SpotShadow.cpp revision 3bd3fa1f1d437e22aee35381a559dcee15a437dd
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 177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#define LOG_TAG "OpenGLRenderer" 187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#define SHADOW_SHRINK_SCALE 0.1f 20c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#define CASTER_Z_CAP_RATIO 0.95f 21c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#define FAKE_UMBRA_SIZE_RATIO 0.01f 22c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#define OCLLUDED_UMBRA_SHRINK_FACTOR 0.95f 237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include <math.h> 25f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#include <stdlib.h> 267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include <utils/Log.h> 277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2863d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui#include "ShadowTessellator.h" 297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include "SpotShadow.h" 307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include "Vertex.h" 31c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#include "utils/MathUtils.h" 327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 33c50a03d78aaedd0003377e98710e7038bda330e9ztenghui// TODO: After we settle down the new algorithm, we can remove the old one and 34c50a03d78aaedd0003377e98710e7038bda330e9ztenghui// its utility functions. 35c50a03d78aaedd0003377e98710e7038bda330e9ztenghui// Right now, we still need to keep it for comparison purpose and future expansion. 367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuinamespace android { 377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuinamespace uirenderer { 387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 39726118b35240957710d4d85fb5747e2ba8b934f7Chris Craikstatic const double EPSILON = 1e-7; 40726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 41726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik/** 42c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * For each polygon's vertex, the light center will project it to the receiver 43c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * as one of the outline vertex. 44c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * For each outline vertex, we need to store the position and normal. 45c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * Normal here is defined against the edge by the current vertex and the next vertex. 46c50a03d78aaedd0003377e98710e7038bda330e9ztenghui */ 47c50a03d78aaedd0003377e98710e7038bda330e9ztenghuistruct OutlineData { 48c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 position; 49c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 normal; 50c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float radius; 51c50a03d78aaedd0003377e98710e7038bda330e9ztenghui}; 52c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 53c50a03d78aaedd0003377e98710e7038bda330e9ztenghui/** 54726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Calculate the angle between and x and a y coordinate. 55726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * The atan2 range from -PI to PI. 56726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik */ 57b79a3e301a8d89b9e1b1f6f3d7fd6aa56610a6f0Chris Craikstatic float angle(const Vector2& point, const Vector2& center) { 58726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik return atan2(point.y - center.y, point.x - center.x); 59726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik} 60726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 62726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Calculate the intersection of a ray with the line segment defined by two points. 637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 64726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Returns a negative value in error conditions. 65726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 66726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param rayOrigin The start of the ray 67726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param dx The x vector of the ray 68726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param dy The y vector of the ray 69726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param p1 The first point defining the line segment 70726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param p2 The second point defining the line segment 71726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @return The distance along the ray if it intersects with the line segment, negative if otherwise 727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 73b79a3e301a8d89b9e1b1f6f3d7fd6aa56610a6f0Chris Craikstatic float rayIntersectPoints(const Vector2& rayOrigin, float dx, float dy, 74726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const Vector2& p1, const Vector2& p2) { 75726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // The math below is derived from solving this formula, basically the 76726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // intersection point should stay on both the ray and the edge of (p1, p2). 77726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // solve([p1x+t*(p2x-p1x)=dx*t2+px,p1y+t*(p2y-p1y)=dy*t2+py],[t,t2]); 78726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 79726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik double divisor = (dx * (p1.y - p2.y) + dy * p2.x - dy * p1.x); 80726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik if (divisor == 0) return -1.0f; // error, invalid divisor 81726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 82726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik#if DEBUG_SHADOW 83726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik double interpVal = (dx * (p1.y - rayOrigin.y) + dy * rayOrigin.x - dy * p1.x) / divisor; 8499af9429cda84ad0af1d7fcecb580295b0046882ztenghui if (interpVal < 0 || interpVal > 1) { 8599af9429cda84ad0af1d7fcecb580295b0046882ztenghui ALOGW("rayIntersectPoints is hitting outside the segment %f", interpVal); 8699af9429cda84ad0af1d7fcecb580295b0046882ztenghui } 87726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik#endif 88726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 89726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik double distance = (p1.x * (rayOrigin.y - p2.y) + p2.x * (p1.y - rayOrigin.y) + 90726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik rayOrigin.x * (p2.y - p1.y)) / divisor; 91726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 92726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik return distance; // may be negative in error cases 937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points by their X coordinates 977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points the points as a Vector2 array. 997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param pointsLength the number of vertices of the polygon. 1007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 1017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::xsort(Vector2* points, int pointsLength) { 1027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui quicksortX(points, 0, pointsLength - 1); 1037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 1047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 1067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * compute the convex hull of a collection of Points 1077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points the points as a Vector2 array. 1097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param pointsLength the number of vertices of the polygon. 1107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param retPoly pre allocated array of floats to put the vertices 1117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return the number of points in the polygon 0 if no intersection 1127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 1137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuiint SpotShadow::hull(Vector2* points, int pointsLength, Vector2* retPoly) { 1147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui xsort(points, pointsLength); 1157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int n = pointsLength; 1167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 lUpper[n]; 1177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[0] = points[0]; 1187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[1] = points[1]; 1197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int lUpperSize = 2; 1217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 2; i < n; i++) { 1237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize] = points[i]; 1247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpperSize++; 1257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 126f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui while (lUpperSize > 2 && !ccw( 127f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lUpper[lUpperSize - 3].x, lUpper[lUpperSize - 3].y, 128f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lUpper[lUpperSize - 2].x, lUpper[lUpperSize - 2].y, 129f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lUpper[lUpperSize - 1].x, lUpper[lUpperSize - 1].y)) { 1307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Remove the middle point of the three last 1317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize - 2].x = lUpper[lUpperSize - 1].x; 1327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize - 2].y = lUpper[lUpperSize - 1].y; 1337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpperSize--; 1347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 lLower[n]; 1387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[0] = points[n - 1]; 1397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[1] = points[n - 2]; 1407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int lLowerSize = 2; 1427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = n - 3; i >= 0; i--) { 1447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[lLowerSize] = points[i]; 1457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLowerSize++; 1467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 147f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui while (lLowerSize > 2 && !ccw( 148f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lLower[lLowerSize - 3].x, lLower[lLowerSize - 3].y, 149f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lLower[lLowerSize - 2].x, lLower[lLowerSize - 2].y, 150f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lLower[lLowerSize - 1].x, lLower[lLowerSize - 1].y)) { 1517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Remove the middle point of the three last 1527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[lLowerSize - 2] = lLower[lLowerSize - 1]; 1537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLowerSize--; 1547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 157726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // output points in CW ordering 158726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const int total = lUpperSize + lLowerSize - 2; 159726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik int outIndex = total - 1; 1607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < lUpperSize; i++) { 161726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik retPoly[outIndex] = lUpper[i]; 162726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik outIndex--; 1637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 1; i < lLowerSize - 1; i++) { 166726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik retPoly[outIndex] = lLower[i]; 167726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik outIndex--; 1687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Add test harness which verify that all the points are inside the hull. 170726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik return total; 1717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 1727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 174f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether the 3 points form a counter clockwise turn. 1757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return true if a right hand turn 1777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 178f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuibool SpotShadow::ccw(double ax, double ay, double bx, double by, 1797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double cx, double cy) { 1807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return (bx - ax) * (cy - ay) - (by - ay) * (cx - ax) > EPSILON; 1817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 1827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 1847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Calculates the intersection of poly1 with poly2 and put in poly2. 