17b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/* 27b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Copyright (C) 2014 The Android Open Source Project 37b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 47b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Licensed under the Apache License, Version 2.0 (the "License"); 57b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * you may not use this file except in compliance with the License. 67b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * You may obtain a copy of the License at 77b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 87b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * http://www.apache.org/licenses/LICENSE-2.0 97b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Unless required by applicable law or agreed to in writing, software 117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * distributed under the License is distributed on an "AS IS" BASIS, 127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * See the License for the specific language governing permissions and 147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * limitations under the License. 157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 17512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// The highest z value can't be higher than (CASTER_Z_CAP_RATIO * light.z) 18c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#define CASTER_Z_CAP_RATIO 0.95f 19512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 20512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// When there is no umbra, then just fake the umbra using 21512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// centroid * (1 - FAKE_UMBRA_SIZE_RATIO) + outline * FAKE_UMBRA_SIZE_RATIO 22512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#define FAKE_UMBRA_SIZE_RATIO 0.05f 23512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 24512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// When the polygon is about 90 vertices, the penumbra + umbra can reach 270 rays. 25512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// That is consider pretty fine tessllated polygon so far. 26512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// This is just to prevent using too much some memory when edge slicing is not 27512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// needed any more. 28512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#define FINE_TESSELLATED_POLYGON_RAY_NUMBER 270 29512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui/** 30512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * Extra vertices for the corner for smoother corner. 31512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * Only for outer loop. 32512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * Note that we use such extra memory to avoid an extra loop. 33512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui */ 34512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// For half circle, we could add EXTRA_VERTEX_PER_PI vertices. 35512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// Set to 1 if we don't want to have any. 36512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#define SPOT_EXTRA_CORNER_VERTEX_PER_PI 18 37512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 38512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// For the whole polygon, the sum of all the deltas b/t normals is 2 * M_PI, 39512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// therefore, the maximum number of extra vertices will be twice bigger. 401bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck#define SPOT_MAX_EXTRA_CORNER_VERTEX_NUMBER (2 * SPOT_EXTRA_CORNER_VERTEX_PER_PI) 41512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 42512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// For each RADIANS_DIVISOR, we would allocate one more vertex b/t the normals. 43512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#define SPOT_CORNER_RADIANS_DIVISOR (M_PI / SPOT_EXTRA_CORNER_VERTEX_PER_PI) 44512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 45138c21fbec12bead3c7ca1f181c3fd35542ccb00Chris Craik#define PENUMBRA_ALPHA 0.0f 46138c21fbec12bead3c7ca1f181c3fd35542ccb00Chris Craik#define UMBRA_ALPHA 1.0f 477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 489db58c031f8ffa102a6d585cb585bed3bdb911a9Chris Craik#include "SpotShadow.h" 497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5063d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui#include "ShadowTessellator.h" 517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include "Vertex.h" 522dc236b2bae13b9a0ed9b3f7320502aecd7983b3Tom Hudson#include "VertexBuffer.h" 53c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#include "utils/MathUtils.h" 547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 559db58c031f8ffa102a6d585cb585bed3bdb911a9Chris Craik#include <math.h> 569db58c031f8ffa102a6d585cb585bed3bdb911a9Chris Craik#include <stdlib.h> 579db58c031f8ffa102a6d585cb585bed3bdb911a9Chris Craik#include <utils/Log.h> 581bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck#include <algorithm> 599db58c031f8ffa102a6d585cb585bed3bdb911a9Chris Craik 60c50a03d78aaedd0003377e98710e7038bda330e9ztenghui// TODO: After we settle down the new algorithm, we can remove the old one and 61c50a03d78aaedd0003377e98710e7038bda330e9ztenghui// its utility functions. 62c50a03d78aaedd0003377e98710e7038bda330e9ztenghui// Right now, we still need to keep it for comparison purpose and future expansion. 637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuinamespace android { 647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuinamespace uirenderer { 657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 669122b1b168d2a74d51517ed7282f4d6a8adea367ztenghuistatic const float EPSILON = 1e-7; 67726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 68726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik/** 69c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * For each polygon's vertex, the light center will project it to the receiver 70c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * as one of the outline vertex. 71c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * For each outline vertex, we need to store the position and normal. 72c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * Normal here is defined against the edge by the current vertex and the next vertex. 73c50a03d78aaedd0003377e98710e7038bda330e9ztenghui */ 74c50a03d78aaedd0003377e98710e7038bda330e9ztenghuistruct OutlineData { 75c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 position; 76c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 normal; 77c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float radius; 78c50a03d78aaedd0003377e98710e7038bda330e9ztenghui}; 79c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 80c50a03d78aaedd0003377e98710e7038bda330e9ztenghui/** 81512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * For each vertex, we need to keep track of its angle, whether it is penumbra or 82512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * umbra, and its corresponding vertex index. 83512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui */ 84512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghuistruct SpotShadow::VertexAngleData { 85512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // The angle to the vertex from the centroid. 86512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float mAngle; 87512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // True is the vertex comes from penumbra, otherwise it comes from umbra. 88512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui bool mIsPenumbra; 89512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // The index of the vertex described by this data. 90512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int mVertexIndex; 91512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui void set(float angle, bool isPenumbra, int index) { 92512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui mAngle = angle; 93512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui mIsPenumbra = isPenumbra; 94512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui mVertexIndex = index; 95512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 96512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui}; 97512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 98512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui/** 99726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Calculate the angle between and x and a y coordinate. 100726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * The atan2 range from -PI to PI. 101726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik */ 102b79a3e301a8d89b9e1b1f6f3d7fd6aa56610a6f0Chris Craikstatic float angle(const Vector2& point, const Vector2& center) { 103726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik return atan2(point.y - center.y, point.x - center.x); 104726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik} 105726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 1067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 107726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Calculate the intersection of a ray with the line segment defined by two points. 1087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 109726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Returns a negative value in error conditions. 110726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 111726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param rayOrigin The start of the ray 112726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param dx The x vector of the ray 113726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param dy The y vector of the ray 114726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param p1 The first point defining the line segment 115726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param p2 The second point defining the line segment 116726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @return The distance along the ray if it intersects with the line segment, negative if otherwise 1177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 1181bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reckstatic float rayIntersectPoints(const Vector2& rayOrigin, float dx, float dy, const Vector2& p1, 1191bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck const Vector2& p2) { 120726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // The math below is derived from solving this formula, basically the 121726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // intersection point should stay on both the ray and the edge of (p1, p2). 122726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // solve([p1x+t*(p2x-p1x)=dx*t2+px,p1y+t*(p2y-p1y)=dy*t2+py],[t,t2]); 123726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 1249122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float divisor = (dx * (p1.y - p2.y) + dy * p2.x - dy * p1.x); 1251bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck if (divisor == 0) return -1.0f; // error, invalid divisor 126726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 127726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik#if DEBUG_SHADOW 1289122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float interpVal = (dx * (p1.y - rayOrigin.y) + dy * rayOrigin.x - dy * p1.x) / divisor; 12999af9429cda84ad0af1d7fcecb580295b0046882ztenghui if (interpVal < 0 || interpVal > 1) { 13099af9429cda84ad0af1d7fcecb580295b0046882ztenghui ALOGW("rayIntersectPoints is hitting outside the segment %f", interpVal); 13199af9429cda84ad0af1d7fcecb580295b0046882ztenghui } 132726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik#endif 133726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 1349122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float distance = (p1.x * (rayOrigin.y - p2.y) + p2.x * (p1.y - rayOrigin.y) + 1351bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck rayOrigin.x * (p2.y - p1.y)) / 1361bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck divisor; 137726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 1381bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck return distance; // may be negative in error cases 1397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 1407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 1427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points by their X coordinates 1437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points the points as a Vector2 array. 