SpotShadow.cpp revision 3932063bc75dc1e4efc2c428ca208d2e2290164d
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 19512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// The highest z value can't be higher than (CASTER_Z_CAP_RATIO * light.z) 20c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#define CASTER_Z_CAP_RATIO 0.95f 21512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 22512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// When there is no umbra, then just fake the umbra using 23512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// centroid * (1 - FAKE_UMBRA_SIZE_RATIO) + outline * FAKE_UMBRA_SIZE_RATIO 24512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#define FAKE_UMBRA_SIZE_RATIO 0.05f 25512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 26512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// When the polygon is about 90 vertices, the penumbra + umbra can reach 270 rays. 27512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// That is consider pretty fine tessllated polygon so far. 28512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// This is just to prevent using too much some memory when edge slicing is not 29512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// needed any more. 30512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#define FINE_TESSELLATED_POLYGON_RAY_NUMBER 270 31512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui/** 32512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * Extra vertices for the corner for smoother corner. 33512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * Only for outer loop. 34512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * Note that we use such extra memory to avoid an extra loop. 35512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui */ 36512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// For half circle, we could add EXTRA_VERTEX_PER_PI vertices. 37512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// Set to 1 if we don't want to have any. 38512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#define SPOT_EXTRA_CORNER_VERTEX_PER_PI 18 39512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 40512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// For the whole polygon, the sum of all the deltas b/t normals is 2 * M_PI, 41512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// therefore, the maximum number of extra vertices will be twice bigger. 42512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#define SPOT_MAX_EXTRA_CORNER_VERTEX_NUMBER (2 * SPOT_EXTRA_CORNER_VERTEX_PER_PI) 43512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 44512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui// For each RADIANS_DIVISOR, we would allocate one more vertex b/t the normals. 45512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#define SPOT_CORNER_RADIANS_DIVISOR (M_PI / SPOT_EXTRA_CORNER_VERTEX_PER_PI) 46512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include <math.h> 49f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#include <stdlib.h> 507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include <utils/Log.h> 517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 5263d41abb40b3ce40d8b9bccb1cf186e8158a3687ztenghui#include "ShadowTessellator.h" 537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include "SpotShadow.h" 547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui#include "Vertex.h" 55c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#include "utils/MathUtils.h" 567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 57c50a03d78aaedd0003377e98710e7038bda330e9ztenghui// TODO: After we settle down the new algorithm, we can remove the old one and 58c50a03d78aaedd0003377e98710e7038bda330e9ztenghui// its utility functions. 59c50a03d78aaedd0003377e98710e7038bda330e9ztenghui// Right now, we still need to keep it for comparison purpose and future expansion. 607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuinamespace android { 617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuinamespace uirenderer { 627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 639122b1b168d2a74d51517ed7282f4d6a8adea367ztenghuistatic const float EPSILON = 1e-7; 64726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 65726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik/** 66c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * For each polygon's vertex, the light center will project it to the receiver 67c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * as one of the outline vertex. 68c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * For each outline vertex, we need to store the position and normal. 69c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * Normal here is defined against the edge by the current vertex and the next vertex. 70c50a03d78aaedd0003377e98710e7038bda330e9ztenghui */ 71c50a03d78aaedd0003377e98710e7038bda330e9ztenghuistruct OutlineData { 72c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 position; 73c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 normal; 74c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float radius; 75c50a03d78aaedd0003377e98710e7038bda330e9ztenghui}; 76c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 77c50a03d78aaedd0003377e98710e7038bda330e9ztenghui/** 78512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * For each vertex, we need to keep track of its angle, whether it is penumbra or 79512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * umbra, and its corresponding vertex index. 80512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui */ 81512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghuistruct SpotShadow::VertexAngleData { 82512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // The angle to the vertex from the centroid. 83512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float mAngle; 84512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // True is the vertex comes from penumbra, otherwise it comes from umbra. 85512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui bool mIsPenumbra; 86512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // The index of the vertex described by this data. 87512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int mVertexIndex; 88512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui void set(float angle, bool isPenumbra, int index) { 89512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui mAngle = angle; 90512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui mIsPenumbra = isPenumbra; 91512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui mVertexIndex = index; 92512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 93512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui}; 94512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 95512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui/** 96726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Calculate the angle between and x and a y coordinate. 97726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * The atan2 range from -PI to PI. 98726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik */ 99b79a3e301a8d89b9e1b1f6f3d7fd6aa56610a6f0Chris Craikstatic float angle(const Vector2& point, const Vector2& center) { 100726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik return atan2(point.y - center.y, point.x - center.x); 101726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik} 102726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 1037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 104726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Calculate the intersection of a ray with the line segment defined by two points. 1057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 106726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * Returns a negative value in error conditions. 107726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 108726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param rayOrigin The start of the ray 109726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param dx The x vector of the ray 110726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param dy The y vector of the ray 111726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param p1 The first point defining the line segment 112726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @param p2 The second point defining the line segment 113726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik * @return The distance along the ray if it intersects with the line segment, negative if otherwise 1147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 115b79a3e301a8d89b9e1b1f6f3d7fd6aa56610a6f0Chris Craikstatic float rayIntersectPoints(const Vector2& rayOrigin, float dx, float dy, 116726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const Vector2& p1, const Vector2& p2) { 117726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // The math below is derived from solving this formula, basically the 118726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // intersection point should stay on both the ray and the edge of (p1, p2). 119726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // solve([p1x+t*(p2x-p1x)=dx*t2+px,p1y+t*(p2y-p1y)=dy*t2+py],[t,t2]); 120726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 1219122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float divisor = (dx * (p1.y - p2.y) + dy * p2.x - dy * p1.x); 122726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik if (divisor == 0) return -1.0f; // error, invalid divisor 123726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 124726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik#if DEBUG_SHADOW 1259122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float interpVal = (dx * (p1.y - rayOrigin.y) + dy * rayOrigin.x - dy * p1.x) / divisor; 12699af9429cda84ad0af1d7fcecb580295b0046882ztenghui if (interpVal < 0 || interpVal > 1) { 12799af9429cda84ad0af1d7fcecb580295b0046882ztenghui ALOGW("rayIntersectPoints is hitting outside the segment %f", interpVal); 12899af9429cda84ad0af1d7fcecb580295b0046882ztenghui } 129726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik#endif 130726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 1319122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float distance = (p1.x * (rayOrigin.y - p2.y) + p2.x * (p1.y - rayOrigin.y) + 132726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik rayOrigin.x * (p2.y - p1.y)) / divisor; 133726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik 134726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik return distance; // may be negative in error cases 1357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 1367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 1387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points by their X coordinates 1397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points the points as a Vector2 array. 1417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param pointsLength the number of vertices of the polygon. 1427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 1437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::xsort(Vector2* points, int pointsLength) { 1447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui quicksortX(points, 0, pointsLength - 1); 1457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 1467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 1487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * compute the convex hull of a collection of Points 1497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 1507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points the points as a Vector2 array. 1517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param pointsLength the number of vertices of the polygon. 