GrTessellator.cpp revision 531237ef3aaf0d3c86e0853fde3b4c8f517bc662
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) 256531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco , fRightPolyNext(nullptr) { 257e9709e831954c3427d5cb839e84221a177bfedebethannicholas recompute(); 258e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 259e9709e831954c3427d5cb839e84221a177bfedebethannicholas int fWinding; // 1 == edge goes downward; -1 = edge goes upward. 260e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* fTop; // The top vertex in vertex-sort-order (sweep_lt). 261e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* fBottom; // The bottom vertex in vertex-sort-order. 262e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fLeft; // The linked list of edges in the active edge list. 263e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fRight; // " 264e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fPrevEdgeAbove; // The linked list of edges in the bottom Vertex's "edges above". 265e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fNextEdgeAbove; // " 266e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fPrevEdgeBelow; // The linked list of edges in the top Vertex's "edges below". 267e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* fNextEdgeBelow; // " 268e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* fLeftPoly; // The Poly to the left of this edge, if any. 269e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* fRightPoly; // The Poly to the right of this edge, if any. 270531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* fLeftPolyPrev; 271531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* fLeftPolyNext; 272531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* fRightPolyPrev; 273531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* fRightPolyNext; 274e9709e831954c3427d5cb839e84221a177bfedebethannicholas double fDX; // The line equation for this edge, in implicit form. 275e9709e831954c3427d5cb839e84221a177bfedebethannicholas double fDY; // fDY * x + fDX * y + fC = 0, for point (x, y) on the line. 276e9709e831954c3427d5cb839e84221a177bfedebethannicholas double fC; 277e9709e831954c3427d5cb839e84221a177bfedebethannicholas double dist(const SkPoint& p) const { 278e9709e831954c3427d5cb839e84221a177bfedebethannicholas return fDY * p.fX - fDX * p.fY + fC; 279e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 280e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool isRightOf(Vertex* v) const { 281e9709e831954c3427d5cb839e84221a177bfedebethannicholas return dist(v->fPoint) < 0.0; 282e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 283e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool isLeftOf(Vertex* v) const { 284e9709e831954c3427d5cb839e84221a177bfedebethannicholas return dist(v->fPoint) > 0.0; 285e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 286e9709e831954c3427d5cb839e84221a177bfedebethannicholas void recompute() { 287e9709e831954c3427d5cb839e84221a177bfedebethannicholas fDX = static_cast<double>(fBottom->fPoint.fX) - fTop->fPoint.fX; 288e9709e831954c3427d5cb839e84221a177bfedebethannicholas fDY = static_cast<double>(fBottom->fPoint.fY) - fTop->fPoint.fY; 289e9709e831954c3427d5cb839e84221a177bfedebethannicholas fC = static_cast<double>(fTop->fPoint.fY) * fBottom->fPoint.fX - 290e9709e831954c3427d5cb839e84221a177bfedebethannicholas static_cast<double>(fTop->fPoint.fX) * fBottom->fPoint.fY; 291e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 292e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool intersect(const Edge& other, SkPoint* p) { 293e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("intersecting %g -> %g with %g -> %g\n", 294e9709e831954c3427d5cb839e84221a177bfedebethannicholas fTop->fID, fBottom->fID, 295e9709e831954c3427d5cb839e84221a177bfedebethannicholas other.fTop->fID, other.fBottom->fID); 296e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (fTop == other.fTop || fBottom == other.fBottom) { 297e9709e831954c3427d5cb839e84221a177bfedebethannicholas return false; 298e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 299e9709e831954c3427d5cb839e84221a177bfedebethannicholas double denom = fDX * other.fDY - fDY * other.fDX; 300e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (denom == 0.0) { 301e9709e831954c3427d5cb839e84221a177bfedebethannicholas return false; 302e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 303e9709e831954c3427d5cb839e84221a177bfedebethannicholas double dx = static_cast<double>(fTop->fPoint.fX) - other.fTop->fPoint.fX; 304e9709e831954c3427d5cb839e84221a177bfedebethannicholas double dy = static_cast<double>(fTop->fPoint.fY) - other.fTop->fPoint.fY; 305e9709e831954c3427d5cb839e84221a177bfedebethannicholas double sNumer = dy * other.fDX - dx * other.fDY; 306e9709e831954c3427d5cb839e84221a177bfedebethannicholas double tNumer = dy * fDX - dx * fDY; 307e9709e831954c3427d5cb839e84221a177bfedebethannicholas // If (sNumer / denom) or (tNumer / denom) is not in [0..1], exit early. 308e9709e831954c3427d5cb839e84221a177bfedebethannicholas // This saves us doing the divide below unless absolutely necessary. 309e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (denom > 0.0 ? (sNumer < 0.0 || sNumer > denom || tNumer < 0.0 || tNumer > denom) 310e9709e831954c3427d5cb839e84221a177bfedebethannicholas : (sNumer > 0.0 || sNumer < denom || tNumer > 0.0 || tNumer < denom)) { 311e9709e831954c3427d5cb839e84221a177bfedebethannicholas return false; 312e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 313e9709e831954c3427d5cb839e84221a177bfedebethannicholas double s = sNumer / denom; 314e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(s >= 0.0 && s <= 1.0); 315e9709e831954c3427d5cb839e84221a177bfedebethannicholas p->fX = SkDoubleToScalar(fTop->fPoint.fX + s * fDX); 316e9709e831954c3427d5cb839e84221a177bfedebethannicholas p->fY = SkDoubleToScalar(fTop->fPoint.fY + s * fDY); 317e9709e831954c3427d5cb839e84221a177bfedebethannicholas return true; 318e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 319e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool isActive(EdgeList* activeEdges) const { 320e9709e831954c3427d5cb839e84221a177bfedebethannicholas return activeEdges && (fLeft || fRight || activeEdges->fHead == this); 321e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 322e9709e831954c3427d5cb839e84221a177bfedebethannicholas}; 323e9709e831954c3427d5cb839e84221a177bfedebethannicholas 324e9709e831954c3427d5cb839e84221a177bfedebethannicholas/***************************************************************************************/ 325e9709e831954c3427d5cb839e84221a177bfedebethannicholas 326e9709e831954c3427d5cb839e84221a177bfedebethannicholasstruct Poly { 327531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Poly(Vertex* v, int winding) 328531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco : fFirstVertex(v) 329531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco , fWinding(winding) 330e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fHead(nullptr) 331e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fTail(nullptr) 332e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fNext(nullptr) 333e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fPartner(nullptr) 334e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fCount(0) 335e9709e831954c3427d5cb839e84221a177bfedebethannicholas { 336e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 337e9709e831954c3427d5cb839e84221a177bfedebethannicholas static int gID = 0; 338e9709e831954c3427d5cb839e84221a177bfedebethannicholas fID = gID++; 339e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("*** created Poly %d\n", fID); 340e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 341e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 342531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco typedef enum { kLeft_Side, kRight_Side } Side; 343e9709e831954c3427d5cb839e84221a177bfedebethannicholas struct MonotonePoly { 344531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco MonotonePoly(Edge* edge, Side side) 345531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco : fSide(side) 346531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco , fFirstEdge(nullptr) 347531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco , fLastEdge(nullptr) 348e9709e831954c3427d5cb839e84221a177bfedebethannicholas , fPrev(nullptr) 349531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco , fNext(nullptr) { 350531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco this->addEdge(edge); 351531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } 352e9709e831954c3427d5cb839e84221a177bfedebethannicholas Side fSide; 353531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* fFirstEdge; 354531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* fLastEdge; 355e9709e831954c3427d5cb839e84221a177bfedebethannicholas MonotonePoly* fPrev; 356e9709e831954c3427d5cb839e84221a177bfedebethannicholas MonotonePoly* fNext; 357531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco void addEdge(Edge* edge) { 358e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco if (fSide == kRight_Side) { 359531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco list_insert<Edge, &Edge::fRightPolyPrev, &Edge::fRightPolyNext>( 360531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco edge, fLastEdge, nullptr, &fFirstEdge, &fLastEdge); 361e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 362531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco list_insert<Edge, &Edge::fLeftPolyPrev, &Edge::fLeftPolyNext>( 363531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco edge, fLastEdge, nullptr, &fFirstEdge, &fLastEdge); 364e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 365e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 366e9709e831954c3427d5cb839e84221a177bfedebethannicholas 367e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint* emit(SkPoint* data) { 368531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* e = fFirstEdge; 369531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco e->fTop->fPrev = e->fTop->fNext = nullptr; 370531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco VertexList vertices; 371531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco vertices.append(e->fTop); 372531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco while (e != nullptr) { 373531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco e->fBottom->fPrev = e->fBottom->fNext = nullptr; 374531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco if (kRight_Side == fSide) { 375531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco vertices.append(e->fBottom); 376531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco e = e->fRightPolyNext; 377531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } else { 378531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco vertices.prepend(e->fBottom); 379531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco e = e->fLeftPolyNext; 380531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } 381531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } 382531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Vertex* first = vertices.fHead; 383e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* v = first->fNext; 384531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco while (v != vertices.fTail) { 385e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(v && v->fPrev && v->fNext); 386e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* prev = v->fPrev; 387e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* curr = v; 388e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* next = v->fNext; 389e9709e831954c3427d5cb839e84221a177bfedebethannicholas double ax = static_cast<double>(curr->fPoint.fX) - prev->fPoint.fX; 390e9709e831954c3427d5cb839e84221a177bfedebethannicholas double ay = static_cast<double>(curr->fPoint.fY) - prev->fPoint.fY; 391e9709e831954c3427d5cb839e84221a177bfedebethannicholas double bx = static_cast<double>(next->fPoint.fX) - curr->fPoint.fX; 392e9709e831954c3427d5cb839e84221a177bfedebethannicholas double by = static_cast<double>(next->fPoint.fY) - curr->fPoint.fY; 393e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (ax * by - ay * bx >= 0.0) { 394e9709e831954c3427d5cb839e84221a177bfedebethannicholas data = emit_triangle(prev, curr, next, data); 395e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fPrev->fNext = v->fNext; 396e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fNext->fPrev = v->fPrev; 