SpotShadow.cpp revision 28c3ea018771562a9150f30c6a088e5bf7502972
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 207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include <math.h> 22f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#include <stdlib.h> 237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include <utils/Log.h> 247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2563d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui#include "ShadowTessellator.h" 267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include "SpotShadow.h" 277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include "Vertex.h" 287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuinamespace android { 307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuinamespace uirenderer { 317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 32726118b35240957710d4d85fb5747e2ba8b934f7Chris Craikstatic const double EPSILON = 1e-7; 33726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 34726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik/** 35726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Calculate the angle between and x and a y coordinate. 36726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * The atan2 range from -PI to PI. 37726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik */ 38b79a3e301a8d89b9e1b1f6f3d7fd6aa56610a6f0Chris Craikstatic float angle(const Vector2& point, const Vector2& center) { 39726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik return atan2(point.y - center.y, point.x - center.x); 40726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik} 41726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 43726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Calculate the intersection of a ray with the line segment defined by two points. 447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 45726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Returns a negative value in error conditions. 46726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 47726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param rayOrigin The start of the ray 48726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param dx The x vector of the ray 49726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param dy The y vector of the ray 50726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param p1 The first point defining the line segment 51726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param p2 The second point defining the line segment 52726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @return The distance along the ray if it intersects with the line segment, negative if otherwise 537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 54b79a3e301a8d89b9e1b1f6f3d7fd6aa56610a6f0Chris Craikstatic float rayIntersectPoints(const Vector2& rayOrigin, float dx, float dy, 55726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const Vector2& p1, const Vector2& p2) { 56726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // The math below is derived from solving this formula, basically the 57726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // intersection point should stay on both the ray and the edge of (p1, p2). 58726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // solve([p1x+t*(p2x-p1x)=dx*t2+px,p1y+t*(p2y-p1y)=dy*t2+py],[t,t2]); 59726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 60726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik double divisor = (dx * (p1.y - p2.y) + dy * p2.x - dy * p1.x); 61726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik if (divisor == 0) return -1.0f; // error, invalid divisor 62726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 63726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik#if DEBUG_SHADOW 64726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik double interpVal = (dx * (p1.y - rayOrigin.y) + dy * rayOrigin.x - dy * p1.x) / divisor; 6599af9429cda84ad0af1d7fcecb580295b0046882ztenghui if (interpVal < 0 || interpVal > 1) { 6699af9429cda84ad0af1d7fcecb580295b0046882ztenghui ALOGW("rayIntersectPoints is hitting outside the segment %f", interpVal); 6799af9429cda84ad0af1d7fcecb580295b0046882ztenghui } 68726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik#endif 69726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 70726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik double distance = (p1.x * (rayOrigin.y - p2.y) + p2.x * (p1.y - rayOrigin.y) + 71726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik rayOrigin.x * (p2.y - p1.y)) / divisor; 72726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 73726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik return distance; // may be negative in error cases 747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points by their X coordinates 787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points the points as a Vector2 array. 807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param pointsLength the number of vertices of the polygon. 817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::xsort(Vector2* points, int pointsLength) { 837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui quicksortX(points, 0, pointsLength - 1); 847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * compute the convex hull of a collection of Points 887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points the points as a Vector2 array. 907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param pointsLength the number of vertices of the polygon. 917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param retPoly pre allocated array of floats to put the vertices 927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return the number of points in the polygon 0 if no intersection 937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuiint SpotShadow::hull(Vector2* points, int pointsLength, Vector2* retPoly) { 957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui xsort(points, pointsLength); 967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int n = pointsLength; 977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 lUpper[n]; 987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[0] = points[0]; 997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[1] = points[1]; 1007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int lUpperSize = 2; 1027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 2; i < n; i++) { 1047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize] = points[i]; 1057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpperSize++; 1067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 107f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui while (lUpperSize > 2 && !ccw( 108f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lUpper[lUpperSize - 3].x, lUpper[lUpperSize - 3].y, 109f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lUpper[lUpperSize - 2].x, lUpper[lUpperSize - 2].y, 110f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lUpper[lUpperSize - 1].x, lUpper[lUpperSize - 1].y)) { 1117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Remove the middle point of the three last 1127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize - 2].x = lUpper[lUpperSize - 1].x; 1137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize - 2].y = lUpper[lUpperSize - 1].y; 1147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpperSize--; 1157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 lLower[n]; 1197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[0] = points[n - 1]; 1207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[1] = points[n - 2]; 1217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int lLowerSize = 2; 1237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = n - 3; i >= 0; i--) { 1257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[lLowerSize] = points[i]; 1267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLowerSize++; 1277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 128f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui while (lLowerSize > 2 && !ccw( 129f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lLower[lLowerSize - 3].x, lLower[lLowerSize - 3].y, 130f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lLower[lLowerSize - 2].x, lLower[lLowerSize - 2].y, 131f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lLower[lLowerSize - 1].x, lLower[lLowerSize - 1].y)) { 1327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Remove the middle point of the three last 1337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[lLowerSize - 2] = lLower[lLowerSize - 1]; 1347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLowerSize--; 1357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 138726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // output points in CW ordering 