SpotShadow.cpp revision f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952
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 257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include "SpotShadow.h" 267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include "Vertex.h" 277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuinamespace android { 297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuinamespace uirenderer { 307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Calculate the intersection of a ray with a polygon. 337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * It assumes the ray originates inside the polygon. 347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly The polygon, which is represented in a Vector2 array. 367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polyLength The length of caster's polygon in terms of number of 377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * vertices. 387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param point the start of the ray 397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param dx the x vector of the ray 407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param dy the y vector of the ray 417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return the distance along the ray if it intersects with the polygon FP_NAN if otherwise 427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuifloat SpotShadow::rayIntersectPoly(const Vector2* poly, int polyLength, 447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui const Vector2& point, float dx, float dy) { 457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double px = point.x; 467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double py = point.y; 477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int p1 = polyLength - 1; 487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int p2 = 0; p2 < polyLength; p2++) { 497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double p1x = poly[p1].x; 507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double p1y = poly[p1].y; 517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double p2x = poly[p2].x; 527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double p2y = poly[p2].y; 537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // The math below is derived from solving this formula, basically the 547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // intersection point should stay on both the ray and the edge of (p1, p2). 557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // solve([p1x+t*(p2x-p1x)=dx*t2+px,p1y+t*(p2y-p1y)=dy*t2+py],[t,t2]); 567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double div = (dx * (p1y - p2y) + dy * p2x - dy * p1x); 577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (div != 0) { 587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double t = (dx * (p1y - py) + dy * px - dy * p1x) / (div); 597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (t >= 0 && t <= 1) { 607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double t2 = (p1x * (py - p2y) + p2x * (p1y - py) + 617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui px * (p2y - p1y)) / div; 627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (t2 > 0) { 637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return (float)t2; 647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui p1 = p2; 687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return FP_NAN; 707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Calculate the centroid of a 2d polygon. 747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly The polygon, which is represented in a Vector2 array. 767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polyLength The length of the polygon in terms of number of vertices. 777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return the centroid of the polygon. 787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuiVector2 SpotShadow::centroid2d(const Vector2* poly, int polyLength) { 807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double sumx = 0; 817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double sumy = 0; 827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int p1 = polyLength - 1; 837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double area = 0; 847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int p2 = 0; p2 < polyLength; p2++) { 857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double x1 = poly[p1].x; 867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double y1 = poly[p1].y; 877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double x2 = poly[p2].x; 887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double y2 = poly[p2].y; 897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double a = (x1 * y2 - x2 * y1); 907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui sumx += (x1 + x2) * a; 917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui sumy += (y1 + y2) * a; 927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui area += a; 937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui p1 = p2; 947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double centroidx = sumx / (3 * area); 977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double centroidy = sumy / (3 * area); 987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return Vector2((float)centroidx, (float)centroidy); 997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 1007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 1027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points by their X coordinates 1037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points the points as a Vector2 array. 1057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param pointsLength the number of vertices of the polygon. 1067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 1077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::xsort(Vector2* points, int pointsLength) { 1087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui quicksortX(points, 0, pointsLength - 1); 1097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 1107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 1127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * compute the convex hull of a collection of Points 1137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points the points as a Vector2 array. 1157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param pointsLength the number of vertices of the polygon. 1167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param retPoly pre allocated array of floats to put the vertices 1177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return the number of points in the polygon 0 if no intersection 1187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 1197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuiint SpotShadow::hull(Vector2* points, int pointsLength, Vector2* retPoly) { 1207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui xsort(points, pointsLength); 1217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int n = pointsLength; 1227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 lUpper[n]; 1237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[0] = points[0]; 1247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[1] = points[1]; 1257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int lUpperSize = 2; 1277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 2; i < n; i++) { 1297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize] = points[i]; 1307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpperSize++; 1317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 132f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui while (lUpperSize > 2 && !ccw( 133f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lUpper[lUpperSize - 3].x, lUpper[lUpperSize - 3].y, 134f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lUpper[lUpperSize - 2].x, lUpper[lUpperSize - 2].y, 135f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lUpper[lUpperSize - 1].x, lUpper[lUpperSize - 1].y)) { 1367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Remove the middle point of the three last 1377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize - 2].x = lUpper[lUpperSize - 1].x; 1387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize - 2].y = lUpper[lUpperSize - 1].y; 1397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpperSize--; 1407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 lLower[n]; 1447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[0] = points[n - 1]; 1457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[1] = points[n - 2]; 1467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int lLowerSize = 2; 1487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = n - 3; i >= 0; i--) { 1507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[lLowerSize] = points[i]; 