397e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fPrev == first) { 398e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = v->fNext; 399e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 400e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = v->fPrev; 401e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 402e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 403e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = v->fNext; 404e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 405e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 406e9709e831954c3427d5cb839e84221a177bfedebethannicholas return data; 407e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 408e9709e831954c3427d5cb839e84221a177bfedebethannicholas }; 409531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Poly* addEdge(Edge* e, Side side, SkChunkAlloc& alloc) { 410531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco LOG("addEdge (%g,%g)-(%g,%g) to poly %d, %s side\n", 411531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco e->fTop->fPoint.fX, e->fTop->fPoint.fY, e->fBottom->fPoint.fX, e->fBottom->fPoint.fY, 412531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fID, side == kLeft_Side ? "left" : "right"); 413e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* partner = fPartner; 414e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* poly = this; 415e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (partner) { 416e9709e831954c3427d5cb839e84221a177bfedebethannicholas fPartner = partner->fPartner = nullptr; 417e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 418531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco if (!fTail) { 419531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fHead = fTail = ALLOC_NEW(MonotonePoly, (e, side), alloc); 420531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fCount += 2; 421531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } else if (side == fTail->fSide) { 422531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fTail->addEdge(e); 423531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fCount++; 424531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } else { 425531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco if (e->fBottom == fTail->fLastEdge->fBottom) { 426531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco return poly; 427e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 428531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco e = ALLOC_NEW(Edge, (fTail->fLastEdge->fBottom, e->fBottom, 1), alloc); 429531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fTail->addEdge(e); 430531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fCount++; 431e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (partner) { 432531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco partner->addEdge(e, side, alloc); 433e9709e831954c3427d5cb839e84221a177bfedebethannicholas poly = partner; 434e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 435531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco MonotonePoly* m = ALLOC_NEW(MonotonePoly, (e, side), alloc); 436531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco m->fPrev = fTail; 437531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fTail->fNext = m; 438531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fTail = m; 439531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco fCount += 2; 440e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 441e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 442e9709e831954c3427d5cb839e84221a177bfedebethannicholas return poly; 443e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 444e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint* emit(SkPoint *data) { 445e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (fCount < 3) { 446e9709e831954c3427d5cb839e84221a177bfedebethannicholas return data; 447e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 448e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("emit() %d, size %d\n", fID, fCount); 449e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (MonotonePoly* m = fHead; m != nullptr; m = m->fNext) { 450e9709e831954c3427d5cb839e84221a177bfedebethannicholas data = m->emit(data); 451e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 452e9709e831954c3427d5cb839e84221a177bfedebethannicholas return data; 453e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 454531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Vertex* lastVertex() const { return fTail ? fTail->fLastEdge->fBottom : fFirstVertex; } 455531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Vertex* fFirstVertex; 456e9709e831954c3427d5cb839e84221a177bfedebethannicholas int fWinding; 457e9709e831954c3427d5cb839e84221a177bfedebethannicholas MonotonePoly* fHead; 458e9709e831954c3427d5cb839e84221a177bfedebethannicholas MonotonePoly* fTail; 459e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* fNext; 460e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* fPartner; 461e9709e831954c3427d5cb839e84221a177bfedebethannicholas int fCount; 462e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 463e9709e831954c3427d5cb839e84221a177bfedebethannicholas int fID; 464e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 465e9709e831954c3427d5cb839e84221a177bfedebethannicholas}; 466e9709e831954c3427d5cb839e84221a177bfedebethannicholas 467e9709e831954c3427d5cb839e84221a177bfedebethannicholas/***************************************************************************************/ 468e9709e831954c3427d5cb839e84221a177bfedebethannicholas 469e9709e831954c3427d5cb839e84221a177bfedebethannicholasbool coincident(const SkPoint& a, const SkPoint& b) { 470e9709e831954c3427d5cb839e84221a177bfedebethannicholas return a == b; 471e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 472e9709e831954c3427d5cb839e84221a177bfedebethannicholas 473e9709e831954c3427d5cb839e84221a177bfedebethannicholasPoly* new_poly(Poly** head, Vertex* v, int winding, SkChunkAlloc& alloc) { 474531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Poly* poly = ALLOC_NEW(Poly, (v, winding), alloc); 475e9709e831954c3427d5cb839e84221a177bfedebethannicholas poly->fNext = *head; 476e9709e831954c3427d5cb839e84221a177bfedebethannicholas *head = poly; 477e9709e831954c3427d5cb839e84221a177bfedebethannicholas return poly; 478e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 479e9709e831954c3427d5cb839e84221a177bfedebethannicholas 480e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* append_point_to_contour(const SkPoint& p, Vertex* prev, Vertex** head, 481e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc& alloc) { 482e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* v = ALLOC_NEW(Vertex, (p), alloc); 483e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 484e9709e831954c3427d5cb839e84221a177bfedebethannicholas static float gID = 0.0f; 485e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fID = gID++; 486e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 487e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (prev) { 488e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = v; 489e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fPrev = prev; 490e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 491e9709e831954c3427d5cb839e84221a177bfedebethannicholas *head = v; 492e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 493e9709e831954c3427d5cb839e84221a177bfedebethannicholas return v; 494e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 495e9709e831954c3427d5cb839e84221a177bfedebethannicholas 496e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* generate_quadratic_points(const SkPoint& p0, 497e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint& p1, 498e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint& p2, 499e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar tolSqd, 500e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* prev, 501e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex** head, 502e9709e831954c3427d5cb839e84221a177bfedebethannicholas int pointsLeft, 503e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc& alloc) { 504e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar d = p1.distanceToLineSegmentBetweenSqd(p0, p2); 505e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (pointsLeft < 2 || d < tolSqd || !SkScalarIsFinite(d)) { 506e9709e831954c3427d5cb839e84221a177bfedebethannicholas return append_point_to_contour(p2, prev, head, alloc); 507e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 508e9709e831954c3427d5cb839e84221a177bfedebethannicholas 509e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint q[] = { 510e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(p0.fX, p1.fX), SkScalarAve(p0.fY, p1.fY) }, 511e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(p1.fX, p2.fX), SkScalarAve(p1.fY, p2.fY) }, 512e9709e831954c3427d5cb839e84221a177bfedebethannicholas }; 513e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint r = { SkScalarAve(q[0].fX, q[1].fX), SkScalarAve(q[0].fY, q[1].fY) }; 514e9709e831954c3427d5cb839e84221a177bfedebethannicholas 515e9709e831954c3427d5cb839e84221a177bfedebethannicholas pointsLeft >>= 1; 516e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_quadratic_points(p0, q[0], r, tolSqd, prev, head, pointsLeft, alloc); 517e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_quadratic_points(r, q[1], p2, tolSqd, prev, head, pointsLeft, alloc); 518e9709e831954c3427d5cb839e84221a177bfedebethannicholas return prev; 519e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 520e9709e831954c3427d5cb839e84221a177bfedebethannicholas 521e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* generate_cubic_points(const SkPoint& p0, 522e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint& p1, 523e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint& p2, 524e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint& p3, 525e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar tolSqd, 526e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* prev, 527e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex** head, 528e9709e831954c3427d5cb839e84221a177bfedebethannicholas int pointsLeft, 529e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc& alloc) { 530e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar d1 = p1.distanceToLineSegmentBetweenSqd(p0, p3); 531e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar d2 = p2.distanceToLineSegmentBetweenSqd(p0, p3); 532e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (pointsLeft < 2 || (d1 < tolSqd && d2 < tolSqd) || 533e9709e831954c3427d5cb839e84221a177bfedebethannicholas !SkScalarIsFinite(d1) || !SkScalarIsFinite(d2)) { 534e9709e831954c3427d5cb839e84221a177bfedebethannicholas return append_point_to_contour(p3, prev, head, alloc); 535e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 536e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint q[] = { 537e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(p0.fX, p1.fX), SkScalarAve(p0.fY, p1.fY) }, 538e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(p1.fX, p2.fX), SkScalarAve(p1.fY, p2.fY) }, 539e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(p2.fX, p3.fX), SkScalarAve(p2.fY, p3.fY) } 540e9709e831954c3427d5cb839e84221a177bfedebethannicholas }; 541e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint r[] = { 542e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(q[0].fX, q[1].fX), SkScalarAve(q[0].fY, q[1].fY) }, 543e9709e831954c3427d5cb839e84221a177bfedebethannicholas { SkScalarAve(q[1].fX, q[2].fX), SkScalarAve(q[1].fY, q[2].fY) } 544e9709e831954c3427d5cb839e84221a177bfedebethannicholas }; 545e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint s = { SkScalarAve(r[0].fX, r[1].fX), SkScalarAve(r[0].fY, r[1].fY) }; 546e9709e831954c3427d5cb839e84221a177bfedebethannicholas pointsLeft >>= 1; 547e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_cubic_points(p0, q[0], r[0], s, tolSqd, prev, head, pointsLeft, alloc); 548e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_cubic_points(s, r[1], q[2], p3, tolSqd, prev, head, pointsLeft, alloc); 549e9709e831954c3427d5cb839e84221a177bfedebethannicholas return prev; 550e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 551e9709e831954c3427d5cb839e84221a177bfedebethannicholas 552e9709e831954c3427d5cb839e84221a177bfedebethannicholas// Stage 1: convert the input path to a set of linear contours (linked list of Vertices). 