18550ecf849cb7ccc3482517b74d2214b347927791eztenghui * Note that both poly1 and poly2 must be in CW order already! 1867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly1 The 1st polygon, as a Vector2 array. 1887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly1Length The number of vertices of 1st polygon. 1897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly2 The 2nd and output polygon, as a Vector2 array. 1907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly2Length The number of vertices of 2nd polygon. 1917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return number of vertices in output polygon as poly2. 1927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 19350ecf849cb7ccc3482517b74d2214b347927791eztenghuiint SpotShadow::intersection(const Vector2* poly1, int poly1Length, 1947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2* poly2, int poly2Length) { 19550ecf849cb7ccc3482517b74d2214b347927791eztenghui#if DEBUG_SHADOW 1962e023f3827dfc0dfc1ed7c3dd54d02b4a993f0b4ztenghui if (!ShadowTessellator::isClockwise(poly1, poly1Length)) { 19750ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("Poly1 is not clockwise! Intersection is wrong!"); 19850ecf849cb7ccc3482517b74d2214b347927791eztenghui } 1992e023f3827dfc0dfc1ed7c3dd54d02b4a993f0b4ztenghui if (!ShadowTessellator::isClockwise(poly2, poly2Length)) { 20050ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("Poly2 is not clockwise! Intersection is wrong!"); 20150ecf849cb7ccc3482517b74d2214b347927791eztenghui } 20250ecf849cb7ccc3482517b74d2214b347927791eztenghui#endif 2037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 poly[poly1Length * poly2Length + 2]; 2047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int count = 0; 2057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int pcount = 0; 2067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // If one vertex from one polygon sits inside another polygon, add it and 2087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // count them. 2097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < poly1Length; i++) { 2107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (testPointInsidePolygon(poly1[i], poly2, poly2Length)) { 2117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count] = poly1[i]; 2127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 2137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui pcount++; 2147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int insidePoly2 = pcount; 2197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < poly2Length; i++) { 2207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (testPointInsidePolygon(poly2[i], poly1, poly1Length)) { 2217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count] = poly2[i]; 2227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 2237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int insidePoly1 = count - insidePoly2; 2277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // If all vertices from poly1 are inside poly2, then just return poly1. 2287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (insidePoly2 == poly1Length) { 2297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui memcpy(poly2, poly1, poly1Length * sizeof(Vector2)); 2307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return poly1Length; 2317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // If all vertices from poly2 are inside poly1, then just return poly2. 2347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (insidePoly1 == poly2Length) { 2357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return poly2Length; 2367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Since neither polygon fully contain the other one, we need to add all the 2397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // intersection points. 2401aa5d2d7068147ff781cfe911a93f01593a68c79John Reck Vector2 intersection = {0, 0}; 2417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < poly2Length; i++) { 2427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int j = 0; j < poly1Length; j++) { 2437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int poly2LineStart = i; 2447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int poly2LineEnd = ((i + 1) % poly2Length); 2457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int poly1LineStart = j; 2467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int poly1LineEnd = ((j + 1) % poly1Length); 2477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui bool found = lineIntersection( 2487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly2[poly2LineStart].x, poly2[poly2LineStart].y, 2497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly2[poly2LineEnd].x, poly2[poly2LineEnd].y, 2507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly1[poly1LineStart].x, poly1[poly1LineStart].y, 2517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly1[poly1LineEnd].x, poly1[poly1LineEnd].y, 2527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui intersection); 2537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (found) { 2547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count].x = intersection.x; 2557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count].y = intersection.y; 2567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 2577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } else { 2587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 delta = poly2[i] - poly1[j]; 259f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (delta.lengthSquared() < EPSILON) { 2607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count] = poly2[i]; 2617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 2627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (count == 0) { 2687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return 0; 2697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Sort the result polygon around the center. 2721aa5d2d7068147ff781cfe911a93f01593a68c79John Reck Vector2 center = {0.0f, 0.0f}; 2737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < count; i++) { 2747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui center += poly[i]; 2757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui center /= count; 2777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui sort(poly, count, center); 2787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 279f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#if DEBUG_SHADOW 280f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Since poly2 is overwritten as the result, we need to save a copy to do 281f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // our verification. 282f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 oldPoly2[poly2Length]; 283f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui int oldPoly2Length = poly2Length; 284f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui memcpy(oldPoly2, poly2, sizeof(Vector2) * poly2Length); 285f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#endif 2867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 287f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Filter the result out from poly and put it into poly2. 2887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly2[0] = poly[0]; 289f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui int lastOutputIndex = 0; 2907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 1; i < count; i++) { 291f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta = poly[i] - poly2[lastOutputIndex]; 292f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (delta.lengthSquared() >= EPSILON) { 293f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui poly2[++lastOutputIndex] = poly[i]; 294f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } else { 295f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // If the vertices are too close, pick the inner one, because the 296f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // inner one is more likely to be an intersection point. 297f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta1 = poly[i] - center; 298f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta2 = poly2[lastOutputIndex] - center; 299f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (delta1.lengthSquared() < delta2.lengthSquared()) { 300f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui poly2[lastOutputIndex] = poly[i]; 301f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 3027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 304f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui int resultLength = lastOutputIndex + 1; 305f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 306f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#if DEBUG_SHADOW 307f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testConvex(poly2, resultLength, "intersection"); 308f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testConvex(poly1, poly1Length, "input poly1"); 309f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testConvex(oldPoly2, oldPoly2Length, "input poly2"); 310f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 311f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testIntersection(poly1, poly1Length, oldPoly2, oldPoly2Length, poly2, resultLength); 312f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#endif 3137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return resultLength; 3157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points about a center point 3197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly The in and out polyogon as a Vector2 array. 3217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polyLength The number of vertices of the polygon. 3227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param center the center ctr[0] = x , ctr[1] = y to sort around. 