1457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param pointsLength the number of vertices of the polygon. 1467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 1477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::xsort(Vector2* points, int pointsLength) { 1481bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck auto cmp = [](const Vector2& a, const Vector2& b) -> bool { return a.x < b.x; }; 1491e4209e3871493ccfb09e43634d4082f49c227beJohn Reck std::sort(points, points + pointsLength, cmp); 1507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 1517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 1537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * compute the convex hull of a collection of Points 1547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points the points as a Vector2 array. 1567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param pointsLength the number of vertices of the polygon. 1577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param retPoly pre allocated array of floats to put the vertices 1587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return the number of points in the polygon 0 if no intersection 1597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 1607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuiint SpotShadow::hull(Vector2* points, int pointsLength, Vector2* retPoly) { 1617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui xsort(points, pointsLength); 1627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int n = pointsLength; 1637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 lUpper[n]; 1647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[0] = points[0]; 1657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[1] = points[1]; 1667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int lUpperSize = 2; 1687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 2; i < n; i++) { 1707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize] = points[i]; 1717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpperSize++; 1727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1731bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck while (lUpperSize > 2 && 1741bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck !ccw(lUpper[lUpperSize - 3].x, lUpper[lUpperSize - 3].y, lUpper[lUpperSize - 2].x, 1751bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck lUpper[lUpperSize - 2].y, lUpper[lUpperSize - 1].x, lUpper[lUpperSize - 1].y)) { 1767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Remove the middle point of the three last 1777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize - 2].x = lUpper[lUpperSize - 1].x; 1787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize - 2].y = lUpper[lUpperSize - 1].y; 1797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpperSize--; 1807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 lLower[n]; 1847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[0] = points[n - 1]; 1857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[1] = points[n - 2]; 1867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int lLowerSize = 2; 1887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = n - 3; i >= 0; i--) { 1907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[lLowerSize] = points[i]; 1917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLowerSize++; 1927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1931bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck while (lLowerSize > 2 && 1941bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck !ccw(lLower[lLowerSize - 3].x, lLower[lLowerSize - 3].y, lLower[lLowerSize - 2].x, 1951bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck lLower[lLowerSize - 2].y, lLower[lLowerSize - 1].x, lLower[lLowerSize - 1].y)) { 1967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Remove the middle point of the three last 1977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[lLowerSize - 2] = lLower[lLowerSize - 1]; 1987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLowerSize--; 1997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 202726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // output points in CW ordering 203726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const int total = lUpperSize + lLowerSize - 2; 204726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik int outIndex = total - 1; 2057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < lUpperSize; i++) { 206726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik retPoly[outIndex] = lUpper[i]; 207726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik outIndex--; 2087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 1; i < lLowerSize - 1; i++) { 211726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik retPoly[outIndex] = lLower[i]; 212726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik outIndex--; 2137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Add test harness which verify that all the points are inside the hull. 215726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik return total; 2167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 2177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 219f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether the 3 points form a counter clockwise turn. 2207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 2217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return true if a right hand turn 2227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 2231bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reckbool SpotShadow::ccw(float ax, float ay, float bx, float by, float cx, float cy) { 2247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return (bx - ax) * (cy - ay) - (by - ay) * (cx - ax) > EPSILON; 2257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 2267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 2287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points about a center point 2297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 2307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly The in and out polyogon as a Vector2 array. 2317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polyLength The number of vertices of the polygon. 2327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param center the center ctr[0] = x , ctr[1] = y to sort around. 2337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 2347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::sort(Vector2* poly, int polyLength, const Vector2& center) { 2357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui quicksortCirc(poly, 0, polyLength - 1, center); 2367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 2377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 2397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Swap points pointed to by i and j 2407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 2417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::swap(Vector2* points, int i, int j) { 2427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 temp = points[i]; 2437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui points[i] = points[j]; 2447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui points[j] = temp; 2457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 2467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 2487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * quick sort implementation about the center. 2497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 2501bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reckvoid SpotShadow::quicksortCirc(Vector2* points, int low, int high, const Vector2& center) { 2517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int i = low, j = high; 2527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int p = low + (high - low) / 2; 2537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float pivot = angle(points[p], center); 2547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (i <= j) { 255726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik while (angle(points[i], center) > pivot) { 2567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 2577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 258726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik while (angle(points[j], center) < pivot) { 2597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 2607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i <= j) { 2637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui swap(points, i, j); 2647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 2657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 2667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (low < j) quicksortCirc(points, low, j, center); 2697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i < high) quicksortCirc(points, i, high, center); 2707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 2717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 2737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Test whether a point is inside the polygon. 2747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 2757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param testPoint the point to test 2767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly the polygon 2777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return true if the testPoint is inside the poly. 2787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 2791bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reckbool SpotShadow::testPointInsidePolygon(const Vector2 testPoint, const Vector2* poly, int len) { 2807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui bool c = false; 2819122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float testx = testPoint.x; 2829122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float testy = testPoint.y; 2837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0, j = len - 1; i < len; j = i++) { 2849122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float startX = poly[j].x; 2859122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float startY = poly[j].y; 2869122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float endX = poly[i].x; 2879122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float endY = poly[i].y; 2887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2891bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck if (((endY > testy) != (startY > testy)) && 2901bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck (testx < (startX - endX) * (testy - endY) / (startY - endY) + endX)) { 2917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui c = !c; 2927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return c; 2957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 2967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 2987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Reverse the polygon 2997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polygon the polygon as a Vector2 array 3017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param len the number of points of the polygon 3027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::reverse(Vector2* polygon, int len) { 3047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int n = len / 2; 3057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < n; i++) { 3067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 tmp = polygon[i]; 3077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int k = len - 1 - i; 3087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui polygon[i] = polygon[k]; 3097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui polygon[k] = tmp; 3107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Compute a horizontal circular polygon about point (x , y , height) of radius 3157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * (size) 3167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points number of the points of the output polygon. 