553e9709e831954c3427d5cb839e84221a177bfedebethannicholas 554e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid path_to_contours(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds, 555e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex** contours, SkChunkAlloc& alloc, bool *isLinear) { 556e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar toleranceSqd = tolerance * tolerance; 557e9709e831954c3427d5cb839e84221a177bfedebethannicholas 558e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint pts[4]; 559e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool done = false; 560e9709e831954c3427d5cb839e84221a177bfedebethannicholas *isLinear = true; 561e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPath::Iter iter(path, false); 562e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* prev = nullptr; 563e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* head = nullptr; 564e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (path.isInverseFillType()) { 565e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint quad[4]; 566e9709e831954c3427d5cb839e84221a177bfedebethannicholas clipBounds.toQuad(quad); 567e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (int i = 3; i >= 0; i--) { 568e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = append_point_to_contour(quad[i], prev, &head, alloc); 569e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 570e9709e831954c3427d5cb839e84221a177bfedebethannicholas head->fPrev = prev; 571e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = head; 572e9709e831954c3427d5cb839e84221a177bfedebethannicholas *contours++ = head; 573e9709e831954c3427d5cb839e84221a177bfedebethannicholas head = prev = nullptr; 574e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 575e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkAutoConicToQuads converter; 576e9709e831954c3427d5cb839e84221a177bfedebethannicholas while (!done) { 577e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPath::Verb verb = iter.next(pts); 578e9709e831954c3427d5cb839e84221a177bfedebethannicholas switch (verb) { 579e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kConic_Verb: { 580e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkScalar weight = iter.conicWeight(); 581e9709e831954c3427d5cb839e84221a177bfedebethannicholas const SkPoint* quadPts = converter.computeQuads(pts, weight, toleranceSqd); 582e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (int i = 0; i < converter.countQuads(); ++i) { 583e9709e831954c3427d5cb839e84221a177bfedebethannicholas int pointsLeft = GrPathUtils::quadraticPointCount(quadPts, tolerance); 584e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_quadratic_points(quadPts[0], quadPts[1], quadPts[2], 585e9709e831954c3427d5cb839e84221a177bfedebethannicholas toleranceSqd, prev, &head, pointsLeft, alloc); 586e9709e831954c3427d5cb839e84221a177bfedebethannicholas quadPts += 2; 587e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 588e9709e831954c3427d5cb839e84221a177bfedebethannicholas *isLinear = false; 589e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 590e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 591e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kMove_Verb: 592e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (head) { 593e9709e831954c3427d5cb839e84221a177bfedebethannicholas head->fPrev = prev; 594e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = head; 595e9709e831954c3427d5cb839e84221a177bfedebethannicholas *contours++ = head; 596e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 597e9709e831954c3427d5cb839e84221a177bfedebethannicholas head = prev = nullptr; 598e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = append_point_to_contour(pts[0], prev, &head, alloc); 599e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 600e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kLine_Verb: { 601e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = append_point_to_contour(pts[1], prev, &head, alloc); 602e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 603e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 604e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kQuad_Verb: { 605e9709e831954c3427d5cb839e84221a177bfedebethannicholas int pointsLeft = GrPathUtils::quadraticPointCount(pts, tolerance); 606e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_quadratic_points(pts[0], pts[1], pts[2], toleranceSqd, prev, 607e9709e831954c3427d5cb839e84221a177bfedebethannicholas &head, pointsLeft, alloc); 608e9709e831954c3427d5cb839e84221a177bfedebethannicholas *isLinear = false; 609e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 610e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 611e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kCubic_Verb: { 612e9709e831954c3427d5cb839e84221a177bfedebethannicholas int pointsLeft = GrPathUtils::cubicPointCount(pts, tolerance); 613e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = generate_cubic_points(pts[0], pts[1], pts[2], pts[3], 614e9709e831954c3427d5cb839e84221a177bfedebethannicholas toleranceSqd, prev, &head, pointsLeft, alloc); 615e9709e831954c3427d5cb839e84221a177bfedebethannicholas *isLinear = false; 616e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 617e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 618e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kClose_Verb: 619e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (head) { 620e9709e831954c3427d5cb839e84221a177bfedebethannicholas head->fPrev = prev; 621e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = head; 622e9709e831954c3427d5cb839e84221a177bfedebethannicholas *contours++ = head; 623e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 624e9709e831954c3427d5cb839e84221a177bfedebethannicholas head = prev = nullptr; 625e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 626e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kDone_Verb: 627e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (head) { 628e9709e831954c3427d5cb839e84221a177bfedebethannicholas head->fPrev = prev; 629e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = head; 630e9709e831954c3427d5cb839e84221a177bfedebethannicholas *contours++ = head; 631e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 632e9709e831954c3427d5cb839e84221a177bfedebethannicholas done = true; 633e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 634e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 635e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 636e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 637e9709e831954c3427d5cb839e84221a177bfedebethannicholas 638e9709e831954c3427d5cb839e84221a177bfedebethannicholasinline bool apply_fill_type(SkPath::FillType fillType, int winding) { 639e9709e831954c3427d5cb839e84221a177bfedebethannicholas switch (fillType) { 640e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kWinding_FillType: 641e9709e831954c3427d5cb839e84221a177bfedebethannicholas return winding != 0; 642e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kEvenOdd_FillType: 643e9709e831954c3427d5cb839e84221a177bfedebethannicholas return (winding & 1) != 0; 644e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kInverseWinding_FillType: 645e9709e831954c3427d5cb839e84221a177bfedebethannicholas return winding == 1; 646e9709e831954c3427d5cb839e84221a177bfedebethannicholas case SkPath::kInverseEvenOdd_FillType: 647e9709e831954c3427d5cb839e84221a177bfedebethannicholas return (winding & 1) == 1; 648e9709e831954c3427d5cb839e84221a177bfedebethannicholas default: 649e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(false); 650e9709e831954c3427d5cb839e84221a177bfedebethannicholas return false; 651e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 652e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 653e9709e831954c3427d5cb839e84221a177bfedebethannicholas 654e9709e831954c3427d5cb839e84221a177bfedebethannicholasEdge* new_edge(Vertex* prev, Vertex* next, SkChunkAlloc& alloc, Comparator& c) { 655e9709e831954c3427d5cb839e84221a177bfedebethannicholas int winding = c.sweep_lt(prev->fPoint, next->fPoint) ? 1 : -1; 656e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* top = winding < 0 ? next : prev; 657e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* bottom = winding < 0 ? prev : next; 658e9709e831954c3427d5cb839e84221a177bfedebethannicholas return ALLOC_NEW(Edge, (top, bottom, winding), alloc); 659e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 660e9709e831954c3427d5cb839e84221a177bfedebethannicholas 661e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid remove_edge(Edge* edge, EdgeList* edges) { 662e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("removing edge %g -> %g\n", edge->fTop->fID, edge->fBottom->fID); 663e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(edge->isActive(edges)); 664e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_remove<Edge, &Edge::fLeft, &Edge::fRight>(edge, &edges->fHead, &edges->fTail); 665e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 666e9709e831954c3427d5cb839e84221a177bfedebethannicholas 667e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid insert_edge(Edge* edge, Edge* prev, EdgeList* edges) { 668e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("inserting edge %g -> %g\n", edge->fTop->fID, edge->fBottom->fID); 669e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(!edge->isActive(edges)); 670e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next = prev ? prev->fRight : edges->fHead; 671e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_insert<Edge, &Edge::fLeft, &Edge::fRight>(edge, prev, next, &edges->fHead, &edges->fTail); 672e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 673e9709e831954c3427d5cb839e84221a177bfedebethannicholas 674e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid find_enclosing_edges(Vertex* v, EdgeList* edges, Edge** left, Edge** right) { 675e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fFirstEdgeAbove) { 676e9709e831954c3427d5cb839e84221a177bfedebethannicholas *left = v->fFirstEdgeAbove->fLeft; 677e9709e831954c3427d5cb839e84221a177bfedebethannicholas *right = v->fLastEdgeAbove->fRight; 678e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 679e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 680e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next = nullptr; 681e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* prev; 682e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (prev = edges->fTail; prev != nullptr; prev = prev->fLeft) { 683e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (prev->isLeftOf(v)) { 684e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 685e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 686e9709e831954c3427d5cb839e84221a177bfedebethannicholas next = prev; 687e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 688e9709e831954c3427d5cb839e84221a177bfedebethannicholas *left = prev; 689e9709e831954c3427d5cb839e84221a177bfedebethannicholas *right = next; 690e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 691e9709e831954c3427d5cb839e84221a177bfedebethannicholas 692e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid find_enclosing_edges(Edge* edge, EdgeList* edges, Comparator& c, Edge** left, Edge** right) { 693e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* prev = nullptr; 694e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next; 695e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (next = edges->fHead; next != nullptr; next = next->fRight) { 696e9709e831954c3427d5cb839e84221a177bfedebethannicholas if ((c.sweep_gt(edge->fTop->fPoint, next->fTop->fPoint) && next->isRightOf(edge->fTop)) || 697e9709e831954c3427d5cb839e84221a177bfedebethannicholas (c.sweep_gt(next->fTop->fPoint, edge->fTop->fPoint) && edge->isLeftOf(next->fTop)) || 698e9709e831954c3427d5cb839e84221a177bfedebethannicholas (c.sweep_lt(edge->fBottom->fPoint, next->fBottom->fPoint) && 699e9709e831954c3427d5cb839e84221a177bfedebethannicholas next->isRightOf(edge->fBottom)) || 700e9709e831954c3427d5cb839e84221a177bfedebethannicholas (c.sweep_lt(next->fBottom->fPoint, edge->fBottom->fPoint) && 701e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->isLeftOf(next->fBottom))) { 702e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 703e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 704e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = next; 705e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 706e9709e831954c3427d5cb839e84221a177bfedebethannicholas *left = prev; 707e9709e831954c3427d5cb839e84221a177bfedebethannicholas *right = next; 708e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 709e9709e831954c3427d5cb839e84221a177bfedebethannicholas 