139726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const int total = lUpperSize + lLowerSize - 2; 140726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik int outIndex = total - 1; 1417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < lUpperSize; i++) { 142726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik retPoly[outIndex] = lUpper[i]; 143726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik outIndex--; 1447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 1; i < lLowerSize - 1; i++) { 147726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik retPoly[outIndex] = lLower[i]; 148726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik outIndex--; 1497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Add test harness which verify that all the points are inside the hull. 151726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik return total; 1527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 1537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 155f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether the 3 points form a counter clockwise turn. 1567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return true if a right hand turn 1587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 159f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuibool SpotShadow::ccw(double ax, double ay, double bx, double by, 1607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double cx, double cy) { 1617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return (bx - ax) * (cy - ay) - (by - ay) * (cx - ax) > EPSILON; 1627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 1637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 1657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Calculates the intersection of poly1 with poly2 and put in poly2. 16650ecf849cb7ccc3482517b74d2214b347927791eztenghui * Note that both poly1 and poly2 must be in CW order already! 1677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly1 The 1st polygon, as a Vector2 array. 1697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly1Length The number of vertices of 1st polygon. 1707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly2 The 2nd and output polygon, as a Vector2 array. 1717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly2Length The number of vertices of 2nd polygon. 1727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return number of vertices in output polygon as poly2. 1737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 17450ecf849cb7ccc3482517b74d2214b347927791eztenghuiint SpotShadow::intersection(const Vector2* poly1, int poly1Length, 1757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2* poly2, int poly2Length) { 17650ecf849cb7ccc3482517b74d2214b347927791eztenghui#if DEBUG_SHADOW 17750ecf849cb7ccc3482517b74d2214b347927791eztenghui if (!isClockwise(poly1, poly1Length)) { 17850ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("Poly1 is not clockwise! Intersection is wrong!"); 17950ecf849cb7ccc3482517b74d2214b347927791eztenghui } 18050ecf849cb7ccc3482517b74d2214b347927791eztenghui if (!isClockwise(poly2, poly2Length)) { 18150ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("Poly2 is not clockwise! Intersection is wrong!"); 18250ecf849cb7ccc3482517b74d2214b347927791eztenghui } 18350ecf849cb7ccc3482517b74d2214b347927791eztenghui#endif 1847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 poly[poly1Length * poly2Length + 2]; 1857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int count = 0; 1867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int pcount = 0; 1877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // If one vertex from one polygon sits inside another polygon, add it and 1897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // count them. 1907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < poly1Length; i++) { 1917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (testPointInsidePolygon(poly1[i], poly2, poly2Length)) { 1927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count] = poly1[i]; 1937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 1947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui pcount++; 1957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int insidePoly2 = pcount; 2007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < poly2Length; i++) { 2017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (testPointInsidePolygon(poly2[i], poly1, poly1Length)) { 2027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count] = poly2[i]; 2037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 2047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int insidePoly1 = count - insidePoly2; 2087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // If all vertices from poly1 are inside poly2, then just return poly1. 2097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (insidePoly2 == poly1Length) { 2107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui memcpy(poly2, poly1, poly1Length * sizeof(Vector2)); 2117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return poly1Length; 2127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // If all vertices from poly2 are inside poly1, then just return poly2. 2157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (insidePoly1 == poly2Length) { 2167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return poly2Length; 2177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Since neither polygon fully contain the other one, we need to add all the 2207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // intersection points. 2217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 intersection; 2227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < poly2Length; i++) { 2237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int j = 0; j < poly1Length; j++) { 2247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int poly2LineStart = i; 2257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int poly2LineEnd = ((i + 1) % poly2Length); 2267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int poly1LineStart = j; 2277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int poly1LineEnd = ((j + 1) % poly1Length); 2287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui bool found = lineIntersection( 2297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly2[poly2LineStart].x, poly2[poly2LineStart].y, 2307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly2[poly2LineEnd].x, poly2[poly2LineEnd].y, 2317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly1[poly1LineStart].x, poly1[poly1LineStart].y, 2327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly1[poly1LineEnd].x, poly1[poly1LineEnd].y, 2337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui intersection); 2347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (found) { 2357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count].x = intersection.x; 2367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count].y = intersection.y; 2377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 2387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } else { 2397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 delta = poly2[i] - poly1[j]; 240f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (delta.lengthSquared() < EPSILON) { 2417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count] = poly2[i]; 2427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 2437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (count == 0) { 2497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return 0; 2507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Sort the result polygon around the center. 2537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 center(0.0f, 0.0f); 2547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < count; i++) { 2557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui center += poly[i]; 2567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui center /= count; 2587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui sort(poly, count, center); 2597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 260f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#if DEBUG_SHADOW 261f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Since poly2 is overwritten as the result, we need to save a copy to do 262f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // our verification. 263f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 oldPoly2[poly2Length]; 264f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui int oldPoly2Length = poly2Length; 265f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui memcpy(oldPoly2, poly2, sizeof(Vector2) * poly2Length); 266f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#endif 2677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 268f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Filter the result out from poly and put it into poly2. 