1517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLowerSize++; 1527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 153f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui while (lLowerSize > 2 && !ccw( 154f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lLower[lLowerSize - 3].x, lLower[lLowerSize - 3].y, 155f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lLower[lLowerSize - 2].x, lLower[lLowerSize - 2].y, 156f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lLower[lLowerSize - 1].x, lLower[lLowerSize - 1].y)) { 1577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Remove the middle point of the three last 1587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[lLowerSize - 2] = lLower[lLowerSize - 1]; 1597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLowerSize--; 1607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int count = 0; 1637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < lUpperSize; i++) { 1657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui retPoly[count] = lUpper[i]; 1667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 1677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 1; i < lLowerSize - 1; i++) { 1707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui retPoly[count] = lLower[i]; 1717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 1727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Add test harness which verify that all the points are inside the hull. 1747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return count; 1757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 1767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 178f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether the 3 points form a counter clockwise turn. 1797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param ax the x coordinate of point a 1817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param ay the y coordinate of point a 1827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param bx the x coordinate of point b 1837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param by the y coordinate of point b 1847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param cx the x coordinate of point c 1857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param cy the y coordinate of point c 1867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return true if a right hand turn 1877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 188f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuibool SpotShadow::ccw(double ax, double ay, double bx, double by, 1897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double cx, double cy) { 1907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return (bx - ax) * (cy - ay) - (by - ay) * (cx - ax) > EPSILON; 1917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 1927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 1947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Calculates the intersection of poly1 with poly2 and put in poly2. 1957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly1 The 1st polygon, as a Vector2 array. 1987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly1Length The number of vertices of 1st polygon. 1997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly2 The 2nd and output polygon, as a Vector2 array. 2007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly2Length The number of vertices of 2nd polygon. 2017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return number of vertices in output polygon as poly2. 2027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 2037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuiint SpotShadow::intersection(Vector2* poly1, int poly1Length, 2047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2* poly2, int poly2Length) { 2057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui makeClockwise(poly1, poly1Length); 2067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui makeClockwise(poly2, poly2Length); 207f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 2087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 poly[poly1Length * poly2Length + 2]; 2097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int count = 0; 2107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int pcount = 0; 2117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // If one vertex from one polygon sits inside another polygon, add it and 2137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // count them. 2147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < poly1Length; i++) { 2157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (testPointInsidePolygon(poly1[i], poly2, poly2Length)) { 2167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count] = poly1[i]; 2177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 2187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui pcount++; 2197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int insidePoly2 = pcount; 2247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < poly2Length; i++) { 2257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (testPointInsidePolygon(poly2[i], poly1, poly1Length)) { 2267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count] = poly2[i]; 2277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 2287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int insidePoly1 = count - insidePoly2; 2327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // If all vertices from poly1 are inside poly2, then just return poly1. 2337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (insidePoly2 == poly1Length) { 2347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui memcpy(poly2, poly1, poly1Length * sizeof(Vector2)); 2357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return poly1Length; 2367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // If all vertices from poly2 are inside poly1, then just return poly2. 2397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (insidePoly1 == poly2Length) { 2407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return poly2Length; 2417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Since neither polygon fully contain the other one, we need to add all the 2447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // intersection points. 2457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 intersection; 2467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < poly2Length; i++) { 2477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int j = 0; j < poly1Length; j++) { 2487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int poly2LineStart = i; 2497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int poly2LineEnd = ((i + 1) % poly2Length); 2507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int poly1LineStart = j; 2517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int poly1LineEnd = ((j + 1) % poly1Length); 2527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui bool found = lineIntersection( 2537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly2[poly2LineStart].x, poly2[poly2LineStart].y, 2547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly2[poly2LineEnd].x, poly2[poly2LineEnd].y, 2557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly1[poly1LineStart].x, poly1[poly1LineStart].y, 2567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly1[poly1LineEnd].x, poly1[poly1LineEnd].y, 2577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui intersection); 2587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (found) { 2597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count].x = intersection.x; 2607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count].y = intersection.y; 2617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 2627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } else { 2637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 delta = poly2[i] - poly1[j]; 264f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (delta.lengthSquared() < EPSILON) { 2657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly[count] = poly2[i]; 2667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui count++; 2677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (count == 0) { 2737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return 0; 2747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Sort the result polygon around the center. 2777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 center(0.0f, 0.0f); 2787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < count; i++) { 2797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui center += poly[i]; 2807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui center /= count; 2827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui sort(poly, count, center); 2837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 284f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#if DEBUG_SHADOW 285f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Since poly2 is overwritten as the result, we need to save a copy to do 286f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // our verification. 