3237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::sort(Vector2* poly, int polyLength, const Vector2& center) { 3257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui quicksortCirc(poly, 0, polyLength - 1, center); 3267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Swap points pointed to by i and j 3307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::swap(Vector2* points, int i, int j) { 3327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 temp = points[i]; 3337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui points[i] = points[j]; 3347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui points[j] = temp; 3357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * quick sort implementation about the center. 3397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::quicksortCirc(Vector2* points, int low, int high, 3417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui const Vector2& center) { 3427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int i = low, j = high; 3437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int p = low + (high - low) / 2; 3447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float pivot = angle(points[p], center); 3457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (i <= j) { 346726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik while (angle(points[i], center) > pivot) { 3477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 3487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 349726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik while (angle(points[j], center) < pivot) { 3507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 3517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i <= j) { 3547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui swap(points, i, j); 3557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 3567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 3577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (low < j) quicksortCirc(points, low, j, center); 3607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i < high) quicksortCirc(points, i, high, center); 3617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points by x axis 3657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points points to sort 3677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param low start index 3687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param high end index 3697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::quicksortX(Vector2* points, int low, int high) { 3717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int i = low, j = high; 3727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int p = low + (high - low) / 2; 3737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float pivot = points[p].x; 3747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (i <= j) { 3757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (points[i].x < pivot) { 3767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 3777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (points[j].x > pivot) { 3797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 3807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i <= j) { 3837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui swap(points, i, j); 3847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 3857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 3867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (low < j) quicksortX(points, low, j); 3897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i < high) quicksortX(points, i, high); 3907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Test whether a point is inside the polygon. 3947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param testPoint the point to test 3967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly the polygon 3977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return true if the testPoint is inside the poly. 3987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuibool SpotShadow::testPointInsidePolygon(const Vector2 testPoint, 4007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui const Vector2* poly, int len) { 4017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui bool c = false; 4027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double testx = testPoint.x; 4037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double testy = testPoint.y; 4047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0, j = len - 1; i < len; j = i++) { 4057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double startX = poly[j].x; 4067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double startY = poly[j].y; 4077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double endX = poly[i].x; 4087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double endY = poly[i].y; 4097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (((endY > testy) != (startY > testy)) && 4117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui (testx < (startX - endX) * (testy - endY) 4127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui / (startY - endY) + endX)) { 4137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui c = !c; 4147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return c; 4177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 4187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Make the polygon turn clockwise. 4217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polygon the polygon as a Vector2 array. 4237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param len the number of points of the polygon 4247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 4257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::makeClockwise(Vector2* polygon, int len) { 4267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (polygon == 0 || len == 0) { 4277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return; 4287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4292e023f3827dfc0dfc1ed7c3dd54d02b4a993f0b4ztenghui if (!ShadowTessellator::isClockwise(polygon, len)) { 4307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui reverse(polygon, len); 4317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 4337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Reverse the polygon 4367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polygon the polygon as a Vector2 array 4387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param len the number of points of the polygon 4397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 4407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::reverse(Vector2* polygon, int len) { 4417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int n = len / 2; 4427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < n; i++) { 4437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 tmp = polygon[i]; 4447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int k = len - 1 - i; 4457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui polygon[i] = polygon[k]; 4467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui polygon[k] = tmp; 4477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 4497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Intersects two lines in parametric form. This function is called in a tight 4527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * loop, and we need double precision to get things right. 4537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param x1 the x coordinate point 1 of line 1 4557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param y1 the y coordinate point 1 of line 1 4567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param x2 the x coordinate point 2 of line 1 4577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param y2 the y coordinate point 2 of line 1 4587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param x3 the x coordinate point 1 of line 2 4597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param y3 the y coordinate point 1 of line 2 4607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param x4 the x coordinate point 2 of line 2 4617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param y4 the y coordinate point 2 of line 2 4627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param ret the x,y location of the intersection 4637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return true if it found an intersection 4647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 4657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuiinline bool SpotShadow::lineIntersection(double x1, double y1, double x2, double y2, 4667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double x3, double y3, double x4, double y4, Vector2& ret) { 4677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double d = (x1 - x2) * (y3 - y4) - (y1 - y2) * (x3 - x4); 4687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (d == 0.0) return false; 4697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double dx = (x1 * y2 - y1 * x2); 4717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double dy = (x3 * y4 - y3 * x4); 4727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double x = (dx * (x3 - x4) - (x1 - x2) * dy) / d; 4737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double y = (dx * (y3 - y4) - (y1 - y2) * dy) / d; 4747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // The intersection should be in the middle of the point 1 and point 2, 4767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // likewise point 3 and point 4. 4777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (((x - x1) * (x - x2) > EPSILON) 4787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui || ((x - x3) * (x - x4) > EPSILON) 4797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui || ((y - y1) * (y - y2) > EPSILON) 4807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui || ((y - y3) * (y - y4) > EPSILON)) { 4817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Not interesected 4827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return false; 4837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ret.x = x; 4857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ret.y = y; 4867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return true; 4877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 4897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Compute a horizontal circular polygon about point (x , y , height) of radius 4927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * (size) 4937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points number of the points of the output polygon. 4957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param lightCenter the center of the light. 4967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param size the light size. 4977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param ret result polygon. 4987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 4997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::computeLightPolygon(int points, const Vector3& lightCenter, 5007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float size, Vector3* ret) { 5017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Caching all the sin / cos values and store them in a look up table. 