2697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly2[0] = poly[0]; 270f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui int lastOutputIndex = 0; 2717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 1; i < count; i++) { 272f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta = poly[i] - poly2[lastOutputIndex]; 273f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (delta.lengthSquared() >= EPSILON) { 274f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui poly2[++lastOutputIndex] = poly[i]; 275f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } else { 276f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // If the vertices are too close, pick the inner one, because the 277f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // inner one is more likely to be an intersection point. 278f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta1 = poly[i] - center; 279f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta2 = poly2[lastOutputIndex] - center; 280f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (delta1.lengthSquared() < delta2.lengthSquared()) { 281f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui poly2[lastOutputIndex] = poly[i]; 282f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 2837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 285f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui int resultLength = lastOutputIndex + 1; 286f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 287f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#if DEBUG_SHADOW 288f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testConvex(poly2, resultLength, "intersection"); 289f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testConvex(poly1, poly1Length, "input poly1"); 290f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testConvex(oldPoly2, oldPoly2Length, "input poly2"); 291f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 292f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testIntersection(poly1, poly1Length, oldPoly2, oldPoly2Length, poly2, resultLength); 293f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#endif 2947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return resultLength; 2967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 2977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 2997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points about a center point 3007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly The in and out polyogon as a Vector2 array. 3027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polyLength The number of vertices of the polygon. 3037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param center the center ctr[0] = x , ctr[1] = y to sort around. 3047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::sort(Vector2* poly, int polyLength, const Vector2& center) { 3067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui quicksortCirc(poly, 0, polyLength - 1, center); 3077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Swap points pointed to by i and j 3117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::swap(Vector2* points, int i, int j) { 3137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 temp = points[i]; 3147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui points[i] = points[j]; 3157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui points[j] = temp; 3167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * quick sort implementation about the center. 3207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::quicksortCirc(Vector2* points, int low, int high, 3227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui const Vector2& center) { 3237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int i = low, j = high; 3247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int p = low + (high - low) / 2; 3257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float pivot = angle(points[p], center); 3267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (i <= j) { 327726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik while (angle(points[i], center) > pivot) { 3287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 3297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 330726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik while (angle(points[j], center) < pivot) { 3317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 3327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i <= j) { 3357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui swap(points, i, j); 3367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 3377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 3387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (low < j) quicksortCirc(points, low, j, center); 3417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i < high) quicksortCirc(points, i, high, center); 3427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points by x axis 3467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points points to sort 3487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param low start index 3497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param high end index 3507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::quicksortX(Vector2* points, int low, int high) { 3527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int i = low, j = high; 3537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int p = low + (high - low) / 2; 3547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float pivot = points[p].x; 3557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (i <= j) { 3567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (points[i].x < pivot) { 3577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 3587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (points[j].x > pivot) { 3607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 3617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i <= j) { 3647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui swap(points, i, j); 3657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 3667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 3677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (low < j) quicksortX(points, low, j); 3707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i < high) quicksortX(points, i, high); 3717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Test whether a point is inside the polygon. 3757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param testPoint the point to test 3777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly the polygon 3787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return true if the testPoint is inside the poly. 3797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuibool SpotShadow::testPointInsidePolygon(const Vector2 testPoint, 3817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui const Vector2* poly, int len) { 3827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui bool c = false; 3837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double testx = testPoint.x; 3847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double testy = testPoint.y; 3857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0, j = len - 1; i < len; j = i++) { 3867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double startX = poly[j].x; 3877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double startY = poly[j].y; 3887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double endX = poly[i].x; 3897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double endY = poly[i].y; 3907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (((endY > testy) != (startY > testy)) && 3927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui (testx < (startX - endX) * (testy - endY) 3937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui / (startY - endY) + endX)) { 3947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui c = !c; 3957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return c; 3987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Make the polygon turn clockwise. 4027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polygon the polygon as a Vector2 array. 4047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param len the number of points of the polygon 4057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 4067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::makeClockwise(Vector2* polygon, int len) { 4077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (polygon == 0 || len == 0) { 4087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return; 4097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (!isClockwise(polygon, len)) { 4117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui reverse(polygon, len); 4127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 4147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Test whether the polygon is order in clockwise. 