom == edge->fNextEdgeBelow->fBottom || 866e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->isLeftOf(edge->fNextEdgeBelow->fBottom))) { 867e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_edges_below(edge, edge->fNextEdgeBelow, activeEdges, c); 868e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 869e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 870e9709e831954c3427d5cb839e84221a177bfedebethannicholas 871e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid split_edge(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c, SkChunkAlloc& alloc); 872e9709e831954c3427d5cb839e84221a177bfedebethannicholas 873e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid cleanup_active_edges(Edge* edge, EdgeList* activeEdges, Comparator& c, SkChunkAlloc& alloc) { 874e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* top = edge->fTop; 875e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* bottom = edge->fBottom; 876e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fLeft) { 877e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* leftTop = edge->fLeft->fTop; 878e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* leftBottom = edge->fLeft->fBottom; 879e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (c.sweep_gt(top->fPoint, leftTop->fPoint) && !edge->fLeft->isLeftOf(top)) { 880e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge->fLeft, edge->fTop, activeEdges, c, alloc); 881e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_gt(leftTop->fPoint, top->fPoint) && !edge->isRightOf(leftTop)) { 882e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, leftTop, activeEdges, c, alloc); 883e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_lt(bottom->fPoint, leftBottom->fPoint) && 884e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->fLeft->isLeftOf(bottom)) { 885e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge->fLeft, bottom, activeEdges, c, alloc); 886e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_lt(leftBottom->fPoint, bottom->fPoint) && !edge->isRightOf(leftBottom)) { 887e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, leftBottom, activeEdges, c, alloc); 888e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 889e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 890e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fRight) { 891e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* rightTop = edge->fRight->fTop; 892e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* rightBottom = edge->fRight->fBottom; 893e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (c.sweep_gt(top->fPoint, rightTop->fPoint) && !edge->fRight->isRightOf(top)) { 894e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge->fRight, top, activeEdges, c, alloc); 895e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_gt(rightTop->fPoint, top->fPoint) && !edge->isLeftOf(rightTop)) { 896e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, rightTop, activeEdges, c, alloc); 897e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_lt(bottom->fPoint, rightBottom->fPoint) && 898e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->fRight->isRightOf(bottom)) { 899e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge->fRight, bottom, activeEdges, c, alloc); 900e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_lt(rightBottom->fPoint, bottom->fPoint) && 901e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->isLeftOf(rightBottom)) { 902e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, rightBottom, activeEdges, c, alloc); 903e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 904e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 905e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 906e9709e831954c3427d5cb839e84221a177bfedebethannicholas 907e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid split_edge(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c, SkChunkAlloc& alloc) { 908e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("splitting edge (%g -> %g) at vertex %g (%g, %g)\n", 909e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fTop->fID, edge->fBottom->fID, 910e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fID, v->fPoint.fX, v->fPoint.fY); 911e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (c.sweep_lt(v->fPoint, edge->fTop->fPoint)) { 912e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_top(edge, v, activeEdges, c); 913e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_gt(v->fPoint, edge->fBottom->fPoint)) { 914e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_bottom(edge, v, activeEdges, c); 915e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 916e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* newEdge = ALLOC_NEW(Edge, (v, edge->fBottom, edge->fWinding), alloc); 917e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_below(newEdge, v, c); 918e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_above(newEdge, edge->fBottom, c); 919e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_bottom(edge, v, activeEdges, c); 920e9709e831954c3427d5cb839e84221a177bfedebethannicholas cleanup_active_edges(edge, activeEdges, c, alloc); 921e9709e831954c3427d5cb839e84221a177bfedebethannicholas fix_active_state(newEdge, activeEdges, c); 922e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_collinear_edges(newEdge, activeEdges, c); 923e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 924e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 925e9709e831954c3427d5cb839e84221a177bfedebethannicholas 926e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_vertices(Vertex* src, Vertex* dst, Vertex** head, Comparator& c, SkChunkAlloc& alloc) { 927e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("found coincident verts at %g, %g; merging %g into %g\n", src->fPoint.fX, src->fPoint.fY, 928e9709e831954c3427d5cb839e84221a177bfedebethannicholas src->fID, dst->fID); 929e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* edge = src->fFirstEdgeAbove; edge;) { 930e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next = edge->fNextEdgeAbove; 931e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_bottom(edge, dst, nullptr, c); 932e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge = next; 933e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 934e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* edge = src->fFirstEdgeBelow; edge;) { 935e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next = edge->fNextEdgeBelow; 936e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_top(edge, dst, nullptr, c); 937e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge = next; 938e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 939e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_remove<Vertex, &Vertex::fPrev, &Vertex::fNext>(src, head, nullptr); 940e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 941e9709e831954c3427d5cb839e84221a177bfedebethannicholas 942e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* check_for_intersection(Edge* edge, Edge* other, EdgeList* activeEdges, Comparator& c, 943e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc& alloc) { 944e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint p; 945e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!edge || !other) { 946e9709e831954c3427d5cb839e84221a177bfedebethannicholas return nullptr; 947e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 948e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->intersect(*other, &p)) { 949e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* v; 950e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("found intersection, pt is %g, %g\n", p.fX, p.fY); 951e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (p == edge->fTop->fPoint || c.sweep_lt(p, edge->fTop->fPoint)) { 952e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(other, edge->fTop, activeEdges, c, alloc); 953e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = edge->fTop; 954e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (p == edge->fBottom->fPoint || c.sweep_gt(p, edge->fBottom->fPoint)) { 955e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(other, edge->fBottom, activeEdges, c, alloc); 956e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = edge->fBottom; 957e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (p == other->fTop->fPoint || c.sweep_lt(p, other->fTop->fPoint)) { 958e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, other->fTop, activeEdges, c, alloc); 959e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = other->fTop; 960e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (p == other->fBottom->fPoint || c.sweep_gt(p, other->fBottom->fPoint)) { 961e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, other->fBottom, activeEdges, c, alloc); 962e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = other->fBottom; 963e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 964e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* nextV = edge->fTop; 965e9709e831954c3427d5cb839e84221a177bfedebethannicholas while (c.sweep_lt(p, nextV->fPoint)) { 966e9709e831954c3427d5cb839e84221a177bfedebethannicholas nextV = nextV->fPrev; 967e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 968e9709e831954c3427d5cb839e84221a177bfedebethannicholas while (c.sweep_lt(nextV->fPoint, p)) { 969e9709e831954c3427d5cb839e84221a177bfedebethannicholas nextV = nextV->fNext; 970e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 971e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* prevV = nextV->fPrev; 972e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (coincident(prevV->fPoint, p)) { 973e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = prevV; 974e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (coincident(nextV->fPoint, p)) { 975e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = nextV; 976e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 977e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = ALLOC_NEW(Vertex, (p), alloc); 978e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("inserting between %g (%g, %g) and %g (%g, %g)\n", 979e9709e831954c3427d5cb839e84221a177bfedebethannicholas prevV->fID, prevV->fPoint.fX, prevV->fPoint.fY, 980e9709e831954c3427d5cb839e84221a177bfedebethannicholas nextV->fID, nextV->fPoint.fX, nextV->fPoint.fY); 981e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 982e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fID = (nextV->fID + prevV->fID) * 0.5f; 983e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 984e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fPrev = prevV; 985e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fNext = nextV; 986e9709e831954c3427d5cb839e84221a177bfedebethannicholas prevV->fNext = v; 987e9709e831954c3427d5cb839e84221a177bfedebethannicholas nextV->fPrev = v; 988e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 989e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, v, activeEdges, c, alloc); 990e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(other, v, activeEdges, c, alloc); 991e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 992e9709e831954c3427d5cb839e84221a177bfedebethannicholas return v; 993e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 994e9709e831954c3427d5cb839e84221a177bfedebethannicholas return nullptr; 995e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 996e9709e831954c3427d5cb839e84221a177bfedebethannicholas 997e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid sanitize_contours(Vertex** contours, int contourCnt) { 998e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (int i = 0; i < contourCnt; ++i) { 999e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(contours[i]); 1000e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Vertex* v = contours[i];;) { 1001e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (coincident(v->fPrev->fPoint, v->fPoint)) { 1002e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("vertex %g,%g coincident; removing\n", v->fPoint.fX, v->fPoint.fY); 1003e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fPrev == v) { 1004e9709e831954c3427d5cb839e84221a177bfedebethannicholas contours[i] = nullptr; 1005e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 1006e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1007e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fPrev->fNext = v->fNext; 1008e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fNext->fPrev = v->fPrev; 