1 | #include "Bvh.h"
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2 | #include "Camera.h"
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3 | #include "Plane3.h"
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4 | #include "glInterface.h"
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5 | #include "Triangle3.h"
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6 | #include "SceneEntity.h"
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7 | #include "Geometry.h"
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8 | #include "RenderState.h"
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9 | #include "Material.h"
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10 | #include "gzstream.h"
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11 |
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12 | #include <queue>
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13 | #include <stack>
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14 | #include <fstream>
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15 | #include <iostream>
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16 | #include <iomanip>
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17 |
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18 |
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19 | #ifdef _CRT_SET
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20 | #define _CRTDBG_MAP_ALLOC
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21 | #include <stdlib.h>
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22 | #include <crtdbg.h>
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23 |
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24 | // redefine new operator
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25 | #define DEBUG_NEW new(_NORMAL_BLOCK, __FILE__, __LINE__)
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26 | #define new DEBUG_NEW
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27 | #endif
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28 |
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29 | #define INVALID_TEST ((unsigned int)-1)
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30 |
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31 | using namespace std;
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32 |
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33 | namespace CHCDemoEngine
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34 | {
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35 |
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36 | int BvhNode::sCurrentState = 0;
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37 |
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38 |
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39 | /*
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40 | 3 x---------x 2
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41 | |\ \
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42 | | \ \
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43 | | \ \
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44 | | 4 x---------x 5
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45 | | | |
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46 | 0 x | x 1 |
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47 | \ | |
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48 | \ | |
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49 | \| |
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50 | 7 x---------x 6
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51 | */
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52 |
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53 | static unsigned int sIndices[] =
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54 | {7, // degenerated
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55 | 7, 6, 4, 5, 3, 2, 0, 1,
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56 | 1, 4, // degenerated
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57 | 4, 3, 7, 0, 6, 1, 5, 2,
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58 | 2 // degenerated
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59 | };
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60 |
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61 |
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62 | const static int sNumIndicesPerBox = 20;
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63 |
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64 | /* Order of vertices
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65 | 0 = (0, 0, 0)
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66 | 1 = (1, 0, 0)
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67 | 2 = (1, 1, 0)
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68 | 3 = (0, 1, 0)
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69 | 4 = (0, 1, 1)
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70 | 5 = (1, 1, 1)
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71 | 6 = (1, 0, 1)
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72 | 7 = (0, 0, 1)
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73 | */
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74 |
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75 | static Plane3 sNearPlane;
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76 | static float sNear;
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77 | static Frustum sFrustum;
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78 |
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79 | /// these values are valid for all nodes
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80 | static int sClipPlaneAABBVertexIndices[12];
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81 |
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82 |
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83 | #define ALIGN_INDICES
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84 |
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85 | BvhNode::BvhNode(BvhNode *parent):
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86 | mParent(parent),
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87 | mAxis(-1),
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88 | mDepth(0),
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89 | mFirst(-1),
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90 | mLast(-1),
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91 | mNumTestNodes(1),
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92 | mTestNodesIdx(-1),
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93 | mIndicesPtr(-1),
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94 | mId(0),
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95 | mIsMaxDepthForVirtualLeaf(false),
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96 | mIsVirtualLeaf(false)
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97 | {
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98 | for (int i = 0; i < NUM_STATES; ++ i)
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99 | {
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100 | mPlaneMask[i] = 0;
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101 | mPreferredPlane[i]= 0;
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102 | mLastRenderedFrame[i] = -1;
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103 | }
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104 | }
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105 |