4177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polygon the polygon as a Vector2 array 4197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param len the number of points of the polygon 4207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 42150ecf849cb7ccc3482517b74d2214b347927791eztenghuibool SpotShadow::isClockwise(const Vector2* polygon, int len) { 4227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double sum = 0; 4237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double p1x = polygon[len - 1].x; 4247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double p1y = polygon[len - 1].y; 4257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < len; i++) { 4267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double p2x = polygon[i].x; 4287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double p2y = polygon[i].y; 4297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui sum += p1x * p2y - p2x * p1y; 4307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui p1x = p2x; 4317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui p1y = p2y; 4327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return sum < 0; 4347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 4357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Reverse the polygon 4387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polygon the polygon as a Vector2 array 4407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param len the number of points of the polygon 4417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 4427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::reverse(Vector2* polygon, int len) { 4437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int n = len / 2; 4447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < n; i++) { 4457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 tmp = polygon[i]; 4467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int k = len - 1 - i; 4477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui polygon[i] = polygon[k]; 4487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui polygon[k] = tmp; 4497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 4517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Intersects two lines in parametric form. This function is called in a tight 4547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * loop, and we need double precision to get things right. 4557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param x1 the x coordinate point 1 of line 1 4577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param y1 the y coordinate point 1 of line 1 4587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param x2 the x coordinate point 2 of line 1 4597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param y2 the y coordinate point 2 of line 1 4607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param x3 the x coordinate point 1 of line 2 4617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param y3 the y coordinate point 1 of line 2 4627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param x4 the x coordinate point 2 of line 2 4637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param y4 the y coordinate point 2 of line 2 4647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param ret the x,y location of the intersection 4657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return true if it found an intersection 4667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 4677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuiinline bool SpotShadow::lineIntersection(double x1, double y1, double x2, double y2, 4687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double x3, double y3, double x4, double y4, Vector2& ret) { 4697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double d = (x1 - x2) * (y3 - y4) - (y1 - y2) * (x3 - x4); 4707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (d == 0.0) return false; 4717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double dx = (x1 * y2 - y1 * x2); 4737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double dy = (x3 * y4 - y3 * x4); 4747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double x = (dx * (x3 - x4) - (x1 - x2) * dy) / d; 4757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double y = (dx * (y3 - y4) - (y1 - y2) * dy) / d; 4767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // The intersection should be in the middle of the point 1 and point 2, 4787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // likewise point 3 and point 4. 4797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (((x - x1) * (x - x2) > EPSILON) 4807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui || ((x - x3) * (x - x4) > EPSILON) 4817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui || ((y - y1) * (y - y2) > EPSILON) 4827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui || ((y - y3) * (y - y4) > EPSILON)) { 4837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Not interesected 4847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return false; 4857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ret.x = x; 4877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ret.y = y; 4887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return true; 4897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 4917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Compute a horizontal circular polygon about point (x , y , height) of radius 4947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * (size) 4957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points number of the points of the output polygon. 4977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param lightCenter the center of the light. 4987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param size the light size. 4997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param ret result polygon. 5007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 5017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::computeLightPolygon(int points, const Vector3& lightCenter, 5027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float size, Vector3* ret) { 5037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Caching all the sin / cos values and store them in a look up table. 5047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < points; i++) { 5057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double angle = 2 * i * M_PI / points; 506726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik ret[i].x = cosf(angle) * size + lightCenter.x; 507726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik ret[i].y = sinf(angle) * size + lightCenter.y; 5087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ret[i].z = lightCenter.z; 5097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 5117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 5137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* Generate the shadow from a spot light. 5147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* 5157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param poly x,y,z vertexes of a convex polygon that occludes the light source 5167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param polyLength number of vertexes of the occluding polygon 5177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param lightCenter the center of the light 5187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param lightSize the radius of the light source 5197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param lightVertexCount the vertex counter for the light polygon 5207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param shadowTriangleStrip return an (x,y,alpha) triangle strip representing the shadow. Return 5217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* empty strip if error. 