1527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param retPoly pre allocated array of floats to put the vertices 1537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return the number of points in the polygon 0 if no intersection 1547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 1557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuiint SpotShadow::hull(Vector2* points, int pointsLength, Vector2* retPoly) { 1567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui xsort(points, pointsLength); 1577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int n = pointsLength; 1587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 lUpper[n]; 1597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[0] = points[0]; 1607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[1] = points[1]; 1617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int lUpperSize = 2; 1637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 2; i < n; i++) { 1657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize] = points[i]; 1667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpperSize++; 1677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 168f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui while (lUpperSize > 2 && !ccw( 169f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lUpper[lUpperSize - 3].x, lUpper[lUpperSize - 3].y, 170f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lUpper[lUpperSize - 2].x, lUpper[lUpperSize - 2].y, 171f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lUpper[lUpperSize - 1].x, lUpper[lUpperSize - 1].y)) { 1727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Remove the middle point of the three last 1737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize - 2].x = lUpper[lUpperSize - 1].x; 1747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpper[lUpperSize - 2].y = lUpper[lUpperSize - 1].y; 1757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lUpperSize--; 1767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 lLower[n]; 1807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[0] = points[n - 1]; 1817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[1] = points[n - 2]; 1827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int lLowerSize = 2; 1847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 1857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = n - 3; i >= 0; i--) { 1867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[lLowerSize] = points[i]; 1877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLowerSize++; 1887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 189f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui while (lLowerSize > 2 && !ccw( 190f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lLower[lLowerSize - 3].x, lLower[lLowerSize - 3].y, 191f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lLower[lLowerSize - 2].x, lLower[lLowerSize - 2].y, 192f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lLower[lLowerSize - 1].x, lLower[lLowerSize - 1].y)) { 1937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // Remove the middle point of the three last 1947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLower[lLowerSize - 2] = lLower[lLowerSize - 1]; 1957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui lLowerSize--; 1967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 1987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 199726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik // output points in CW ordering 200726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik const int total = lUpperSize + lLowerSize - 2; 201726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik int outIndex = total - 1; 2027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < lUpperSize; i++) { 203726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik retPoly[outIndex] = lUpper[i]; 204726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik outIndex--; 2057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 1; i < lLowerSize - 1; i++) { 208726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik retPoly[outIndex] = lLower[i]; 209726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik outIndex--; 2107b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2117b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Add test harness which verify that all the points are inside the hull. 212726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik return total; 2137b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 2147b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2157b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 216f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether the 3 points form a counter clockwise turn. 2177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 2187b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return true if a right hand turn 2197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 2209122b1b168d2a74d51517ed7282f4d6a8adea367ztenghuibool SpotShadow::ccw(float ax, float ay, float bx, float by, 2219122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float cx, float cy) { 2227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return (bx - ax) * (cy - ay) - (by - ay) * (cx - ax) > EPSILON; 2237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 2247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 2267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points about a center point 2277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 2287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly The in and out polyogon as a Vector2 array. 2297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polyLength The number of vertices of the polygon. 2307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param center the center ctr[0] = x , ctr[1] = y to sort around. 2317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 2327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::sort(Vector2* poly, int polyLength, const Vector2& center) { 2337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui quicksortCirc(poly, 0, polyLength - 1, center); 2347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 2357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 2377b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Swap points pointed to by i and j 2387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 2397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::swap(Vector2* points, int i, int j) { 2407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 temp = points[i]; 2417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui points[i] = points[j]; 2427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui points[j] = temp; 2437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 2447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 2467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * quick sort implementation about the center. 2477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 2487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::quicksortCirc(Vector2* points, int low, int high, 2497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui const Vector2& center) { 2507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int i = low, j = high; 2517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int p = low + (high - low) / 2; 2527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float pivot = angle(points[p], center); 2537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (i <= j) { 254726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik while (angle(points[i], center) > pivot) { 2557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 2567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 257726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik while (angle(points[j], center) < pivot) { 2587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 2597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i <= j) { 2627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui swap(points, i, j); 2637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 2647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 2657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (low < j) quicksortCirc(points, low, j, center); 2687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i < high) quicksortCirc(points, i, high, center); 2697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 2707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2717b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 2727b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Sort points by x axis 2737b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 2747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points points to sort 2757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param low start index 2767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param high end index 2777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 2787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::quicksortX(Vector2* points, int low, int high) { 2797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int i = low, j = high; 2807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int p = low + (high - low) / 2; 2817b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float pivot = points[p].x; 2827b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (i <= j) { 2837b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (points[i].x < pivot) { 2847b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 2857b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui while (points[j].x > pivot) { 2877b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 2887b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2897b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 2907b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i <= j) { 2917b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui swap(points, i, j); 2927b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui i++; 2937b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui j--; 2947b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2957b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 2967b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (low < j) quicksortX(points, low, j); 2977b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (i < high) quicksortX(points, i, high); 2987b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 2997b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3007b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3017b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Test whether a point is inside the polygon. 3027b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3037b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param testPoint the point to test 3047b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param poly the polygon 3057b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @return true if the testPoint is inside the poly. 3067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3077b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuibool SpotShadow::testPointInsidePolygon(const Vector2 testPoint, 3087b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui const Vector2* poly, int len) { 3097b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui bool c = false; 3109122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float testx = testPoint.x; 3119122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float testy = testPoint.y; 3127b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0, j = len - 1; i < len; j = i++) { 3139122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float startX = poly[j].x; 3149122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float startY = poly[j].y; 3159122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float endX = poly[i].x; 3169122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float endY = poly[i].y; 3177b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 318512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui if (((endY > testy) != (startY > testy)) 319512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui && (testx < (startX - endX) * (testy - endY) 3207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui / (startY - endY) + endX)) { 3217b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui c = !c; 3227b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3237b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return c; 3257b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3267b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3277b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3287b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Make the polygon turn clockwise. 3297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polygon the polygon as a Vector2 array. 