1009e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (contours[i] == v) { 1010e9709e831954c3427d5cb839e84221a177bfedebethannicholas contours[i] = v->fNext; 1011e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1012e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = v->fPrev; 1013e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1014e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = v->fNext; 1015e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v == contours[i]) break; 1016e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1017e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1018e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1019e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1020e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1021e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_coincident_vertices(Vertex** vertices, Comparator& c, SkChunkAlloc& alloc) { 1022e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Vertex* v = (*vertices)->fNext; v != nullptr; v = v->fNext) { 1023e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (c.sweep_lt(v->fPoint, v->fPrev->fPoint)) { 1024e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fPoint = v->fPrev->fPoint; 1025e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1026e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (coincident(v->fPrev->fPoint, v->fPoint)) { 1027e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_vertices(v->fPrev, v, vertices, c, alloc); 1028e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1029e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1030e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1031e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1032e9709e831954c3427d5cb839e84221a177bfedebethannicholas// Stage 2: convert the contours to a mesh of edges connecting the vertices. 1033e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1034e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* build_edges(Vertex** contours, int contourCnt, Comparator& c, SkChunkAlloc& alloc) { 1035e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* vertices = nullptr; 1036e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* prev = nullptr; 1037e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (int i = 0; i < contourCnt; ++i) { 1038e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Vertex* v = contours[i]; v != nullptr;) { 1039e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* vNext = v->fNext; 1040e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* edge = new_edge(v->fPrev, v, alloc, c); 1041e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fWinding > 0) { 1042e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_below(edge, v->fPrev, c); 1043e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_above(edge, v, c); 1044e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1045e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_below(edge, v, c); 1046e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_above(edge, v->fPrev, c); 1047e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1048e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_collinear_edges(edge, nullptr, c); 1049e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (prev) { 1050e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = v; 1051e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fPrev = prev; 1052e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1053e9709e831954c3427d5cb839e84221a177bfedebethannicholas vertices = v; 1054e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1055e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = v; 1056e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = vNext; 1057e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v == contours[i]) break; 1058e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1059e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1060e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (prev) { 1061e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = vertices->fPrev = nullptr; 1062e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1063e9709e831954c3427d5cb839e84221a177bfedebethannicholas return vertices; 1064e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1065e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1066e9709e831954c3427d5cb839e84221a177bfedebethannicholas// Stage 3: sort the vertices by increasing sweep direction. 1067e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1068e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* sorted_merge(Vertex* a, Vertex* b, Comparator& c); 1069e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1070e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid front_back_split(Vertex* v, Vertex** pFront, Vertex** pBack) { 1071e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* fast; 1072e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* slow; 1073e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!v || !v->fNext) { 1074e9709e831954c3427d5cb839e84221a177bfedebethannicholas *pFront = v; 1075e9709e831954c3427d5cb839e84221a177bfedebethannicholas *pBack = nullptr; 1076e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1077e9709e831954c3427d5cb839e84221a177bfedebethannicholas slow = v; 1078e9709e831954c3427d5cb839e84221a177bfedebethannicholas fast = v->fNext; 1079e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1080e9709e831954c3427d5cb839e84221a177bfedebethannicholas while (fast != nullptr) { 1081e9709e831954c3427d5cb839e84221a177bfedebethannicholas fast = fast->fNext; 1082e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (fast != nullptr) { 1083e9709e831954c3427d5cb839e84221a177bfedebethannicholas slow = slow->fNext; 1084e9709e831954c3427d5cb839e84221a177bfedebethannicholas fast = fast->fNext; 1085e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1086e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1087e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1088e9709e831954c3427d5cb839e84221a177bfedebethannicholas *pFront = v; 1089e9709e831954c3427d5cb839e84221a177bfedebethannicholas *pBack = slow->fNext; 1090e9709e831954c3427d5cb839e84221a177bfedebethannicholas slow->fNext->fPrev = nullptr; 1091e9709e831954c3427d5cb839e84221a177bfedebethannicholas slow->fNext = nullptr; 1092e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1093e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1094e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1095e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_sort(Vertex** head, Comparator& c) { 1096e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!