5227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* 5237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui*/ 52450ecf849cb7ccc3482517b74d2214b347927791eztenghuiVertexBufferMode SpotShadow::createSpotShadow(bool isCasterOpaque, const Vector3* poly, 52550ecf849cb7ccc3482517b74d2214b347927791eztenghui int polyLength, const Vector3& lightCenter, float lightSize, 52650ecf849cb7ccc3482517b74d2214b347927791eztenghui int lightVertexCount, VertexBuffer& retStrips) { 5277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector3 light[lightVertexCount * 3]; 5287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui computeLightPolygon(lightVertexCount, lightCenter, lightSize, light); 52950ecf849cb7ccc3482517b74d2214b347927791eztenghui computeSpotShadow(isCasterOpaque, light, lightVertexCount, lightCenter, poly, 53050ecf849cb7ccc3482517b74d2214b347927791eztenghui polyLength, retStrips); 53150ecf849cb7ccc3482517b74d2214b347927791eztenghui return kVertexBufferMode_TwoPolyRingShadow; 5327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 5337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 5357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Generate the shadow spot light of shape lightPoly and a object poly 5367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 5377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param lightPoly x,y,z vertex of a convex polygon that is the light source 5387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param lightPolyLength number of vertexes of the light source polygon 5397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly x,y,z vertexes of a convex polygon that occludes the light source 5407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polyLength number of vertexes of the occluding polygon 5417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param shadowTriangleStrip return an (x,y,alpha) triangle strip representing the shadow. Return 5427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * empty strip if error. 5437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 54450ecf849cb7ccc3482517b74d2214b347927791eztenghuivoid SpotShadow::computeSpotShadow(bool isCasterOpaque, const Vector3* lightPoly, 54550ecf849cb7ccc3482517b74d2214b347927791eztenghui int lightPolyLength, const Vector3& lightCenter, const Vector3* poly, 54650ecf849cb7ccc3482517b74d2214b347927791eztenghui int polyLength, VertexBuffer& shadowTriangleStrip) { 5477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Point clouds for all the shadowed vertices 5487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 shadowRegion[lightPolyLength * polyLength]; 5497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Shadow polygon from one point light. 5507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 outline[polyLength]; 5517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 umbraMem[polyLength * lightPolyLength]; 5527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2* umbra = umbraMem; 5537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int umbraLength = 0; 5557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Validate input, receiver is always at z = 0 plane. 5577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui bool inputPolyPositionValid = true; 5587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 5597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (poly[i].z >= lightPoly[0].z) { 5607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui inputPolyPositionValid = false; 561b79a3e301a8d89b9e1b1f6f3d7fd6aa56610a6f0Chris Craik ALOGW("polygon above the light"); 5627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui break; 5637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // If the caster's position is invalid, don't draw anything. 5677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (!inputPolyPositionValid) { 5687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return; 5697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Calculate the umbra polygon based on intersections of all outlines 5727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int k = 0; 5737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int j = 0; j < lightPolyLength; j++) { 5747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int m = 0; 5757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 57628c3ea018771562a9150f30c6a088e5bf7502972ztenghui // After validating the input, deltaZ is guaranteed to be positive. 57750ecf849cb7ccc3482517b74d2214b347927791eztenghui float deltaZ = lightPoly[j].z - poly[i].z; 57850ecf849cb7ccc3482517b74d2214b347927791eztenghui float ratioZ = lightPoly[j].z / deltaZ; 57950ecf849cb7ccc3482517b74d2214b347927791eztenghui float x = lightPoly[j].x - ratioZ * (lightPoly[j].x - poly[i].x); 58050ecf849cb7ccc3482517b74d2214b347927791eztenghui float y = lightPoly[j].y - ratioZ * (lightPoly[j].y - poly[i].y); 5817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 newPoint = Vector2(x, y); 5837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui shadowRegion[k] = newPoint; 5847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui outline[m] = newPoint; 5857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui k++; 5877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui m++; 5887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // For the first light polygon's vertex, use the outline as the umbra. 5917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Later on, use the intersection of the outline and existing umbra. 5927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (umbraLength == 0) { 5937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 5947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbra[i] = outline[i]; 5957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbraLength = polyLength; 5977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } else { 5987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int col = ((j * 255) / lightPolyLength); 5997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbraLength = intersection(outline, polyLength, umbra, umbraLength); 6007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (umbraLength == 0) { 6017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui break; 6027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Generate the penumbra area using the hull of all shadow regions. 6077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int shadowRegionLength = k; 6087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 penumbra[k]; 6097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int penumbraLength = hull(shadowRegion, shadowRegionLength, penumbra); 6107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6115176c974f1d9af833b7584e895fcba61e6e7427aztenghui Vector2 fakeUmbra[polyLength]; 6127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (umbraLength < 3) { 6135176c974f1d9af833b7584e895fcba61e6e7427aztenghui // If there is no real umbra, make a fake one. 6147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 61550ecf849cb7ccc3482517b74d2214b347927791eztenghui float deltaZ = lightCenter.z - poly[i].z; 61650ecf849cb7ccc3482517b74d2214b347927791eztenghui float ratioZ = lightCenter.z / deltaZ; 61750ecf849cb7ccc3482517b74d2214b347927791eztenghui float x = lightCenter.x - ratioZ * (lightCenter.x - poly[i].x); 61850ecf849cb7ccc3482517b74d2214b347927791eztenghui float y = lightCenter.y - ratioZ * (lightCenter.y - poly[i].y); 6197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6205176c974f1d9af833b7584e895fcba61e6e7427aztenghui fakeUmbra[i].x = x; 6215176c974f1d9af833b7584e895fcba61e6e7427aztenghui fakeUmbra[i].y = y; 6227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Shrink the centroid's shadow by 10%. 6257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Study the magic number of 10%. 62663d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui Vector2 shadowCentroid = 62763d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui ShadowTessellator::centroid2d(fakeUmbra, polyLength); 6287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 6295176c974f1d9af833b7584e895fcba61e6e7427aztenghui fakeUmbra[i] = shadowCentroid * (1.0f - SHADOW_SHRINK_SCALE) + 6305176c974f1d9af833b7584e895fcba61e6e7427aztenghui fakeUmbra[i] * SHADOW_SHRINK_SCALE; 6317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#if DEBUG_SHADOW 6337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ALOGD("No real umbra make a fake one, centroid2d = %f , %f", 6347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui shadowCentroid.x, shadowCentroid.y); 6357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#endif 6367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Set the fake umbra, whose size is the same as the original polygon. 6375176c974f1d9af833b7584e895fcba61e6e7427aztenghui umbra = fakeUmbra; 6387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbraLength = polyLength; 6397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 64150ecf849cb7ccc3482517b74d2214b347927791eztenghui generateTriangleStrip(isCasterOpaque, penumbra, penumbraLength, umbra, 64250ecf849cb7ccc3482517b74d2214b347927791eztenghui umbraLength, poly, polyLength, shadowTriangleStrip); 6437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 6447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 646726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Converts a polygon specified with CW vertices into an array of distance-from-centroid values. 647726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * 648726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Returns false in error conditions 649726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * 650726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param poly Array of vertices. Note that these *must* be CW. 651726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param polyLength The number of vertices in the polygon. 