5027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < points; i++) { 5037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double angle = 2 * i * M_PI / points; 504726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik ret[i].x = cosf(angle) * size + lightCenter.x; 505726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik ret[i].y = sinf(angle) * size + lightCenter.y; 5067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ret[i].z = lightCenter.z; 5077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 5097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 5117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* Generate the shadow from a spot light. 5127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* 5137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param poly x,y,z vertexes of a convex polygon that occludes the light source 5147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param polyLength number of vertexes of the occluding polygon 5157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param lightCenter the center of the light 5167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param lightSize the radius of the light source 5177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param lightVertexCount the vertex counter for the light polygon 5187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param shadowTriangleStrip return an (x,y,alpha) triangle strip representing the shadow. Return 5197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* empty strip if error. 5207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* 5217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui*/ 522c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 523c50a03d78aaedd0003377e98710e7038bda330e9ztenghuivoid SpotShadow::createSpotShadow_old(bool isCasterOpaque, const Vector3* poly, 52450ecf849cb7ccc3482517b74d2214b347927791eztenghui int polyLength, const Vector3& lightCenter, float lightSize, 52550ecf849cb7ccc3482517b74d2214b347927791eztenghui int lightVertexCount, VertexBuffer& retStrips) { 5267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector3 light[lightVertexCount * 3]; 5277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui computeLightPolygon(lightVertexCount, lightCenter, lightSize, light); 528c50a03d78aaedd0003377e98710e7038bda330e9ztenghui computeSpotShadow_old(isCasterOpaque, light, lightVertexCount, lightCenter, poly, 52950ecf849cb7ccc3482517b74d2214b347927791eztenghui polyLength, retStrips); 5307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 5317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 5337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Generate the shadow spot light of shape lightPoly and a object poly 5347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 5357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param lightPoly x,y,z vertex of a convex polygon that is the light source 5367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param lightPolyLength number of vertexes of the light source polygon 5377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly x,y,z vertexes of a convex polygon that occludes the light source 5387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polyLength number of vertexes of the occluding polygon 5397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param shadowTriangleStrip return an (x,y,alpha) triangle strip representing the shadow. Return 5407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * empty strip if error. 5417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 542c50a03d78aaedd0003377e98710e7038bda330e9ztenghuivoid SpotShadow::computeSpotShadow_old(bool isCasterOpaque, const Vector3* lightPoly, 543c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int lightPolyLength, const Vector3& lightCenter, const Vector3* poly, int polyLength, 544c50a03d78aaedd0003377e98710e7038bda330e9ztenghui VertexBuffer& shadowTriangleStrip) { 5457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Point clouds for all the shadowed vertices 5467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 shadowRegion[lightPolyLength * polyLength]; 5477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Shadow polygon from one point light. 5487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 outline[polyLength]; 5497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 umbraMem[polyLength * lightPolyLength]; 5507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2* umbra = umbraMem; 5517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int umbraLength = 0; 5537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Validate input, receiver is always at z = 0 plane. 5557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui bool inputPolyPositionValid = true; 5567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 5577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (poly[i].z >= lightPoly[0].z) { 5587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui inputPolyPositionValid = false; 559b79a3e301a8d89b9e1b1f6f3d7fd6aa56610a6f0Chris Craik ALOGW("polygon above the light"); 5607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui break; 5617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // If the caster's position is invalid, don't draw anything. 5657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (!inputPolyPositionValid) { 5667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return; 5677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Calculate the umbra polygon based on intersections of all outlines 5707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int k = 0; 5717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int j = 0; j < lightPolyLength; j++) { 5727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int m = 0; 5737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 57428c3ea018771562a9150f30c6a088e5bf7502972ztenghui // After validating the input, deltaZ is guaranteed to be positive. 57550ecf849cb7ccc3482517b74d2214b347927791eztenghui float deltaZ = lightPoly[j].z - poly[i].z; 57650ecf849cb7ccc3482517b74d2214b347927791eztenghui float ratioZ = lightPoly[j].z / deltaZ; 57750ecf849cb7ccc3482517b74d2214b347927791eztenghui float x = lightPoly[j].x - ratioZ * (lightPoly[j].x - poly[i].x); 57850ecf849cb7ccc3482517b74d2214b347927791eztenghui float y = lightPoly[j].y - ratioZ * (lightPoly[j].y - poly[i].y); 5797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5801aa5d2d7068147ff781cfe911a93f01593a68c79John Reck Vector2 newPoint = {x, y}; 5817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui shadowRegion[k] = newPoint; 5827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui outline[m] = newPoint; 5837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui k++; 5857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui m++; 5867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // For the first light polygon's vertex, use the outline as the umbra. 5897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Later on, use the intersection of the outline and existing umbra. 5907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (umbraLength == 0) { 5917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 5927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbra[i] = outline[i]; 5937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbraLength = polyLength; 5957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } else { 5967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int col = ((j * 255) / lightPolyLength); 5977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbraLength = intersection(outline, polyLength, umbra, umbraLength); 5987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (umbraLength == 0) { 5997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui break; 6007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Generate the penumbra area using the hull of all shadow regions. 6057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int shadowRegionLength = k; 6067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 penumbra[k]; 6077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int penumbraLength = hull(shadowRegion, shadowRegionLength, penumbra); 6087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6095176c974f1d9af833b7584e895fcba61e6e7427aztenghui Vector2 fakeUmbra[polyLength]; 6107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (umbraLength < 3) { 6115176c974f1d9af833b7584e895fcba61e6e7427aztenghui // If there is no real umbra, make a fake one. 6127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 61350ecf849cb7ccc3482517b74d2214b347927791eztenghui float deltaZ = lightCenter.z - poly[i].z; 61450ecf849cb7ccc3482517b74d2214b347927791eztenghui float ratioZ = lightCenter.z / deltaZ; 61550ecf849cb7ccc3482517b74d2214b347927791eztenghui float x = lightCenter.x - ratioZ * (lightCenter.x - poly[i].x); 61650ecf849cb7ccc3482517b74d2214b347927791eztenghui float y = lightCenter.y - ratioZ * (lightCenter.y - poly[i].y); 6177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6185176c974f1d9af833b7584e895fcba61e6e7427aztenghui fakeUmbra[i].x = x; 6195176c974f1d9af833b7584e895fcba61e6e7427aztenghui fakeUmbra[i].y = y; 6207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Shrink the centroid's shadow by 10%. 6237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Study the magic number of 10%. 62463d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui Vector2 shadowCentroid = 62563d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui ShadowTessellator::centroid2d(fakeUmbra, polyLength); 6267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 6275176c974f1d9af833b7584e895fcba61e6e7427aztenghui fakeUmbra[i] = shadowCentroid * (1.0f - SHADOW_SHRINK_SCALE) + 6285176c974f1d9af833b7584e895fcba61e6e7427aztenghui fakeUmbra[i] * SHADOW_SHRINK_SCALE; 6297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#if DEBUG_SHADOW 6317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ALOGD("No real umbra make a fake one, centroid2d = %f , %f", 6327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui shadowCentroid.x, shadowCentroid.y); 6337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#endif 6347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Set the fake umbra, whose size is the same as the original polygon. 6355176c974f1d9af833b7584e895fcba61e6e7427aztenghui umbra = fakeUmbra; 6367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbraLength = polyLength; 6377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 639c50a03d78aaedd0003377e98710e7038bda330e9ztenghui generateTriangleStrip(isCasterOpaque, 1.0, penumbra, penumbraLength, umbra, 64050ecf849cb7ccc3482517b74d2214b347927791eztenghui umbraLength, poly, polyLength, shadowTriangleStrip); 6417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 6427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 643c50a03d78aaedd0003377e98710e7038bda330e9ztenghuifloat SpotShadow::projectCasterToOutline(Vector2& outline, 644c50a03d78aaedd0003377e98710e7038bda330e9ztenghui const Vector3& lightCenter, const Vector3& polyVertex) { 645c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float lightToPolyZ = lightCenter.z - polyVertex.z; 646c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float ratioZ = CASTER_Z_CAP_RATIO; 647c50a03d78aaedd0003377e98710e7038bda330e9ztenghui if (lightToPolyZ != 0) { 648c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // If any caster's vertex is almost above the light, we just keep it as 95% 649c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // of the height of the light. 