710e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid fix_active_state(Edge* edge, EdgeList* activeEdges, Comparator& c) { 711e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->isActive(activeEdges)) { 712e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fBottom->fProcessed || !edge->fTop->fProcessed) { 713e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge(edge, activeEdges); 714e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 715e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (edge->fTop->fProcessed && !edge->fBottom->fProcessed) { 716e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* left; 717e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* right; 718e9709e831954c3427d5cb839e84221a177bfedebethannicholas find_enclosing_edges(edge, activeEdges, c, &left, &right); 719e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge(edge, left, activeEdges); 720e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 721e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 722e9709e831954c3427d5cb839e84221a177bfedebethannicholas 723e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid insert_edge_above(Edge* edge, Vertex* v, Comparator& c) { 724e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fTop->fPoint == edge->fBottom->fPoint || 725e9709e831954c3427d5cb839e84221a177bfedebethannicholas c.sweep_gt(edge->fTop->fPoint, edge->fBottom->fPoint)) { 726e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 727e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 728e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("insert edge (%g -> %g) above vertex %g\n", edge->fTop->fID, edge->fBottom->fID, v->fID); 729e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* prev = nullptr; 730e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next; 731e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (next = v->fFirstEdgeAbove; next; next = next->fNextEdgeAbove) { 732e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (next->isRightOf(edge->fTop)) { 733e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 734e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 735e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = next; 736e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 737e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_insert<Edge, &Edge::fPrevEdgeAbove, &Edge::fNextEdgeAbove>( 738e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge, prev, next, &v->fFirstEdgeAbove, &v->fLastEdgeAbove); 739e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 740e9709e831954c3427d5cb839e84221a177bfedebethannicholas 741e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid insert_edge_below(Edge* edge, Vertex* v, Comparator& c) { 742e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fTop->fPoint == edge->fBottom->fPoint || 743e9709e831954c3427d5cb839e84221a177bfedebethannicholas c.sweep_gt(edge->fTop->fPoint, edge->fBottom->fPoint)) { 744e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 745e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 746e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("insert edge (%g -> %g) below vertex %g\n", edge->fTop->fID, edge->fBottom->fID, v->fID); 747e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* prev = nullptr; 748e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next; 749e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (next = v->fFirstEdgeBelow; next; next = next->fNextEdgeBelow) { 750e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (next->isRightOf(edge->fBottom)) { 751e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 752e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 753e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = next; 754e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 755e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_insert<Edge, &Edge::fPrevEdgeBelow, &Edge::fNextEdgeBelow>( 756e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge, prev, next, &v->fFirstEdgeBelow, &v->fLastEdgeBelow); 757e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 758e9709e831954c3427d5cb839e84221a177bfedebethannicholas 759e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid remove_edge_above(Edge* edge) { 760e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("removing edge (%g -> %g) above vertex %g\n", edge->fTop->fID, edge->fBottom->fID, 761e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fBottom->fID); 762e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_remove<Edge, &Edge::fPrevEdgeAbove, &Edge::fNextEdgeAbove>( 763e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge, &edge->fBottom->fFirstEdgeAbove, &edge->fBottom->fLastEdgeAbove); 764e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 765e9709e831954c3427d5cb839e84221a177bfedebethannicholas 766e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid remove_edge_below(Edge* edge) { 767e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("removing edge (%g -> %g) below vertex %g\n", edge->fTop->fID, edge->fBottom->fID, 768e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fTop->fID); 769e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_remove<Edge, &Edge::fPrevEdgeBelow, &Edge::fNextEdgeBelow>( 770e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge, &edge->fTop->fFirstEdgeBelow, &edge->fTop->fLastEdgeBelow); 771e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 772e9709e831954c3427d5cb839e84221a177bfedebethannicholas 773e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid erase_edge_if_zero_winding(Edge* edge, EdgeList* edges) { 774e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fWinding != 0) { 775e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 776e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 777e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("erasing edge (%g -> %g)\n", edge->fTop->fID, edge->fBottom->fID); 778e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge_above(edge); 779e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge_below(edge); 780e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->isActive(edges)) { 781e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge(edge, edges); 782e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 783e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 784e9709e831954c3427d5cb839e84221a177bfedebethannicholas 785e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_collinear_edges(Edge* edge, EdgeList* activeEdges, Comparator& c); 786e9709e831954c3427d5cb839e84221a177bfedebethannicholas 787e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid set_top(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c) { 788e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge_below(edge); 789e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fTop = v; 790e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->recompute(); 791e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_below(edge, v, c); 792e9709e831954c3427d5cb839e84221a177bfedebethannicholas fix_active_state(edge, activeEdges, c); 793e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_collinear_edges(edge, activeEdges, c); 794e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 795e9709e831954c3427d5cb839e84221a177bfedebethannicholas 796e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid set_bottom(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c) { 797e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge_above(edge); 798e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fBottom = v; 799e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->recompute(); 800e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_above(edge, v, c); 801e9709e831954c3427d5cb839e84221a177bfedebethannicholas fix_active_state(edge, activeEdges, c); 802e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_collinear_edges(edge, activeEdges, c); 803e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 804e9709e831954c3427d5cb839e84221a177bfedebethannicholas 805e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_edges_above(Edge* edge, Edge* other, EdgeList* activeEdges, Comparator& c) { 806e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (coincident(edge->fTop->fPoint, other->fTop->fPoint)) { 807e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("merging coincident above edges (%g, %g) -> (%g, %g)\n", 808e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fTop->fPoint.fX, edge->fTop->fPoint.fY, 809e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fBottom->fPoint.fX, edge->fBottom->fPoint.fY); 810e9709e831954c3427d5cb839e84221a177bfedebethannicholas other->fWinding += edge->fWinding; 811e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(other, activeEdges); 812e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fWinding = 0; 813e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(edge, activeEdges); 814e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_lt(edge->fTop->fPoint, other->fTop->fPoint)) { 815e9709e831954c3427d5cb839e84221a177bfedebethannicholas other->fWinding += edge->fWinding; 816e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(other, activeEdges); 817e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_bottom(edge, other->fTop, activeEdges, c); 818e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 819e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fWinding += other->fWinding; 820e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(edge, activeEdges); 821e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_bottom(other, edge->fTop, activeEdges, c); 822e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 823e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 824e9709e831954c3427d5cb839e84221a177bfedebethannicholas 825e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_edges_below(Edge* edge, Edge* other, EdgeList* activeEdges, Comparator& c) { 826e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (coincident(edge->fBottom->fPoint, other->fBottom->fPoint)) { 827e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("merging coincident below edges (%g, %g) -> (%g, %g)\n", 828e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fTop->fPoint.fX, edge->fTop->fPoint.fY, 829e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fBottom->fPoint.fX, edge->fBottom->fPoint.fY); 830e9709e831954c3427d5cb839e84221a177bfedebethannicholas other->fWinding += edge->fWinding; 831e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(other, activeEdges); 832e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fWinding = 0; 833e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(edge, activeEdges); 834e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_lt(edge->fBottom->fPoint, other->fBottom->fPoint)) { 835e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fWinding += other->fWinding; 836e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(edge, activeEdges); 837e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_top(other, edge->fBottom, activeEdges, c); 838e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 839e9709e831954c3427d5cb839e84221a177bfedebethannicholas other->fWinding += edge->fWinding; 840e9709e831954c3427d5cb839e84221a177bfedebethannicholas erase_edge_if_zero_winding(other, activeEdges); 841e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_top(edge, other->fBottom, activeEdges, c); 842e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 843e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 844e9709e831954c3427d5cb839e84221a177bfedebethannicholas 845e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_collinear_edges(Edge* edge, EdgeList* activeEdges, Comparator& c) { 846e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fPrevEdgeAbove && (edge->fTop == edge->fPrevEdgeAbove->fTop || 847e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->fPrevEdgeAbove->isLeftOf(edge->fTop))) { 848e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_edges_above(edge, edge->fPrevEdgeAbove, activeEdges, c); 849e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (edge->fNextEdgeAbove && (edge->fTop == edge->fNextEdgeAbove->fTop || 850e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->isLeftOf(edge->fNextEdgeAbove->fTop))) { 851e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_edges_above(edge, edge->fNextEdgeAbove, activeEdges, c); 852e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 853e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fPrevEdgeBelow && (edge->fBottom == edge->fPrevEdgeBelow->fBottom || 