3317b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param len the number of points of the polygon 3327b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3337b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::makeClockwise(Vector2* polygon, int len) { 3347b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui if (polygon == 0 || len == 0) { 3357b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui return; 3367b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3372e023f3827dfc0dfc1ed7c3dd54d02b4a993f0b4ztenghui if (!ShadowTessellator::isClockwise(polygon, len)) { 3387b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui reverse(polygon, len); 3397b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3407b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3417b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3427b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3437b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Reverse the polygon 3447b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3457b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param polygon the polygon as a Vector2 array 3467b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param len the number of points of the polygon 3477b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::reverse(Vector2* polygon, int len) { 3497b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int n = len / 2; 3507b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < n; i++) { 3517b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui Vector2 tmp = polygon[i]; 3527b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui int k = len - 1 - i; 3537b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui polygon[i] = polygon[k]; 3547b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui polygon[k] = tmp; 3557b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3567b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3577b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3587b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 3597b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * Compute a horizontal circular polygon about point (x , y , height) of radius 3607b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * (size) 3617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 3627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param points number of the points of the output polygon. 3637b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param lightCenter the center of the light. 3647b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param size the light size. 3657b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * @param ret result polygon. 3667b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 3677b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghuivoid SpotShadow::computeLightPolygon(int points, const Vector3& lightCenter, 3687b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui float size, Vector3* ret) { 3697b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui // TODO: Caching all the sin / cos values and store them in a look up table. 3707b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui for (int i = 0; i < points; i++) { 3719122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float angle = 2 * i * M_PI / points; 372726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik ret[i].x = cosf(angle) * size + lightCenter.x; 373726118b35240957710d4d85fb5747e2ba8b934f7Chris Craik ret[i].y = sinf(angle) * size + lightCenter.y; 3747b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui ret[i].z = lightCenter.z; 3757b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 3767b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 3777b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 3787b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 379512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * From light center, project one vertex to the z=0 surface and get the outline. 3807b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 381512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @param outline The result which is the outline position. 382512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @param lightCenter The center of light. 383512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @param polyVertex The input polygon's vertex. 384512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * 385512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @return float The ratio of (polygon.z / light.z - polygon.z) 3867b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui */ 387c50a03d78aaedd0003377e98710e7038bda330e9ztenghuifloat SpotShadow::projectCasterToOutline(Vector2& outline, 388c50a03d78aaedd0003377e98710e7038bda330e9ztenghui const Vector3& lightCenter, const Vector3& polyVertex) { 389c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float lightToPolyZ = lightCenter.z - polyVertex.z; 390c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float ratioZ = CASTER_Z_CAP_RATIO; 391c50a03d78aaedd0003377e98710e7038bda330e9ztenghui if (lightToPolyZ != 0) { 392c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // If any caster's vertex is almost above the light, we just keep it as 95% 393c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // of the height of the light. 3943bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui ratioZ = MathUtils::clamp(polyVertex.z / lightToPolyZ, 0.0f, CASTER_Z_CAP_RATIO); 395c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 396c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 397c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outline.x = polyVertex.x - ratioZ * (lightCenter.x - polyVertex.x); 398c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outline.y = polyVertex.y - ratioZ * (lightCenter.y - polyVertex.y); 399c50a03d78aaedd0003377e98710e7038bda330e9ztenghui return ratioZ; 400c50a03d78aaedd0003377e98710e7038bda330e9ztenghui} 401c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 402c50a03d78aaedd0003377e98710e7038bda330e9ztenghui/** 403c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * Generate the shadow spot light of shape lightPoly and a object poly 404c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * 405c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param isCasterOpaque whether the caster is opaque 406c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param lightCenter the center of the light 407c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param lightSize the radius of the light 408c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param poly x,y,z vertexes of a convex polygon that occludes the light source 409c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param polyLength number of vertexes of the occluding polygon 410c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * @param shadowTriangleStrip return an (x,y,alpha) triangle strip representing the shadow. Return 411c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * empty strip if error. 412c50a03d78aaedd0003377e98710e7038bda330e9ztenghui */ 413c50a03d78aaedd0003377e98710e7038bda330e9ztenghuivoid SpotShadow::createSpotShadow(bool isCasterOpaque, const Vector3& lightCenter, 414c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float lightSize, const Vector3* poly, int polyLength, const Vector3& polyCentroid, 415c50a03d78aaedd0003377e98710e7038bda330e9ztenghui VertexBuffer& shadowTriangleStrip) { 4163bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui if (CC_UNLIKELY(lightCenter.z <= 0)) { 4173bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui ALOGW("Relative Light Z is not positive. No spot shadow!"); 4183bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui return; 4193bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui } 420512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui if (CC_UNLIKELY(polyLength < 3)) { 421512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#if DEBUG_SHADOW 422512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ALOGW("Invalid polygon length. No spot shadow!"); 423512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#endif 424512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui return; 425512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 426c50a03d78aaedd0003377e98710e7038bda330e9ztenghui OutlineData outlineData[polyLength]; 427c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 outlineCentroid; 428c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Calculate the projected outline for each polygon's vertices from the light center. 429c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 430c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // O Light 431c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // / 432c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // / 433c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // . Polygon vertex 434c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // / 435c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // / 436c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // O Outline vertices 437c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 438c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Ratio = (Poly - Outline) / (Light - Poly) 439c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Outline.x = Poly.x - Ratio * (Light.x - Poly.x) 440c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Outline's radius / Light's radius = Ratio 441c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 442c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Compute the last outline vertex to make sure we can get the normal and outline 443c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // in one single loop. 444c50a03d78aaedd0003377e98710e7038bda330e9ztenghui projectCasterToOutline(outlineData[polyLength - 1].position, lightCenter, 445c50a03d78aaedd0003377e98710e7038bda330e9ztenghui poly[polyLength - 1]); 446c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 447c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Take the outline's polygon, calculate the normal for each outline edge. 448c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int currentNormalIndex = polyLength - 1; 449c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int nextNormalIndex = 0; 450c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 451c50a03d78aaedd0003377e98710e7038bda330e9ztenghui for (int i = 0; i < polyLength; i++) { 452c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float ratioZ = projectCasterToOutline(outlineData[i].position, 453c50a03d78aaedd0003377e98710e7038bda330e9ztenghui lightCenter, poly[i]); 454c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outlineData[i].radius = ratioZ * lightSize; 455c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 456c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outlineData[currentNormalIndex].normal = ShadowTessellator::calculateNormal( 457c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outlineData[currentNormalIndex].position, 458c50a03d78aaedd0003377e98710e7038bda330e9ztenghui outlineData[nextNormalIndex].position); 459c50a03d78aaedd0003377e98710e7038bda330e9ztenghui currentNormalIndex = (currentNormalIndex + 1) % polyLength; 460c50a03d78aaedd0003377e98710e7038bda330e9ztenghui nextNormalIndex++; 461c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 462c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 463c50a03d78aaedd0003377e98710e7038bda330e9ztenghui projectCasterToOutline(outlineCentroid, lightCenter, polyCentroid); 464c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 465c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int penumbraIndex = 0; 466512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // Then each polygon's vertex produce at minmal 2 penumbra vertices. 467512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // Since the size can be dynamic here, we keep track of the size and update 468512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // the real size at the end. 469512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int allocatedPenumbraLength = 2 * polyLength + SPOT_MAX_EXTRA_CORNER_VERTEX_NUMBER; 470512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui Vector2 penumbra[allocatedPenumbraLength]; 471512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int totalExtraCornerSliceNumber = 0; 472c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 473c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 umbra[polyLength]; 474c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 475512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // When centroid is covered by all circles from outline, then we consider 476512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // the umbra is invalid, and we will tune down the shadow strength. 