6503bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui ratioZ = MathUtils::clamp(polyVertex.z / lightToPolyZ, 0.0f, CASTER_Z_CAP_RATIO); 651c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 652c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 653c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outline.x = polyVertex.x - ratioZ * (lightCenter.x - polyVertex.x); 654c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outline.y = polyVertex.y - ratioZ * (lightCenter.y - polyVertex.y); 655c50a03d78aaedd0003377e98710e7038bda330e9ztenghui return ratioZ; 656c50a03d78aaedd0003377e98710e7038bda330e9ztenghui} 657c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 658c50a03d78aaedd0003377e98710e7038bda330e9ztenghui/** 659c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * Generate the shadow spot light of shape lightPoly and a object poly 660c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * 661c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param isCasterOpaque whether the caster is opaque 662c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param lightCenter the center of the light 663c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param lightSize the radius of the light 664c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param poly x,y,z vertexes of a convex polygon that occludes the light source 665c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param polyLength number of vertexes of the occluding polygon 666c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param shadowTriangleStrip return an (x,y,alpha) triangle strip representing the shadow. Return 667c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * empty strip if error. 668c50a03d78aaedd0003377e98710e7038bda330e9ztenghui */ 669c50a03d78aaedd0003377e98710e7038bda330e9ztenghuivoid SpotShadow::createSpotShadow(bool isCasterOpaque, const Vector3& lightCenter, 670c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float lightSize, const Vector3* poly, int polyLength, const Vector3& polyCentroid, 671c50a03d78aaedd0003377e98710e7038bda330e9ztenghui VertexBuffer& shadowTriangleStrip) { 6723bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui if (CC_UNLIKELY(lightCenter.z <= 0)) { 6733bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui ALOGW("Relative Light Z is not positive. No spot shadow!"); 6743bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui return; 6753bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui } 676c50a03d78aaedd0003377e98710e7038bda330e9ztenghui OutlineData outlineData[polyLength]; 677c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 outlineCentroid; 678c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Calculate the projected outline for each polygon's vertices from the light center. 679c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 680c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // O Light 681c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // / 682c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // / 683c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // . Polygon vertex 684c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // / 685c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // / 686c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // O Outline vertices 687c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 688c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Ratio = (Poly - Outline) / (Light - Poly) 689c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Outline.x = Poly.x - Ratio * (Light.x - Poly.x) 690c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Outline's radius / Light's radius = Ratio 691c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 692c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Compute the last outline vertex to make sure we can get the normal and outline 693c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // in one single loop. 694c50a03d78aaedd0003377e98710e7038bda330e9ztenghui projectCasterToOutline(outlineData[polyLength - 1].position, lightCenter, 695c50a03d78aaedd0003377e98710e7038bda330e9ztenghui poly[polyLength - 1]); 696c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 697c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Take the outline's polygon, calculate the normal for each outline edge. 698c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int currentNormalIndex = polyLength - 1; 699c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int nextNormalIndex = 0; 700c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 701c50a03d78aaedd0003377e98710e7038bda330e9ztenghui for (int i = 0; i < polyLength; i++) { 702c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float ratioZ = projectCasterToOutline(outlineData[i].position, 703c50a03d78aaedd0003377e98710e7038bda330e9ztenghui lightCenter, poly[i]); 704c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outlineData[i].radius = ratioZ * lightSize; 705c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 706c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outlineData[currentNormalIndex].normal = ShadowTessellator::calculateNormal( 707c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outlineData[currentNormalIndex].position, 708c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outlineData[nextNormalIndex].position); 709c50a03d78aaedd0003377e98710e7038bda330e9ztenghui currentNormalIndex = (currentNormalIndex + 1) % polyLength; 710c50a03d78aaedd0003377e98710e7038bda330e9ztenghui nextNormalIndex++; 711c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 712c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 713c50a03d78aaedd0003377e98710e7038bda330e9ztenghui projectCasterToOutline(outlineCentroid, lightCenter, polyCentroid); 714c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 715c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int penumbraIndex = 0; 716c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int penumbraLength = polyLength * 3; 717c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 penumbra[penumbraLength]; 718c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 719c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 umbra[polyLength]; 720c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float distOutline = 0; 721c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float ratioVI = 0; 722c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 723c50a03d78aaedd0003377e98710e7038bda330e9ztenghui bool hasValidUmbra = true; 724c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // We need the maxRatioVI to decrease the spot shadow strength accordingly. 725c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float maxRaitoVI = 1.0; 726c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 727c50a03d78aaedd0003377e98710e7038bda330e9ztenghui for (int i = 0; i < polyLength; i++) { 728c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Generate all the penumbra's vertices only using the (outline vertex + normal * radius) 729c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // There is no guarantee that the penumbra is still convex, but for 730c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // each outline vertex, it will connect to all its corresponding penumbra vertices as 731c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // triangle fans. And for neighber penumbra vertex, it will be a trapezoid. 732c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 733c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Penumbra Vertices marked as Pi 734c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Outline Vertices marked as Vi 735c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (P3) 736c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (P2) | ' (P4) 737c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (P1)' | | ' 738c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // ' | | ' 739c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (P0) ------------------------------------------------(P5) 740c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | (V0) |(V1) 741c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 742c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 743c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 744c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 745c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 746c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 747c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 748c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 749c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (V3)-----------------------------------(V2) 750c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int preNormalIndex = (i + polyLength - 1) % polyLength; 751c50a03d78aaedd0003377e98710e7038bda330e9ztenghui penumbra[penumbraIndex++] = outlineData[i].position + 752c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outlineData[preNormalIndex].normal * outlineData[i].radius; 753c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 754c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int currentNormalIndex = i; 755c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (TODO) Depending on how roundness we want for each corner, we can subdivide 756c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // further here and/or introduce some heuristic to decide how much the 757c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // subdivision should be. 758c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 avgNormal = 759c50a03d78aaedd0003377e98710e7038bda330e9ztenghui (outlineData[preNormalIndex].normal + outlineData[currentNormalIndex].normal) / 2; 760c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 761c50a03d78aaedd0003377e98710e7038bda330e9ztenghui penumbra[penumbraIndex++] = outlineData[i].position + 762c50a03d78aaedd0003377e98710e7038bda330e9ztenghui avgNormal * outlineData[i].radius; 763c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 764c50a03d78aaedd0003377e98710e7038bda330e9ztenghui penumbra[penumbraIndex++] = outlineData[i].position + 765c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outlineData[currentNormalIndex].normal * outlineData[i].radius; 766c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 767c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Compute the umbra by the intersection from the outline's centroid! 768c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 769c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (V) ------------------------------------ 770c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' | 771c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' | 772c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' (I) | 773c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' | 774c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' (C) | 775c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 776c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 777c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 778c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 779c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // ------------------------------------ 780c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 781c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Connect a line b/t the outline vertex (V) and the centroid (C), it will 782c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // intersect with the outline vertex's circle at point (I). 