3187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param lightCenter the center of the light. 3197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param size the light size. 3207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param ret result polygon. 3217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3221bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reckvoid SpotShadow::computeLightPolygon(int points, const Vector3& lightCenter, float size, 3231bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck Vector3* ret) { 3247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Caching all the sin / cos values and store them in a look up table. 3257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < points; i++) { 3269122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float angle = 2 * i * M_PI / points; 327726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik ret[i].x = cosf(angle) * size + lightCenter.x; 328726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik ret[i].y = sinf(angle) * size + lightCenter.y; 3297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ret[i].z = lightCenter.z; 3307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 334512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * From light center, project one vertex to the z=0 surface and get the outline. 3357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 336512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @param outline The result which is the outline position. 337512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @param lightCenter The center of light. 338512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @param polyVertex The input polygon's vertex. 339512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * 340512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @return float The ratio of (polygon.z / light.z - polygon.z) 3417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3421bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reckfloat SpotShadow::projectCasterToOutline(Vector2& outline, const Vector3& lightCenter, 3431bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck const Vector3& polyVertex) { 344c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float lightToPolyZ = lightCenter.z - polyVertex.z; 345c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float ratioZ = CASTER_Z_CAP_RATIO; 346c50a03d78aaedd0003377e98710e7038bda330e9ztenghui if (lightToPolyZ != 0) { 347c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // If any caster's vertex is almost above the light, we just keep it as 95% 348c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // of the height of the light. 3493bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui ratioZ = MathUtils::clamp(polyVertex.z / lightToPolyZ, 0.0f, CASTER_Z_CAP_RATIO); 350c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 351c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 352c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outline.x = polyVertex.x - ratioZ * (lightCenter.x - polyVertex.x); 353c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outline.y = polyVertex.y - ratioZ * (lightCenter.y - polyVertex.y); 354c50a03d78aaedd0003377e98710e7038bda330e9ztenghui return ratioZ; 355c50a03d78aaedd0003377e98710e7038bda330e9ztenghui} 356c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 357c50a03d78aaedd0003377e98710e7038bda330e9ztenghui/** 358c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * Generate the shadow spot light of shape lightPoly and a object poly 359c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * 360c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param isCasterOpaque whether the caster is opaque 361c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param lightCenter the center of the light 362c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param lightSize the radius of the light 363c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param poly x,y,z vertexes of a convex polygon that occludes the light source 364c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param polyLength number of vertexes of the occluding polygon 365c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param shadowTriangleStrip return an (x,y,alpha) triangle strip representing the shadow. Return 366c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * empty strip if error. 367c50a03d78aaedd0003377e98710e7038bda330e9ztenghui */ 3681bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reckvoid SpotShadow::createSpotShadow(bool isCasterOpaque, const Vector3& lightCenter, float lightSize, 3691bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck const Vector3* poly, int polyLength, const Vector3& polyCentroid, 3701bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck VertexBuffer& shadowTriangleStrip) { 3713bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui if (CC_UNLIKELY(lightCenter.z <= 0)) { 3723bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui ALOGW("Relative Light Z is not positive. No spot shadow!"); 3733bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui return; 3743bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui } 375512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui if (CC_UNLIKELY(polyLength < 3)) { 376512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#if DEBUG_SHADOW 377512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ALOGW("Invalid polygon length. No spot shadow!"); 378512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#endif 379512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui return; 380512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 381c50a03d78aaedd0003377e98710e7038bda330e9ztenghui OutlineData outlineData[polyLength]; 382c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 outlineCentroid; 383c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Calculate the projected outline for each polygon's vertices from the light center. 384c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 385c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // O Light 386c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // / 387c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // / 388c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // . Polygon vertex 389c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // / 390c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // / 391c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // O Outline vertices 392c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 393c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Ratio = (Poly - Outline) / (Light - Poly) 394c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Outline.x = Poly.x - Ratio * (Light.x - Poly.x) 395c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Outline's radius / Light's radius = Ratio 396c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 397c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Compute the last outline vertex to make sure we can get the normal and outline 398c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // in one single loop. 3991bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck projectCasterToOutline(outlineData[polyLength - 1].position, lightCenter, poly[polyLength - 1]); 400c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 401c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Take the outline's polygon, calculate the normal for each outline edge. 402c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int currentNormalIndex = polyLength - 1; 403c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int nextNormalIndex = 0; 404c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 405c50a03d78aaedd0003377e98710e7038bda330e9ztenghui for (int i = 0; i < polyLength; i++) { 4061bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck float ratioZ = projectCasterToOutline(outlineData[i].position, lightCenter, poly[i]); 407c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outlineData[i].radius = ratioZ * lightSize; 408c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 409c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outlineData[currentNormalIndex].normal = ShadowTessellator::calculateNormal( 4101bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck outlineData[currentNormalIndex].position, outlineData[nextNormalIndex].position); 411c50a03d78aaedd0003377e98710e7038bda330e9ztenghui currentNormalIndex = (currentNormalIndex + 1) % polyLength; 412c50a03d78aaedd0003377e98710e7038bda330e9ztenghui nextNormalIndex++; 413c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 414c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 415c50a03d78aaedd0003377e98710e7038bda330e9ztenghui projectCasterToOutline(outlineCentroid, lightCenter, polyCentroid); 416c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 417c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int penumbraIndex = 0; 418512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // Then each polygon's vertex produce at minmal 2 penumbra vertices. 419512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // Since the size can be dynamic here, we keep track of the size and update 420512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // the real size at the end. 421512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int allocatedPenumbraLength = 2 * polyLength + SPOT_MAX_EXTRA_CORNER_VERTEX_NUMBER; 422512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui Vector2 penumbra[allocatedPenumbraLength]; 423512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int totalExtraCornerSliceNumber = 0; 424c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 425c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 umbra[polyLength]; 426c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 427512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // When centroid is covered by all circles from outline, then we consider 428512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // the umbra is invalid, and we will tune down the shadow strength. 429c50a03d78aaedd0003377e98710e7038bda330e9ztenghui bool hasValidUmbra = true; 430512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // We need the minimal of RaitoVI to decrease the spot shadow strength accordingly. 431512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float minRaitoVI = FLT_MAX; 432c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 433c50a03d78aaedd0003377e98710e7038bda330e9ztenghui for (int i = 0; i < polyLength; i++) { 434c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Generate all the penumbra's vertices only using the (outline vertex + normal * radius) 435c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // There is no guarantee that the penumbra is still convex, but for 436c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // each outline vertex, it will connect to all its corresponding penumbra vertices as 437c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // triangle fans. And for neighber penumbra vertex, it will be a trapezoid. 