287f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 oldPoly2[poly2Length]; 288f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui int oldPoly2Length = poly2Length; 289f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui memcpy(oldPoly2, poly2, sizeof(Vector2) * poly2Length); 290f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#endif 2917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 292f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Filter the result out from poly and put it into poly2. 2937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly2[0] = poly[0]; 294f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui int lastOutputIndex = 0; 2957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 1; i < count; i++) { 296f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta = poly[i] - poly2[lastOutputIndex]; 297f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (delta.lengthSquared() >= EPSILON) { 298f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui poly2[++lastOutputIndex] = poly[i]; 299f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } else { 300f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // If the vertices are too close, pick the inner one, because the 301f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // inner one is more likely to be an intersection point. 302f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta1 = poly[i] - center; 303f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta2 = poly2[lastOutputIndex] - center; 304f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (delta1.lengthSquared() < delta2.lengthSquared()) { 305f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui poly2[lastOutputIndex] = poly[i]; 306f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 3077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 309f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui int resultLength = lastOutputIndex + 1; 310f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 311f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#if DEBUG_SHADOW 312f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testConvex(poly2, resultLength, "intersection"); 313f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testConvex(poly1, poly1Length, "input poly1"); 314f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testConvex(oldPoly2, oldPoly2Length, "input poly2"); 315f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 316f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testIntersection(poly1, poly1Length, oldPoly2, oldPoly2Length, poly2, resultLength); 317f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#endif 3187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return resultLength; 3207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points about a center point 3247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly The in and out polyogon as a Vector2 array. 3267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polyLength The number of vertices of the polygon. 3277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param center the center ctr[0] = x , ctr[1] = y to sort around. 3287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::sort(Vector2* poly, int polyLength, const Vector2& center) { 3307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui quicksortCirc(poly, 0, polyLength - 1, center); 3317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 334f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Calculate the angle between and x and a y coordinate. 335f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * The atan2 range from -PI to PI, if we want to sort the vertices as clockwise, 336f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * we just negate the return angle. 3377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuifloat SpotShadow::angle(const Vector2& point, const Vector2& center) { 339f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui return -(float)atan2(point.y - center.y, point.x - center.x); 3407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Swap points pointed to by i and j 3447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::swap(Vector2* points, int i, int j) { 3467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 temp = points[i]; 3477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui points[i] = points[j]; 3487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui points[j] = temp; 3497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * quick sort implementation about the center. 3537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::quicksortCirc(Vector2* points, int low, int high, 3557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui const Vector2& center) { 3567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int i = low, j = high; 3577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int p = low + (high - low) / 2; 3587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float pivot = angle(points[p], center); 3597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (i <= j) { 3607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (angle(points[i], center) < pivot) { 3617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 3627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (angle(points[j], center) > pivot) { 3647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 3657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i <= j) { 3687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui swap(points, i, j); 3697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 3707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 3717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (low < j) quicksortCirc(points, low, j, center); 3747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i < high) quicksortCirc(points, i, high, center); 3757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points by x axis 3797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points points to sort 3817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param low start index 3827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param high end index 3837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::quicksortX(Vector2* points, int low, int high) { 3857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int i = low, j = high; 3867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int p = low + (high - low) / 2; 3877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float pivot = points[p].x; 3887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (i <= j) { 3897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (points[i].x < pivot) { 3907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 3917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (points[j].x > pivot) { 3937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 3947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i <= j) { 3977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui swap(points, i, j); 3987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 3997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 4007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (low < j) quicksortX(points, low, j); 4037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i < high) quicksortX(points, i, high); 4047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 4057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Test whether a point is inside the polygon. 4087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param testPoint the point to test 4107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly the polygon 4117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return true if the testPoint is inside the poly. 4127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 4137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuibool SpotShadow::testPointInsidePolygon(const Vector2 testPoint, 4147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui const Vector2* poly, int len) { 4157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui bool c = false; 4167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double testx = testPoint.x; 4177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double testy = testPoint.y; 4187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0, j = len - 1; i < len; j = i++) { 4197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double startX = poly[j].x; 4207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double startY = poly[j].y; 4217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double endX = poly[i].x; 4227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double endY = poly[i].y; 4237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (((endY > testy) != (startY > testy)) && 4257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui (testx < (startX - endX) * (testy - endY) 4267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui / (startY - endY) + endX)) { 4277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui c = !c; 4287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return c; 4317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 4327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Make the polygon turn clockwise. 