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106 |
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107 | BvhNode::~BvhNode()
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108 | {
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109 | }
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110 |
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111 |
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112 | void BvhNode::ResetVisibility()
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113 | {
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114 | for (int i = 0; i < NUM_STATES; ++ i)
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115 | {
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116 | mVisibility[i].Reset();
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117 | mLastRenderedFrame[i] = -1;
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118 | mPlaneMask[i] = 0;
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119 | mPreferredPlane[i]= 0;
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120 | }
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121 | }
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122 |
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123 |
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124 | void BvhNode::VisibilityInfo::Reset()
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125 | {
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126 | mIsVisible = false;
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127 | mAssumedVisibleFrameId = 0;
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128 | mLastVisitedFrame = -1;
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129 | mTimesInvisible = 0;
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130 | mIsFrustumCulled = false;
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131 | mIsNew = true;
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132 | mLastQueriedFrame = -1;
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133 | }
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134 |
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135 |
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136 | BvhInterior::~BvhInterior()
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137 | {
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138 | DEL_PTR(mBack);
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139 | DEL_PTR(mFront);
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140 | }
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141 |
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142 |
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143 | BvhLeaf::~BvhLeaf()
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144 | {
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145 | }
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146 |
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147 |
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148 | /**********************************************************/
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149 | /* class Bvh implementation */
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150 | /**********************************************************/
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151 |
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152 |
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153 |
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154 | inline AxisAlignedBox3 ComputeBoundingBox(SceneEntity **entities, int numEntities)
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155 | {
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156 | AxisAlignedBox3 box = entities[0]->GetWorldBoundingBox();
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157 |
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158 | for (int i = 1; i < numEntities; ++ i)
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159 | {
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160 | box.Include(entities[i]->GetWorldBoundingBox());
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161 | }
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162 |
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163 | return box;
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164 | }
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165 |
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166 |
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167 | Bvh::Bvh()
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168 | {
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169 | Init();
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170 | }
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171 |
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172 |
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173 | Bvh::Bvh(const SceneEntityContainer &entities)
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174 | {
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175 | Init();
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176 |
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177 | mGeometrySize = entities.size();
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178 | mGeometry = new SceneEntity*[mGeometrySize];
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179 |
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180 | SceneEntityContainer::const_iterator it, it_end = entities.end();
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181 |
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182 | int i = 0;
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183 | for (it = entities.begin(); it != it_end; ++ it, ++ i)
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184 | {
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185 | mGeometry[i] = (*it);
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186 | }
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187 | }
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188 |
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189 |
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190 | Bvh::~Bvh()
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191 | {
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192 | if (mVertices) delete [] mVertices;
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193 | if (mIndices) delete [] mIndices;
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194 | if (mTestIndices) delete [] mTestIndices;
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195 | if (mGeometry) delete [] mGeometry;
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196 |
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197 | if (mRoot) delete mRoot;
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198 | // delete vbo
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199 | glDeleteBuffersARB(1, &mVboId);
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200 | }
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201 |
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202 |
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203 | void Bvh::Init()
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204 | {
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205 | //mStaticRoot = NULL;
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206 | mDynamicRoot = NULL;
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207 | mRoot = NULL;
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208 |