438c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 439c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Penumbra Vertices marked as Pi 440c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Outline Vertices marked as Vi 441c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (P3) 442c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (P2) | ' (P4) 443c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (P1)' | | ' 444c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // ' | | ' 445c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (P0) ------------------------------------------------(P5) 446c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | (V0) |(V1) 447c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 448c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 449c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 450c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 451c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 452c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 453c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 454c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 455c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (V3)-----------------------------------(V2) 456c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int preNormalIndex = (i + polyLength - 1) % polyLength; 457c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 458512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui const Vector2& previousNormal = outlineData[preNormalIndex].normal; 459512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui const Vector2& currentNormal = outlineData[i].normal; 460512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 461512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // Depending on how roundness we want for each corner, we can subdivide 462c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // further here and/or introduce some heuristic to decide how much the 463c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // subdivision should be. 464512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int currentExtraSliceNumber = ShadowTessellator::getExtraVertexNumber( 465512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui previousNormal, currentNormal, SPOT_CORNER_RADIANS_DIVISOR); 466c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 467512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int currentCornerSliceNumber = 1 + currentExtraSliceNumber; 468512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui totalExtraCornerSliceNumber += currentExtraSliceNumber; 469512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#if DEBUG_SHADOW 470512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ALOGD("currentExtraSliceNumber should be %d", currentExtraSliceNumber); 471512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ALOGD("currentCornerSliceNumber should be %d", currentCornerSliceNumber); 472512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ALOGD("totalCornerSliceNumber is %d", totalExtraCornerSliceNumber); 473512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#endif 474512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui if (CC_UNLIKELY(totalExtraCornerSliceNumber > SPOT_MAX_EXTRA_CORNER_VERTEX_NUMBER)) { 475512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui currentCornerSliceNumber = 1; 476512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 477512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui for (int k = 0; k <= currentCornerSliceNumber; k++) { 478512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui Vector2 avgNormal = 479512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui (previousNormal * (currentCornerSliceNumber - k) + currentNormal * k) / 480512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui currentCornerSliceNumber; 481512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui avgNormal.normalize(); 4821bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck penumbra[penumbraIndex++] = outlineData[i].position + avgNormal * outlineData[i].radius; 483512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 484c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 485c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Compute the umbra by the intersection from the outline's centroid! 486c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 487c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (V) ------------------------------------ 488c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' | 489c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' | 490c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' (I) | 491c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' | 492c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' (C) | 493c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 494c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 495c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 496c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 497c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // ------------------------------------ 498c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 499c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Connect a line b/t the outline vertex (V) and the centroid (C), it will 500c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // intersect with the outline vertex's circle at point (I). 501c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Now, ratioVI = VI / VC, ratioIC = IC / VC 502c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Then the intersetion point can be computed as Ixy = Vxy * ratioIC + Cxy * ratioVI; 503c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 504512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // When all of the outline circles cover the the outline centroid, (like I is 505c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // on the other side of C), there is no real umbra any more, so we just fake 506c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // a small area around the centroid as the umbra, and tune down the spot 507c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // shadow's umbra strength to simulate the effect the whole shadow will 508c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // become lighter in this case. 509c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // The ratio can be simulated by using the inverse of maximum of ratioVI for 510c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // all (V). 511512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float distOutline = (outlineData[i].position - outlineCentroid).length(); 5123bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui if (CC_UNLIKELY(distOutline == 0)) { 513c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // If the outline has 0 area, then there is no spot shadow anyway. 514c50a03d78aaedd0003377e98710e7038bda330e9ztenghui ALOGW("Outline has 0 area, no spot shadow!"); 515c50a03d78aaedd0003377e98710e7038bda330e9ztenghui return; 516c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 517512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 518512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float ratioVI = outlineData[i].radius / distOutline; 5199db58c031f8ffa102a6d585cb585bed3bdb911a9Chris Craik minRaitoVI = std::min(minRaitoVI, ratioVI); 520512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui if (ratioVI >= (1 - FAKE_UMBRA_SIZE_RATIO)) { 521512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ratioVI = (1 - FAKE_UMBRA_SIZE_RATIO); 522c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 523c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // When we know we don't have valid umbra, don't bother to compute the 524c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // values below. But we can't skip the loop yet since we want to know the 525c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // maximum ratio. 526512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float ratioIC = 1 - ratioVI; 527512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui umbra[i] = outlineData[i].position * ratioIC + outlineCentroid * ratioVI; 528c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 529c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 530512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui hasValidUmbra = (minRaitoVI <= 1.0); 531c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float shadowStrengthScale = 1.0; 532c50a03d78aaedd0003377e98710e7038bda330e9ztenghui if (!hasValidUmbra) { 533512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#if DEBUG_SHADOW 534c50a03d78aaedd0003377e98710e7038bda330e9ztenghui ALOGW("The object is too close to the light or too small, no real umbra!"); 535512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#endif 536c50a03d78aaedd0003377e98710e7038bda330e9ztenghui for (int i = 0; i < polyLength; i++) { 537c50a03d78aaedd0003377e98710e7038bda330e9ztenghui umbra[i] = outlineData[i].position * FAKE_UMBRA_SIZE_RATIO + 5381bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck outlineCentroid * (1 - FAKE_UMBRA_SIZE_RATIO); 539c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 540512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui shadowStrengthScale = 1.0 / minRaitoVI; 541c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 542c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 543512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int penumbraLength = penumbraIndex; 544512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int umbraLength = polyLength; 545512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 546c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#if DEBUG_SHADOW 5471bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck ALOGD("penumbraLength is %d , allocatedPenumbraLength %d", penumbraLength, 5481bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck allocatedPenumbraLength); 549c50a03d78aaedd0003377e98710e7038bda330e9ztenghui dumpPolygon(poly, polyLength, "input poly"); 550c50a03d78aaedd0003377e98710e7038bda330e9ztenghui dumpPolygon(penumbra, penumbraLength, "penumbra"); 551512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui dumpPolygon(umbra, umbraLength, "umbra"); 552c50a03d78aaedd0003377e98710e7038bda330e9ztenghui ALOGD("hasValidUmbra is %d and shadowStrengthScale is %f", hasValidUmbra, shadowStrengthScale); 553c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#endif 554c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 555512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // The penumbra and umbra needs to be in convex shape to keep consistency 556512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // and quality. 557512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // Since we are still shooting rays to penumbra, it needs to be convex. 558512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // Umbra can be represented as a fan from the centroid, but visually umbra 559512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // looks nicer when it is convex. 560512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui Vector2 finalUmbra[umbraLength]; 561512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui Vector2 finalPenumbra[penumbraLength]; 562512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int finalUmbraLength = hull(umbra, umbraLength, finalUmbra); 563512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int finalPenumbraLength = hull(penumbra, penumbraLength, finalPenumbra); 564512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 5651bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck generateTriangleStrip(isCasterOpaque, shadowStrengthScale, finalPenumbra, finalPenumbraLength, 5661bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck finalUmbra, finalUmbraLength, poly, polyLength, shadowTriangleStrip, 5671bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck outlineCentroid); 568c50a03d78aaedd0003377e98710e7038bda330e9ztenghui} 569c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 5707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 571512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * This is only for experimental purpose. 572512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * After intersections are calculated, we could smooth the polygon if needed. 573512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * So far, we don't think it is more appealing yet. 5747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 575512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @param level The level of smoothness. 