4357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polygon the polygon as a Vector2 array. 4377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param len the number of points of the polygon 4387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 4397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::makeClockwise(Vector2* polygon, int len) { 4407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (polygon == 0 || len == 0) { 4417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return; 4427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (!isClockwise(polygon, len)) { 4447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui reverse(polygon, len); 4457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 4477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Test whether the polygon is order in clockwise. 4507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polygon the polygon as a Vector2 array 4527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param len the number of points of the polygon 4537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 4547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuibool SpotShadow::isClockwise(Vector2* polygon, int len) { 4557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double sum = 0; 4567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double p1x = polygon[len - 1].x; 4577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double p1y = polygon[len - 1].y; 4587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < len; i++) { 4597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double p2x = polygon[i].x; 4617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double p2y = polygon[i].y; 4627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui sum += p1x * p2y - p2x * p1y; 4637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui p1x = p2x; 4647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui p1y = p2y; 4657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return sum < 0; 4677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 4687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Reverse the polygon 4717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polygon the polygon as a Vector2 array 4737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param len the number of points of the polygon 4747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 4757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::reverse(Vector2* polygon, int len) { 4767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int n = len / 2; 4777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < n; i++) { 4787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 tmp = polygon[i]; 4797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int k = len - 1 - i; 4807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui polygon[i] = polygon[k]; 4817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui polygon[k] = tmp; 4827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 4837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 4847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 4857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 4867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Intersects two lines in parametric form. This function is called in a tight 4877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * loop, and we need double precision to get things right. 4887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 4897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param x1 the x coordinate point 1 of line 1 4907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param y1 the y coordinate point 1 of line 1 4917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param x2 the x coordinate point 2 of line 1 4927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param y2 the y coordinate point 2 of line 1 4937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param x3 the x coordinate point 1 of line 2 4947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param y3 the y coordinate point 1 of line 2 4957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param x4 the x coordinate point 2 of line 2 4967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param y4 the y coordinate point 2 of line 2 4977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param ret the x,y location of the intersection 4987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return true if it found an intersection 4997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 5007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuiinline bool SpotShadow::lineIntersection(double x1, double y1, double x2, double y2, 5017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double x3, double y3, double x4, double y4, Vector2& ret) { 5027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double d = (x1 - x2) * (y3 - y4) - (y1 - y2) * (x3 - x4); 5037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (d == 0.0) return false; 5047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double dx = (x1 * y2 - y1 * x2); 5067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double dy = (x3 * y4 - y3 * x4); 5077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double x = (dx * (x3 - x4) - (x1 - x2) * dy) / d; 5087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double y = (dx * (y3 - y4) - (y1 - y2) * dy) / d; 5097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // The intersection should be in the middle of the point 1 and point 2, 5117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // likewise point 3 and point 4. 5127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (((x - x1) * (x - x2) > EPSILON) 5137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui || ((x - x3) * (x - x4) > EPSILON) 5147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui || ((y - y1) * (y - y2) > EPSILON) 5157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui || ((y - y3) * (y - y4) > EPSILON)) { 5167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Not interesected 5177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return false; 5187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ret.x = x; 5207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ret.y = y; 5217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return true; 5227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 5247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 5267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Compute a horizontal circular polygon about point (x , y , height) of radius 5277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * (size) 5287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 5297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points number of the points of the output polygon. 5307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param lightCenter the center of the light. 5317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param size the light size. 5327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param ret result polygon. 5337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 5347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::computeLightPolygon(int points, const Vector3& lightCenter, 5357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float size, Vector3* ret) { 5367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Caching all the sin / cos values and store them in a look up table. 5377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < points; i++) { 5387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui double angle = 2 * i * M_PI / points; 5397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ret[i].x = sinf(angle) * size + lightCenter.x; 5407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ret[i].y = cosf(angle) * size + lightCenter.y; 5417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ret[i].z = lightCenter.z; 5427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 5437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 5447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 5467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* Generate the shadow from a spot light. 