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209 | mVertices = NULL;
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210 | mIndices = NULL;
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211 | mTestIndices = NULL;
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212 | mCurrentIndicesPtr = 0;
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213 | mNumNodes = 0;
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214 |
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215 | // nodes are tested using the subnodes from 3 levels below
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216 | mMaxDepthForTestingChildren = 3;
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217 | //mMaxDepthForTestingChildren = 4;
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218 |
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219 | // the ratio of area between node and subnodes where
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220 | // testing the subnodes as proxy is still considered feasable
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221 | mAreaRatioThreshold = 2.0f;
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222 | //mAreaRatioThreshold = 1.4f;
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223 |
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224 | mVboId = -1;
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225 |
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226 | mMaxDepthForDynamicBranch = 10;
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227 | }
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228 |
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229 |
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230 |
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231 |
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232 | //////////////////////
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233 | //-- functions that are used during the main traversal
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234 |
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235 | void Bvh::PullUpLastVisited(BvhNode *node, int frameId) const
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236 | {
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237 | BvhNode *parent = node->GetParent();
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238 |
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239 | while (parent && (parent->GetLastVisitedFrame() != frameId))
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240 | {
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241 | parent->SetLastVisitedFrame(frameId);
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242 | parent = parent->GetParent();
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243 | }
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244 | }
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245 |
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246 |
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247 | void Bvh::MakeParentsVisible(BvhNode *node)
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248 | {
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249 | BvhNode *parent = node->GetParent();
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250 |
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251 | while (parent && (!parent->IsVisible()))
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252 | {
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253 | parent->SetVisible(true);
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254 | parent = parent->GetParent();
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255 | }
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256 | }
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257 |
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258 |
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259 | ////////////////////////////////
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260 |
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261 | void Bvh::CollectLeaves(BvhNode *node, BvhLeafContainer &leaves)
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262 | {
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263 | stack<BvhNode *> tStack;
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264 | tStack.push(node);
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265 |
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266 | while (!tStack.empty())
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267 | {
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268 | BvhNode *node = tStack.top();
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269 |
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270 | tStack.pop();
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271 |
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272 | if (!node->IsLeaf())
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273 | {
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274 | BvhInterior *interior = static_cast<BvhInterior *>(node);
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275 |
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276 | tStack.push(interior->mFront);
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277 | tStack.push(interior->mBack);
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278 | }
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279 | else
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280 | {
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281 | leaves.push_back(static_cast<BvhLeaf *>(node));
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282 | }
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283 | }
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284 | }
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285 |
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286 |
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287 | void Bvh::CollectNodes(BvhNode *node, BvhNodeContainer &nodes)
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288 | {
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289 | stack<BvhNode *> tStack;
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290 |
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291 | tStack.push(node);
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292 |
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293 | while (!tStack.empty())
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294 | {
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295 | BvhNode *node = tStack.top();
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296 | tStack.pop();
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297 |
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298 | nodes.push_back(node);
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299 |
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300 | if (!node->IsLeaf())
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301 | {
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302 | BvhInterior *interior = static_cast<BvhInterior *>(node);
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303 |
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304 | tStack.push(interior->mFront);
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305 | tStack.push(interior->mBack);
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306 | }
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307 | }
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308 | }
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309 |