652726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param polyCentroid The centroid of the polygon, from which rays will be cast 653726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param rayDist The output array for the calculated distances, must be SHADOW_RAY_COUNT in size 654726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik */ 655726118b35240957710d4d85fb5747e2ba8b934f7Chris Craikbool convertPolyToRayDist(const Vector2* poly, int polyLength, const Vector2& polyCentroid, 656726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik float* rayDist) { 657726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const int rays = SHADOW_RAY_COUNT; 658726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const float step = M_PI * 2 / rays; 659726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 660726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const Vector2* lastVertex = &(poly[polyLength - 1]); 661726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik float startAngle = angle(*lastVertex, polyCentroid); 662726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 663726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // Start with the ray that's closest to and less than startAngle 664726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik int rayIndex = floor((startAngle - EPSILON) / step); 665726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik rayIndex = (rayIndex + rays) % rays; // ensure positive 666726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 667726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik for (int polyIndex = 0; polyIndex < polyLength; polyIndex++) { 668726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik /* 669726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * For a given pair of vertices on the polygon, poly[i-1] and poly[i], the rays that 670726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * intersect these will be those that are between the two angles from the centroid that the 671726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * vertices define. 672726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * 673726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Because the polygon vertices are stored clockwise, the closest ray with an angle 674726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * *smaller* than that defined by angle(poly[i], centroid) will be the first ray that does 675726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * not intersect with poly[i-1], poly[i]. 676726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik */ 677726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik float currentAngle = angle(poly[polyIndex], polyCentroid); 678726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 679726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // find first ray that will not intersect the line segment poly[i-1] & poly[i] 680726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik int firstRayIndexOnNextSegment = floor((currentAngle - EPSILON) / step); 681726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik firstRayIndexOnNextSegment = (firstRayIndexOnNextSegment + rays) % rays; // ensure positive 682726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 683726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // Iterate through all rays that intersect with poly[i-1], poly[i] line segment. 684726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // This may be 0 rays. 685726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik while (rayIndex != firstRayIndexOnNextSegment) { 686726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik float distanceToIntersect = rayIntersectPoints(polyCentroid, 687726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik cos(rayIndex * step), 688726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik sin(rayIndex * step), 689726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik *lastVertex, poly[polyIndex]); 69050ecf849cb7ccc3482517b74d2214b347927791eztenghui if (distanceToIntersect < 0) { 69150ecf849cb7ccc3482517b74d2214b347927791eztenghui#if DEBUG_SHADOW 69250ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("ERROR: convertPolyToRayDist failed"); 69350ecf849cb7ccc3482517b74d2214b347927791eztenghui#endif 69450ecf849cb7ccc3482517b74d2214b347927791eztenghui return false; // error case, abort 69550ecf849cb7ccc3482517b74d2214b347927791eztenghui } 696726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 697726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik rayDist[rayIndex] = distanceToIntersect; 698726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 699726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik rayIndex = (rayIndex - 1 + rays) % rays; 700726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik } 701726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik lastVertex = &poly[polyIndex]; 702726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik } 703726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 704726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik return true; 705726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik} 706726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 70750ecf849cb7ccc3482517b74d2214b347927791eztenghuiint SpotShadow::calculateOccludedUmbra(const Vector2* umbra, int umbraLength, 70850ecf849cb7ccc3482517b74d2214b347927791eztenghui const Vector3* poly, int polyLength, Vector2* occludedUmbra) { 70950ecf849cb7ccc3482517b74d2214b347927791eztenghui // Occluded umbra area is computed as the intersection of the projected 2D 71050ecf849cb7ccc3482517b74d2214b347927791eztenghui // poly and umbra. 71150ecf849cb7ccc3482517b74d2214b347927791eztenghui for (int i = 0; i < polyLength; i++) { 71250ecf849cb7ccc3482517b74d2214b347927791eztenghui occludedUmbra[i].x = poly[i].x; 71350ecf849cb7ccc3482517b74d2214b347927791eztenghui occludedUmbra[i].y = poly[i].y; 71450ecf849cb7ccc3482517b74d2214b347927791eztenghui } 71550ecf849cb7ccc3482517b74d2214b347927791eztenghui 71650ecf849cb7ccc3482517b74d2214b347927791eztenghui // Both umbra and incoming polygon are guaranteed to be CW, so we can call 71750ecf849cb7ccc3482517b74d2214b347927791eztenghui // intersection() directly. 71850ecf849cb7ccc3482517b74d2214b347927791eztenghui return intersection(umbra, umbraLength, 71950ecf849cb7ccc3482517b74d2214b347927791eztenghui occludedUmbra, polyLength); 72050ecf849cb7ccc3482517b74d2214b347927791eztenghui} 72150ecf849cb7ccc3482517b74d2214b347927791eztenghui 72250ecf849cb7ccc3482517b74d2214b347927791eztenghui#define OCLLUDED_UMBRA_SHRINK_FACTOR 0.95f 723726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik/** 7247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Generate a triangle strip given two convex polygons 7257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 7267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param penumbra The outer polygon x,y vertexes 7277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param penumbraLength The number of vertexes in the outer polygon 7287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param umbra The inner outer polygon x,y vertexes 7297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param umbraLength The number of vertexes in the inner polygon 7307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param shadowTriangleStrip return an (x,y,alpha) triangle strip representing the shadow. Return 7317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * empty strip if error. 7327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui**/ 73350ecf849cb7ccc3482517b74d2214b347927791eztenghuivoid SpotShadow::generateTriangleStrip(bool isCasterOpaque, const Vector2* penumbra, 73450ecf849cb7ccc3482517b74d2214b347927791eztenghui int penumbraLength, const Vector2* umbra, int umbraLength, 73550ecf849cb7ccc3482517b74d2214b347927791eztenghui const Vector3* poly, int polyLength, VertexBuffer& shadowTriangleStrip) { 73663d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui const int rays = SHADOW_RAY_COUNT; 737726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const int size = 2 * rays; 738726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const float step = M_PI * 2 / rays; 7397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Centroid of the umbra. 74063d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui Vector2 centroid = ShadowTessellator::centroid2d(umbra, umbraLength); 7417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#if DEBUG_SHADOW 7427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ALOGD("centroid2d = %f , %f", centroid.x, centroid.y); 7437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#endif 7447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Intersection to the penumbra. 