5477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* 5487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param poly x,y,z vertexes of a convex polygon that occludes the light source 5497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param polyLength number of vertexes of the occluding polygon 5507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param lightCenter the center of the light 5517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param lightSize the radius of the light source 5527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param lightVertexCount the vertex counter for the light polygon 5537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param rays the number of vertexes to create along the edges of the shadow 5547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param layers the number of layers of triangles strips to create 5557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param strength the "darkness" of the shadow 5567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* @param shadowTriangleStrip return an (x,y,alpha) triangle strip representing the shadow. Return 5577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* empty strip if error. 5587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui* 5597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui*/ 5607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::createSpotShadow(const Vector3* poly, int polyLength, 5617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui const Vector3& lightCenter, float lightSize, int lightVertexCount, 5627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int rays, int layers, float strength, VertexBuffer& retStrips) { 5637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector3 light[lightVertexCount * 3]; 5647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui computeLightPolygon(lightVertexCount, lightCenter, lightSize, light); 5657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui computeSpotShadow(light, lightVertexCount, lightCenter, 5667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui poly, polyLength, rays, layers, strength, retStrips); 5677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 5687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 5707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Generate the shadow spot light of shape lightPoly and a object poly 5717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 5727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param lightPoly x,y,z vertex of a convex polygon that is the light source 5737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param lightPolyLength number of vertexes of the light source polygon 5747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly x,y,z vertexes of a convex polygon that occludes the light source 5757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polyLength number of vertexes of the occluding polygon 5767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param rays the number of vertexes to create along the edges of the shadow 5777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param layers the number of layers of triangles strips to create 5787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param strength the "darkness" of the shadow 5797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param shadowTriangleStrip return an (x,y,alpha) triangle strip representing the shadow. Return 5807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * empty strip if error. 5817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 5827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::computeSpotShadow(const Vector3* lightPoly, int lightPolyLength, 5837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui const Vector3& lightCenter, const Vector3* poly, int polyLength, 5847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int rays, int layers, float strength, VertexBuffer& shadowTriangleStrip) { 5857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Point clouds for all the shadowed vertices 5867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 shadowRegion[lightPolyLength * polyLength]; 5877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Shadow polygon from one point light. 5887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 outline[polyLength]; 5897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 umbraMem[polyLength * lightPolyLength]; 5907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2* umbra = umbraMem; 5917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int umbraLength = 0; 5937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Validate input, receiver is always at z = 0 plane. 5957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui bool inputPolyPositionValid = true; 5967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 5977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (poly[i].z <= 0.00001) { 5987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui inputPolyPositionValid = false; 5997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ALOGE("polygon below the surface"); 6007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui break; 6017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (poly[i].z >= lightPoly[0].z) { 6037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui inputPolyPositionValid = false; 6047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ALOGE("polygon above the light"); 6057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui break; 6067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // If the caster's position is invalid, don't draw anything. 6107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (!inputPolyPositionValid) { 6117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return; 6127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Calculate the umbra polygon based on intersections of all outlines 6157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int k = 0; 6167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int j = 0; j < lightPolyLength; j++) { 6177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int m = 0; 6187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 6197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float t = lightPoly[j].z - poly[i].z; 6207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (t == 0) { 6217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return; 6227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui t = lightPoly[j].z / t; 6247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float x = lightPoly[j].x - t * (lightPoly[j].x - poly[i].x); 6257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float y = lightPoly[j].y - t * (lightPoly[j].y - poly[i].y); 6267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 newPoint = Vector2(x, y); 6287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui shadowRegion[k] = newPoint; 6297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui outline[m] = newPoint; 6307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui k++; 6327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui m++; 6337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // For the first light polygon's vertex, use the outline as the umbra. 6367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Later on, use the intersection of the outline and existing umbra. 6377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (umbraLength == 0) { 6387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 6397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbra[i] = outline[i]; 6407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbraLength = polyLength; 6427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } else { 6437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int col = ((j * 255) / lightPolyLength); 6447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbraLength = intersection(outline, polyLength, umbra, umbraLength); 6457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (umbraLength == 0) { 6467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui break; 6477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Generate the penumbra area using the hull of all shadow regions. 6527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int shadowRegionLength = k; 6537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 penumbra[k]; 6547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int penumbraLength = hull(shadowRegion, shadowRegionLength, penumbra); 6557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // no real umbra make a fake one 6577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (umbraLength < 3) { 6587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // The shadow from the centroid of the light polygon. 