576512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @param rays The total number of rays. 577512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @param rayDist (In and Out) The distance for each ray. 578512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * 579512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui */ 580512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghuivoid SpotShadow::smoothPolygon(int level, int rays, float* rayDist) { 581512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui for (int k = 0; k < level; k++) { 582512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui for (int i = 0; i < rays; i++) { 583512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float p1 = rayDist[(rays - 1 + i) % rays]; 584512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float p2 = rayDist[i]; 585512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float p3 = rayDist[(i + 1) % rays]; 586512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui rayDist[i] = (p1 + p2 * 2 + p3) / 4; 587512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 588512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 589512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 590512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 591d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// Index pair is meant for storing the tessellation information for the penumbra 592d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// area. One index must come from exterior tangent of the circles, the other one 593d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// must come from the interior tangent of the circles. 594d2dcd6fded3a036f334a88bf9593398833f2919aztenghuistruct IndexPair { 595d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int outerIndex; 596d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int innerIndex; 597d2dcd6fded3a036f334a88bf9593398833f2919aztenghui}; 5987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 599d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// For one penumbra vertex, find the cloest umbra vertex and return its index. 600d2dcd6fded3a036f334a88bf9593398833f2919aztenghuiinline int getClosestUmbraIndex(const Vector2& pivot, const Vector2* polygon, int polygonLength) { 601d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float minLengthSquared = FLT_MAX; 602d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int resultIndex = -1; 603d2dcd6fded3a036f334a88bf9593398833f2919aztenghui bool hasDecreased = false; 604d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Starting with some negative offset, assuming both umbra and penumbra are starting 605d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // at the same angle, this can help to find the result faster. 606d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Normally, loop 3 times, we can find the closest point. 607d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int offset = polygonLength - 2; 608d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < polygonLength; i++) { 609d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int currentIndex = (i + offset) % polygonLength; 610d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float currentLengthSquared = (pivot - polygon[currentIndex]).lengthSquared(); 611d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (currentLengthSquared < minLengthSquared) { 612d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (minLengthSquared != FLT_MAX) { 613d2dcd6fded3a036f334a88bf9593398833f2919aztenghui hasDecreased = true; 614d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 615d2dcd6fded3a036f334a88bf9593398833f2919aztenghui minLengthSquared = currentLengthSquared; 616d2dcd6fded3a036f334a88bf9593398833f2919aztenghui resultIndex = currentIndex; 617d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } else if (currentLengthSquared > minLengthSquared && hasDecreased) { 618d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Early break b/c we have found the closet one and now the length 619d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // is increasing again. 620d2dcd6fded3a036f334a88bf9593398833f2919aztenghui break; 621512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 622512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 6231bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck if (resultIndex == -1) { 624d2dcd6fded3a036f334a88bf9593398833f2919aztenghui ALOGE("resultIndex is -1, the polygon must be invalid!"); 625d2dcd6fded3a036f334a88bf9593398833f2919aztenghui resultIndex = 0; 626d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 627d2dcd6fded3a036f334a88bf9593398833f2919aztenghui return resultIndex; 628512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 6297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6303932063bc75dc1e4efc2c428ca208d2e2290164dztenghui// Allow some epsilon here since the later ray intersection did allow for some small 6313932063bc75dc1e4efc2c428ca208d2e2290164dztenghui// floating point error, when the intersection point is slightly outside the segment. 632d2dcd6fded3a036f334a88bf9593398833f2919aztenghuiinline bool sameDirections(bool isPositiveCross, float a, float b) { 633d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (isPositiveCross) { 6343932063bc75dc1e4efc2c428ca208d2e2290164dztenghui return a >= -EPSILON && b >= -EPSILON; 635d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } else { 6363932063bc75dc1e4efc2c428ca208d2e2290164dztenghui return a <= EPSILON && b <= EPSILON; 637512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 638512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 639512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 640d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// Find the right polygon edge to shoot the ray at. 641d2dcd6fded3a036f334a88bf9593398833f2919aztenghuiinline int findPolyIndex(bool isPositiveCross, int startPolyIndex, const Vector2& umbraDir, 6421bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck const Vector2* polyToCentroid, int polyLength) { 643d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Make sure we loop with a bound. 644d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < polyLength; i++) { 645d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int currentIndex = (i + startPolyIndex) % polyLength; 646d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const Vector2& currentToCentroid = polyToCentroid[currentIndex]; 647d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const Vector2& nextToCentroid = polyToCentroid[(currentIndex + 1) % polyLength]; 648d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 649d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float currentCrossUmbra = currentToCentroid.cross(umbraDir); 650d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float umbraCrossNext = umbraDir.cross(nextToCentroid); 651d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (sameDirections(isPositiveCross, currentCrossUmbra, umbraCrossNext)) { 652512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#if DEBUG_SHADOW 6531bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck ALOGD("findPolyIndex loop %d times , index %d", i, currentIndex); 654512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#endif 655d2dcd6fded3a036f334a88bf9593398833f2919aztenghui return currentIndex; 656512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 657512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 658d2dcd6fded3a036f334a88bf9593398833f2919aztenghui LOG_ALWAYS_FATAL("Can't find the right polygon's edge from startPolyIndex %d", startPolyIndex); 659d2dcd6fded3a036f334a88bf9593398833f2919aztenghui return -1; 660512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 661512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 662d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// Generate the index pair for penumbra / umbra vertices, and more penumbra vertices 663d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// if needed. 664d2dcd6fded3a036f334a88bf9593398833f2919aztenghuiinline void genNewPenumbraAndPairWithUmbra(const Vector2* penumbra, int penumbraLength, 6651bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck const Vector2* umbra, int umbraLength, 6661bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck Vector2* newPenumbra, int& newPenumbraIndex, 6671bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck IndexPair* verticesPair, int& verticesPairIndex) { 668d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // In order to keep everything in just one loop, we need to pre-compute the 669d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // closest umbra vertex for the last penumbra vertex. 6701bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck int previousClosestUmbraIndex = 6711bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck getClosestUmbraIndex(penumbra[penumbraLength - 1], umbra, umbraLength); 672d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < penumbraLength; i++) { 673d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const Vector2& currentPenumbraVertex = penumbra[i]; 674d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // For current penumbra vertex, starting from previousClosestUmbraIndex, 675d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // then check the next one until the distance increase. 676d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // The last one before the increase is the umbra vertex we need to pair with. 6773932063bc75dc1e4efc2c428ca208d2e2290164dztenghui float currentLengthSquared = 6783932063bc75dc1e4efc2c428ca208d2e2290164dztenghui (currentPenumbraVertex - umbra[previousClosestUmbraIndex]).lengthSquared(); 6793932063bc75dc1e4efc2c428ca208d2e2290164dztenghui int currentClosestUmbraIndex = previousClosestUmbraIndex; 680d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int indexDelta = 0; 681d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int j = 1; j < umbraLength; j++) { 682d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int newUmbraIndex = (previousClosestUmbraIndex + j) % umbraLength; 683d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float newLengthSquared = (currentPenumbraVertex - umbra[newUmbraIndex]).lengthSquared(); 684d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (newLengthSquared > currentLengthSquared) { 6853932063bc75dc1e4efc2c428ca208d2e2290164dztenghui // currentClosestUmbraIndex is the umbra vertex's index which has 6863932063bc75dc1e4efc2c428ca208d2e2290164dztenghui // currently found smallest distance, so we can simply break here. 687512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui break; 688512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } else { 689d2dcd6fded3a036f334a88bf9593398833f2919aztenghui currentLengthSquared = newLengthSquared; 690d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexDelta++; 6913932063bc75dc1e4efc2c428ca208d2e2290164dztenghui currentClosestUmbraIndex = newUmbraIndex; 69250ecf849cb7ccc3482517b74d2214b347927791eztenghui } 69350ecf849cb7ccc3482517b74d2214b347927791eztenghui } 694d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 695d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (indexDelta > 1) { 6961bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck // For those umbra don't have penumbra, generate new penumbra vertices by 6971bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck // interpolation. 698d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 699d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Assuming Pi for penumbra vertices, and Ui for umbra vertices. 700d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // In the case like below P1 paired with U1 and P2 paired with U5. 701d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // U2 to U4 are unpaired umbra vertices. 702d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 703d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // P1 P2 704d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 705d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // U1 U2 U3 U4 U5 706d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 707d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // We will need to generate 3 more penumbra vertices P1.1, P1.2, P1.3 708d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // to pair with U2 to U4. 709d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 710d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // P1 P1.1 P1.2 P1.3 P2 711d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | | | | 712d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // U1 U2 U3 U4 U5 713d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 714d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // That distance ratio b/t Ui to U1 and Ui to U5 decides its paired penumbra 715d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // vertex's location. 