854e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->fPrevEdgeBelow->isLeftOf(edge->fBottom))) { 855e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_edges_below(edge, edge->fPrevEdgeBelow, activeEdges, c); 856e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (edge->fNextEdgeBelow && (edge->fBottom == edge->fNextEdgeBelow->fBottom || 857e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->isLeftOf(edge->fNextEdgeBelow->fBottom))) { 858e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_edges_below(edge, edge->fNextEdgeBelow, activeEdges, c); 859e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 860e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 861e9709e831954c3427d5cb839e84221a177bfedebethannicholas 862e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid split_edge(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c, SkChunkAlloc& alloc); 863e9709e831954c3427d5cb839e84221a177bfedebethannicholas 864e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid cleanup_active_edges(Edge* edge, EdgeList* activeEdges, Comparator& c, SkChunkAlloc& alloc) { 865e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* top = edge->fTop; 866e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* bottom = edge->fBottom; 867e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fLeft) { 868e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* leftTop = edge->fLeft->fTop; 869e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* leftBottom = edge->fLeft->fBottom; 870e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (c.sweep_gt(top->fPoint, leftTop->fPoint) && !edge->fLeft->isLeftOf(top)) { 871e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge->fLeft, edge->fTop, activeEdges, c, alloc); 872e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_gt(leftTop->fPoint, top->fPoint) && !edge->isRightOf(leftTop)) { 873e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, leftTop, activeEdges, c, alloc); 874e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_lt(bottom->fPoint, leftBottom->fPoint) && 875e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->fLeft->isLeftOf(bottom)) { 876e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge->fLeft, bottom, activeEdges, c, alloc); 877e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_lt(leftBottom->fPoint, bottom->fPoint) && !edge->isRightOf(leftBottom)) { 878e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, leftBottom, activeEdges, c, alloc); 879e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 880e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 881e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fRight) { 882e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* rightTop = edge->fRight->fTop; 883e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* rightBottom = edge->fRight->fBottom; 884e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (c.sweep_gt(top->fPoint, rightTop->fPoint) && !edge->fRight->isRightOf(top)) { 885e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge->fRight, top, activeEdges, c, alloc); 886e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_gt(rightTop->fPoint, top->fPoint) && !edge->isLeftOf(rightTop)) { 887e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, rightTop, activeEdges, c, alloc); 888e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_lt(bottom->fPoint, rightBottom->fPoint) && 889e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->fRight->isRightOf(bottom)) { 890e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge->fRight, bottom, activeEdges, c, alloc); 891e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_lt(rightBottom->fPoint, bottom->fPoint) && 892e9709e831954c3427d5cb839e84221a177bfedebethannicholas !edge->isLeftOf(rightBottom)) { 893e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, rightBottom, activeEdges, c, alloc); 894e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 895e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 896e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 897e9709e831954c3427d5cb839e84221a177bfedebethannicholas 898e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid split_edge(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c, SkChunkAlloc& alloc) { 899e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("splitting edge (%g -> %g) at vertex %g (%g, %g)\n", 900e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge->fTop->fID, edge->fBottom->fID, 901e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fID, v->fPoint.fX, v->fPoint.fY); 902e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (c.sweep_lt(v->fPoint, edge->fTop->fPoint)) { 903e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_top(edge, v, activeEdges, c); 904e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (c.sweep_gt(v->fPoint, edge->fBottom->fPoint)) { 905e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_bottom(edge, v, activeEdges, c); 906e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 907e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* newEdge = ALLOC_NEW(Edge, (v, edge->fBottom, edge->fWinding), alloc); 908e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_below(newEdge, v, c); 909e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_above(newEdge, edge->fBottom, c); 910e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_bottom(edge, v, activeEdges, c); 911e9709e831954c3427d5cb839e84221a177bfedebethannicholas cleanup_active_edges(edge, activeEdges, c, alloc); 912e9709e831954c3427d5cb839e84221a177bfedebethannicholas fix_active_state(newEdge, activeEdges, c); 913e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_collinear_edges(newEdge, activeEdges, c); 914e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 915e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 916e9709e831954c3427d5cb839e84221a177bfedebethannicholas 917e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_vertices(Vertex* src, Vertex* dst, Vertex** head, Comparator& c, SkChunkAlloc& alloc) { 918e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("found coincident verts at %g, %g; merging %g into %g\n", src->fPoint.fX, src->fPoint.fY, 919e9709e831954c3427d5cb839e84221a177bfedebethannicholas src->fID, dst->fID); 920e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* edge = src->fFirstEdgeAbove; edge;) { 921e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next = edge->fNextEdgeAbove; 922e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_bottom(edge, dst, nullptr, c); 923e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge = next; 924e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 925e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* edge = src->fFirstEdgeBelow; edge;) { 926e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* next = edge->fNextEdgeBelow; 927e9709e831954c3427d5cb839e84221a177bfedebethannicholas set_top(edge, dst, nullptr, c); 928e9709e831954c3427d5cb839e84221a177bfedebethannicholas edge = next; 929e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 930e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco list_remove<Vertex, &Vertex::fPrev, &Vertex::fNext>(src, head, nullptr); 931e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 932e9709e831954c3427d5cb839e84221a177bfedebethannicholas 933e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* check_for_intersection(Edge* edge, Edge* other, EdgeList* activeEdges, Comparator& c, 934e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc& alloc) { 935e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint p; 936e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!edge || !other) { 937e9709e831954c3427d5cb839e84221a177bfedebethannicholas return nullptr; 938e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 939e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->intersect(*other, &p)) { 940e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* v; 941e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("found intersection, pt is %g, %g\n", p.fX, p.fY); 942e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (p == edge->fTop->fPoint || c.sweep_lt(p, edge->fTop->fPoint)) { 943e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(other, edge->fTop, activeEdges, c, alloc); 944e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = edge->fTop; 945e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (p == edge->fBottom->fPoint || c.sweep_gt(p, edge->fBottom->fPoint)) { 946e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(other, edge->fBottom, activeEdges, c, alloc); 947e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = edge->fBottom; 948e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (p == other->fTop->fPoint || c.sweep_lt(p, other->fTop->fPoint)) { 949e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, other->fTop, activeEdges, c, alloc); 950e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = other->fTop; 951e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (p == other->fBottom->fPoint || c.sweep_gt(p, other->fBottom->fPoint)) { 952e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, other->fBottom, activeEdges, c, alloc); 953e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = other->fBottom; 954e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 955e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* nextV = edge->fTop; 956e9709e831954c3427d5cb839e84221a177bfedebethannicholas while (c.sweep_lt(p, nextV->fPoint)) { 957e9709e831954c3427d5cb839e84221a177bfedebethannicholas nextV = nextV->fPrev; 958e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 959e9709e831954c3427d5cb839e84221a177bfedebethannicholas while (c.sweep_lt(nextV->fPoint, p)) { 960e9709e831954c3427d5cb839e84221a177bfedebethannicholas nextV = nextV->fNext; 961e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 962e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* prevV = nextV->fPrev; 963e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (coincident(prevV->fPoint, p)) { 964e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = prevV; 965e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else if (coincident(nextV->fPoint, p)) { 966e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = nextV; 967e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 968e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = ALLOC_NEW(Vertex, (p), alloc); 969e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("inserting between %g (%g, %g) and %g (%g, %g)\n", 970e9709e831954c3427d5cb839e84221a177bfedebethannicholas prevV->fID, prevV->fPoint.fX, prevV->fPoint.fY, 971e9709e831954c3427d5cb839e84221a177bfedebethannicholas nextV->fID, nextV->fPoint.fX, nextV->fPoint.fY); 972e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 973e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fID = (nextV->fID + prevV->fID) * 0.5f; 974e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 975e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fPrev = prevV; 976e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fNext = nextV; 977e9709e831954c3427d5cb839e84221a177bfedebethannicholas prevV->fNext = v; 978e9709e831954c3427d5cb839e84221a177bfedebethannicholas nextV->fPrev = v; 979e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 980e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(edge, v, activeEdges, c, alloc); 981e9709e831954c3427d5cb839e84221a177bfedebethannicholas split_edge(other, v, activeEdges, c, alloc); 982e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 983e9709e831954c3427d5cb839e84221a177bfedebethannicholas return v; 984e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 985e9709e831954c3427d5cb839e84221a177bfedebethannicholas return nullptr; 986e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 987e9709e831954c3427d5cb839e84221a177bfedebethannicholas 988e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid sanitize_contours(Vertex** contours, int contourCnt) { 989e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (int i = 0; i < contourCnt; ++i) { 990e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(contours[i]); 991e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Vertex* v = contours[i];;) { 992e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (coincident(v->fPrev->fPoint, v->fPoint)) { 993e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("vertex %g,%g coincident; removing\n", v->fPoint.fX, v->fPoint.fY); 994e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fPrev == v) { 995e9709e831954c3427d5cb839e84221a177bfedebethannicholas contours[i] = nullptr; 996e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 997e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 