*head || !(*head)->fNext) { 1097e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 1098e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1099e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1100e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* a; 1101e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* b; 1102e9709e831954c3427d5cb839e84221a177bfedebethannicholas front_back_split(*head, &a, &b); 1103e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1104e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_sort(&a, c); 1105e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_sort(&b, c); 1106e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1107e9709e831954c3427d5cb839e84221a177bfedebethannicholas *head = sorted_merge(a, b, c); 1108e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1109e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1110e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* sorted_merge(Vertex* a, Vertex* b, Comparator& c) { 1111e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco VertexList vertices; 1112e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1113e9709e831954c3427d5cb839e84221a177bfedebethannicholas while (a && b) { 1114e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (c.sweep_lt(a->fPoint, b->fPoint)) { 1115e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* next = a->fNext; 1116e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco vertices.append(a); 1117e9709e831954c3427d5cb839e84221a177bfedebethannicholas a = next; 1118e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1119e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* next = b->fNext; 1120e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco vertices.append(b); 1121e9709e831954c3427d5cb839e84221a177bfedebethannicholas b = next; 1122e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1123e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1124e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (a) { 1125e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco vertices.insert(a, vertices.fTail, a->fNext); 1126e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1127e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (b) { 1128e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco vertices.insert(b, vertices.fTail, b->fNext); 1129e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1130e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco return vertices.fHead; 1131e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1132e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1133e9709e831954c3427d5cb839e84221a177bfedebethannicholas// Stage 4: Simplify the mesh by inserting new vertices at intersecting edges. 1134e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1135e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid simplify(Vertex* vertices, Comparator& c, SkChunkAlloc& alloc) { 1136e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("simplifying complex polygons\n"); 1137e9709e831954c3427d5cb839e84221a177bfedebethannicholas EdgeList activeEdges; 1138e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Vertex* v = vertices; v != nullptr; v = v->fNext) { 1139e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) { 1140e9709e831954c3427d5cb839e84221a177bfedebethannicholas continue; 1141e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1142e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 1143e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("\nvertex %g: (%g,%g)\n", v->fID, v->fPoint.fX, v->fPoint.fY); 1144e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 1145e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* leftEnclosingEdge = nullptr; 1146e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* rightEnclosingEdge = nullptr; 1147e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool restartChecks; 1148e9709e831954c3427d5cb839e84221a177bfedebethannicholas do { 1149e9709e831954c3427d5cb839e84221a177bfedebethannicholas restartChecks = false; 1150e9709e831954c3427d5cb839e84221a177bfedebethannicholas find_enclosing_edges(v, &activeEdges, &leftEnclosingEdge, &rightEnclosingEdge); 1151e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fFirstEdgeBelow) { 1152e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* edge = v->fFirstEdgeBelow; edge != nullptr; edge = edge->fNextEdgeBelow) { 1153e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (check_for_intersection(edge, leftEnclosingEdge, &activeEdges, c, alloc)) { 1154e9709e831954c3427d5cb839e84221a177bfedebethannicholas restartChecks = true; 1155e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 1156e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1157e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (check_for_intersection(edge, rightEnclosingEdge, &activeEdges, c, alloc)) { 1158e9709e831954c3427d5cb839e84221a177bfedebethannicholas restartChecks = true; 1159e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 1160e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1161e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1162e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1163e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (Vertex* pv = check_for_intersection(leftEnclosingEdge, rightEnclosingEdge, 1164e9709e831954c3427d5cb839e84221a177bfedebethannicholas &activeEdges, c, alloc)) { 1165e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (c.sweep_lt(pv->fPoint, v->fPoint)) { 1166e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = pv; 1167e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1168e9709e831954c3427d5cb839e84221a177bfedebethannicholas restartChecks = true; 1169e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1170e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1171e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1172e9709e831954c3427d5cb839e84221a177bfedebethannicholas } while (restartChecks); 1173e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* e = v->fFirstEdgeAbove; e; e = e->fNextEdgeAbove) { 1174e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge(e, &activeEdges); 1175e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1176e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* leftEdge = leftEnclosingEdge; 1177e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* e = v->fFirstEdgeBelow; e; e = e->fNextEdgeBelow) { 1178e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge(e, leftEdge, &activeEdges); 1179e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftEdge = e; 1180e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1181e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fProcessed = true; 1182e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1183e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1184e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1185e9709e831954c3427d5cb839e84221a177bfedebethannicholas// Stage 5: Tessellate the simplified mesh into monotone polygons. 1186e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1187e9709e831954c3427d5cb839e84221a177bfedebethannicholasPoly* tessellate(Vertex* vertices, SkChunkAlloc& alloc) { 1188e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("tessellating simple polygons\n"); 1189e9709e831954c3427d5cb839e84221a177bfedebethannicholas EdgeList activeEdges; 1190e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* polys = nullptr; 1191e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Vertex* v = vertices; v != nullptr; v = v->fNext) { 1192e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) { 1193e9709e831954c3427d5cb839e84221a177bfedebethannicholas continue; 1194e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1195e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 1196e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("\nvertex %g: (%g,%g)\n", v->fID, v->fPoint.fX, v->fPoint.fY); 1197e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 1198e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* leftEnclosingEdge = nullptr; 1199e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* rightEnclosingEdge = nullptr; 1200e9709e831954c3427d5cb839e84221a177bfedebethannicholas find_enclosing_edges(v, &activeEdges, &leftEnclosingEdge, &rightEnclosingEdge); 1201e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* leftPoly = nullptr; 1202e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* rightPoly = nullptr; 1203e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fFirstEdgeAbove) { 1204e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftPoly = v->fFirstEdgeAbove->fLeftPoly; 1205e9709e831954c3427d5cb839e84221a177bfedebethannicholas rightPoly = v->fLastEdgeAbove->fRightPoly; 1206e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1207e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftPoly = leftEnclosingEdge ? leftEnclosingEdge->fRightPoly : nullptr; 1208e9709e831954c3427d5cb839e84221a177bfedebethannicholas rightPoly = rightEnclosingEdge ? rightEnclosingEdge->fLeftPoly : nullptr; 1209e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1210e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 1211e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("edges above:\n"); 1212e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* e = v->fFirstEdgeAbove; e; e = e->fNextEdgeAbove) { 1213e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("%g -> %g, lpoly %d, rpoly %d\n", e->fTop->fID, e->fBottom->fID, 1214e9709e831954c3427d5cb839e84221a177bfedebethannicholas e->fLeftPoly ? e->fLeftPoly->fID : -1, e->fRightPoly ? e->fRightPoly->fID : -1); 1215e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1216e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("edges below:\n"); 1217e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* e = v->fFirstEdgeBelow; e; e = e->fNextEdgeBelow) { 1218e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("%g -> %g, lpoly %d, rpoly %d\n", e->fTop->fID, e->fBottom->fID, 1219e9709e831954c3427d5cb839e84221a177bfedebethannicholas e->fLeftPoly ? e->fLeftPoly->fID : -1, e->fRightPoly ? e->fRightPoly->fID : -1); 1220e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1221e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 1222e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fFirstEdgeAbove) { 1223e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (leftPoly) { 1224531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco leftPoly = leftPoly->addEdge(v->fFirstEdgeAbove, Poly::kRight_Side, alloc); 1225e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1226e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (rightPoly) { 1227531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco rightPoly = rightPoly->addEdge(v->fLastEdgeAbove, Poly::kLeft_Side, alloc); 1228e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1229e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* e = v->fFirstEdgeAbove; e != v->fLastEdgeAbove; e = e->fNextEdgeAbove) { 1230e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* leftEdge = e; 1231e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* rightEdge = e->fNextEdgeAbove; 1232e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(rightEdge->isRightOf(leftEdge->fTop)); 1233e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge(leftEdge, &activeEdges); 1234e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (leftEdge->fRightPoly) { 1235531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco leftEdge->fRightPoly->addEdge(e, Poly::kLeft_Side, alloc); 1236e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1237531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco if (rightEdge->fLeftPoly) { 1238531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco rightEdge->fLeftPoly->addEdge(e, Poly::kRight_Side, alloc); 1239e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1240e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1241e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge(v->fLastEdgeAbove, &activeEdges); 1242e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!v->fFirstEdgeBelow) { 1243e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (leftPoly && rightPoly && leftPoly != rightPoly) { 1244e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(leftPoly->fPartner == nullptr && rightPoly->fPartner == nullptr); 1245e9709e831954c3427d5cb839e84221a177bfedebethannicholas rightPoly->fPartner = leftPoly; 1246e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftPoly->fPartner = rightPoly; 1247e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1248e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1249e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1250e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fFirstEdgeBelow) { 1251e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!v->fFirstEdgeAbove) { 125293e3fff79eaaa86bc2fb740a42111a074ccc73absenorblanco if (leftPoly && rightPoly) { 1253531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco if (leftPoly == rightPoly) { 1254531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco if (leftPoly->fTail && leftPoly->fTail->fSide == Poly::kLeft_Side) { 1255531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco leftPoly = new_poly(&polys, leftPoly->lastVertex(), 1256531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco leftPoly->fWinding, alloc); 1257531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco leftEnclosingEdge->fRightPoly = leftPoly; 1258531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } else { 1259531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco rightPoly = new_poly(&polys, rightPoly->lastVertex(), 1260531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco rightPoly->fWinding, alloc); 1261531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco rightEnclosingEdge->fLeftPoly = rightPoly; 1262531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } 1263e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1264531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* join = ALLOC_NEW(Edge, (leftPoly->lastVertex(), v, 1), alloc); 1265531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco leftPoly = leftPoly->addEdge(join, Poly::kRight_Side, alloc); 1266531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco rightPoly = rightPoly->addEdge(join, Poly::kLeft_Side, alloc); 1267e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1268e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1269e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* leftEdge = v->fFirstEdgeBelow; 1270e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftEdge->fLeftPoly = leftPoly; 1271e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge(leftEdge, leftEnclosingEdge, &activeEdges); 1272e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* rightEdge = leftEdge->fNextEdgeBelow; rightEdge; 1273e9709e831954c3427d5cb839e84221a177bfedebethannicholas rightEdge = rightEdge->fNextEdgeBelow) { 1274e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge(rightEdge, leftEdge, &activeEdges); 1275e9709e831954c3427d5cb839e84221a177bfedebethannicholas int winding = leftEdge->fLeftPoly ? leftEdge->fLeftPoly->fWinding : 0; 1276e9709e831954c3427d5cb839e84221a177bfedebethannicholas winding += leftEdge->fWinding; 1277e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (winding != 0) { 1278e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* poly = new_poly(&polys, v, winding, alloc); 1279e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftEdge->fRightPoly = rightEdge->fLeftPoly = poly; 1280e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1281e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftEdge = rightEdge; 1282e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1283e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fLastEdgeBelow->fRightPoly = rightPoly; 1284e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1285e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 1286e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("\nactive edges:\n"); 1287e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* e = activeEdges.fHead; e != nullptr; e = e->fRight) { 1288e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("%g -> %g, lpoly %d, rpoly %d\n", e->fTop->fID, e->fBottom->fID, 1289e9709e831954c3427d5cb839e84221a177bfedebethannicholas e->fLeftPoly ? e->fLeftPoly->fID : -1, e->fRightPoly ? e->fRightPoly->fID : -1); 1290e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1291e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 1292e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1293e9709e831954c3427d5cb839e84221a177bfedebethannicholas return polys; 1294e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1295e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1296e9709e831954c3427d5cb839e84221a177bfedebethannicholas// This is a driver function which calls stages 2-5 in turn. 1297e9709e831954c3427d5cb839e84221a177bfedebethannicholas 12989d524f22bfde5dc3dc8f48e1be39bdebd3bb0304halcanaryPoly* contours_to_polys(Vertex** contours, int contourCnt, const SkRect& pathBounds, 1299e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc& alloc) { 1300e9709e831954c3427d5cb839e84221a177bfedebethannicholas Comparator c; 1301e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (pathBounds.width() > pathBounds.height()) { 1302e9709e831954c3427d5cb839e84221a177bfedebethannicholas c.sweep_lt = sweep_lt_horiz; 1303e9709e831954c3427d5cb839e84221a177bfedebethannicholas c.sweep_gt = sweep_gt_horiz; 1304e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1305e9709e831954c3427d5cb839e84221a177bfedebethannicholas c.sweep_lt = sweep_lt_vert; 1306e9709e831954c3427d5cb839e84221a177bfedebethannicholas c.sweep_gt = sweep_gt_vert; 1307e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1308e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 1309e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (int i = 0; i < contourCnt; ++i) { 1310e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* v = contours[i]; 1311e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(v); 1312e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("path.moveTo(%20.20g, %20.20g);\n", v->fPoint.fX, v->fPoint.fY); 1313e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (v = v->fNext; v != contours[i]; v = v->fNext) { 1314e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("path.lineTo(%20.20g, %20.20g);\n", v->fPoint.fX, v->fPoint.fY); 1315e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1316e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1317e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 1318e9709e831954c3427d5cb839e84221a177bfedebethannicholas sanitize_contours(contours, contourCnt); 1319e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* vertices = build_edges(contours, contourCnt, c, alloc); 1320e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!vertices) { 1321e9709e831954c3427d5cb839e84221a177bfedebethannicholas return nullptr; 1322e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1323e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1324e9709e831954c3427d5cb839e84221a177bfedebethannicholas // Sort vertices in Y (secondarily in X). 