7457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float penumbraDistPerRay[rays]; 7467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Intersection to the umbra. 7477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float umbraDistPerRay[rays]; 74850ecf849cb7ccc3482517b74d2214b347927791eztenghui // Intersection to the occluded umbra area. 74950ecf849cb7ccc3482517b74d2214b347927791eztenghui float occludedUmbraDistPerRay[rays]; 7507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 751726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // convert CW polygons to ray distance encoding, aborting on conversion failure 752726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik if (!convertPolyToRayDist(umbra, umbraLength, centroid, umbraDistPerRay)) return; 753726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik if (!convertPolyToRayDist(penumbra, penumbraLength, centroid, penumbraDistPerRay)) return; 7547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 75550ecf849cb7ccc3482517b74d2214b347927791eztenghui bool hasOccludedUmbraArea = false; 75650ecf849cb7ccc3482517b74d2214b347927791eztenghui if (isCasterOpaque) { 75750ecf849cb7ccc3482517b74d2214b347927791eztenghui Vector2 occludedUmbra[polyLength + umbraLength]; 75850ecf849cb7ccc3482517b74d2214b347927791eztenghui int occludedUmbraLength = calculateOccludedUmbra(umbra, umbraLength, poly, polyLength, 75950ecf849cb7ccc3482517b74d2214b347927791eztenghui occludedUmbra); 76050ecf849cb7ccc3482517b74d2214b347927791eztenghui // Make sure the centroid is inside the umbra, otherwise, fall back to the 76150ecf849cb7ccc3482517b74d2214b347927791eztenghui // approach as if there is no occluded umbra area. 76250ecf849cb7ccc3482517b74d2214b347927791eztenghui if (testPointInsidePolygon(centroid, occludedUmbra, occludedUmbraLength)) { 76350ecf849cb7ccc3482517b74d2214b347927791eztenghui hasOccludedUmbraArea = true; 76450ecf849cb7ccc3482517b74d2214b347927791eztenghui // Shrink the occluded umbra area to avoid pixel level artifacts. 76550ecf849cb7ccc3482517b74d2214b347927791eztenghui for (int i = 0; i < occludedUmbraLength; i ++) { 76650ecf849cb7ccc3482517b74d2214b347927791eztenghui occludedUmbra[i] = centroid + (occludedUmbra[i] - centroid) * 76750ecf849cb7ccc3482517b74d2214b347927791eztenghui OCLLUDED_UMBRA_SHRINK_FACTOR; 76850ecf849cb7ccc3482517b74d2214b347927791eztenghui } 76950ecf849cb7ccc3482517b74d2214b347927791eztenghui if (!convertPolyToRayDist(occludedUmbra, occludedUmbraLength, centroid, 77050ecf849cb7ccc3482517b74d2214b347927791eztenghui occludedUmbraDistPerRay)) { 77150ecf849cb7ccc3482517b74d2214b347927791eztenghui return; 77250ecf849cb7ccc3482517b74d2214b347927791eztenghui } 77350ecf849cb7ccc3482517b74d2214b347927791eztenghui } 77450ecf849cb7ccc3482517b74d2214b347927791eztenghui } 77550ecf849cb7ccc3482517b74d2214b347927791eztenghui 77650ecf849cb7ccc3482517b74d2214b347927791eztenghui AlphaVertex* shadowVertices = 77750ecf849cb7ccc3482517b74d2214b347927791eztenghui shadowTriangleStrip.alloc<AlphaVertex>(SHADOW_VERTEX_COUNT); 7787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 77963d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui // Calculate the vertices (x, y, alpha) in the shadow area. 78050ecf849cb7ccc3482517b74d2214b347927791eztenghui AlphaVertex centroidXYA; 78150ecf849cb7ccc3482517b74d2214b347927791eztenghui AlphaVertex::set(¢roidXYA, centroid.x, centroid.y, 1.0f); 782726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik for (int rayIndex = 0; rayIndex < rays; rayIndex++) { 783726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik float dx = cosf(step * rayIndex); 784726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik float dy = sinf(step * rayIndex); 785726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 78650ecf849cb7ccc3482517b74d2214b347927791eztenghui // penumbra ring 78750ecf849cb7ccc3482517b74d2214b347927791eztenghui float penumbraDistance = penumbraDistPerRay[rayIndex]; 788726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik AlphaVertex::set(&shadowVertices[rayIndex], 78950ecf849cb7ccc3482517b74d2214b347927791eztenghui dx * penumbraDistance + centroid.x, 79050ecf849cb7ccc3482517b74d2214b347927791eztenghui dy * penumbraDistance + centroid.y, 0.0f); 791726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 79250ecf849cb7ccc3482517b74d2214b347927791eztenghui // umbra ring 79350ecf849cb7ccc3482517b74d2214b347927791eztenghui float umbraDistance = umbraDistPerRay[rayIndex]; 794726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik AlphaVertex::set(&shadowVertices[rays + rayIndex], 79550ecf849cb7ccc3482517b74d2214b347927791eztenghui dx * umbraDistance + centroid.x, dy * umbraDistance + centroid.y, 1.0f); 79650ecf849cb7ccc3482517b74d2214b347927791eztenghui 79750ecf849cb7ccc3482517b74d2214b347927791eztenghui // occluded umbra ring 79850ecf849cb7ccc3482517b74d2214b347927791eztenghui if (hasOccludedUmbraArea) { 79950ecf849cb7ccc3482517b74d2214b347927791eztenghui float occludedUmbraDistance = occludedUmbraDistPerRay[rayIndex]; 80050ecf849cb7ccc3482517b74d2214b347927791eztenghui AlphaVertex::set(&shadowVertices[2 * rays + rayIndex], 80150ecf849cb7ccc3482517b74d2214b347927791eztenghui dx * occludedUmbraDistance + centroid.x, 80250ecf849cb7ccc3482517b74d2214b347927791eztenghui dy * occludedUmbraDistance + centroid.y, 1.0f); 80350ecf849cb7ccc3482517b74d2214b347927791eztenghui } else { 80450ecf849cb7ccc3482517b74d2214b347927791eztenghui // Put all vertices of the occluded umbra ring at the centroid. 80550ecf849cb7ccc3482517b74d2214b347927791eztenghui shadowVertices[2 * rays + rayIndex] = centroidXYA; 80650ecf849cb7ccc3482517b74d2214b347927791eztenghui } 8077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 8087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 8097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 8107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 8117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * This is only for experimental purpose. 8127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * After intersections are calculated, we could smooth the polygon if needed. 8137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * So far, we don't think it is more appealing yet. 8147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 8157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param level The level of smoothness. 8167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param rays The total number of rays. 8177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param rayDist (In and Out) The distance for each ray. 8187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 8197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 8207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::smoothPolygon(int level, int rays, float* rayDist) { 8217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int k = 0; k < level; k++) { 8227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < rays; i++) { 8237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float p1 = rayDist[(rays - 1 + i) % rays]; 8247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float p2 = rayDist[i]; 8257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float p3 = rayDist[(i + 1) % rays]; 8267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui rayDist[i] = (p1 + p2 * 2 + p3) / 4; 8277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 8287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 8297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 8307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 831f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#if DEBUG_SHADOW 832f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 833f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#define TEST_POINT_NUMBER 128 834f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 835f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 836f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Calculate the bounds for generating random test points. 