998e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fPrev->fNext = v->fNext; 999e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fNext->fPrev = v->fPrev; 1000e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (contours[i] == v) { 1001e9709e831954c3427d5cb839e84221a177bfedebethannicholas contours[i] = v->fNext; 1002e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1003e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = v->fPrev; 1004e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1005e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = v->fNext; 1006e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v == contours[i]) break; 1007e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1008e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1009e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1010e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1011e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1012e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_coincident_vertices(Vertex** vertices, Comparator& c, SkChunkAlloc& alloc) { 1013e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Vertex* v = (*vertices)->fNext; v != nullptr; v = v->fNext) { 1014e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (c.sweep_lt(v->fPoint, v->fPrev->fPoint)) { 1015e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fPoint = v->fPrev->fPoint; 1016e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1017e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (coincident(v->fPrev->fPoint, v->fPoint)) { 1018e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_vertices(v->fPrev, v, vertices, c, alloc); 1019e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1020e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1021e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1022e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1023e9709e831954c3427d5cb839e84221a177bfedebethannicholas// Stage 2: convert the contours to a mesh of edges connecting the vertices. 1024e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1025e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* build_edges(Vertex** contours, int contourCnt, Comparator& c, SkChunkAlloc& alloc) { 1026e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* vertices = nullptr; 1027e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* prev = nullptr; 1028e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (int i = 0; i < contourCnt; ++i) { 1029e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Vertex* v = contours[i]; v != nullptr;) { 1030e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* vNext = v->fNext; 1031e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* edge = new_edge(v->fPrev, v, alloc, c); 1032e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (edge->fWinding > 0) { 1033e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_below(edge, v->fPrev, c); 1034e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_above(edge, v, c); 1035e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1036e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_below(edge, v, c); 1037e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge_above(edge, v->fPrev, c); 1038e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1039e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_collinear_edges(edge, nullptr, c); 1040e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (prev) { 1041e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = v; 1042e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fPrev = prev; 1043e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1044e9709e831954c3427d5cb839e84221a177bfedebethannicholas vertices = v; 1045e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1046e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev = v; 1047e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = vNext; 1048e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v == contours[i]) break; 1049e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1050e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1051e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (prev) { 1052e9709e831954c3427d5cb839e84221a177bfedebethannicholas prev->fNext = vertices->fPrev = nullptr; 1053e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1054e9709e831954c3427d5cb839e84221a177bfedebethannicholas return vertices; 1055e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1056e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1057e9709e831954c3427d5cb839e84221a177bfedebethannicholas// Stage 3: sort the vertices by increasing sweep direction. 1058e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1059e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* sorted_merge(Vertex* a, Vertex* b, Comparator& c); 1060e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1061e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid front_back_split(Vertex* v, Vertex** pFront, Vertex** pBack) { 1062e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* fast; 1063e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* slow; 1064e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!v || !v->fNext) { 1065e9709e831954c3427d5cb839e84221a177bfedebethannicholas *pFront = v; 1066e9709e831954c3427d5cb839e84221a177bfedebethannicholas *pBack = nullptr; 1067e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1068e9709e831954c3427d5cb839e84221a177bfedebethannicholas slow = v; 1069e9709e831954c3427d5cb839e84221a177bfedebethannicholas fast = v->fNext; 1070e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1071e9709e831954c3427d5cb839e84221a177bfedebethannicholas while (fast != nullptr) { 1072e9709e831954c3427d5cb839e84221a177bfedebethannicholas fast = fast->fNext; 1073e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (fast != nullptr) { 1074e9709e831954c3427d5cb839e84221a177bfedebethannicholas slow = slow->fNext; 1075e9709e831954c3427d5cb839e84221a177bfedebethannicholas fast = fast->fNext; 1076e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1077e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1078e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1079e9709e831954c3427d5cb839e84221a177bfedebethannicholas *pFront = v; 1080e9709e831954c3427d5cb839e84221a177bfedebethannicholas *pBack = slow->fNext; 1081e9709e831954c3427d5cb839e84221a177bfedebethannicholas slow->fNext->fPrev = nullptr; 1082e9709e831954c3427d5cb839e84221a177bfedebethannicholas slow->fNext = nullptr; 1083e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1084e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1085e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1086e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid merge_sort(Vertex** head, Comparator& c) { 1087e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!*head || !(*head)->fNext) { 1088e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 1089e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1090e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1091e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* a; 1092e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* b; 1093e9709e831954c3427d5cb839e84221a177bfedebethannicholas front_back_split(*head, &a, &b); 1094e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1095e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_sort(&a, c); 1096e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_sort(&b, c); 1097e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1098e9709e831954c3427d5cb839e84221a177bfedebethannicholas *head = sorted_merge(a, b, c); 1099e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1100e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1101e9709e831954c3427d5cb839e84221a177bfedebethannicholasVertex* sorted_merge(Vertex* a, Vertex* b, Comparator& c) { 1102e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco VertexList vertices; 1103e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1104e9709e831954c3427d5cb839e84221a177bfedebethannicholas while (a && b) { 1105e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (c.sweep_lt(a->fPoint, b->fPoint)) { 1106e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* next = a->fNext; 1107e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco vertices.append(a); 1108e9709e831954c3427d5cb839e84221a177bfedebethannicholas a = next; 1109e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1110e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* next = b->fNext; 1111e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco vertices.append(b); 1112e9709e831954c3427d5cb839e84221a177bfedebethannicholas b = next; 1113e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1114e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1115e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (a) { 1116e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco vertices.insert(a, vertices.fTail, a->fNext); 1117e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1118e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (b) { 1119e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco vertices.insert(b, vertices.fTail, b->fNext); 1120e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1121e6eaa320e8dac34396dc364aa0863574d7b5291csenorblanco return vertices.fHead; 1122e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1123e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1124e9709e831954c3427d5cb839e84221a177bfedebethannicholas// Stage 4: Simplify the mesh by inserting new vertices at intersecting edges. 1125e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1126e9709e831954c3427d5cb839e84221a177bfedebethannicholasvoid simplify(Vertex* vertices, Comparator& c, SkChunkAlloc& alloc) { 1127e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("simplifying complex polygons\n"); 1128e9709e831954c3427d5cb839e84221a177bfedebethannicholas EdgeList activeEdges; 1129e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Vertex* v = vertices; v != nullptr; v = v->fNext) { 1130e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) { 1131e9709e831954c3427d5cb839e84221a177bfedebethannicholas continue; 1132e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1133e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 1134e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("\nvertex %g: (%g,%g)\n", v->fID, v->fPoint.fX, v->fPoint.fY); 1135e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 1136e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* leftEnclosingEdge = nullptr; 1137e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* rightEnclosingEdge = nullptr; 1138e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool restartChecks; 1139e9709e831954c3427d5cb839e84221a177bfedebethannicholas do { 1140e9709e831954c3427d5cb839e84221a177bfedebethannicholas restartChecks = false; 1141e9709e831954c3427d5cb839e84221a177bfedebethannicholas find_enclosing_edges(v, &activeEdges, &leftEnclosingEdge, &rightEnclosingEdge); 1142e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fFirstEdgeBelow) { 1143e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* edge = v->fFirstEdgeBelow; edge != nullptr; edge = edge->fNextEdgeBelow) { 1144e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (check_for_intersection(edge, leftEnclosingEdge, &activeEdges, c, alloc)) { 1145e9709e831954c3427d5cb839e84221a177bfedebethannicholas restartChecks = true; 1146e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 1147e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1148e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (check_for_intersection(edge, rightEnclosingEdge, &activeEdges, c, alloc)) { 1149e9709e831954c3427d5cb839e84221a177bfedebethannicholas restartChecks = true; 1150e9709e831954c3427d5cb839e84221a177bfedebethannicholas break; 1151e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1152e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1153e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1154e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (Vertex* pv = check_for_intersection(leftEnclosingEdge, rightEnclosingEdge, 1155e9709e831954c3427d5cb839e84221a177bfedebethannicholas &activeEdges, c, alloc)) { 1156e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (c.sweep_lt(pv->fPoint, v->fPoint)) { 1157e9709e831954c3427d5cb839e84221a177bfedebethannicholas v = pv; 1158e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1159e9709e831954c3427d5cb839e84221a177bfedebethannicholas restartChecks = true; 1160e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1161e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1162e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1163e9709e831954c3427d5cb839e84221a177bfedebethannicholas } while (restartChecks); 1164e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* e = v->fFirstEdgeAbove; e; e = e->fNextEdgeAbove) { 1165e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge(e, &activeEdges); 1166e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1167e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* leftEdge = leftEnclosingEdge; 1168e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* e = v->fFirstEdgeBelow; e; e = e->fNextEdgeBelow) { 1169e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge(e, leftEdge, &activeEdges); 1170e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftEdge = e; 1171e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1172e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fProcessed = true; 1173e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1174e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1175e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1176e9709e831954c3427d5cb839e84221a177bfedebethannicholas// Stage 5: Tessellate the simplified mesh into monotone polygons. 