1325e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_sort(&vertices, c); 1326e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_coincident_vertices(&vertices, c, alloc); 1327e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 1328e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Vertex* v = vertices; v != nullptr; v = v->fNext) { 1329e9709e831954c3427d5cb839e84221a177bfedebethannicholas static float gID = 0.0f; 1330e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fID = gID++; 1331e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1332e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 1333e9709e831954c3427d5cb839e84221a177bfedebethannicholas simplify(vertices, c, alloc); 1334e9709e831954c3427d5cb839e84221a177bfedebethannicholas return tessellate(vertices, alloc); 1335e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1336e9709e831954c3427d5cb839e84221a177bfedebethannicholas 13379d524f22bfde5dc3dc8f48e1be39bdebd3bb0304halcanaryPoly* path_to_polys(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds, 1338e9709e831954c3427d5cb839e84221a177bfedebethannicholas int contourCnt, SkChunkAlloc& alloc, bool* isLinear) { 1339e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPath::FillType fillType = path.getFillType(); 1340e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (SkPath::IsInverseFillType(fillType)) { 1341e9709e831954c3427d5cb839e84221a177bfedebethannicholas contourCnt++; 1342e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1343e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkAutoTDeleteArray<Vertex*> contours(new Vertex* [contourCnt]); 1344e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1345e9709e831954c3427d5cb839e84221a177bfedebethannicholas path_to_contours(path, tolerance, clipBounds, contours.get(), alloc, isLinear); 1346e9709e831954c3427d5cb839e84221a177bfedebethannicholas return contours_to_polys(contours.get(), contourCnt, path.getBounds(), alloc); 1347e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1348e9709e831954c3427d5cb839e84221a177bfedebethannicholas 13499d524f22bfde5dc3dc8f48e1be39bdebd3bb0304halcanaryvoid get_contour_count_and_size_estimate(const SkPath& path, SkScalar tolerance, int* contourCnt, 1350e9709e831954c3427d5cb839e84221a177bfedebethannicholas int* sizeEstimate) { 1351e9709e831954c3427d5cb839e84221a177bfedebethannicholas int maxPts = GrPathUtils::worstCasePointCount(path, contourCnt, tolerance); 1352e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (maxPts <= 0) { 1353e9709e831954c3427d5cb839e84221a177bfedebethannicholas *contourCnt = 0; 1354e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 1355e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1356e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (maxPts > ((int)SK_MaxU16 + 1)) { 1357e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkDebugf("Path not rendered, too many verts (%d)\n", maxPts); 1358e9709e831954c3427d5cb839e84221a177bfedebethannicholas *contourCnt = 0; 1359e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 1360e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1361e9709e831954c3427d5cb839e84221a177bfedebethannicholas // For the initial size of the chunk allocator, estimate based on the point count: 1362e9709e831954c3427d5cb839e84221a177bfedebethannicholas // one vertex per point for the initial passes, plus two for the vertices in the 1363e9709e831954c3427d5cb839e84221a177bfedebethannicholas // resulting Polys, since the same point may end up in two Polys. Assume minimal 1364e9709e831954c3427d5cb839e84221a177bfedebethannicholas // connectivity of one Edge per Vertex (will grow for intersections). 1365e9709e831954c3427d5cb839e84221a177bfedebethannicholas *sizeEstimate = maxPts * (3 * sizeof(Vertex) + sizeof(Edge)); 1366e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1367e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1368e9709e831954c3427d5cb839e84221a177bfedebethannicholasint count_points(Poly* polys, SkPath::FillType fillType) { 1369e9709e831954c3427d5cb839e84221a177bfedebethannicholas int count = 0; 1370e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Poly* poly = polys; poly; poly = poly->fNext) { 1371e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (apply_fill_type(fillType, poly->fWinding) && poly->fCount >= 3) { 1372e9709e831954c3427d5cb839e84221a177bfedebethannicholas count += (poly->fCount - 2) * (TESSELLATOR_WIREFRAME ? 6 : 3); 1373e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1374e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1375e9709e831954c3427d5cb839e84221a177bfedebethannicholas return count; 1376e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1377e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1378e9709e831954c3427d5cb839e84221a177bfedebethannicholas} // namespace 1379e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1380e9709e831954c3427d5cb839e84221a177bfedebethannicholasnamespace GrTessellator { 1381e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1382e9709e831954c3427d5cb839e84221a177bfedebethannicholas// Stage 6: Triangulate the monotone polygons into a vertex buffer. 