477c50a03d78aaedd0003377e98710e7038bda330e9ztenghui bool hasValidUmbra = true; 478512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // We need the minimal of RaitoVI to decrease the spot shadow strength accordingly. 479512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float minRaitoVI = FLT_MAX; 480c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 481c50a03d78aaedd0003377e98710e7038bda330e9ztenghui for (int i = 0; i < polyLength; i++) { 482c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Generate all the penumbra's vertices only using the (outline vertex + normal * radius) 483c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // There is no guarantee that the penumbra is still convex, but for 484c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // each outline vertex, it will connect to all its corresponding penumbra vertices as 485c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // triangle fans. And for neighber penumbra vertex, it will be a trapezoid. 486c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 487c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Penumbra Vertices marked as Pi 488c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Outline Vertices marked as Vi 489c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (P3) 490c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (P2) | ' (P4) 491c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (P1)' | | ' 492c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // ' | | ' 493c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (P0) ------------------------------------------------(P5) 494c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | (V0) |(V1) 495c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 496c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 497c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 498c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 499c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 500c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 501c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 502c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 503c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (V3)-----------------------------------(V2) 504c50a03d78aaedd0003377e98710e7038bda330e9ztenghui int preNormalIndex = (i + polyLength - 1) % polyLength; 505c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 506512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui const Vector2& previousNormal = outlineData[preNormalIndex].normal; 507512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui const Vector2& currentNormal = outlineData[i].normal; 508512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 509512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // Depending on how roundness we want for each corner, we can subdivide 510c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // further here and/or introduce some heuristic to decide how much the 511c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // subdivision should be. 512512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int currentExtraSliceNumber = ShadowTessellator::getExtraVertexNumber( 513512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui previousNormal, currentNormal, SPOT_CORNER_RADIANS_DIVISOR); 514c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 515512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int currentCornerSliceNumber = 1 + currentExtraSliceNumber; 516512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui totalExtraCornerSliceNumber += currentExtraSliceNumber; 517512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#if DEBUG_SHADOW 518512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ALOGD("currentExtraSliceNumber should be %d", currentExtraSliceNumber); 519512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ALOGD("currentCornerSliceNumber should be %d", currentCornerSliceNumber); 520512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ALOGD("totalCornerSliceNumber is %d", totalExtraCornerSliceNumber); 521512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#endif 522512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui if (CC_UNLIKELY(totalExtraCornerSliceNumber > SPOT_MAX_EXTRA_CORNER_VERTEX_NUMBER)) { 523512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui currentCornerSliceNumber = 1; 524512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 525512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui for (int k = 0; k <= currentCornerSliceNumber; k++) { 526512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui Vector2 avgNormal = 527512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui (previousNormal * (currentCornerSliceNumber - k) + currentNormal * k) / 528512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui currentCornerSliceNumber; 529512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui avgNormal.normalize(); 530512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui penumbra[penumbraIndex++] = outlineData[i].position + 531512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui avgNormal * outlineData[i].radius; 532512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 533c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 534c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 535c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Compute the umbra by the intersection from the outline's centroid! 536c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 537c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // (V) ------------------------------------ 538c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' | 539c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' | 540c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' (I) | 541c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' | 542c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | ' (C) | 543c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 544c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 545c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 546c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // | | 547c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // ------------------------------------ 548c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 549c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Connect a line b/t the outline vertex (V) and the centroid (C), it will 550c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // intersect with the outline vertex's circle at point (I). 551c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Now, ratioVI = VI / VC, ratioIC = IC / VC 552c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // Then the intersetion point can be computed as Ixy = Vxy * ratioIC + Cxy * ratioVI; 553c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // 554512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // When all of the outline circles cover the the outline centroid, (like I is 555c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // on the other side of C), there is no real umbra any more, so we just fake 556c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // a small area around the centroid as the umbra, and tune down the spot 557c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // shadow's umbra strength to simulate the effect the whole shadow will 558c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // become lighter in this case. 559c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // The ratio can be simulated by using the inverse of maximum of ratioVI for 560c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // all (V). 561512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float distOutline = (outlineData[i].position - outlineCentroid).length(); 5623bd3fa1f1d437e22aee35381a559dcee15a437ddztenghui if (CC_UNLIKELY(distOutline == 0)) { 563c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // If the outline has 0 area, then there is no spot shadow anyway. 564c50a03d78aaedd0003377e98710e7038bda330e9ztenghui ALOGW("Outline has 0 area, no spot shadow!"); 565c50a03d78aaedd0003377e98710e7038bda330e9ztenghui return; 566c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 567512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 568512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float ratioVI = outlineData[i].radius / distOutline; 569512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui minRaitoVI = MathUtils::min(minRaitoVI, ratioVI); 570512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui if (ratioVI >= (1 - FAKE_UMBRA_SIZE_RATIO)) { 571512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ratioVI = (1 - FAKE_UMBRA_SIZE_RATIO); 572c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 573c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // When we know we don't have valid umbra, don't bother to compute the 574c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // values below. But we can't skip the loop yet since we want to know the 575c50a03d78aaedd0003377e98710e7038bda330e9ztenghui // maximum ratio. 576512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float ratioIC = 1 - ratioVI; 577512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui umbra[i] = outlineData[i].position * ratioIC + outlineCentroid * ratioVI; 578c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 579c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 580512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui hasValidUmbra = (minRaitoVI <= 1.0); 581c50a03d78aaedd0003377e98710e7038bda330e9ztenghui float shadowStrengthScale = 1.0; 582c50a03d78aaedd0003377e98710e7038bda330e9ztenghui if (!hasValidUmbra) { 583512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#if DEBUG_SHADOW 584c50a03d78aaedd0003377e98710e7038bda330e9ztenghui ALOGW("The object is too close to the light or too small, no real umbra!"); 585512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#endif 586c50a03d78aaedd0003377e98710e7038bda330e9ztenghui for (int i = 0; i < polyLength; i++) { 587c50a03d78aaedd0003377e98710e7038bda330e9ztenghui umbra[i] = outlineData[i].position * FAKE_UMBRA_SIZE_RATIO + 588512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui outlineCentroid * (1 - FAKE_UMBRA_SIZE_RATIO); 589c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 590512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui shadowStrengthScale = 1.0 / minRaitoVI; 591c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 592c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 593512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int penumbraLength = penumbraIndex; 594512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int umbraLength = polyLength; 595512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 596c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#if DEBUG_SHADOW 597512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ALOGD("penumbraLength is %d , allocatedPenumbraLength %d", penumbraLength, allocatedPenumbraLength); 598c50a03d78aaedd0003377e98710e7038bda330e9ztenghui dumpPolygon(poly, polyLength, "input poly"); 599c50a03d78aaedd0003377e98710e7038bda330e9ztenghui dumpPolygon(penumbra, penumbraLength, "penumbra"); 600512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui dumpPolygon(umbra, umbraLength, "umbra"); 601c50a03d78aaedd0003377e98710e7038bda330e9ztenghui ALOGD("hasValidUmbra is %d and shadowStrengthScale is %f", hasValidUmbra, shadowStrengthScale); 602c50a03d78aaedd0003377e98710e7038bda330e9ztenghui#endif 603c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 604512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // The penumbra and umbra needs to be in convex shape to keep consistency 605512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // and quality. 606512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // Since we are still shooting rays to penumbra, it needs to be convex. 607512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // Umbra can be represented as a fan from the centroid, but visually umbra 608512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // looks nicer when it is convex. 