1177e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1178e9709e831954c3427d5cb839e84221a177bfedebethannicholasPoly* tessellate(Vertex* vertices, SkChunkAlloc& alloc) { 1179e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("tessellating simple polygons\n"); 1180e9709e831954c3427d5cb839e84221a177bfedebethannicholas EdgeList activeEdges; 1181e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* polys = nullptr; 1182e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Vertex* v = vertices; v != nullptr; v = v->fNext) { 1183e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) { 1184e9709e831954c3427d5cb839e84221a177bfedebethannicholas continue; 1185e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1186e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 1187e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("\nvertex %g: (%g,%g)\n", v->fID, v->fPoint.fX, v->fPoint.fY); 1188e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 1189e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* leftEnclosingEdge = nullptr; 1190e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* rightEnclosingEdge = nullptr; 1191e9709e831954c3427d5cb839e84221a177bfedebethannicholas find_enclosing_edges(v, &activeEdges, &leftEnclosingEdge, &rightEnclosingEdge); 1192e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* leftPoly = nullptr; 1193e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* rightPoly = nullptr; 1194e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fFirstEdgeAbove) { 1195e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftPoly = v->fFirstEdgeAbove->fLeftPoly; 1196e9709e831954c3427d5cb839e84221a177bfedebethannicholas rightPoly = v->fLastEdgeAbove->fRightPoly; 1197e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1198e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftPoly = leftEnclosingEdge ? leftEnclosingEdge->fRightPoly : nullptr; 1199e9709e831954c3427d5cb839e84221a177bfedebethannicholas rightPoly = rightEnclosingEdge ? rightEnclosingEdge->fLeftPoly : nullptr; 1200e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1201e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 1202e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("edges above:\n"); 1203e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* e = v->fFirstEdgeAbove; e; e = e->fNextEdgeAbove) { 1204e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("%g -> %g, lpoly %d, rpoly %d\n", e->fTop->fID, e->fBottom->fID, 1205e9709e831954c3427d5cb839e84221a177bfedebethannicholas e->fLeftPoly ? e->fLeftPoly->fID : -1, e->fRightPoly ? e->fRightPoly->fID : -1); 1206e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1207e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("edges below:\n"); 1208e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* e = v->fFirstEdgeBelow; e; e = e->fNextEdgeBelow) { 1209e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("%g -> %g, lpoly %d, rpoly %d\n", e->fTop->fID, e->fBottom->fID, 1210e9709e831954c3427d5cb839e84221a177bfedebethannicholas e->fLeftPoly ? e->fLeftPoly->fID : -1, e->fRightPoly ? e->fRightPoly->fID : -1); 1211e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1212e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 1213e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fFirstEdgeAbove) { 1214e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (leftPoly) { 1215531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco leftPoly = leftPoly->addEdge(v->fFirstEdgeAbove, Poly::kRight_Side, alloc); 1216e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1217e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (rightPoly) { 1218531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco rightPoly = rightPoly->addEdge(v->fLastEdgeAbove, Poly::kLeft_Side, alloc); 1219e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1220e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* e = v->fFirstEdgeAbove; e != v->fLastEdgeAbove; e = e->fNextEdgeAbove) { 1221e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* leftEdge = e; 1222e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* rightEdge = e->fNextEdgeAbove; 1223e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(rightEdge->isRightOf(leftEdge->fTop)); 1224e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge(leftEdge, &activeEdges); 1225e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (leftEdge->fRightPoly) { 1226531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco leftEdge->fRightPoly->addEdge(e, Poly::kLeft_Side, alloc); 1227e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1228531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco if (rightEdge->fLeftPoly) { 1229531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco rightEdge->fLeftPoly->addEdge(e, Poly::kRight_Side, alloc); 1230e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1231e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1232e9709e831954c3427d5cb839e84221a177bfedebethannicholas remove_edge(v->fLastEdgeAbove, &activeEdges); 1233e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!v->fFirstEdgeBelow) { 1234e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (leftPoly && rightPoly && leftPoly != rightPoly) { 1235e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(leftPoly->fPartner == nullptr && rightPoly->fPartner == nullptr); 1236e9709e831954c3427d5cb839e84221a177bfedebethannicholas rightPoly->fPartner = leftPoly; 1237e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftPoly->fPartner = rightPoly; 1238e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1239e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1240e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1241e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (v->fFirstEdgeBelow) { 1242e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!v->fFirstEdgeAbove) { 1243531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco if (leftPoly) { 1244531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco if (leftPoly == rightPoly) { 1245531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco if (leftPoly->fTail && leftPoly->fTail->fSide == Poly::kLeft_Side) { 1246531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco leftPoly = new_poly(&polys, leftPoly->lastVertex(), 1247531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco leftPoly->fWinding, alloc); 1248531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco leftEnclosingEdge->fRightPoly = leftPoly; 1249531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } else { 1250531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco rightPoly = new_poly(&polys, rightPoly->lastVertex(), 1251531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco rightPoly->fWinding, alloc); 1252531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco rightEnclosingEdge->fLeftPoly = rightPoly; 1253531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco } 1254e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1255531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco Edge* join = ALLOC_NEW(Edge, (leftPoly->lastVertex(), v, 1), alloc); 1256531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco leftPoly = leftPoly->addEdge(join, Poly::kRight_Side, alloc); 1257531237ef3aaf0d3c86e0853fde3b4c8f517bc662senorblanco rightPoly = rightPoly->addEdge(join, Poly::kLeft_Side, alloc); 1258e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1259e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1260e9709e831954c3427d5cb839e84221a177bfedebethannicholas Edge* leftEdge = v->fFirstEdgeBelow; 1261e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftEdge->fLeftPoly = leftPoly; 1262e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge(leftEdge, leftEnclosingEdge, &activeEdges); 1263e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* rightEdge = leftEdge->fNextEdgeBelow; rightEdge; 1264e9709e831954c3427d5cb839e84221a177bfedebethannicholas rightEdge = rightEdge->fNextEdgeBelow) { 1265e9709e831954c3427d5cb839e84221a177bfedebethannicholas insert_edge(rightEdge, leftEdge, &activeEdges); 1266e9709e831954c3427d5cb839e84221a177bfedebethannicholas int winding = leftEdge->fLeftPoly ? leftEdge->fLeftPoly->fWinding : 0; 1267e9709e831954c3427d5cb839e84221a177bfedebethannicholas winding += leftEdge->fWinding; 1268e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (winding != 0) { 1269e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* poly = new_poly(&polys, v, winding, alloc); 1270e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftEdge->fRightPoly = rightEdge->fLeftPoly = poly; 1271e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1272e9709e831954c3427d5cb839e84221a177bfedebethannicholas leftEdge = rightEdge; 1273e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1274e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fLastEdgeBelow->fRightPoly = rightPoly; 1275e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1276e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 1277e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("\nactive edges:\n"); 1278e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Edge* e = activeEdges.fHead; e != nullptr; e = e->fRight) { 1279e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("%g -> %g, lpoly %d, rpoly %d\n", e->fTop->fID, e->fBottom->fID, 1280e9709e831954c3427d5cb839e84221a177bfedebethannicholas e->fLeftPoly ? e->fLeftPoly->fID : -1, e->fRightPoly ? e->fRightPoly->fID : -1); 1281e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1282e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 1283e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1284e9709e831954c3427d5cb839e84221a177bfedebethannicholas return polys; 1285e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1286e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1287e9709e831954c3427d5cb839e84221a177bfedebethannicholas// This is a driver function which calls stages 2-5 in turn. 1288e9709e831954c3427d5cb839e84221a177bfedebethannicholas 12899d524f22bfde5dc3dc8f48e1be39bdebd3bb0304halcanaryPoly* contours_to_polys(Vertex** contours, int contourCnt, const SkRect& pathBounds, 1290e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc& alloc) { 1291e9709e831954c3427d5cb839e84221a177bfedebethannicholas Comparator c; 1292e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (pathBounds.width() > pathBounds.height()) { 1293e9709e831954c3427d5cb839e84221a177bfedebethannicholas c.sweep_lt = sweep_lt_horiz; 1294e9709e831954c3427d5cb839e84221a177bfedebethannicholas c.sweep_gt = sweep_gt_horiz; 1295e9709e831954c3427d5cb839e84221a177bfedebethannicholas } else { 1296e9709e831954c3427d5cb839e84221a177bfedebethannicholas c.sweep_lt = sweep_lt_vert; 1297e9709e831954c3427d5cb839e84221a177bfedebethannicholas c.sweep_gt = sweep_gt_vert; 1298e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1299e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 1300e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (int i = 0; i < contourCnt; ++i) { 1301e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* v = contours[i]; 1302e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(v); 1303e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("path.moveTo(%20.20g, %20.20g);\n", v->fPoint.fX, v->fPoint.fY); 1304e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (v = v->fNext; v != contours[i]; v = v->fNext) { 1305e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("path.lineTo(%20.20g, %20.20g);\n", v->fPoint.fX, v->fPoint.fY); 1306e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1307e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1308e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 1309e9709e831954c3427d5cb839e84221a177bfedebethannicholas sanitize_contours(contours, contourCnt); 1310e9709e831954c3427d5cb839e84221a177bfedebethannicholas Vertex* vertices = build_edges(contours, contourCnt, c, alloc); 1311e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (!vertices) { 1312e9709e831954c3427d5cb839e84221a177bfedebethannicholas return nullptr; 1313e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1314e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1315e9709e831954c3427d5cb839e84221a177bfedebethannicholas // Sort vertices in Y (secondarily in X). 