716d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int newPenumbraNumber = indexDelta - 1; 717d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 718a1f563134065abb360096cc06f6bfe4a8cca7a48Keith Mok float accumulatedDeltaLength[indexDelta]; 719d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float totalDeltaLength = 0; 720d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 721d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // To save time, cache the previous umbra vertex info outside the loop 722d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // and update each loop. 723d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 previousClosestUmbra = umbra[previousClosestUmbraIndex]; 724d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 skippedUmbra; 725d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Use umbra data to precompute the length b/t unpaired umbra vertices, 726d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // and its ratio against the total length. 727d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int k = 0; k < indexDelta; k++) { 728d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int skippedUmbraIndex = (previousClosestUmbraIndex + k + 1) % umbraLength; 729d2dcd6fded3a036f334a88bf9593398833f2919aztenghui skippedUmbra = umbra[skippedUmbraIndex]; 730d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float currentDeltaLength = (skippedUmbra - previousClosestUmbra).length(); 731d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 732d2dcd6fded3a036f334a88bf9593398833f2919aztenghui totalDeltaLength += currentDeltaLength; 733d2dcd6fded3a036f334a88bf9593398833f2919aztenghui accumulatedDeltaLength[k] = totalDeltaLength; 734d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 735d2dcd6fded3a036f334a88bf9593398833f2919aztenghui previousClosestUmbra = skippedUmbra; 736512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 737512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 738d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const Vector2& previousPenumbra = penumbra[(i + penumbraLength - 1) % penumbraLength]; 739d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Then for each unpaired umbra vertex, create a new penumbra by the ratio, 740d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // and pair them togehter. 741d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int k = 0; k < newPenumbraNumber; k++) { 742d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float weightForCurrentPenumbra = 1.0f; 743d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (totalDeltaLength != 0.0f) { 744d2dcd6fded3a036f334a88bf9593398833f2919aztenghui weightForCurrentPenumbra = accumulatedDeltaLength[k] / totalDeltaLength; 745d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 746d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float weightForPreviousPenumbra = 1.0f - weightForCurrentPenumbra; 747512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 748d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 interpolatedPenumbra = currentPenumbraVertex * weightForCurrentPenumbra + 7491bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck previousPenumbra * weightForPreviousPenumbra; 750512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 751d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int skippedUmbraIndex = (previousClosestUmbraIndex + k + 1) % umbraLength; 752edaecc1db0584fa017822dfc2da0c968b53967e6Andreas Gampe verticesPair[verticesPairIndex].outerIndex = newPenumbraIndex; 753edaecc1db0584fa017822dfc2da0c968b53967e6Andreas Gampe verticesPair[verticesPairIndex].innerIndex = skippedUmbraIndex; 754edaecc1db0584fa017822dfc2da0c968b53967e6Andreas Gampe verticesPairIndex++; 755d2dcd6fded3a036f334a88bf9593398833f2919aztenghui newPenumbra[newPenumbraIndex++] = interpolatedPenumbra; 756512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 757512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 758edaecc1db0584fa017822dfc2da0c968b53967e6Andreas Gampe verticesPair[verticesPairIndex].outerIndex = newPenumbraIndex; 759edaecc1db0584fa017822dfc2da0c968b53967e6Andreas Gampe verticesPair[verticesPairIndex].innerIndex = currentClosestUmbraIndex; 760edaecc1db0584fa017822dfc2da0c968b53967e6Andreas Gampe verticesPairIndex++; 761d2dcd6fded3a036f334a88bf9593398833f2919aztenghui newPenumbra[newPenumbraIndex++] = currentPenumbraVertex; 7627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 763d2dcd6fded3a036f334a88bf9593398833f2919aztenghui previousClosestUmbraIndex = currentClosestUmbraIndex; 764512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 765512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 766512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 767d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// Precompute all the polygon's vector, return true if the reference cross product is positive. 7681bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reckinline bool genPolyToCentroid(const Vector2* poly2d, int polyLength, const Vector2& centroid, 7691bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck Vector2* polyToCentroid) { 770d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int j = 0; j < polyLength; j++) { 771d2dcd6fded3a036f334a88bf9593398833f2919aztenghui polyToCentroid[j] = poly2d[j] - centroid; 7723932063bc75dc1e4efc2c428ca208d2e2290164dztenghui // Normalize these vectors such that we can use epsilon comparison after 7733932063bc75dc1e4efc2c428ca208d2e2290164dztenghui // computing their cross products with another normalized vector. 7743932063bc75dc1e4efc2c428ca208d2e2290164dztenghui polyToCentroid[j].normalize(); 7757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 776d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float refCrossProduct = 0; 777d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int j = 0; j < polyLength; j++) { 778d2dcd6fded3a036f334a88bf9593398833f2919aztenghui refCrossProduct = polyToCentroid[j].cross(polyToCentroid[(j + 1) % polyLength]); 779d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (refCrossProduct != 0) { 780d2dcd6fded3a036f334a88bf9593398833f2919aztenghui break; 781d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 782512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 783d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 784d2dcd6fded3a036f334a88bf9593398833f2919aztenghui return refCrossProduct > 0; 7857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 7867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 787d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// For one umbra vertex, shoot an ray from centroid to it. 788d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// If the ray hit the polygon first, then return the intersection point as the 789d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// closer vertex. 790d2dcd6fded3a036f334a88bf9593398833f2919aztenghuiinline Vector2 getCloserVertex(const Vector2& umbraVertex, const Vector2& centroid, 7911bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck const Vector2* poly2d, int polyLength, const Vector2* polyToCentroid, 7921bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck bool isPositiveCross, int& previousPolyIndex) { 793d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 umbraToCentroid = umbraVertex - centroid; 794d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float distanceToUmbra = umbraToCentroid.length(); 795d2dcd6fded3a036f334a88bf9593398833f2919aztenghui umbraToCentroid = umbraToCentroid / distanceToUmbra; 796d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 797d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // previousPolyIndex is updated for each item such that we can minimize the 798d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // looping inside findPolyIndex(); 7991bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck previousPolyIndex = findPolyIndex(isPositiveCross, previousPolyIndex, umbraToCentroid, 8001bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck polyToCentroid, polyLength); 801d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 802d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float dx = umbraToCentroid.x; 803d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float dy = umbraToCentroid.y; 8041bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck float distanceToIntersectPoly = 8051bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck rayIntersectPoints(centroid, dx, dy, poly2d[previousPolyIndex], 8061bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck poly2d[(previousPolyIndex + 1) % polyLength]); 807d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (distanceToIntersectPoly < 0) { 808d2dcd6fded3a036f334a88bf9593398833f2919aztenghui distanceToIntersectPoly = 0; 809512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 810f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 811d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Pick the closer one as the occluded area vertex. 812d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 closerVertex; 813d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (distanceToIntersectPoly < distanceToUmbra) { 814d2dcd6fded3a036f334a88bf9593398833f2919aztenghui closerVertex.x = centroid.x + dx * distanceToIntersectPoly; 815d2dcd6fded3a036f334a88bf9593398833f2919aztenghui closerVertex.y = centroid.y + dy * distanceToIntersectPoly; 816d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } else { 817d2dcd6fded3a036f334a88bf9593398833f2919aztenghui closerVertex = umbraVertex; 818512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 819512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 820d2dcd6fded3a036f334a88bf9593398833f2919aztenghui return closerVertex; 821512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 822512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 823512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui/** 824512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * Generate a triangle strip given two convex polygon 825512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui**/ 82664bb413a664001c95c8439cf097dc3033f4ed733Andreas Gampevoid SpotShadow::generateTriangleStrip(bool isCasterOpaque, float shadowStrengthScale, 8271bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck Vector2* penumbra, int penumbraLength, Vector2* umbra, 8281bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck int umbraLength, const Vector3* poly, int polyLength, 8291bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck VertexBuffer& shadowTriangleStrip, const Vector2& centroid) { 830512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui bool hasOccludedUmbraArea = false; 831512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui Vector2 poly2d[polyLength]; 832f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 833512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui if (isCasterOpaque) { 834512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui for (int i = 0; i < polyLength; i++) { 835512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui poly2d[i].x = poly[i].x; 836512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui poly2d[i].y = poly[i].y; 837512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 838512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // Make sure the centroid is inside the umbra, otherwise, fall back to the 839512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // approach as if there is no occluded umbra area. 840512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui if (testPointInsidePolygon(centroid, poly2d, polyLength)) { 841512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui hasOccludedUmbraArea = true; 842512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 843512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 844512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 845d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // For each penumbra vertex, find its corresponding closest umbra vertex index. 