609512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui Vector2 finalUmbra[umbraLength]; 610512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui Vector2 finalPenumbra[penumbraLength]; 611512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int finalUmbraLength = hull(umbra, umbraLength, finalUmbra); 612512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int finalPenumbraLength = hull(penumbra, penumbraLength, finalPenumbra); 613512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 614512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui generateTriangleStrip(isCasterOpaque, shadowStrengthScale, finalPenumbra, 615512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui finalPenumbraLength, finalUmbra, finalUmbraLength, poly, polyLength, 616512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui shadowTriangleStrip, outlineCentroid); 617512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 618c50a03d78aaedd0003377e98710e7038bda330e9ztenghui} 619c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 6207b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui/** 621512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * This is only for experimental purpose. 622512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * After intersections are calculated, we could smooth the polygon if needed. 623512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * So far, we don't think it is more appealing yet. 6247b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui * 625512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @param level The level of smoothness. 626512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @param rays The total number of rays. 627512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * @param rayDist (In and Out) The distance for each ray. 628512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * 629512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui */ 630512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghuivoid SpotShadow::smoothPolygon(int level, int rays, float* rayDist) { 631512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui for (int k = 0; k < level; k++) { 632512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui for (int i = 0; i < rays; i++) { 633512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float p1 = rayDist[(rays - 1 + i) % rays]; 634512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float p2 = rayDist[i]; 635512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui float p3 = rayDist[(i + 1) % rays]; 636512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui rayDist[i] = (p1 + p2 * 2 + p3) / 4; 637512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 638512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 639512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 640512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 641d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// Index pair is meant for storing the tessellation information for the penumbra 642d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// area. One index must come from exterior tangent of the circles, the other one 643d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// must come from the interior tangent of the circles. 644d2dcd6fded3a036f334a88bf9593398833f2919aztenghuistruct IndexPair { 645d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int outerIndex; 646d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int innerIndex; 647d2dcd6fded3a036f334a88bf9593398833f2919aztenghui}; 6487b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 649d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// For one penumbra vertex, find the cloest umbra vertex and return its index. 650d2dcd6fded3a036f334a88bf9593398833f2919aztenghuiinline int getClosestUmbraIndex(const Vector2& pivot, const Vector2* polygon, int polygonLength) { 651d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float minLengthSquared = FLT_MAX; 652d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int resultIndex = -1; 653d2dcd6fded3a036f334a88bf9593398833f2919aztenghui bool hasDecreased = false; 654d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Starting with some negative offset, assuming both umbra and penumbra are starting 655d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // at the same angle, this can help to find the result faster. 656d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Normally, loop 3 times, we can find the closest point. 657d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int offset = polygonLength - 2; 658d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < polygonLength; i++) { 659d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int currentIndex = (i + offset) % polygonLength; 660d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float currentLengthSquared = (pivot - polygon[currentIndex]).lengthSquared(); 661d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (currentLengthSquared < minLengthSquared) { 662d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (minLengthSquared != FLT_MAX) { 663d2dcd6fded3a036f334a88bf9593398833f2919aztenghui hasDecreased = true; 664d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 665d2dcd6fded3a036f334a88bf9593398833f2919aztenghui minLengthSquared = currentLengthSquared; 666d2dcd6fded3a036f334a88bf9593398833f2919aztenghui resultIndex = currentIndex; 667d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } else if (currentLengthSquared > minLengthSquared && hasDecreased) { 668d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Early break b/c we have found the closet one and now the length 669d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // is increasing again. 670d2dcd6fded3a036f334a88bf9593398833f2919aztenghui break; 671512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 672512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 673d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if(resultIndex == -1) { 674d2dcd6fded3a036f334a88bf9593398833f2919aztenghui ALOGE("resultIndex is -1, the polygon must be invalid!"); 675d2dcd6fded3a036f334a88bf9593398833f2919aztenghui resultIndex = 0; 676d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 677d2dcd6fded3a036f334a88bf9593398833f2919aztenghui return resultIndex; 678512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 6797b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 6803932063bc75dc1e4efc2c428ca208d2e2290164dztenghui// Allow some epsilon here since the later ray intersection did allow for some small 6813932063bc75dc1e4efc2c428ca208d2e2290164dztenghui// floating point error, when the intersection point is slightly outside the segment. 682d2dcd6fded3a036f334a88bf9593398833f2919aztenghuiinline bool sameDirections(bool isPositiveCross, float a, float b) { 683d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (isPositiveCross) { 6843932063bc75dc1e4efc2c428ca208d2e2290164dztenghui return a >= -EPSILON && b >= -EPSILON; 685d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } else { 6863932063bc75dc1e4efc2c428ca208d2e2290164dztenghui return a <= EPSILON && b <= EPSILON; 687512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 688512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 689512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 690d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// Find the right polygon edge to shoot the ray at. 691d2dcd6fded3a036f334a88bf9593398833f2919aztenghuiinline int findPolyIndex(bool isPositiveCross, int startPolyIndex, const Vector2& umbraDir, 692d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const Vector2* polyToCentroid, int polyLength) { 693d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Make sure we loop with a bound. 694d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < polyLength; i++) { 695d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int currentIndex = (i + startPolyIndex) % polyLength; 696d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const Vector2& currentToCentroid = polyToCentroid[currentIndex]; 697d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const Vector2& nextToCentroid = polyToCentroid[(currentIndex + 1) % polyLength]; 698d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 699d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float currentCrossUmbra = currentToCentroid.cross(umbraDir); 700d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float umbraCrossNext = umbraDir.cross(nextToCentroid); 701d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (sameDirections(isPositiveCross, currentCrossUmbra, umbraCrossNext)) { 702512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#if DEBUG_SHADOW 703d2dcd6fded3a036f334a88bf9593398833f2919aztenghui ALOGD("findPolyIndex loop %d times , index %d", i, currentIndex ); 704512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#endif 705d2dcd6fded3a036f334a88bf9593398833f2919aztenghui return currentIndex; 706512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 707512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 708d2dcd6fded3a036f334a88bf9593398833f2919aztenghui LOG_ALWAYS_FATAL("Can't find the right polygon's edge from startPolyIndex %d", startPolyIndex); 709d2dcd6fded3a036f334a88bf9593398833f2919aztenghui return -1; 710512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 711512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 712d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// Generate the index pair for penumbra / umbra vertices, and more penumbra vertices 713d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// if needed. 714d2dcd6fded3a036f334a88bf9593398833f2919aztenghuiinline void genNewPenumbraAndPairWithUmbra(const Vector2* penumbra, int penumbraLength, 715d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const Vector2* umbra, int umbraLength, Vector2* newPenumbra, int& newPenumbraIndex, 716d2dcd6fded3a036f334a88bf9593398833f2919aztenghui IndexPair* verticesPair, int& verticesPairIndex) { 717d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // In order to keep everything in just one loop, we need to pre-compute the 718d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // closest umbra vertex for the last penumbra vertex. 719d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int previousClosestUmbraIndex = getClosestUmbraIndex(penumbra[penumbraLength - 1], 720d2dcd6fded3a036f334a88bf9593398833f2919aztenghui umbra, umbraLength); 721d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < penumbraLength; i++) { 722d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const Vector2& currentPenumbraVertex = penumbra[i]; 723d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // For current penumbra vertex, starting from previousClosestUmbraIndex, 724d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // then check the next one until the distance increase. 725d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // The last one before the increase is the umbra vertex we need to pair with. 7263932063bc75dc1e4efc2c428ca208d2e2290164dztenghui float currentLengthSquared = 7273932063bc75dc1e4efc2c428ca208d2e2290164dztenghui (currentPenumbraVertex - umbra[previousClosestUmbraIndex]).lengthSquared(); 7283932063bc75dc1e4efc2c428ca208d2e2290164dztenghui int currentClosestUmbraIndex = previousClosestUmbraIndex; 729d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int indexDelta = 0; 730d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int j = 1; j < umbraLength; j++) { 731d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int newUmbraIndex = (previousClosestUmbraIndex + j) % umbraLength; 732d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float newLengthSquared = (currentPenumbraVertex - umbra[newUmbraIndex]).lengthSquared(); 733d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (newLengthSquared > currentLengthSquared) { 7343932063bc75dc1e4efc2c428ca208d2e2290164dztenghui // currentClosestUmbraIndex is the umbra vertex's index which has 7353932063bc75dc1e4efc2c428ca208d2e2290164dztenghui // currently found smallest distance, so we can simply break here. 736512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui break; 737512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } else { 738d2dcd6fded3a036f334a88bf9593398833f2919aztenghui currentLengthSquared = newLengthSquared; 739d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexDelta++; 7403932063bc75dc1e4efc2c428ca208d2e2290164dztenghui currentClosestUmbraIndex = newUmbraIndex; 74150ecf849cb7ccc3482517b74d2214b347927791eztenghui } 74250ecf849cb7ccc3482517b74d2214b347927791eztenghui } 743d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 744d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (indexDelta > 1) { 745d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // For those umbra don't have penumbra, generate new penumbra vertices by interpolation. 