783c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Now, ratioVI = VI / VC, ratioIC = IC / VC 784c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Then the intersetion point can be computed as Ixy = Vxy * ratioIC + Cxy * ratioVI; 785c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 786c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // When one of the outline circle cover the the outline centroid, (like I is 787c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // on the other side of C), there is no real umbra any more, so we just fake 788c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // a small area around the centroid as the umbra, and tune down the spot 789c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // shadow's umbra strength to simulate the effect the whole shadow will 790c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // become lighter in this case. 791c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // The ratio can be simulated by using the inverse of maximum of ratioVI for 792c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // all (V). 793c50a03d78aaedd0003377e98710e7038bda330e9ztenghui distOutline = (outlineData[i].position - outlineCentroid).length(); 7943bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui if (CC_UNLIKELY(distOutline == 0)) { 795c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // If the outline has 0 area, then there is no spot shadow anyway. 796c50a03d78aaedd0003377e98710e7038bda330e9ztenghui ALOGW("Outline has 0 area, no spot shadow!"); 797c50a03d78aaedd0003377e98710e7038bda330e9ztenghui return; 798c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 799c50a03d78aaedd0003377e98710e7038bda330e9ztenghui ratioVI = outlineData[i].radius / distOutline; 800c50a03d78aaedd0003377e98710e7038bda330e9ztenghui if (ratioVI >= 1.0) { 801c50a03d78aaedd0003377e98710e7038bda330e9ztenghui maxRaitoVI = ratioVI; 802c50a03d78aaedd0003377e98710e7038bda330e9ztenghui hasValidUmbra = false; 803c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 804c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // When we know we don't have valid umbra, don't bother to compute the 805c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // values below. But we can't skip the loop yet since we want to know the 806c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // maximum ratio. 807c50a03d78aaedd0003377e98710e7038bda330e9ztenghui if (hasValidUmbra) { 808c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float ratioIC = (distOutline - outlineData[i].radius) / distOutline; 809c50a03d78aaedd0003377e98710e7038bda330e9ztenghui umbra[i] = outlineData[i].position * ratioIC + outlineCentroid * ratioVI; 810c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 811c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 812c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 813c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float shadowStrengthScale = 1.0; 814c50a03d78aaedd0003377e98710e7038bda330e9ztenghui if (!hasValidUmbra) { 815c50a03d78aaedd0003377e98710e7038bda330e9ztenghui ALOGW("The object is too close to the light or too small, no real umbra!"); 816c50a03d78aaedd0003377e98710e7038bda330e9ztenghui for (int i = 0; i < polyLength; i++) { 817c50a03d78aaedd0003377e98710e7038bda330e9ztenghui umbra[i] = outlineData[i].position * FAKE_UMBRA_SIZE_RATIO + 818c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outlineCentroid * (1 - FAKE_UMBRA_SIZE_RATIO); 819c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 820c50a03d78aaedd0003377e98710e7038bda330e9ztenghui shadowStrengthScale = 1.0 / maxRaitoVI; 821c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 822c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 823c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#if DEBUG_SHADOW 824c50a03d78aaedd0003377e98710e7038bda330e9ztenghui dumpPolygon(poly, polyLength, "input poly"); 825c50a03d78aaedd0003377e98710e7038bda330e9ztenghui dumpPolygon(outline, polyLength, "outline"); 826c50a03d78aaedd0003377e98710e7038bda330e9ztenghui dumpPolygon(penumbra, penumbraLength, "penumbra"); 827c50a03d78aaedd0003377e98710e7038bda330e9ztenghui dumpPolygon(umbra, polyLength, "umbra"); 828c50a03d78aaedd0003377e98710e7038bda330e9ztenghui ALOGD("hasValidUmbra is %d and shadowStrengthScale is %f", hasValidUmbra, shadowStrengthScale); 829c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#endif 830c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 831c50a03d78aaedd0003377e98710e7038bda330e9ztenghui generateTriangleStrip(isCasterOpaque, shadowStrengthScale, penumbra, 832c50a03d78aaedd0003377e98710e7038bda330e9ztenghui penumbraLength, umbra, polyLength, poly, polyLength, shadowTriangleStrip); 833c50a03d78aaedd0003377e98710e7038bda330e9ztenghui} 834c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 8357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 836726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Converts a polygon specified with CW vertices into an array of distance-from-centroid values. 837726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * 838726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Returns false in error conditions 839726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * 840726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param poly Array of vertices. Note that these *must* be CW. 841726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param polyLength The number of vertices in the polygon. 842726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param polyCentroid The centroid of the polygon, from which rays will be cast 843726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param rayDist The output array for the calculated distances, must be SHADOW_RAY_COUNT in size 844726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik */ 845726118b35240957710d4d85fb5747e2ba8b934f7Chris Craikbool convertPolyToRayDist(const Vector2* poly, int polyLength, const Vector2& polyCentroid, 846726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik float* rayDist) { 847726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const int rays = SHADOW_RAY_COUNT; 848726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const float step = M_PI * 2 / rays; 849726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 850726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const Vector2* lastVertex = &(poly[polyLength - 1]); 851726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik float startAngle = angle(*lastVertex, polyCentroid); 852726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 853726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // Start with the ray that's closest to and less than startAngle 854726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik int rayIndex = floor((startAngle - EPSILON) / step); 855726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik rayIndex = (rayIndex + rays) % rays; // ensure positive 856726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 857726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik for (int polyIndex = 0; polyIndex < polyLength; polyIndex++) { 858726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik /* 859726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * For a given pair of vertices on the polygon, poly[i-1] and poly[i], the rays that 860726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * intersect these will be those that are between the two angles from the centroid that the 861726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * vertices define. 862726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * 863726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Because the polygon vertices are stored clockwise, the closest ray with an angle 864726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * *smaller* than that defined by angle(poly[i], centroid) will be the first ray that does 865726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * not intersect with poly[i-1], poly[i]. 866726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik */ 867726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik float currentAngle = angle(poly[polyIndex], polyCentroid); 868726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 869726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // find first ray that will not intersect the line segment poly[i-1] & poly[i] 870726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik int firstRayIndexOnNextSegment = floor((currentAngle - EPSILON) / step); 871726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik firstRayIndexOnNextSegment = (firstRayIndexOnNextSegment + rays) % rays; // ensure positive 872726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 873726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // Iterate through all rays that intersect with poly[i-1], poly[i] line segment. 874726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // This may be 0 rays. 875726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik while (rayIndex != firstRayIndexOnNextSegment) { 876726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik float distanceToIntersect = rayIntersectPoints(polyCentroid, 877726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik cos(rayIndex * step), 878726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik sin(rayIndex * step), 879726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik *lastVertex, poly[polyIndex]); 88050ecf849cb7ccc3482517b74d2214b347927791eztenghui if (distanceToIntersect < 0) { 88150ecf849cb7ccc3482517b74d2214b347927791eztenghui#if DEBUG_SHADOW 88250ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("ERROR: convertPolyToRayDist failed"); 88350ecf849cb7ccc3482517b74d2214b347927791eztenghui#endif 88450ecf849cb7ccc3482517b74d2214b347927791eztenghui return false; // error case, abort 88550ecf849cb7ccc3482517b74d2214b347927791eztenghui } 886726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 887726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik rayDist[rayIndex] = distanceToIntersect; 888726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 889726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik rayIndex = (rayIndex - 1 + rays) % rays; 890726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik } 891726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik lastVertex = &poly[polyIndex]; 892726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik } 893726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 894726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik return true; 895726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik} 896726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 89750ecf849cb7ccc3482517b74d2214b347927791eztenghuiint SpotShadow::calculateOccludedUmbra(const Vector2* umbra, int umbraLength, 89850ecf849cb7ccc3482517b74d2214b347927791eztenghui const Vector3* poly, int polyLength, Vector2* occludedUmbra) { 89950ecf849cb7ccc3482517b74d2214b347927791eztenghui // Occluded umbra area is computed as the intersection of the projected 2D 90050ecf849cb7ccc3482517b74d2214b347927791eztenghui // poly and umbra. 