846d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 847d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Penumbra Vertices marked as Pi 848d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Umbra Vertices marked as Ui 849d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // (P3) 850d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // (P2) | ' (P4) 851d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // (P1)' | | ' 852d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // ' | | ' 853d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // (P0) ------------------------------------------------(P5) 854d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | (U0) |(U1) 855d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 856d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | |(U2) (P5.1) 857d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 858d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 859d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 860d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 861d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 862d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 863d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // (U4)-----------------------------------(U3) (P6) 864d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 865d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // At least, like P0, P1, P2, they will find the matching umbra as U0. 866d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // If we jump over some umbra vertex without matching penumbra vertex, then 867d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // we will generate some new penumbra vertex by interpolation. Like P6 is 868d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // matching U3, but U2 is not matched with any penumbra vertex. 869d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // So interpolate P5.1 out and match U2. 870d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // In this way, every umbra vertex will have a matching penumbra vertex. 871d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 872d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // The total pair number can be as high as umbraLength + penumbraLength. 873d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const int maxNewPenumbraLength = umbraLength + penumbraLength; 874d2dcd6fded3a036f334a88bf9593398833f2919aztenghui IndexPair verticesPair[maxNewPenumbraLength]; 875d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int verticesPairIndex = 0; 876d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 877d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Cache all the existing penumbra vertices and newly interpolated vertices into a 878d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // a new array. 879d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 newPenumbra[maxNewPenumbraLength]; 880d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int newPenumbraIndex = 0; 881d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 882d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // For each penumbra vertex, find its closet umbra vertex by comparing the 883d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // neighbor umbra vertices. 884d2dcd6fded3a036f334a88bf9593398833f2919aztenghui genNewPenumbraAndPairWithUmbra(penumbra, penumbraLength, umbra, umbraLength, newPenumbra, 8851bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck newPenumbraIndex, verticesPair, verticesPairIndex); 886d2dcd6fded3a036f334a88bf9593398833f2919aztenghui ShadowTessellator::checkOverflow(verticesPairIndex, maxNewPenumbraLength, "Spot pair"); 887d2dcd6fded3a036f334a88bf9593398833f2919aztenghui ShadowTessellator::checkOverflow(newPenumbraIndex, maxNewPenumbraLength, "Spot new penumbra"); 888d2dcd6fded3a036f334a88bf9593398833f2919aztenghui#if DEBUG_SHADOW 889d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < umbraLength; i++) { 890d2dcd6fded3a036f334a88bf9593398833f2919aztenghui ALOGD("umbra i %d, [%f, %f]", i, umbra[i].x, umbra[i].y); 891d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 892d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < newPenumbraIndex; i++) { 893d2dcd6fded3a036f334a88bf9593398833f2919aztenghui ALOGD("new penumbra i %d, [%f, %f]", i, newPenumbra[i].x, newPenumbra[i].y); 894d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 895d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < verticesPairIndex; i++) { 896d2dcd6fded3a036f334a88bf9593398833f2919aztenghui ALOGD("index i %d, [%d, %d]", i, verticesPair[i].outerIndex, verticesPair[i].innerIndex); 897512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 898d2dcd6fded3a036f334a88bf9593398833f2919aztenghui#endif 899512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 900d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // For the size of vertex buffer, we need 3 rings, one has newPenumbraSize, 901d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // one has umbraLength, the last one has at most umbraLength. 902d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 903d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // For the size of index buffer, the umbra area needs (2 * umbraLength + 2). 904d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // The penumbra one can vary a bit, but it is bounded by (2 * verticesPairIndex + 2). 905d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // And 2 more for jumping between penumbra to umbra. 906d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const int newPenumbraLength = newPenumbraIndex; 907d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const int totalVertexCount = newPenumbraLength + umbraLength * 2; 908d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const int totalIndexCount = 2 * umbraLength + 2 * verticesPairIndex + 6; 9091bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck AlphaVertex* shadowVertices = shadowTriangleStrip.alloc<AlphaVertex>(totalVertexCount); 9101bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck uint16_t* indexBuffer = shadowTriangleStrip.allocIndices<uint16_t>(totalIndexCount); 911512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int vertexBufferIndex = 0; 912d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int indexBufferIndex = 0; 913512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 914d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Fill the IB and VB for the penumbra area. 915d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < newPenumbraLength; i++) { 9161bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck AlphaVertex::set(&shadowVertices[vertexBufferIndex++], newPenumbra[i].x, newPenumbra[i].y, 9171bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck PENUMBRA_ALPHA); 918d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 9199c555566bfef718464546dcab3640f64d2fdc55dTeng-Hui Zhu // Since the umbra can be a faked one when the occluder is too high, the umbra should be lighter 9209c555566bfef718464546dcab3640f64d2fdc55dTeng-Hui Zhu // in this case. 9219c555566bfef718464546dcab3640f64d2fdc55dTeng-Hui Zhu float scaledUmbraAlpha = UMBRA_ALPHA * shadowStrengthScale; 9229c555566bfef718464546dcab3640f64d2fdc55dTeng-Hui Zhu 923d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < umbraLength; i++) { 924d2dcd6fded3a036f334a88bf9593398833f2919aztenghui AlphaVertex::set(&shadowVertices[vertexBufferIndex++], umbra[i].x, umbra[i].y, 9251bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck scaledUmbraAlpha); 926512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 927512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 928d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < verticesPairIndex; i++) { 929d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = verticesPair[i].outerIndex; 930d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // All umbra index need to be offseted by newPenumbraSize. 931d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = verticesPair[i].innerIndex + newPenumbraLength; 932d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 933d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = verticesPair[0].outerIndex; 934d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = verticesPair[0].innerIndex + newPenumbraLength; 935d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 936d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Now fill the IB and VB for the umbra area. 937d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // First duplicated the index from previous strip and the first one for the 938d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // degenerated triangles. 939d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex] = indexBuffer[indexBufferIndex - 1]; 940d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBufferIndex++; 941d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = newPenumbraLength + 0; 942d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Save the first VB index for umbra area in order to close the loop. 943d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int savedStartIndex = vertexBufferIndex; 944512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 945512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui if (hasOccludedUmbraArea) { 946d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Precompute all the polygon's vector, and the reference cross product, 947d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // in order to find the right polygon edge for the ray to intersect. 948d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 polyToCentroid[polyLength]; 949d2dcd6fded3a036f334a88bf9593398833f2919aztenghui bool isPositiveCross = genPolyToCentroid(poly2d, polyLength, centroid, polyToCentroid); 950d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 951d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Because both the umbra and polygon are going in the same direction, 952d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // we can save the previous polygon index to make sure we have less polygon 953d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // vertex to compute for each ray. 954d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int previousPolyIndex = 0; 955d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < umbraLength; i++) { 956d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Shoot a ray from centroid to each umbra vertices and pick the one with 957d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // shorter distance to the centroid, b/t the umbra vertex or the intersection point. 9581bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck Vector2 closerVertex = 9591bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck getCloserVertex(umbra[i], centroid, poly2d, polyLength, polyToCentroid, 9601bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck isPositiveCross, previousPolyIndex); 961d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 962d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // We already stored the umbra vertices, just need to add the occlued umbra's ones. 963d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = newPenumbraLength + i; 964d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = vertexBufferIndex; 9651bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck AlphaVertex::set(&shadowVertices[vertexBufferIndex++], closerVertex.x, closerVertex.y, 9661bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck scaledUmbraAlpha); 967512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 968512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } else { 969d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // If there is no occluded umbra at all, then draw the triangle fan 970d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // starting from the centroid to all umbra vertices. 