746d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 747d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Assuming Pi for penumbra vertices, and Ui for umbra vertices. 748d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // In the case like below P1 paired with U1 and P2 paired with U5. 749d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // U2 to U4 are unpaired umbra vertices. 750d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 751d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // P1 P2 752d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 753d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // U1 U2 U3 U4 U5 754d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 755d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // We will need to generate 3 more penumbra vertices P1.1, P1.2, P1.3 756d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // to pair with U2 to U4. 757d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 758d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // P1 P1.1 P1.2 P1.3 P2 759d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | | | | 760d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // U1 U2 U3 U4 U5 761d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 762d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // That distance ratio b/t Ui to U1 and Ui to U5 decides its paired penumbra 763d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // vertex's location. 764d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int newPenumbraNumber = indexDelta - 1; 765d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 766d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float accumulatedDeltaLength[newPenumbraNumber]; 767d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float totalDeltaLength = 0; 768d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 769d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // To save time, cache the previous umbra vertex info outside the loop 770d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // and update each loop. 771d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 previousClosestUmbra = umbra[previousClosestUmbraIndex]; 772d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 skippedUmbra; 773d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Use umbra data to precompute the length b/t unpaired umbra vertices, 774d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // and its ratio against the total length. 775d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int k = 0; k < indexDelta; k++) { 776d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int skippedUmbraIndex = (previousClosestUmbraIndex + k + 1) % umbraLength; 777d2dcd6fded3a036f334a88bf9593398833f2919aztenghui skippedUmbra = umbra[skippedUmbraIndex]; 778d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float currentDeltaLength = (skippedUmbra - previousClosestUmbra).length(); 779d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 780d2dcd6fded3a036f334a88bf9593398833f2919aztenghui totalDeltaLength += currentDeltaLength; 781d2dcd6fded3a036f334a88bf9593398833f2919aztenghui accumulatedDeltaLength[k] = totalDeltaLength; 782d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 783d2dcd6fded3a036f334a88bf9593398833f2919aztenghui previousClosestUmbra = skippedUmbra; 784512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 785512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 786d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const Vector2& previousPenumbra = penumbra[(i + penumbraLength - 1) % penumbraLength]; 787d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Then for each unpaired umbra vertex, create a new penumbra by the ratio, 788d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // and pair them togehter. 789d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int k = 0; k < newPenumbraNumber; k++) { 790d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float weightForCurrentPenumbra = 1.0f; 791d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (totalDeltaLength != 0.0f) { 792d2dcd6fded3a036f334a88bf9593398833f2919aztenghui weightForCurrentPenumbra = accumulatedDeltaLength[k] / totalDeltaLength; 793d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 794d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float weightForPreviousPenumbra = 1.0f - weightForCurrentPenumbra; 795512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 796d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 interpolatedPenumbra = currentPenumbraVertex * weightForCurrentPenumbra + 797d2dcd6fded3a036f334a88bf9593398833f2919aztenghui previousPenumbra * weightForPreviousPenumbra; 798512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 799d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int skippedUmbraIndex = (previousClosestUmbraIndex + k + 1) % umbraLength; 800d2dcd6fded3a036f334a88bf9593398833f2919aztenghui verticesPair[verticesPairIndex++] = {newPenumbraIndex, skippedUmbraIndex}; 801d2dcd6fded3a036f334a88bf9593398833f2919aztenghui newPenumbra[newPenumbraIndex++] = interpolatedPenumbra; 802512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 803512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 804d2dcd6fded3a036f334a88bf9593398833f2919aztenghui verticesPair[verticesPairIndex++] = {newPenumbraIndex, currentClosestUmbraIndex}; 805d2dcd6fded3a036f334a88bf9593398833f2919aztenghui newPenumbra[newPenumbraIndex++] = currentPenumbraVertex; 8067b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 807d2dcd6fded3a036f334a88bf9593398833f2919aztenghui previousClosestUmbraIndex = currentClosestUmbraIndex; 808512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 809512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 810512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 811d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// Precompute all the polygon's vector, return true if the reference cross product is positive. 812d2dcd6fded3a036f334a88bf9593398833f2919aztenghuiinline bool genPolyToCentroid(const Vector2* poly2d, int polyLength, 813d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const Vector2& centroid, Vector2* polyToCentroid) { 814d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int j = 0; j < polyLength; j++) { 815d2dcd6fded3a036f334a88bf9593398833f2919aztenghui polyToCentroid[j] = poly2d[j] - centroid; 8163932063bc75dc1e4efc2c428ca208d2e2290164dztenghui // Normalize these vectors such that we can use epsilon comparison after 8173932063bc75dc1e4efc2c428ca208d2e2290164dztenghui // computing their cross products with another normalized vector. 8183932063bc75dc1e4efc2c428ca208d2e2290164dztenghui polyToCentroid[j].normalize(); 8197b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui } 820d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float refCrossProduct = 0; 821d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int j = 0; j < polyLength; j++) { 822d2dcd6fded3a036f334a88bf9593398833f2919aztenghui refCrossProduct = polyToCentroid[j].cross(polyToCentroid[(j + 1) % polyLength]); 823d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (refCrossProduct != 0) { 824d2dcd6fded3a036f334a88bf9593398833f2919aztenghui break; 825d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 826512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 827d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 828d2dcd6fded3a036f334a88bf9593398833f2919aztenghui return refCrossProduct > 0; 8297b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui} 8307b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui 831d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// For one umbra vertex, shoot an ray from centroid to it. 832d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// If the ray hit the polygon first, then return the intersection point as the 833d2dcd6fded3a036f334a88bf9593398833f2919aztenghui// closer vertex. 834d2dcd6fded3a036f334a88bf9593398833f2919aztenghuiinline Vector2 getCloserVertex(const Vector2& umbraVertex, const Vector2& centroid, 835d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const Vector2* poly2d, int polyLength, const Vector2* polyToCentroid, 836d2dcd6fded3a036f334a88bf9593398833f2919aztenghui bool isPositiveCross, int& previousPolyIndex) { 837d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 umbraToCentroid = umbraVertex - centroid; 838d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float distanceToUmbra = umbraToCentroid.length(); 839d2dcd6fded3a036f334a88bf9593398833f2919aztenghui umbraToCentroid = umbraToCentroid / distanceToUmbra; 840d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 841d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // previousPolyIndex is updated for each item such that we can minimize the 842d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // looping inside findPolyIndex(); 843d2dcd6fded3a036f334a88bf9593398833f2919aztenghui previousPolyIndex = findPolyIndex(isPositiveCross, previousPolyIndex, 844d2dcd6fded3a036f334a88bf9593398833f2919aztenghui umbraToCentroid, polyToCentroid, polyLength); 845d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 846d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float dx = umbraToCentroid.x; 847d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float dy = umbraToCentroid.y; 848d2dcd6fded3a036f334a88bf9593398833f2919aztenghui float distanceToIntersectPoly = rayIntersectPoints(centroid, dx, dy, 849d2dcd6fded3a036f334a88bf9593398833f2919aztenghui poly2d[previousPolyIndex], poly2d[(previousPolyIndex + 1) % polyLength]); 850d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (distanceToIntersectPoly < 0) { 851d2dcd6fded3a036f334a88bf9593398833f2919aztenghui distanceToIntersectPoly = 0; 852512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 853f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 854d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Pick the closer one as the occluded area vertex. 855d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 closerVertex; 856d2dcd6fded3a036f334a88bf9593398833f2919aztenghui if (distanceToIntersectPoly < distanceToUmbra) { 857d2dcd6fded3a036f334a88bf9593398833f2919aztenghui closerVertex.x = centroid.x + dx * distanceToIntersectPoly; 858d2dcd6fded3a036f334a88bf9593398833f2919aztenghui closerVertex.y = centroid.y + dy * distanceToIntersectPoly; 859d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } else { 860d2dcd6fded3a036f334a88bf9593398833f2919aztenghui closerVertex = umbraVertex; 861512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 862512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 863d2dcd6fded3a036f334a88bf9593398833f2919aztenghui return closerVertex; 864512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 865512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 866512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui/** 867512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui * Generate a triangle strip given two convex polygon 868512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui**/ 869512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghuivoid SpotShadow::generateTriangleStrip(bool isCasterOpaque, float shadowStrengthScale, 870512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui Vector2* penumbra, int penumbraLength, Vector2* umbra, int umbraLength, 871512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui const Vector3* poly, int polyLength, VertexBuffer& shadowTriangleStrip, 872512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui const Vector2& centroid) { 873512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui bool hasOccludedUmbraArea = false; 874512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui Vector2 poly2d[polyLength]; 875f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 876512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui if (isCasterOpaque) { 877512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui for (int i = 0; i < polyLength; i++) { 878512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui poly2d[i].x = poly[i].x; 879512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui poly2d[i].y = poly[i].y; 880512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 881512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // Make sure the centroid is inside the umbra, otherwise, fall back to the 882512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // approach as if there is no occluded umbra area. 883512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui if (testPointInsidePolygon(centroid, poly2d, polyLength)) { 884512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui hasOccludedUmbraArea = true; 885512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 886512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 887512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 888d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // For each penumbra vertex, find its corresponding closest umbra vertex index. 