90150ecf849cb7ccc3482517b74d2214b347927791eztenghui for (int i = 0; i < polyLength; i++) { 90250ecf849cb7ccc3482517b74d2214b347927791eztenghui occludedUmbra[i].x = poly[i].x; 90350ecf849cb7ccc3482517b74d2214b347927791eztenghui occludedUmbra[i].y = poly[i].y; 90450ecf849cb7ccc3482517b74d2214b347927791eztenghui } 90550ecf849cb7ccc3482517b74d2214b347927791eztenghui 90650ecf849cb7ccc3482517b74d2214b347927791eztenghui // Both umbra and incoming polygon are guaranteed to be CW, so we can call 90750ecf849cb7ccc3482517b74d2214b347927791eztenghui // intersection() directly. 90850ecf849cb7ccc3482517b74d2214b347927791eztenghui return intersection(umbra, umbraLength, 90950ecf849cb7ccc3482517b74d2214b347927791eztenghui occludedUmbra, polyLength); 91050ecf849cb7ccc3482517b74d2214b347927791eztenghui} 91150ecf849cb7ccc3482517b74d2214b347927791eztenghui 912726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik/** 9137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Generate a triangle strip given two convex polygons 9147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 9157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param penumbra The outer polygon x,y vertexes 9167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param penumbraLength The number of vertexes in the outer polygon 9177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param umbra The inner outer polygon x,y vertexes 9187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param umbraLength The number of vertexes in the inner polygon 9197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param shadowTriangleStrip return an (x,y,alpha) triangle strip representing the shadow. Return 9207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * empty strip if error. 9217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui**/ 922c50a03d78aaedd0003377e98710e7038bda330e9ztenghuivoid SpotShadow::generateTriangleStrip(bool isCasterOpaque, float shadowStrengthScale, 923c50a03d78aaedd0003377e98710e7038bda330e9ztenghui const Vector2* penumbra, int penumbraLength, const Vector2* umbra, int umbraLength, 92450ecf849cb7ccc3482517b74d2214b347927791eztenghui const Vector3* poly, int polyLength, VertexBuffer& shadowTriangleStrip) { 92563d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui const int rays = SHADOW_RAY_COUNT; 926726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const int size = 2 * rays; 927726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const float step = M_PI * 2 / rays; 9287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Centroid of the umbra. 92963d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui Vector2 centroid = ShadowTessellator::centroid2d(umbra, umbraLength); 9307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#if DEBUG_SHADOW 9317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ALOGD("centroid2d = %f , %f", centroid.x, centroid.y); 9327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#endif 9337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Intersection to the penumbra. 9347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float penumbraDistPerRay[rays]; 9357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Intersection to the umbra. 9367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float umbraDistPerRay[rays]; 93750ecf849cb7ccc3482517b74d2214b347927791eztenghui // Intersection to the occluded umbra area. 93850ecf849cb7ccc3482517b74d2214b347927791eztenghui float occludedUmbraDistPerRay[rays]; 9397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 940726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // convert CW polygons to ray distance encoding, aborting on conversion failure 941726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik if (!convertPolyToRayDist(umbra, umbraLength, centroid, umbraDistPerRay)) return; 942726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik if (!convertPolyToRayDist(penumbra, penumbraLength, centroid, penumbraDistPerRay)) return; 9437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 94450ecf849cb7ccc3482517b74d2214b347927791eztenghui bool hasOccludedUmbraArea = false; 94550ecf849cb7ccc3482517b74d2214b347927791eztenghui if (isCasterOpaque) { 94650ecf849cb7ccc3482517b74d2214b347927791eztenghui Vector2 occludedUmbra[polyLength + umbraLength]; 94750ecf849cb7ccc3482517b74d2214b347927791eztenghui int occludedUmbraLength = calculateOccludedUmbra(umbra, umbraLength, poly, polyLength, 94850ecf849cb7ccc3482517b74d2214b347927791eztenghui occludedUmbra); 94950ecf849cb7ccc3482517b74d2214b347927791eztenghui // Make sure the centroid is inside the umbra, otherwise, fall back to the 95050ecf849cb7ccc3482517b74d2214b347927791eztenghui // approach as if there is no occluded umbra area. 95150ecf849cb7ccc3482517b74d2214b347927791eztenghui if (testPointInsidePolygon(centroid, occludedUmbra, occludedUmbraLength)) { 95250ecf849cb7ccc3482517b74d2214b347927791eztenghui hasOccludedUmbraArea = true; 95350ecf849cb7ccc3482517b74d2214b347927791eztenghui // Shrink the occluded umbra area to avoid pixel level artifacts. 95450ecf849cb7ccc3482517b74d2214b347927791eztenghui for (int i = 0; i < occludedUmbraLength; i ++) { 95550ecf849cb7ccc3482517b74d2214b347927791eztenghui occludedUmbra[i] = centroid + (occludedUmbra[i] - centroid) * 95650ecf849cb7ccc3482517b74d2214b347927791eztenghui OCLLUDED_UMBRA_SHRINK_FACTOR; 95750ecf849cb7ccc3482517b74d2214b347927791eztenghui } 95850ecf849cb7ccc3482517b74d2214b347927791eztenghui if (!convertPolyToRayDist(occludedUmbra, occludedUmbraLength, centroid, 95950ecf849cb7ccc3482517b74d2214b347927791eztenghui occludedUmbraDistPerRay)) { 96050ecf849cb7ccc3482517b74d2214b347927791eztenghui return; 96150ecf849cb7ccc3482517b74d2214b347927791eztenghui } 96250ecf849cb7ccc3482517b74d2214b347927791eztenghui } 96350ecf849cb7ccc3482517b74d2214b347927791eztenghui } 96450ecf849cb7ccc3482517b74d2214b347927791eztenghui AlphaVertex* shadowVertices = 96550ecf849cb7ccc3482517b74d2214b347927791eztenghui shadowTriangleStrip.alloc<AlphaVertex>(SHADOW_VERTEX_COUNT); 9667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 96791a8c7c62913c2597e3bf5a6d59d2ed5fc7ba4e0Chris Craik // NOTE: Shadow alpha values are transformed when stored in alphavertices, 96891a8c7c62913c2597e3bf5a6d59d2ed5fc7ba4e0Chris Craik // so that they can be consumed directly by gFS_Main_ApplyVertexAlphaShadowInterp 969c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float transformedMaxAlpha = M_PI * shadowStrengthScale; 97091a8c7c62913c2597e3bf5a6d59d2ed5fc7ba4e0Chris Craik 97163d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui // Calculate the vertices (x, y, alpha) in the shadow area. 97250ecf849cb7ccc3482517b74d2214b347927791eztenghui AlphaVertex centroidXYA; 97391a8c7c62913c2597e3bf5a6d59d2ed5fc7ba4e0Chris Craik AlphaVertex::set(¢roidXYA, centroid.x, centroid.y, transformedMaxAlpha); 974726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik for (int rayIndex = 0; rayIndex < rays; rayIndex++) { 975726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik float dx = cosf(step * rayIndex); 976726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik float dy = sinf(step * rayIndex); 977726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 97850ecf849cb7ccc3482517b74d2214b347927791eztenghui // penumbra ring 97950ecf849cb7ccc3482517b74d2214b347927791eztenghui float penumbraDistance = penumbraDistPerRay[rayIndex]; 980726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik AlphaVertex::set(&shadowVertices[rayIndex], 98150ecf849cb7ccc3482517b74d2214b347927791eztenghui dx * penumbraDistance + centroid.x, 98250ecf849cb7ccc3482517b74d2214b347927791eztenghui dy * penumbraDistance + centroid.y, 0.0f); 983726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 98450ecf849cb7ccc3482517b74d2214b347927791eztenghui // umbra ring 98550ecf849cb7ccc3482517b74d2214b347927791eztenghui float umbraDistance = umbraDistPerRay[rayIndex]; 986726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik AlphaVertex::set(&shadowVertices[rays + rayIndex], 98791a8c7c62913c2597e3bf5a6d59d2ed5fc7ba4e0Chris Craik dx * umbraDistance + centroid.x, 98891a8c7c62913c2597e3bf5a6d59d2ed5fc7ba4e0Chris Craik dy * umbraDistance + centroid.y, 98991a8c7c62913c2597e3bf5a6d59d2ed5fc7ba4e0Chris Craik transformedMaxAlpha); 99050ecf849cb7ccc3482517b74d2214b347927791eztenghui 99150ecf849cb7ccc3482517b74d2214b347927791eztenghui // occluded umbra ring 99250ecf849cb7ccc3482517b74d2214b347927791eztenghui if (hasOccludedUmbraArea) { 99350ecf849cb7ccc3482517b74d2214b347927791eztenghui float occludedUmbraDistance = occludedUmbraDistPerRay[rayIndex]; 99450ecf849cb7ccc3482517b74d2214b347927791eztenghui AlphaVertex::set(&shadowVertices[2 * rays + rayIndex], 99550ecf849cb7ccc3482517b74d2214b347927791eztenghui dx * occludedUmbraDistance + centroid.x, 99691a8c7c62913c2597e3bf5a6d59d2ed5fc7ba4e0Chris Craik dy * occludedUmbraDistance + centroid.y, transformedMaxAlpha); 99750ecf849cb7ccc3482517b74d2214b347927791eztenghui } else { 99850ecf849cb7ccc3482517b74d2214b347927791eztenghui // Put all vertices of the occluded umbra ring at the centroid. 99950ecf849cb7ccc3482517b74d2214b347927791eztenghui shadowVertices[2 * rays + rayIndex] = centroidXYA; 100050ecf849cb7ccc3482517b74d2214b347927791eztenghui } 10017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 10029a89bc6524620c87c7a321433470c668e2b95d69Chris Craik shadowTriangleStrip.setMode(VertexBuffer::kTwoPolyRingShadow); 10039a89bc6524620c87c7a321433470c668e2b95d69Chris Craik shadowTriangleStrip.computeBounds<AlphaVertex>(); 10047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 10057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 10067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 10077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * This is only for experimental purpose. 10087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * After intersections are calculated, we could smooth the polygon if needed. 10097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * So far, we don't think it is more appealing yet. 10107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 10117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param level The level of smoothness. 10127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param rays The total number of rays. 10137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param rayDist (In and Out) The distance for each ray. 10147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 10157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 10167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::smoothPolygon(int level, int rays, float* rayDist) { 10177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int k = 0; k < level; k++) { 10187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < rays; i++) { 10197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float p1 = rayDist[(rays - 1 + i) % rays]; 10207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float p2 = rayDist[i]; 10217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float p3 = rayDist[(i + 1) % rays]; 10227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui rayDist[i] = (p1 + p2 * 2 + p3) / 4; 10237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 10247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 10257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 10267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1027f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#if DEBUG_SHADOW 1028f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1029f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#define TEST_POINT_NUMBER 128 1030f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1031f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 1032f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Calculate the bounds for generating random test points. 