971512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int lastCentroidIndex = vertexBufferIndex; 9721bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck AlphaVertex::set(&shadowVertices[vertexBufferIndex++], centroid.x, centroid.y, 9731bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck scaledUmbraAlpha); 974d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < umbraLength; i++) { 975d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = newPenumbraLength + i; 976512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui indexBuffer[indexBufferIndex++] = lastCentroidIndex; 977512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 978512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 979d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Closing the umbra area triangle's loop here. 980d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = newPenumbraLength; 981d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = savedStartIndex; 982512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 983512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // At the end, update the real index and vertex buffer size. 984512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui shadowTriangleStrip.updateVertexCount(vertexBufferIndex); 985512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui shadowTriangleStrip.updateIndexCount(indexBufferIndex); 986512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ShadowTessellator::checkOverflow(vertexBufferIndex, totalVertexCount, "Spot Vertex Buffer"); 987512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ShadowTessellator::checkOverflow(indexBufferIndex, totalIndexCount, "Spot Index Buffer"); 988512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 989117bdbcfa3e8306dad21e7e01fa71b00cdfa7265Chris Craik shadowTriangleStrip.setMeshFeatureFlags(VertexBuffer::kAlpha | VertexBuffer::kIndices); 990512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui shadowTriangleStrip.computeBounds<AlphaVertex>(); 991512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 992512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 993512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#if DEBUG_SHADOW 994512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 995512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#define TEST_POINT_NUMBER 128 996f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 997f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Calculate the bounds for generating random test points. 998f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 9991bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reckvoid SpotShadow::updateBound(const Vector2 inVector, Vector2& lowerBound, Vector2& upperBound) { 1000f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.x < lowerBound.x) { 1001f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lowerBound.x = inVector.x; 1002f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1003f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1004f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.y < lowerBound.y) { 1005f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lowerBound.y = inVector.y; 1006f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1007f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1008f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.x > upperBound.x) { 1009f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui upperBound.x = inVector.x; 1010f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1011f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1012f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.y > upperBound.y) { 1013f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui upperBound.y = inVector.y; 1014f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1015f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 1016f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1017f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 1018f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * For debug purpose, when things go wrong, dump the whole polygon data. 1019f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 1020c50a03d78aaedd0003377e98710e7038bda330e9ztenghuivoid SpotShadow::dumpPolygon(const Vector2* poly, int polyLength, const char* polyName) { 1021c50a03d78aaedd0003377e98710e7038bda330e9ztenghui for (int i = 0; i < polyLength; i++) { 1022c50a03d78aaedd0003377e98710e7038bda330e9ztenghui ALOGD("polygon %s i %d x %f y %f", polyName, i, poly[i].x, poly[i].y); 1023c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 1024c50a03d78aaedd0003377e98710e7038bda330e9ztenghui} 1025c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 1026c50a03d78aaedd0003377e98710e7038bda330e9ztenghui/** 1027c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * For debug purpose, when things go wrong, dump the whole polygon data. 1028c50a03d78aaedd0003377e98710e7038bda330e9ztenghui */ 1029c50a03d78aaedd0003377e98710e7038bda330e9ztenghuivoid SpotShadow::dumpPolygon(const Vector3* poly, int polyLength, const char* polyName) { 1030f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < polyLength; i++) { 10318d0ec389531d071529fb0a800f10733b057205d9Teng-Hui Zhu ALOGD("polygon %s i %d x %f y %f z %f", polyName, i, poly[i].x, poly[i].y, poly[i].z); 1032f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1033f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 1034f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1035f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 1036f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether the polygon is convex. 1037f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 10381bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reckbool SpotShadow::testConvex(const Vector2* polygon, int polygonLength, const char* name) { 1039f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool isConvex = true; 1040f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < polygonLength; i++) { 1041f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 start = polygon[i]; 1042f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 middle = polygon[(i + 1) % polygonLength]; 1043f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 end = polygon[(i + 2) % polygonLength]; 1044f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 10459122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float delta = (float(middle.x) - start.x) * (float(end.y) - start.y) - 10461bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck (float(middle.y) - start.y) * (float(end.x) - start.x); 1047f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool isCCWOrCoLinear = (delta >= EPSILON); 1048f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1049f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (isCCWOrCoLinear) { 105050ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("(Error Type 2): polygon (%s) is not a convex b/c start (x %f, y %f)," 10511bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck "middle (x %f, y %f) and end (x %f, y %f) , delta is %f !!!", 10521bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck name, start.x, start.y, middle.x, middle.y, end.x, end.y, delta); 1053f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui isConvex = false; 1054f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui break; 1055f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1056f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1057f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui return isConvex; 1058f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 1059f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1060f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 1061f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether or not the polygon (intersection) is within the 2 input polygons. 1062f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Using Marte Carlo method, we generate a random point, and if it is inside the 1063f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * intersection, then it must be inside both source polygons. 1064f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 10651bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reckvoid SpotShadow::testIntersection(const Vector2* poly1, int poly1Length, const Vector2* poly2, 10661bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck int poly2Length, const Vector2* intersection, 10671bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck int intersectionLength) { 1068f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Find the min and max of x and y. 1069c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 lowerBound = {FLT_MAX, FLT_MAX}; 1070c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 upperBound = {-FLT_MAX, -FLT_MAX}; 1071f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < poly1Length; i++) { 1072f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui updateBound(poly1[i], lowerBound, upperBound); 1073f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1074f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < poly2Length; i++) { 1075f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui updateBound(poly2[i], lowerBound, upperBound); 1076f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1077f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1078f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool dumpPoly = false; 1079f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int k = 0; k < TEST_POINT_NUMBER; k++) { 1080f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Generate a random point between minX, minY and maxX, maxY. 10819122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float randomX = rand() / float(RAND_MAX); 10829122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float randomY = rand() / float(RAND_MAX); 1083f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1084f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 testPoint; 1085f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.x = lowerBound.x + randomX * (upperBound.x - lowerBound.x); 1086f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.y = lowerBound.y + randomY * (upperBound.y - lowerBound.y); 1087f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1088f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // If the random point is in both poly 1 and 2, then it must be intersection. 1089f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (testPointInsidePolygon(testPoint, intersection, intersectionLength)) { 1090f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (!testPointInsidePolygon(testPoint, poly1, poly1Length)) { 1091f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPoly = true; 109250ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("(Error Type 1): one point (%f, %f) in the intersection is" 10931bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck " not in the poly1", 10941bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck testPoint.x, testPoint.y); 1095f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1096f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1097f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (!testPointInsidePolygon(testPoint, poly2, poly2Length)) { 1098f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPoly = true; 109950ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("(Error Type 1): one point (%f, %f) in the intersection is" 11001bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck " not in the poly2", 11011bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck testPoint.x, testPoint.y); 1102f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1103f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1104f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1105f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1106f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (dumpPoly) { 1107f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(intersection, intersectionLength, "intersection"); 1108f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 1; i < intersectionLength; i++) { 1109f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta = intersection[i] - intersection[i - 1]; 1110f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui ALOGD("Intersetion i, %d Vs i-1 is delta %f", i, delta.lengthSquared()); 1111f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1112f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1113f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(poly1, poly1Length, "poly 1"); 1114f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(poly2, poly2Length, "poly 2"); 1115f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1116f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 1117f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#endif 1118f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 11191bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck}; // namespace uirenderer 11201bcacfdcab0eaa0cee92bd7f5a1b5e271dd68e52John Reck}; // namespace android 1121