6597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 centShadow[polyLength]; 6607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 6627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float t = lightCenter.z - poly[i].z; 6637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (t == 0) { 6647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return; 6657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui t = lightCenter.z / t; 6677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float x = lightCenter.x - t * (lightCenter.x - poly[i].x); 6687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float y = lightCenter.y - t * (lightCenter.y - poly[i].y); 6697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui centShadow[i].x = x; 6717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui centShadow[i].y = y; 6727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Shrink the centroid's shadow by 10%. 6757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Study the magic number of 10%. 6767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 shadowCentroid = centroid2d(centShadow, polyLength); 6777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < polyLength; i++) { 6787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui centShadow[i] = shadowCentroid * (1.0f - SHADOW_SHRINK_SCALE) + 6797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui centShadow[i] * SHADOW_SHRINK_SCALE; 6807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#if DEBUG_SHADOW 6827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ALOGD("No real umbra make a fake one, centroid2d = %f , %f", 6837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui shadowCentroid.x, shadowCentroid.y); 6847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#endif 6857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Set the fake umbra, whose size is the same as the original polygon. 6867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbra = centShadow; 6877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbraLength = polyLength; 6887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 6897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui generateTriangleStrip(penumbra, penumbraLength, umbra, umbraLength, 6917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui rays, layers, strength, shadowTriangleStrip); 6927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 6937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 6957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Generate a triangle strip given two convex polygons 6967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 6977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param penumbra The outer polygon x,y vertexes 6987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param penumbraLength The number of vertexes in the outer polygon 6997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param umbra The inner outer polygon x,y vertexes 7007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param umbraLength The number of vertexes in the inner polygon 7017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param rays The number of points along the polygons to create 7027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param layers The number of layers of triangle strips between the umbra and penumbra 7037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param strength The max alpha of the umbra 7047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param shadowTriangleStrip return an (x,y,alpha) triangle strip representing the shadow. Return 7057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * empty strip if error. 7067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui**/ 7077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::generateTriangleStrip(const Vector2* penumbra, int penumbraLength, 7087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui const Vector2* umbra, int umbraLength, int rays, int layers, 7097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float strength, VertexBuffer& shadowTriangleStrip) { 7107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 7117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int rings = layers + 1; 7127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int size = rays * rings; 7137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 7147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float step = M_PI * 2 / rays; 7157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Centroid of the umbra. 7167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 centroid = centroid2d(umbra, umbraLength); 7177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#if DEBUG_SHADOW 7187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ALOGD("centroid2d = %f , %f", centroid.x, centroid.y); 7197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#endif 7207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Intersection to the penumbra. 7217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float penumbraDistPerRay[rays]; 7227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Intersection to the umbra. 7237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float umbraDistPerRay[rays]; 7247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 7257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < rays; i++) { 7267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Setup a lookup table for all the sin/cos. 7277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float dx = sinf(step * i); 7287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float dy = cosf(step * i); 7297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui umbraDistPerRay[i] = rayIntersectPoly(umbra, umbraLength, centroid, 7307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui dx, dy); 7317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (isnan(umbraDistPerRay[i])) { 7327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ALOGE("rayIntersectPoly returns NAN"); 7337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return; 7347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 7357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui penumbraDistPerRay[i] = rayIntersectPoly(penumbra, penumbraLength, 7367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui centroid, dx, dy); 7377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (isnan(umbraDistPerRay[i])) { 7387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ALOGE("rayIntersectPoly returns NAN"); 7397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return; 7407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 7417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 7427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 7437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int stripSize = getStripSize(rays, layers); 7447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui AlphaVertex* shadowVertices = shadowTriangleStrip.alloc<AlphaVertex>(stripSize); 7457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int currentIndex = 0; 7467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Calculate the vertex values in the penumbra area. 7477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int r = 0; r < layers; r++) { 7487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int firstInEachLayer = currentIndex; 7497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < rays; i++) { 7507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float dx = sinf(step * i); 7517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float dy = cosf(step * i); 7527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 7537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int j = r; j < (r + 2); j++) { 7547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float layerRatio = j / (float)(rings - 1); 7557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float deltaDist = layerRatio * (umbraDistPerRay[i] - penumbraDistPerRay[i]); 7567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float currentDist = penumbraDistPerRay[i] + deltaDist; 7577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float op = calculateOpacity(layerRatio, deltaDist); 7587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui AlphaVertex::set(&shadowVertices[currentIndex], 7597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui dx * currentDist + centroid.x, 7607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui dy * currentDist + centroid.y, 7617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui layerRatio * op * strength); 7627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui currentIndex++; 7637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 7647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 7657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 7667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Duplicate the vertices from one layer to another one to make triangle 7677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // strip. 