837f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 838f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuivoid SpotShadow::updateBound(const Vector2 inVector, Vector2& lowerBound, 839f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2& upperBound ) { 840f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.x < lowerBound.x) { 841f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lowerBound.x = inVector.x; 842f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 843f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 844f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.y < lowerBound.y) { 845f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lowerBound.y = inVector.y; 846f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 847f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 848f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.x > upperBound.x) { 849f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui upperBound.x = inVector.x; 850f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 851f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 852f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.y > upperBound.y) { 853f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui upperBound.y = inVector.y; 854f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 855f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 856f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 857f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 858f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * For debug purpose, when things go wrong, dump the whole polygon data. 859f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 860f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuistatic void dumpPolygon(const Vector2* poly, int polyLength, const char* polyName) { 861f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < polyLength; i++) { 862f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui ALOGD("polygon %s i %d x %f y %f", polyName, i, poly[i].x, poly[i].y); 863f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 864f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 865f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 866f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 867f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether the polygon is convex. 868f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 869f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuibool SpotShadow::testConvex(const Vector2* polygon, int polygonLength, 870f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui const char* name) { 871f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool isConvex = true; 872f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < polygonLength; i++) { 873f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 start = polygon[i]; 874f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 middle = polygon[(i + 1) % polygonLength]; 875f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 end = polygon[(i + 2) % polygonLength]; 876f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 877f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui double delta = (double(middle.x) - start.x) * (double(end.y) - start.y) - 878f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui (double(middle.y) - start.y) * (double(end.x) - start.x); 879f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool isCCWOrCoLinear = (delta >= EPSILON); 880f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 881f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (isCCWOrCoLinear) { 88250ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("(Error Type 2): polygon (%s) is not a convex b/c start (x %f, y %f)," 883f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui "middle (x %f, y %f) and end (x %f, y %f) , delta is %f !!!", 884f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui name, start.x, start.y, middle.x, middle.y, end.x, end.y, delta); 885f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui isConvex = false; 886f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui break; 887f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 888f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 889f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui return isConvex; 890f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 891f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 892f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 893f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether or not the polygon (intersection) is within the 2 input polygons. 894f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Using Marte Carlo method, we generate a random point, and if it is inside the 895f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * intersection, then it must be inside both source polygons. 896f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 897f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuivoid SpotShadow::testIntersection(const Vector2* poly1, int poly1Length, 898f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui const Vector2* poly2, int poly2Length, 899f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui const Vector2* intersection, int intersectionLength) { 900f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Find the min and max of x and y. 901f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 lowerBound(FLT_MAX, FLT_MAX); 902f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 upperBound(-FLT_MAX, -FLT_MAX); 903f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < poly1Length; i++) { 904f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui updateBound(poly1[i], lowerBound, upperBound); 905f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 906f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < poly2Length; i++) { 907f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui updateBound(poly2[i], lowerBound, upperBound); 908f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 909f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 910f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool dumpPoly = false; 911f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int k = 0; k < TEST_POINT_NUMBER; k++) { 912f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Generate a random point between minX, minY and maxX, maxY. 913f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui double randomX = rand() / double(RAND_MAX); 914f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui double randomY = rand() / double(RAND_MAX); 915f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 916f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 testPoint; 917f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.x = lowerBound.x + randomX * (upperBound.x - lowerBound.x); 918f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.y = lowerBound.y + randomY * (upperBound.y - lowerBound.y); 919f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 920f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // If the random point is in both poly 1 and 2, then it must be intersection. 921f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (testPointInsidePolygon(testPoint, intersection, intersectionLength)) { 922f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (!testPointInsidePolygon(testPoint, poly1, poly1Length)) { 923f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPoly = true; 92450ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("(Error Type 1): one point (%f, %f) in the intersection is" 925f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui " not in the poly1", 926f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.x, testPoint.y); 927f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 928f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 929f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (!testPointInsidePolygon(testPoint, poly2, poly2Length)) { 930f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPoly = true; 93150ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("(Error Type 1): one point (%f, %f) in the intersection is" 932f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui " not in the poly2", 933f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.x, testPoint.y); 934f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 935f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 936f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 937f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 938f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (dumpPoly) { 939f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(intersection, intersectionLength, "intersection"); 940f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 1; i < intersectionLength; i++) { 941f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta = intersection[i] - intersection[i - 1]; 942f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui ALOGD("Intersetion i, %d Vs i-1 is delta %f", i, delta.lengthSquared()); 943f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 944f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 945f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(poly1, poly1Length, "poly 1"); 946f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(poly2, poly2Length, "poly 2"); 947f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 948f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 949f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#endif 950f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 9517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui}; // namespace uirenderer 9527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui}; // namespace android 953