1383e9709e831954c3427d5cb839e84221a177bfedebethannicholas 13849d524f22bfde5dc3dc8f48e1be39bdebd3bb0304halcanaryint PathToTriangles(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds, 13856599efffeef3168dfc68dca99c30454c5c23b859senorblanco VertexAllocator* vertexAllocator, bool* isLinear) { 1386e9709e831954c3427d5cb839e84221a177bfedebethannicholas int contourCnt; 1387e9709e831954c3427d5cb839e84221a177bfedebethannicholas int sizeEstimate; 1388e9709e831954c3427d5cb839e84221a177bfedebethannicholas get_contour_count_and_size_estimate(path, tolerance, &contourCnt, &sizeEstimate); 1389e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (contourCnt <= 0) { 1390e9709e831954c3427d5cb839e84221a177bfedebethannicholas *isLinear = true; 1391e9709e831954c3427d5cb839e84221a177bfedebethannicholas return 0; 1392e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1393e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc alloc(sizeEstimate); 1394e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* polys = path_to_polys(path, tolerance, clipBounds, contourCnt, alloc, isLinear); 1395e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPath::FillType fillType = path.getFillType(); 1396e9709e831954c3427d5cb839e84221a177bfedebethannicholas int count = count_points(polys, fillType); 1397e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (0 == count) { 1398e9709e831954c3427d5cb839e84221a177bfedebethannicholas return 0; 1399e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1400e9709e831954c3427d5cb839e84221a177bfedebethannicholas 14016599efffeef3168dfc68dca99c30454c5c23b859senorblanco SkPoint* verts = vertexAllocator->lock(count); 14026599efffeef3168dfc68dca99c30454c5c23b859senorblanco if (!verts) { 1403e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkDebugf("Could not allocate vertices\n"); 1404e9709e831954c3427d5cb839e84221a177bfedebethannicholas return 0; 1405e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1406e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint* end = verts; 1407e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Poly* poly = polys; poly; poly = poly->fNext) { 1408e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (apply_fill_type(fillType, poly->fWinding)) { 1409e9709e831954c3427d5cb839e84221a177bfedebethannicholas end = poly->emit(end); 1410e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1411e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1412e9709e831954c3427d5cb839e84221a177bfedebethannicholas int actualCount = static_cast<int>(end - verts); 1413e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("actual count: %d\n", actualCount); 1414e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(actualCount <= count); 14156599efffeef3168dfc68dca99c30454c5c23b859senorblanco vertexAllocator->unlock(actualCount); 1416e9709e831954c3427d5cb839e84221a177bfedebethannicholas return actualCount; 1417e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1418e9709e831954c3427d5cb839e84221a177bfedebethannicholas 14199d524f22bfde5dc3dc8f48e1be39bdebd3bb0304halcanaryint PathToVertices(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds, 1420e9709e831954c3427d5cb839e84221a177bfedebethannicholas GrTessellator::WindingVertex** verts) { 1421e9709e831954c3427d5cb839e84221a177bfedebethannicholas int contourCnt; 1422e9709e831954c3427d5cb839e84221a177bfedebethannicholas int sizeEstimate; 1423e9709e831954c3427d5cb839e84221a177bfedebethannicholas get_contour_count_and_size_estimate(path, tolerance, &contourCnt, &sizeEstimate); 1424e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (contourCnt <= 0) { 1425e9709e831954c3427d5cb839e84221a177bfedebethannicholas return 0; 1426e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1427e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc alloc(sizeEstimate); 1428e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool isLinear; 1429e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* polys = path_to_polys(path, tolerance, clipBounds, contourCnt, alloc, &isLinear); 1430e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPath::FillType fillType = path.getFillType(); 1431e9709e831954c3427d5cb839e84221a177bfedebethannicholas int count = count_points(polys, fillType); 1432e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (0 == count) { 1433e9709e831954c3427d5cb839e84221a177bfedebethannicholas *verts = nullptr; 1434e9709e831954c3427d5cb839e84221a177bfedebethannicholas return 0; 1435e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1436e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1437e9709e831954c3427d5cb839e84221a177bfedebethannicholas *verts = new GrTessellator::WindingVertex[count]; 1438e9709e831954c3427d5cb839e84221a177bfedebethannicholas GrTessellator::WindingVertex* vertsEnd = *verts; 1439e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint* points = new SkPoint[count]; 1440e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint* pointsEnd = points; 1441e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Poly* poly = polys; poly; poly = poly->fNext) { 1442e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (apply_fill_type(fillType, poly->fWinding)) { 1443e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint* start = pointsEnd; 1444e9709e831954c3427d5cb839e84221a177bfedebethannicholas pointsEnd = poly->emit(pointsEnd); 1445e9709e831954c3427d5cb839e84221a177bfedebethannicholas while (start != pointsEnd) { 1446e9709e831954c3427d5cb839e84221a177bfedebethannicholas vertsEnd->fPos = *start; 1447e9709e831954c3427d5cb839e84221a177bfedebethannicholas vertsEnd->fWinding = poly->fWinding; 1448e9709e831954c3427d5cb839e84221a177bfedebethannicholas ++start; 1449e9709e831954c3427d5cb839e84221a177bfedebethannicholas ++vertsEnd; 1450e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1451e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1452e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1453e9709e831954c3427d5cb839e84221a177bfedebethannicholas int actualCount = static_cast<int>(vertsEnd - *verts); 1454e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(actualCount <= count); 1455e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(pointsEnd - points == actualCount); 1456e9709e831954c3427d5cb839e84221a177bfedebethannicholas delete[] points; 1457e9709e831954c3427d5cb839e84221a177bfedebethannicholas return actualCount; 1458e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1459e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1460e9709e831954c3427d5cb839e84221a177bfedebethannicholas} // namespace 1461