7687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui shadowVertices[currentIndex++] = shadowVertices[firstInEachLayer]; 7697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui firstInEachLayer++; 7707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui shadowVertices[currentIndex++] = shadowVertices[firstInEachLayer]; 7717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 7727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 7737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int lastInPenumbra = currentIndex - 1; 7747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui shadowVertices[currentIndex++] = shadowVertices[lastInPenumbra]; 7757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 7767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Preallocate the vertices (index as [firstInUmbra - 1]) for jumping from 7777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // the penumbra to umbra. 7787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui currentIndex++; 7797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int firstInUmbra = currentIndex; 7807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 7817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // traverse the umbra area in a zig zag pattern for strips. 7827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int k = 0; k < rays; k++) { 7837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int i = k / 2; 7847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if ((k & 1) == 1) { 7857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i = rays - i - 1; 7867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 7877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float dx = sinf(step * i); 7887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float dy = cosf(step * i); 7897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 7907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float ratio = 1.0; 7917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float deltaDist = ratio * (umbraDistPerRay[i] - penumbraDistPerRay[i]); 7927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float currentDist = penumbraDistPerRay[i] + deltaDist; 7937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float op = calculateOpacity(ratio, deltaDist); 7947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui AlphaVertex::set(&shadowVertices[currentIndex], 7957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui dx * currentDist + centroid.x, dy * currentDist + centroid.y, 7967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ratio * op * strength); 7977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui currentIndex++; 7987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 7997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 8007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 8017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Back fill the one vertex for jumping from penumbra to umbra. 8027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui shadowVertices[firstInUmbra - 1] = shadowVertices[firstInUmbra]; 8037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 8047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#if DEBUG_SHADOW 8057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < currentIndex; i++) { 8067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ALOGD("shadow value: i %d, (x:%f, y:%f, a:%f)", i, shadowVertices[i].x, 8077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui shadowVertices[i].y, shadowVertices[i].alpha); 8087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 8097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#endif 8107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 8117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 8127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 8137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * This is only for experimental purpose. 8147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * After intersections are calculated, we could smooth the polygon if needed. 8157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * So far, we don't think it is more appealing yet. 8167b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 8177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param level The level of smoothness. 8187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param rays The total number of rays. 8197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param rayDist (In and Out) The distance for each ray. 8207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 8217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 8227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::smoothPolygon(int level, int rays, float* rayDist) { 8237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int k = 0; k < level; k++) { 8247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < rays; i++) { 8257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float p1 = rayDist[(rays - 1 + i) % rays]; 8267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float p2 = rayDist[i]; 8277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float p3 = rayDist[(i + 1) % rays]; 8287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui rayDist[i] = (p1 + p2 * 2 + p3) / 4; 8297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 8307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 8317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 8327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 8337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 8347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Calculate the opacity according to the distance and falloff ratio. 8357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 8367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param distRatio The distance ratio of current sample between umbra and 8377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * penumbra area. 8387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param deltaDist The distance between current sample to the penumbra area. 8397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return The opacity according to the distance between umbra and penumbra. 8407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 8417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuifloat SpotShadow::calculateOpacity(float distRatio, float deltaDist) { 8427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Experiment on the opacity calculation. 8437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float falloffRatio = 1 + deltaDist * deltaDist; 8447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return (distRatio + 1 - 1 / falloffRatio) / 2; 8457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 8467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 8477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 8487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Calculate the number of vertex we will create given a number of rays and layers 8497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 8507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param rays number of points around the polygons you want 8517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param layers number of layers of triangle strips you need 8527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return number of vertex (multiply by 3 for number of floats) 8537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 8547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuiint SpotShadow::getStripSize(int rays, int layers) { 8557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return (2 + rays + ((layers) * 2 * (rays + 1))); 8567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 8577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 858f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#if DEBUG_SHADOW 859f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 860f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#define TEST_POINT_NUMBER 128 861f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 862f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 863f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Calculate the bounds for generating random test points. 