1033f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 1034f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuivoid SpotShadow::updateBound(const Vector2 inVector, Vector2& lowerBound, 1035f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2& upperBound ) { 1036f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.x < lowerBound.x) { 1037f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lowerBound.x = inVector.x; 1038f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1039f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1040f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.y < lowerBound.y) { 1041f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lowerBound.y = inVector.y; 1042f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1043f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1044f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.x > upperBound.x) { 1045f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui upperBound.x = inVector.x; 1046f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1047f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1048f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.y > upperBound.y) { 1049f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui upperBound.y = inVector.y; 1050f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1051f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 1052f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1053f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 1054f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * For debug purpose, when things go wrong, dump the whole polygon data. 1055f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 1056c50a03d78aaedd0003377e98710e7038bda330e9ztenghuivoid SpotShadow::dumpPolygon(const Vector2* poly, int polyLength, const char* polyName) { 1057c50a03d78aaedd0003377e98710e7038bda330e9ztenghui for (int i = 0; i < polyLength; i++) { 1058c50a03d78aaedd0003377e98710e7038bda330e9ztenghui ALOGD("polygon %s i %d x %f y %f", polyName, i, poly[i].x, poly[i].y); 1059c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 1060c50a03d78aaedd0003377e98710e7038bda330e9ztenghui} 1061c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 1062c50a03d78aaedd0003377e98710e7038bda330e9ztenghui/** 1063c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * For debug purpose, when things go wrong, dump the whole polygon data. 1064c50a03d78aaedd0003377e98710e7038bda330e9ztenghui */ 1065c50a03d78aaedd0003377e98710e7038bda330e9ztenghuivoid SpotShadow::dumpPolygon(const Vector3* poly, int polyLength, const char* polyName) { 1066f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < polyLength; i++) { 1067f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui ALOGD("polygon %s i %d x %f y %f", polyName, i, poly[i].x, poly[i].y); 1068f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1069f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 1070f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1071f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 1072f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether the polygon is convex. 1073f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 1074f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuibool SpotShadow::testConvex(const Vector2* polygon, int polygonLength, 1075f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui const char* name) { 1076f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool isConvex = true; 1077f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < polygonLength; i++) { 1078f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 start = polygon[i]; 1079f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 middle = polygon[(i + 1) % polygonLength]; 1080f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 end = polygon[(i + 2) % polygonLength]; 1081f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1082f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui double delta = (double(middle.x) - start.x) * (double(end.y) - start.y) - 1083f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui (double(middle.y) - start.y) * (double(end.x) - start.x); 1084f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool isCCWOrCoLinear = (delta >= EPSILON); 1085f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1086f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (isCCWOrCoLinear) { 108750ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("(Error Type 2): polygon (%s) is not a convex b/c start (x %f, y %f)," 1088f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui "middle (x %f, y %f) and end (x %f, y %f) , delta is %f !!!", 1089f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui name, start.x, start.y, middle.x, middle.y, end.x, end.y, delta); 1090f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui isConvex = false; 1091f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui break; 1092f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1093f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1094f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui return isConvex; 1095f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 1096f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1097f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 1098f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether or not the polygon (intersection) is within the 2 input polygons. 1099f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Using Marte Carlo method, we generate a random point, and if it is inside the 1100f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * intersection, then it must be inside both source polygons. 1101f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 1102f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuivoid SpotShadow::testIntersection(const Vector2* poly1, int poly1Length, 1103f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui const Vector2* poly2, int poly2Length, 1104f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui const Vector2* intersection, int intersectionLength) { 1105f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Find the min and max of x and y. 1106c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 lowerBound = {FLT_MAX, FLT_MAX}; 1107c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 upperBound = {-FLT_MAX, -FLT_MAX}; 1108f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < poly1Length; i++) { 1109f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui updateBound(poly1[i], lowerBound, upperBound); 1110f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1111f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < poly2Length; i++) { 1112f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui updateBound(poly2[i], lowerBound, upperBound); 1113f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1114f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1115f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool dumpPoly = false; 1116f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int k = 0; k < TEST_POINT_NUMBER; k++) { 1117f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Generate a random point between minX, minY and maxX, maxY. 1118f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui double randomX = rand() / double(RAND_MAX); 1119f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui double randomY = rand() / double(RAND_MAX); 1120f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1121f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 testPoint; 1122f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.x = lowerBound.x + randomX * (upperBound.x - lowerBound.x); 1123f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.y = lowerBound.y + randomY * (upperBound.y - lowerBound.y); 1124f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1125f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // If the random point is in both poly 1 and 2, then it must be intersection. 1126f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (testPointInsidePolygon(testPoint, intersection, intersectionLength)) { 1127f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (!testPointInsidePolygon(testPoint, poly1, poly1Length)) { 1128f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPoly = true; 112950ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("(Error Type 1): one point (%f, %f) in the intersection is" 1130f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui " not in the poly1", 1131f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.x, testPoint.y); 1132f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1133f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1134f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (!testPointInsidePolygon(testPoint, poly2, poly2Length)) { 1135f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPoly = true; 113650ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("(Error Type 1): one point (%f, %f) in the intersection is" 1137f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui " not in the poly2", 1138f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.x, testPoint.y); 1139f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1140f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1141f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1142f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1143f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (dumpPoly) { 1144f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(intersection, intersectionLength, "intersection"); 1145f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 1; i < intersectionLength; i++) { 1146f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta = intersection[i] - intersection[i - 1]; 1147f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui ALOGD("Intersetion i, %d Vs i-1 is delta %f", i, delta.lengthSquared()); 1148f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1149f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1150f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(poly1, poly1Length, "poly 1"); 1151f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(poly2, poly2Length, "poly 2"); 1152f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1153f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 1154f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#endif 1155f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 11567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui}; // namespace uirenderer 11577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui}; // namespace android 1158