889d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 890d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Penumbra Vertices marked as Pi 891d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Umbra Vertices marked as Ui 892d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // (P3) 893d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // (P2) | ' (P4) 894d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // (P1)' | | ' 895d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // ' | | ' 896d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // (P0) ------------------------------------------------(P5) 897d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | (U0) |(U1) 898d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 899d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | |(U2) (P5.1) 900d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 901d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 902d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 903d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 904d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 905d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // | | 906d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // (U4)-----------------------------------(U3) (P6) 907d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 908d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // At least, like P0, P1, P2, they will find the matching umbra as U0. 909d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // If we jump over some umbra vertex without matching penumbra vertex, then 910d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // we will generate some new penumbra vertex by interpolation. Like P6 is 911d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // matching U3, but U2 is not matched with any penumbra vertex. 912d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // So interpolate P5.1 out and match U2. 913d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // In this way, every umbra vertex will have a matching penumbra vertex. 914d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 915d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // The total pair number can be as high as umbraLength + penumbraLength. 916d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const int maxNewPenumbraLength = umbraLength + penumbraLength; 917d2dcd6fded3a036f334a88bf9593398833f2919aztenghui IndexPair verticesPair[maxNewPenumbraLength]; 918d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int verticesPairIndex = 0; 919d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 920d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Cache all the existing penumbra vertices and newly interpolated vertices into a 921d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // a new array. 922d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 newPenumbra[maxNewPenumbraLength]; 923d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int newPenumbraIndex = 0; 924d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 925d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // For each penumbra vertex, find its closet umbra vertex by comparing the 926d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // neighbor umbra vertices. 927d2dcd6fded3a036f334a88bf9593398833f2919aztenghui genNewPenumbraAndPairWithUmbra(penumbra, penumbraLength, umbra, umbraLength, newPenumbra, 928d2dcd6fded3a036f334a88bf9593398833f2919aztenghui newPenumbraIndex, verticesPair, verticesPairIndex); 929d2dcd6fded3a036f334a88bf9593398833f2919aztenghui ShadowTessellator::checkOverflow(verticesPairIndex, maxNewPenumbraLength, "Spot pair"); 930d2dcd6fded3a036f334a88bf9593398833f2919aztenghui ShadowTessellator::checkOverflow(newPenumbraIndex, maxNewPenumbraLength, "Spot new penumbra"); 931d2dcd6fded3a036f334a88bf9593398833f2919aztenghui#if DEBUG_SHADOW 932d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < umbraLength; i++) { 933d2dcd6fded3a036f334a88bf9593398833f2919aztenghui ALOGD("umbra i %d, [%f, %f]", i, umbra[i].x, umbra[i].y); 934d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 935d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < newPenumbraIndex; i++) { 936d2dcd6fded3a036f334a88bf9593398833f2919aztenghui ALOGD("new penumbra i %d, [%f, %f]", i, newPenumbra[i].x, newPenumbra[i].y); 937d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 938d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < verticesPairIndex; i++) { 939d2dcd6fded3a036f334a88bf9593398833f2919aztenghui ALOGD("index i %d, [%d, %d]", i, verticesPair[i].outerIndex, verticesPair[i].innerIndex); 940512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 941d2dcd6fded3a036f334a88bf9593398833f2919aztenghui#endif 942512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 943d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // For the size of vertex buffer, we need 3 rings, one has newPenumbraSize, 944d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // one has umbraLength, the last one has at most umbraLength. 945d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // 946d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // For the size of index buffer, the umbra area needs (2 * umbraLength + 2). 947d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // The penumbra one can vary a bit, but it is bounded by (2 * verticesPairIndex + 2). 948d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // And 2 more for jumping between penumbra to umbra. 949d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const int newPenumbraLength = newPenumbraIndex; 950d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const int totalVertexCount = newPenumbraLength + umbraLength * 2; 951d2dcd6fded3a036f334a88bf9593398833f2919aztenghui const int totalIndexCount = 2 * umbraLength + 2 * verticesPairIndex + 6; 952512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui AlphaVertex* shadowVertices = 953512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui shadowTriangleStrip.alloc<AlphaVertex>(totalVertexCount); 954512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui uint16_t* indexBuffer = 955512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui shadowTriangleStrip.allocIndices<uint16_t>(totalIndexCount); 956512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int vertexBufferIndex = 0; 957d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int indexBufferIndex = 0; 958512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 959d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Fill the IB and VB for the penumbra area. 960d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < newPenumbraLength; i++) { 961d2dcd6fded3a036f334a88bf9593398833f2919aztenghui AlphaVertex::set(&shadowVertices[vertexBufferIndex++], newPenumbra[i].x, 962d2dcd6fded3a036f334a88bf9593398833f2919aztenghui newPenumbra[i].y, 0.0f); 963d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 964d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < umbraLength; i++) { 965d2dcd6fded3a036f334a88bf9593398833f2919aztenghui AlphaVertex::set(&shadowVertices[vertexBufferIndex++], umbra[i].x, umbra[i].y, 966d2dcd6fded3a036f334a88bf9593398833f2919aztenghui M_PI); 967512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 968512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 969d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < verticesPairIndex; i++) { 970d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = verticesPair[i].outerIndex; 971d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // All umbra index need to be offseted by newPenumbraSize. 972d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = verticesPair[i].innerIndex + newPenumbraLength; 973d2dcd6fded3a036f334a88bf9593398833f2919aztenghui } 974d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = verticesPair[0].outerIndex; 975d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = verticesPair[0].innerIndex + newPenumbraLength; 976d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 977d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Now fill the IB and VB for the umbra area. 978d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // First duplicated the index from previous strip and the first one for the 979d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // degenerated triangles. 980d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex] = indexBuffer[indexBufferIndex - 1]; 981d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBufferIndex++; 982d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = newPenumbraLength + 0; 983d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Save the first VB index for umbra area in order to close the loop. 984d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int savedStartIndex = vertexBufferIndex; 985512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 986512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui if (hasOccludedUmbraArea) { 987d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Precompute all the polygon's vector, and the reference cross product, 988d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // in order to find the right polygon edge for the ray to intersect. 989d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 polyToCentroid[polyLength]; 990d2dcd6fded3a036f334a88bf9593398833f2919aztenghui bool isPositiveCross = genPolyToCentroid(poly2d, polyLength, centroid, polyToCentroid); 991d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 992d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Because both the umbra and polygon are going in the same direction, 993d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // we can save the previous polygon index to make sure we have less polygon 994d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // vertex to compute for each ray. 995d2dcd6fded3a036f334a88bf9593398833f2919aztenghui int previousPolyIndex = 0; 996d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < umbraLength; i++) { 997d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Shoot a ray from centroid to each umbra vertices and pick the one with 998d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // shorter distance to the centroid, b/t the umbra vertex or the intersection point. 999d2dcd6fded3a036f334a88bf9593398833f2919aztenghui Vector2 closerVertex = getCloserVertex(umbra[i], centroid, poly2d, polyLength, 1000d2dcd6fded3a036f334a88bf9593398833f2919aztenghui polyToCentroid, isPositiveCross, previousPolyIndex); 1001d2dcd6fded3a036f334a88bf9593398833f2919aztenghui 1002d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // We already stored the umbra vertices, just need to add the occlued umbra's ones. 1003d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = newPenumbraLength + i; 1004d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = vertexBufferIndex; 1005d2dcd6fded3a036f334a88bf9593398833f2919aztenghui AlphaVertex::set(&shadowVertices[vertexBufferIndex++], 1006d2dcd6fded3a036f334a88bf9593398833f2919aztenghui closerVertex.x, closerVertex.y, M_PI); 1007512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 1008512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } else { 1009d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // If there is no occluded umbra at all, then draw the triangle fan 1010d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // starting from the centroid to all umbra vertices. 