864f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 865f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuivoid SpotShadow::updateBound(const Vector2 inVector, Vector2& lowerBound, 866f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2& upperBound ) { 867f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.x < lowerBound.x) { 868f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lowerBound.x = inVector.x; 869f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 870f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 871f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.y < lowerBound.y) { 872f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lowerBound.y = inVector.y; 873f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 874f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 875f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.x > upperBound.x) { 876f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui upperBound.x = inVector.x; 877f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 878f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 879f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.y > upperBound.y) { 880f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui upperBound.y = inVector.y; 881f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 882f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 883f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 884f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 885f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * For debug purpose, when things go wrong, dump the whole polygon data. 886f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 887f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuistatic void dumpPolygon(const Vector2* poly, int polyLength, const char* polyName) { 888f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < polyLength; i++) { 889f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui ALOGD("polygon %s i %d x %f y %f", polyName, i, poly[i].x, poly[i].y); 890f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 891f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 892f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 893f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 894f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether the polygon is convex. 895f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 896f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuibool SpotShadow::testConvex(const Vector2* polygon, int polygonLength, 897f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui const char* name) { 898f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool isConvex = true; 899f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < polygonLength; i++) { 900f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 start = polygon[i]; 901f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 middle = polygon[(i + 1) % polygonLength]; 902f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 end = polygon[(i + 2) % polygonLength]; 903f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 904f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui double delta = (double(middle.x) - start.x) * (double(end.y) - start.y) - 905f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui (double(middle.y) - start.y) * (double(end.x) - start.x); 906f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool isCCWOrCoLinear = (delta >= EPSILON); 907f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 908f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (isCCWOrCoLinear) { 909f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui ALOGE("(Error Type 2): polygon (%s) is not a convex b/c start (x %f, y %f)," 910f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui "middle (x %f, y %f) and end (x %f, y %f) , delta is %f !!!", 911f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui name, start.x, start.y, middle.x, middle.y, end.x, end.y, delta); 912f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui isConvex = false; 913f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui break; 914f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 915f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 916f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui return isConvex; 917f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 918f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 919f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 920f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether or not the polygon (intersection) is within the 2 input polygons. 921f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Using Marte Carlo method, we generate a random point, and if it is inside the 922f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * intersection, then it must be inside both source polygons. 923f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 924f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuivoid SpotShadow::testIntersection(const Vector2* poly1, int poly1Length, 925f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui const Vector2* poly2, int poly2Length, 926f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui const Vector2* intersection, int intersectionLength) { 927f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Find the min and max of x and y. 928f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 lowerBound(FLT_MAX, FLT_MAX); 929f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 upperBound(-FLT_MAX, -FLT_MAX); 930f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < poly1Length; i++) { 931f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui updateBound(poly1[i], lowerBound, upperBound); 932f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 933f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < poly2Length; i++) { 934f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui updateBound(poly2[i], lowerBound, upperBound); 935f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 936f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 937f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool dumpPoly = false; 938f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int k = 0; k < TEST_POINT_NUMBER; k++) { 939f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Generate a random point between minX, minY and maxX, maxY. 940f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui double randomX = rand() / double(RAND_MAX); 941f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui double randomY = rand() / double(RAND_MAX); 942f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 943f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 testPoint; 944f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.x = lowerBound.x + randomX * (upperBound.x - lowerBound.x); 945f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.y = lowerBound.y + randomY * (upperBound.y - lowerBound.y); 946f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 947f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // If the random point is in both poly 1 and 2, then it must be intersection. 948f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (testPointInsidePolygon(testPoint, intersection, intersectionLength)) { 949f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (!testPointInsidePolygon(testPoint, poly1, poly1Length)) { 950f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPoly = true; 951f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui ALOGE("(Error Type 1): one point (%f, %f) in the intersection is" 952f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui " not in the poly1", 953f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.x, testPoint.y); 954f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 955f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 956f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (!testPointInsidePolygon(testPoint, poly2, poly2Length)) { 957f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPoly = true; 958f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui ALOGE("(Error Type 1): one point (%f, %f) in the intersection is" 959f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui " not in the poly2", 960f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.x, testPoint.y); 961f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 962f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 963f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 964f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 965f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (dumpPoly) { 966f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(intersection, intersectionLength, "intersection"); 967f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 1; i < intersectionLength; i++) { 968f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta = intersection[i] - intersection[i - 1]; 969f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui ALOGD("Intersetion i, %d Vs i-1 is delta %f", i, delta.lengthSquared()); 970f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 971f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 972f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(poly1, poly1Length, "poly 1"); 973f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(poly2, poly2Length, "poly 2"); 974f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 975f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 976f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#endif 977f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 9787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui}; // namespace uirenderer 9797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui}; // namespace android 9807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 9817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 9827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 9837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 984