1316e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_sort(&vertices, c); 1317e9709e831954c3427d5cb839e84221a177bfedebethannicholas merge_coincident_vertices(&vertices, c, alloc); 1318e9709e831954c3427d5cb839e84221a177bfedebethannicholas#if LOGGING_ENABLED 1319e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Vertex* v = vertices; v != nullptr; v = v->fNext) { 1320e9709e831954c3427d5cb839e84221a177bfedebethannicholas static float gID = 0.0f; 1321e9709e831954c3427d5cb839e84221a177bfedebethannicholas v->fID = gID++; 1322e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1323e9709e831954c3427d5cb839e84221a177bfedebethannicholas#endif 1324e9709e831954c3427d5cb839e84221a177bfedebethannicholas simplify(vertices, c, alloc); 1325e9709e831954c3427d5cb839e84221a177bfedebethannicholas return tessellate(vertices, alloc); 1326e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1327e9709e831954c3427d5cb839e84221a177bfedebethannicholas 13289d524f22bfde5dc3dc8f48e1be39bdebd3bb0304halcanaryPoly* path_to_polys(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds, 1329e9709e831954c3427d5cb839e84221a177bfedebethannicholas int contourCnt, SkChunkAlloc& alloc, bool* isLinear) { 1330e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPath::FillType fillType = path.getFillType(); 1331e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (SkPath::IsInverseFillType(fillType)) { 1332e9709e831954c3427d5cb839e84221a177bfedebethannicholas contourCnt++; 1333e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1334e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkAutoTDeleteArray<Vertex*> contours(new Vertex* [contourCnt]); 1335e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1336e9709e831954c3427d5cb839e84221a177bfedebethannicholas path_to_contours(path, tolerance, clipBounds, contours.get(), alloc, isLinear); 1337e9709e831954c3427d5cb839e84221a177bfedebethannicholas return contours_to_polys(contours.get(), contourCnt, path.getBounds(), alloc); 1338e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1339e9709e831954c3427d5cb839e84221a177bfedebethannicholas 13409d524f22bfde5dc3dc8f48e1be39bdebd3bb0304halcanaryvoid get_contour_count_and_size_estimate(const SkPath& path, SkScalar tolerance, int* contourCnt, 1341e9709e831954c3427d5cb839e84221a177bfedebethannicholas int* sizeEstimate) { 1342e9709e831954c3427d5cb839e84221a177bfedebethannicholas int maxPts = GrPathUtils::worstCasePointCount(path, contourCnt, tolerance); 1343e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (maxPts <= 0) { 1344e9709e831954c3427d5cb839e84221a177bfedebethannicholas *contourCnt = 0; 1345e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 1346e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1347e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (maxPts > ((int)SK_MaxU16 + 1)) { 1348e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkDebugf("Path not rendered, too many verts (%d)\n", maxPts); 1349e9709e831954c3427d5cb839e84221a177bfedebethannicholas *contourCnt = 0; 1350e9709e831954c3427d5cb839e84221a177bfedebethannicholas return; 1351e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1352e9709e831954c3427d5cb839e84221a177bfedebethannicholas // For the initial size of the chunk allocator, estimate based on the point count: 1353e9709e831954c3427d5cb839e84221a177bfedebethannicholas // one vertex per point for the initial passes, plus two for the vertices in the 1354e9709e831954c3427d5cb839e84221a177bfedebethannicholas // resulting Polys, since the same point may end up in two Polys. Assume minimal 1355e9709e831954c3427d5cb839e84221a177bfedebethannicholas // connectivity of one Edge per Vertex (will grow for intersections). 1356e9709e831954c3427d5cb839e84221a177bfedebethannicholas *sizeEstimate = maxPts * (3 * sizeof(Vertex) + sizeof(Edge)); 1357e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1358e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1359e9709e831954c3427d5cb839e84221a177bfedebethannicholasint count_points(Poly* polys, SkPath::FillType fillType) { 1360e9709e831954c3427d5cb839e84221a177bfedebethannicholas int count = 0; 1361e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Poly* poly = polys; poly; poly = poly->fNext) { 1362e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (apply_fill_type(fillType, poly->fWinding) && poly->fCount >= 3) { 1363e9709e831954c3427d5cb839e84221a177bfedebethannicholas count += (poly->fCount - 2) * (TESSELLATOR_WIREFRAME ? 6 : 3); 1364e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1365e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1366e9709e831954c3427d5cb839e84221a177bfedebethannicholas return count; 1367e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1368e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1369e9709e831954c3427d5cb839e84221a177bfedebethannicholas} // namespace 1370e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1371e9709e831954c3427d5cb839e84221a177bfedebethannicholasnamespace GrTessellator { 1372e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1373e9709e831954c3427d5cb839e84221a177bfedebethannicholas// Stage 6: Triangulate the monotone polygons into a vertex buffer. 1374e9709e831954c3427d5cb839e84221a177bfedebethannicholas 13759d524f22bfde5dc3dc8f48e1be39bdebd3bb0304halcanaryint PathToTriangles(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds, 13766599efffeef3168dfc68dca99c30454c5c23b859senorblanco VertexAllocator* vertexAllocator, bool* isLinear) { 1377e9709e831954c3427d5cb839e84221a177bfedebethannicholas int contourCnt; 1378e9709e831954c3427d5cb839e84221a177bfedebethannicholas int sizeEstimate; 1379e9709e831954c3427d5cb839e84221a177bfedebethannicholas get_contour_count_and_size_estimate(path, tolerance, &contourCnt, &sizeEstimate); 1380e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (contourCnt <= 0) { 1381e9709e831954c3427d5cb839e84221a177bfedebethannicholas *isLinear = true; 1382e9709e831954c3427d5cb839e84221a177bfedebethannicholas return 0; 1383e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1384e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc alloc(sizeEstimate); 1385e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* polys = path_to_polys(path, tolerance, clipBounds, contourCnt, alloc, isLinear); 1386e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPath::FillType fillType = path.getFillType(); 1387e9709e831954c3427d5cb839e84221a177bfedebethannicholas int count = count_points(polys, fillType); 1388e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (0 == count) { 1389e9709e831954c3427d5cb839e84221a177bfedebethannicholas return 0; 1390e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1391e9709e831954c3427d5cb839e84221a177bfedebethannicholas 13926599efffeef3168dfc68dca99c30454c5c23b859senorblanco SkPoint* verts = vertexAllocator->lock(count); 13936599efffeef3168dfc68dca99c30454c5c23b859senorblanco if (!verts) { 1394e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkDebugf("Could not allocate vertices\n"); 1395e9709e831954c3427d5cb839e84221a177bfedebethannicholas return 0; 1396e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1397e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint* end = verts; 1398e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Poly* poly = polys; poly; poly = poly->fNext) { 1399e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (apply_fill_type(fillType, poly->fWinding)) { 1400e9709e831954c3427d5cb839e84221a177bfedebethannicholas end = poly->emit(end); 1401e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1402e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1403e9709e831954c3427d5cb839e84221a177bfedebethannicholas int actualCount = static_cast<int>(end - verts); 1404e9709e831954c3427d5cb839e84221a177bfedebethannicholas LOG("actual count: %d\n", actualCount); 1405e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(actualCount <= count); 14066599efffeef3168dfc68dca99c30454c5c23b859senorblanco vertexAllocator->unlock(actualCount); 1407e9709e831954c3427d5cb839e84221a177bfedebethannicholas return actualCount; 1408e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1409e9709e831954c3427d5cb839e84221a177bfedebethannicholas 14109d524f22bfde5dc3dc8f48e1be39bdebd3bb0304halcanaryint PathToVertices(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds, 1411e9709e831954c3427d5cb839e84221a177bfedebethannicholas GrTessellator::WindingVertex** verts) { 1412e9709e831954c3427d5cb839e84221a177bfedebethannicholas int contourCnt; 1413e9709e831954c3427d5cb839e84221a177bfedebethannicholas int sizeEstimate; 1414e9709e831954c3427d5cb839e84221a177bfedebethannicholas get_contour_count_and_size_estimate(path, tolerance, &contourCnt, &sizeEstimate); 1415e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (contourCnt <= 0) { 1416e9709e831954c3427d5cb839e84221a177bfedebethannicholas return 0; 1417e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1418e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkChunkAlloc alloc(sizeEstimate); 1419e9709e831954c3427d5cb839e84221a177bfedebethannicholas bool isLinear; 1420e9709e831954c3427d5cb839e84221a177bfedebethannicholas Poly* polys = path_to_polys(path, tolerance, clipBounds, contourCnt, alloc, &isLinear); 1421e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPath::FillType fillType = path.getFillType(); 1422e9709e831954c3427d5cb839e84221a177bfedebethannicholas int count = count_points(polys, fillType); 1423e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (0 == count) { 1424e9709e831954c3427d5cb839e84221a177bfedebethannicholas *verts = nullptr; 1425e9709e831954c3427d5cb839e84221a177bfedebethannicholas return 0; 1426e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1427e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1428e9709e831954c3427d5cb839e84221a177bfedebethannicholas *verts = new GrTessellator::WindingVertex[count]; 1429e9709e831954c3427d5cb839e84221a177bfedebethannicholas GrTessellator::WindingVertex* vertsEnd = *verts; 1430e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint* points = new SkPoint[count]; 1431e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint* pointsEnd = points; 1432e9709e831954c3427d5cb839e84221a177bfedebethannicholas for (Poly* poly = polys; poly; poly = poly->fNext) { 1433e9709e831954c3427d5cb839e84221a177bfedebethannicholas if (apply_fill_type(fillType, poly->fWinding)) { 1434e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkPoint* start = pointsEnd; 1435e9709e831954c3427d5cb839e84221a177bfedebethannicholas pointsEnd = poly->emit(pointsEnd); 1436e9709e831954c3427d5cb839e84221a177bfedebethannicholas while (start != pointsEnd) { 1437e9709e831954c3427d5cb839e84221a177bfedebethannicholas vertsEnd->fPos = *start; 1438e9709e831954c3427d5cb839e84221a177bfedebethannicholas vertsEnd->fWinding = poly->fWinding; 1439e9709e831954c3427d5cb839e84221a177bfedebethannicholas ++start; 1440e9709e831954c3427d5cb839e84221a177bfedebethannicholas ++vertsEnd; 1441e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1442e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1443e9709e831954c3427d5cb839e84221a177bfedebethannicholas } 1444e9709e831954c3427d5cb839e84221a177bfedebethannicholas int actualCount = static_cast<int>(vertsEnd - *verts); 1445e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(actualCount <= count); 1446e9709e831954c3427d5cb839e84221a177bfedebethannicholas SkASSERT(pointsEnd - points == actualCount); 1447e9709e831954c3427d5cb839e84221a177bfedebethannicholas delete[] points; 1448e9709e831954c3427d5cb839e84221a177bfedebethannicholas return actualCount; 1449e9709e831954c3427d5cb839e84221a177bfedebethannicholas} 1450e9709e831954c3427d5cb839e84221a177bfedebethannicholas 1451e9709e831954c3427d5cb839e84221a177bfedebethannicholas} // namespace 1452