1011512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui int lastCentroidIndex = vertexBufferIndex; 1012512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui AlphaVertex::set(&shadowVertices[vertexBufferIndex++], centroid.x, 1013d2dcd6fded3a036f334a88bf9593398833f2919aztenghui centroid.y, M_PI); 1014d2dcd6fded3a036f334a88bf9593398833f2919aztenghui for (int i = 0; i < umbraLength; i++) { 1015d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = newPenumbraLength + i; 1016512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui indexBuffer[indexBufferIndex++] = lastCentroidIndex; 1017512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 1018512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui } 1019d2dcd6fded3a036f334a88bf9593398833f2919aztenghui // Closing the umbra area triangle's loop here. 1020d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = newPenumbraLength; 1021d2dcd6fded3a036f334a88bf9593398833f2919aztenghui indexBuffer[indexBufferIndex++] = savedStartIndex; 1022512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 1023512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui // At the end, update the real index and vertex buffer size. 1024512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui shadowTriangleStrip.updateVertexCount(vertexBufferIndex); 1025512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui shadowTriangleStrip.updateIndexCount(indexBufferIndex); 1026512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ShadowTessellator::checkOverflow(vertexBufferIndex, totalVertexCount, "Spot Vertex Buffer"); 1027512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui ShadowTessellator::checkOverflow(indexBufferIndex, totalIndexCount, "Spot Index Buffer"); 1028512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 1029512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui shadowTriangleStrip.setMode(VertexBuffer::kIndices); 1030512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui shadowTriangleStrip.computeBounds<AlphaVertex>(); 1031512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui} 1032512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 1033512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#if DEBUG_SHADOW 1034512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui 1035512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui#define TEST_POINT_NUMBER 128 1036f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 1037f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Calculate the bounds for generating random test points. 1038f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 1039f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuivoid SpotShadow::updateBound(const Vector2 inVector, Vector2& lowerBound, 1040512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui Vector2& upperBound) { 1041f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.x < lowerBound.x) { 1042f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lowerBound.x = inVector.x; 1043f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1044f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1045f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.y < lowerBound.y) { 1046f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui lowerBound.y = inVector.y; 1047f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1048f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1049f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.x > upperBound.x) { 1050f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui upperBound.x = inVector.x; 1051f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1052f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1053f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (inVector.y > upperBound.y) { 1054f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui upperBound.y = inVector.y; 1055f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1056f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 1057f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1058f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 1059f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * For debug purpose, when things go wrong, dump the whole polygon data. 1060f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 1061c50a03d78aaedd0003377e98710e7038bda330e9ztenghuivoid SpotShadow::dumpPolygon(const Vector2* poly, int polyLength, const char* polyName) { 1062c50a03d78aaedd0003377e98710e7038bda330e9ztenghui for (int i = 0; i < polyLength; i++) { 1063c50a03d78aaedd0003377e98710e7038bda330e9ztenghui ALOGD("polygon %s i %d x %f y %f", polyName, i, poly[i].x, poly[i].y); 1064c50a03d78aaedd0003377e98710e7038bda330e9ztenghui } 1065c50a03d78aaedd0003377e98710e7038bda330e9ztenghui} 1066c50a03d78aaedd0003377e98710e7038bda330e9ztenghui 1067c50a03d78aaedd0003377e98710e7038bda330e9ztenghui/** 1068c50a03d78aaedd0003377e98710e7038bda330e9ztenghui * For debug purpose, when things go wrong, dump the whole polygon data. 1069c50a03d78aaedd0003377e98710e7038bda330e9ztenghui */ 1070c50a03d78aaedd0003377e98710e7038bda330e9ztenghuivoid SpotShadow::dumpPolygon(const Vector3* poly, int polyLength, const char* polyName) { 1071f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < polyLength; i++) { 1072f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui ALOGD("polygon %s i %d x %f y %f", polyName, i, poly[i].x, poly[i].y); 1073f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1074f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 1075f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1076f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 1077f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether the polygon is convex. 1078f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 1079f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuibool SpotShadow::testConvex(const Vector2* polygon, int polygonLength, 1080f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui const char* name) { 1081f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool isConvex = true; 1082f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < polygonLength; i++) { 1083f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 start = polygon[i]; 1084f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 middle = polygon[(i + 1) % polygonLength]; 1085f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 end = polygon[(i + 2) % polygonLength]; 1086f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 10879122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float delta = (float(middle.x) - start.x) * (float(end.y) - start.y) - 10889122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui (float(middle.y) - start.y) * (float(end.x) - start.x); 1089f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool isCCWOrCoLinear = (delta >= EPSILON); 1090f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1091f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (isCCWOrCoLinear) { 109250ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("(Error Type 2): polygon (%s) is not a convex b/c start (x %f, y %f)," 1093f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui "middle (x %f, y %f) and end (x %f, y %f) , delta is %f !!!", 1094f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui name, start.x, start.y, middle.x, middle.y, end.x, end.y, delta); 1095f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui isConvex = false; 1096f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui break; 1097f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1098f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1099f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui return isConvex; 1100f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 1101f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1102f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui/** 1103f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Test whether or not the polygon (intersection) is within the 2 input polygons. 1104f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * Using Marte Carlo method, we generate a random point, and if it is inside the 1105f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui * intersection, then it must be inside both source polygons. 1106f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui */ 1107f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghuivoid SpotShadow::testIntersection(const Vector2* poly1, int poly1Length, 1108f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui const Vector2* poly2, int poly2Length, 1109f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui const Vector2* intersection, int intersectionLength) { 1110f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Find the min and max of x and y. 1111c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 lowerBound = {FLT_MAX, FLT_MAX}; 1112c50a03d78aaedd0003377e98710e7038bda330e9ztenghui Vector2 upperBound = {-FLT_MAX, -FLT_MAX}; 1113f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < poly1Length; i++) { 1114f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui updateBound(poly1[i], lowerBound, upperBound); 1115f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1116f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 0; i < poly2Length; i++) { 1117f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui updateBound(poly2[i], lowerBound, upperBound); 1118f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1119f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1120f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui bool dumpPoly = false; 1121f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int k = 0; k < TEST_POINT_NUMBER; k++) { 1122f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // Generate a random point between minX, minY and maxX, maxY. 11239122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float randomX = rand() / float(RAND_MAX); 11249122b1b168d2a74d51517ed7282f4d6a8adea367ztenghui float randomY = rand() / float(RAND_MAX); 1125f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1126f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 testPoint; 1127f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.x = lowerBound.x + randomX * (upperBound.x - lowerBound.x); 1128f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.y = lowerBound.y + randomY * (upperBound.y - lowerBound.y); 1129f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1130f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui // If the random point is in both poly 1 and 2, then it must be intersection. 1131f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (testPointInsidePolygon(testPoint, intersection, intersectionLength)) { 1132f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (!testPointInsidePolygon(testPoint, poly1, poly1Length)) { 1133f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPoly = true; 113450ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("(Error Type 1): one point (%f, %f) in the intersection is" 1135512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui " not in the poly1", 1136f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.x, testPoint.y); 1137f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1138f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1139f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (!testPointInsidePolygon(testPoint, poly2, poly2Length)) { 1140f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPoly = true; 114150ecf849cb7ccc3482517b74d2214b347927791eztenghui ALOGW("(Error Type 1): one point (%f, %f) in the intersection is" 1142512e643ce83b1d48ad9630a3622276f795cf4fb2ztenghui " not in the poly2", 1143f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui testPoint.x, testPoint.y); 1144f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1145f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1146f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1147f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1148f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui if (dumpPoly) { 1149f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(intersection, intersectionLength, "intersection"); 1150f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui for (int i = 1; i < intersectionLength; i++) { 1151f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui Vector2 delta = intersection[i] - intersection[i - 1]; 1152f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui ALOGD("Intersetion i, %d Vs i-1 is delta %f", i, delta.lengthSquared()); 1153f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1154f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 1155f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(poly1, poly1Length, "poly 1"); 1156f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui dumpPolygon(poly2, poly2Length, "poly 2"); 1157f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui } 1158f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui} 1159f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui#endif 1160f5ca8b4cb178008472e67fa0ae6a3e3fa75d7952ztenghui 11617b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui}; // namespace uirenderer 11627b4516e7ea552ad08d6e7277d311ef11bd8f12e8ztenghui}; // namespace android 1163