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310 |
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311 | typedef pair<BvhNode *, int> tPair;
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312 |
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313 | void Bvh::CollectNodes(BvhNode *root, BvhNodeContainer &nodes, int depth)
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314 | {
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315 | stack<tPair> tStack;
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316 | tStack.push(tPair(root, 0));
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317 |
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318 | while (!tStack.empty())
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319 | {
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320 | BvhNode *node = tStack.top().first;
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321 | const int d = tStack.top().second;
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322 |
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323 | tStack.pop();
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324 |
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325 | // found node in specified depth => take this node
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326 | if ((d == depth) || (node->IsLeaf()))
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327 | {
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328 | nodes.push_back(node);
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329 | }
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330 | else
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331 | {
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332 | BvhInterior *interior = static_cast<BvhInterior *>(node);
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333 |
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334 | tStack.push(tPair(interior->mFront, d + 1));
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335 | tStack.push(tPair(interior->mBack, d + 1));
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336 | }
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337 | }
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338 | }
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339 |
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340 |
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341 | SceneEntity **Bvh::GetGeometry(BvhNode *node, int &geometrySize) const
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342 | {
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343 | geometrySize = node->CountPrimitives();
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344 | return mGeometry + node->mFirst;
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345 | }
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346 |
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347 |
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348 | bool Bvh::TestPlane(BvhNode *node, int i, bool &bIntersect)
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349 | {
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350 | // do the test only if necessary
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351 | if (!(node->mPlaneMask[BvhNode::sCurrentState] & (1 << i)))
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352 | {
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353 | return true;
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354 | }
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355 |
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356 |
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357 | ////////
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358 | //-- test the n-vertex
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359 |
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360 | if ((node->mBox.GetDistance(sClipPlaneAABBVertexIndices[i * 2 + 0], sFrustum.mClipPlanes[i]) > 0.0f))
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361 | {
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362 | // outside
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363 | node->mPreferredPlane[BvhNode::sCurrentState] = i;
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364 | return false;
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365 | }
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366 |
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367 | ////////////
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368 | //-- test the p-vertex
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369 |
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370 | if (node->mBox.GetDistance(sClipPlaneAABBVertexIndices[i * 2 + 1], sFrustum.mClipPlanes[i]) <= 0.0f)
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371 | {
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372 | // completely inside: children don't need to check against this plane no more
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373 | node->mPlaneMask[BvhNode::sCurrentState] ^= 1 << i;
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374 | }
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375 | else
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376 | {
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377 | bIntersect = true;
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378 | }
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379 |
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380 | return true;
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381 | }
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382 |
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383 |
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384 | int Bvh::IsWithinViewFrustum(BvhNode *node)
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385 | {
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386 | bool bIntersect = false;
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387 |
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388 | if (node->GetParent())
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389 | node->mPlaneMask[BvhNode::sCurrentState] = node->GetParent()->mPlaneMask[BvhNode::sCurrentState];
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390 |
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391 | ////////
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392 | //-- apply frustum culling for the planes with index mPreferredPlane to 6
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393 |
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394 | for (int i = node->mPreferredPlane[BvhNode::sCurrentState]; i < 6; ++ i)
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395 | if (!TestPlane(node, i, bIntersect)) return 0;
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396 |
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397 |
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398 | //////////
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399 | //-- apply frustum culling for the planes with index 0 to mPreferredPlane
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400 |
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401 | for (int i = 0; i < node->mPreferredPlane[BvhNode::sCurrentState]; ++ i)
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402 | if (!TestPlane(node, i, bIntersect)) return 0;
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403 |
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404 | return bIntersect ? -1 : 1;
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405 | }
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406 |
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407 |
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408 | static void CalcNPVertexIndices(const Frustum &frustum, int *indices)
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409 | {
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410 | for (int i = 0; i < 6; ++ i)
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411 | {
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412 | // n-vertex
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413 | indices[i * 2 + 0] = AxisAlignedBox3::GetIndexNearestVertex(frustum.mClipPlanes[i].mNormal);
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414 | // p-vertex
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415 | indices[i * 2 + 1] = AxisAlignedBox3::GetIndexFarthestVertex(frustum.mClipPlanes[i].mNormal);
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416 | }
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417 | }
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418 |
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419 |
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420 | void Bvh::InitFrame(Camera *cam)
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421 | {
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422 | // = 0011 1111 which means that at the beginning, all six planes have to frustum culled
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423 | mRoot->mPlaneMask[BvhNode::sCurrentState] = 0x3f;
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424 |
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425 | cam->CalcFrustum(sFrustum);
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426 | CalcNPVertexIndices(sFrustum, sClipPlaneAABBVertexIndices);
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427 |
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428 | // store near plane
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429 | sNearPlane = Plane3(cam->GetDirection(), cam->GetPosition());
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430 | sNear = cam->GetNear();
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431 |
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432 | // rebuild dynamic part of the hierarchy
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433 | if (!mDynamicEntities.empty())
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434 | {
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435 | if (!mDynamicRoot)
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436 | CreateDynamicBranch();
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437 |
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438 | UpdateDynamicBranch(mDynamicRoot);
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439 | }
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440 | }
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441 |
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442 |
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443 | void Bvh::UpdateDistance(BvhNode *node) const
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444 | {
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445 | // q: should we use distance to center rather than the distance to the near plane?
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446 | // distance to near plane can also be used for checking near plane intersection
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447 | //node->mDistance = sNearPlane.Distance(node->GetBox().Center());
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448 | node->mDistance = node->GetBox().GetMinDistance(sNearPlane);
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449 | }
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450 |
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451 |
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452 | float Bvh::CalcMaxDistance(BvhNode *node) const
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453 | {
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454 | #if 1
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455 | return node->GetBox().GetMaxDistance(sNearPlane);
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456 |
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457 | #else
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458 | // use bounding boxes of geometry to determine max dist
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459 | float maxDist = .0f;
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460 |
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461 | int geometrySize;
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462 | SceneEntity **entities = GetGeometry(node, geometrySize);
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463 |
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464 | for (int i = 0; i < geometrySize; ++ i)
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465 | {
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466 | SceneEntity *ent = entities[i];
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467 | float dist = ent->GetWorldBoundingBox().GetMaxDistance(sNearPlane);
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468 |
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469 | if (dist > maxDist) maxDist = dist;
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470 | }
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471 |
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472 | return maxDist;
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473 | #endif
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474 | }
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475 |
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476 |
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477 | void Bvh::RenderBounds(BvhNode *node, RenderState *state, bool useTightBounds)
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478 | {
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479 | // hack: use dummy contayiner as wrapper in order to use multibox function
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480 | static BvhNodeContainer dummy(1);
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481 | dummy[0] = node;
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482 | RenderBounds(dummy, state, useTightBounds);
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483 | }
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484 |
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485 |
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486 | int Bvh::RenderBounds(const BvhNodeContainer &nodes,
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487 | RenderState *state,
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488 | bool useTightBounds)
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489 | {
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490 | int renderedBoxes;
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491 |
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492 | if (!useTightBounds)
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493 | {
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494 | // if not using tight bounds, rendering boxes in immediate mode
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495 | // is preferable to vertex arrays (less setup time)
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496 | BvhNodeContainer::const_iterator nit, nit_end = nodes.end();
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497 |
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498 | for (nit = nodes.begin(); nit != nit_end; ++ nit)
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499 | {
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500 | RenderBoundingBoxImmediate((*nit)->GetBox());
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501 | }
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502 |
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503 | renderedBoxes = (int)nodes.size();
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504 | }
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505 | else
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506 | {
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507 | renderedBoxes = PrepareBoundsWithDrawArrays(nodes);
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508 | RenderBoundsWithDrawArrays(renderedBoxes, state);
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509 | }
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510 |
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511 | return renderedBoxes;
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512 | }
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513 |
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514 |
|
---|
515 | int Bvh::PrepareBoundsWithDrawArrays(const BvhNodeContainer &nodes)
|
---|
516 | {
|
---|
517 | ///////////////////
|
---|
518 | //-- for the first time we come here => create vbo and indices
|
---|
519 |
|
---|
520 | if (!mIndices)
|
---|
521 | {
|
---|
522 | // create list of indices
|
---|
523 | CreateIndices();
|
---|
524 | }
|
---|
525 |
|
---|
526 | if (mVboId == -1)
|
---|
527 | {
|
---|
528 | // prepare the vbo
|
---|
529 | PrepareVertices();
|
---|
530 | }
|
---|
531 |
|
---|
532 | ///////////////
|
---|
533 |
|
---|
534 | int numNodes = 0;
|
---|
535 |
|
---|
536 | BvhNodeContainer::const_iterator nit, nit_end = nodes.end();
|
---|
537 |
|
---|
538 | for (nit = nodes.begin(); nit != nit_end; ++ nit)
|
---|
539 | {
|
---|
540 | BvhNode *node = *nit;
|
---|
541 | const int numIndices = node->mNumTestNodes * sNumIndicesPerBox;
|
---|
542 |
|
---|
543 | // copy indices
|
---|
544 | memcpy(mIndices + numNodes * sNumIndicesPerBox,
|
---|
545 | mTestIndices + node->mIndicesPtr,
|
---|
546 | numIndices * sizeof(unsigned int));
|
---|
547 |
|
---|
548 | numNodes += node->mNumTestNodes;
|
---|
549 | }
|
---|
550 |
|
---|
551 | return numNodes;
|
---|
552 | }
|
---|
553 |
|
---|
554 |
|
---|
555 | void Bvh::RenderBoundsWithDrawArrays(int numNodes, RenderState *state)
|
---|
556 | {
|
---|
557 | /////////
|
---|
558 | //-- Render the vbo
|
---|
559 |
|
---|
560 | if (state->GetCurrentVboId() != mVboId)
|
---|
561 | {
|
---|
562 | glBindBufferARB(GL_ARRAY_BUFFER_ARB, mVboId);
|
---|
563 | // set the vertex pointer to the vertex buffer
|
---|
564 | glVertexPointer(3, GL_FLOAT, 0, (char *)NULL);
|
---|
565 |
|
---|
566 | state->SetCurrentVboId(mVboId);
|
---|
567 | }
|
---|
568 |
|
---|
569 | // we do use the last or the first index (they are generate and only used to connect strips)
|
---|
570 | int numElements = numNodes * sNumIndicesPerBox - 1;
|
---|
571 | // don't render first degenerate index
|
---|
572 | glDrawElements(GL_TRIANGLE_STRIP, numElements, GL_UNSIGNED_INT, mIndices + 1);
|
---|
573 | }
|
---|
574 |
|
---|
575 |
|
---|
576 | void Bvh::CreateIndices()
|
---|
577 | {
|
---|
578 | // collect bvh nodes
|
---|
579 | BvhNodeContainer nodes;
|
---|
580 | CollectNodes(mRoot, nodes);
|
---|
581 |
|
---|
582 | cout << "creating new indices" << endl;
|
---|
583 |
|
---|
584 | int numMaxIndices = 0;
|
---|
585 |
|
---|
586 | BvhNodeContainer::const_iterator lit, lit_end = nodes.end();
|
---|
587 |
|
---|
588 | for (lit = nodes.begin(); lit != lit_end; ++ lit)
|
---|
589 | {
|
---|
590 | int offset = (*lit)->mNumTestNodes * sNumIndicesPerBox;
|
---|
591 | #ifdef ALIGN_INDICES
|
---|
592 | // align with 32 in order to speed up memcopy
|
---|
593 | offset = (offset / 32) * 32 + 32;
|
---|
594 | #endif
|
---|
595 | numMaxIndices += offset;
|
---|
596 | }
|
---|
597 |
|
---|
598 | cout << "creating global indices buffer" << endl;
|
---|
599 |
|
---|
600 | if (mIndices) delete [] mIndices;
|
---|
601 | if (mTestIndices) delete [] mTestIndices;
|
---|
602 |
|
---|
603 | // global buffer: create it once so we don't have
|
---|
604 | // to allocate memory from the chunks of the node
|
---|
605 | mIndices = new unsigned int[numMaxIndices];
|
---|
606 | // create new index buffer for the individual nodes
|
---|
607 | mTestIndices = new unsigned int[numMaxIndices];
|
---|
608 |
|
---|
609 | mCurrentIndicesPtr = 0;
|
---|
610 |
|
---|
611 | for (lit = nodes.begin(); lit != lit_end; ++ lit)
|
---|
612 | {
|
---|
613 | BvhNode *node = *lit;
|
---|
614 |
|
---|
615 | // resize array
|
---|
616 | node->mIndicesPtr = mCurrentIndicesPtr;
|
---|
617 | int numIndices = 0;
|
---|
618 |
|
---|
619 | // the bounding boxes of the test nodes are rendered instead of the node itself
|
---|
620 | // => store their indices
|
---|
621 | for (int i = 0; i < node->mNumTestNodes; ++ i, numIndices += sNumIndicesPerBox)
|
---|
622 | {
|
---|
623 | BvhNode *testNode = mTestNodes[node->mTestNodesIdx + i];
|
---|
624 |
|
---|
625 | // add indices to root node
|
---|
626 | for (int j = 0; j < sNumIndicesPerBox; ++ j)
|
---|
627 | {
|
---|
628 | mTestIndices[mCurrentIndicesPtr + numIndices + j] = sIndices[j] + testNode->GetId() * 8;
|
---|
629 | }
|
---|
630 | }
|
---|
631 |
|
---|
632 | // align with 32
|
---|
633 | #ifdef ALIGN_INDICES
|
---|
634 | const int offset = (numIndices / 32) * 32 + 32;
|
---|
635 | #else
|
---|
636 | const int offset = numIndices;
|
---|
637 | #endif
|
---|
638 | mCurrentIndicesPtr += offset;
|
---|
639 | }
|
---|
640 | }
|
---|
641 |
|
---|
642 |
|
---|
643 | void Bvh::ComputeIds()
|
---|
644 | {
|
---|
645 | // collect all nodes
|
---|
646 | BvhNodeContainer nodes;
|
---|
647 | CollectNodes(mRoot, nodes);
|
---|
648 |
|
---|
649 | // assign unique ids to all nodes of the hierarchy
|
---|
650 | int i = 0;
|
---|
651 | BvhNodeContainer::const_iterator lit, lit_end = nodes.end();
|
---|
652 |
|
---|
653 | for (lit = nodes.begin(); lit != lit_end; ++ lit, ++ i)
|
---|
654 | {
|
---|
655 | (*lit)->SetId(i);
|
---|
656 | }
|
---|
657 | }
|
---|
658 |
|
---|
659 |
|
---|
660 | void Bvh::PrepareVertices()
|
---|
661 | {
|
---|
662 | // collect all nodes
|
---|
663 | BvhNodeContainer nodes;
|
---|
664 |
|
---|
665 | nodes.reserve(GetNumStaticNodes());
|
---|
666 | CollectNodes(mRoot, nodes);
|
---|
667 |
|
---|
668 | const unsigned int bufferSize = 8 * (int)nodes.size();
|
---|
669 | mVertices = new Vector3[bufferSize];
|
---|
670 |
|
---|
671 | int i = 0;
|
---|
672 |
|
---|
673 | // store bounding box vertices
|
---|
674 | BvhNodeContainer::const_iterator lit, lit_end = nodes.end();
|
---|
675 |
|
---|
676 | for (lit = nodes.begin(); lit != lit_end; ++ lit, i += 8)
|
---|
677 | {
|
---|
678 | BvhNode *node = *lit;
|
---|
679 |
|
---|
680 | for (int j = 0; j < 8; ++ j)
|
---|
681 | (static_cast<Vector3 *>(mVertices))[node->GetId() * 8 + j] = node->GetBox().GetVertex(j);
|
---|
682 | }
|
---|
683 |
|
---|
684 | glGenBuffersARB(1, &mVboId);
|
---|
685 | glBindBufferARB(GL_ARRAY_BUFFER_ARB, mVboId);
|
---|
686 | glVertexPointer(3, GL_FLOAT, 0, (char *)NULL);
|
---|
687 |
|
---|
688 | glBufferDataARB(GL_ARRAY_BUFFER_ARB,
|
---|
689 | bufferSize * sizeof(Vector3),
|
---|
690 | mVertices,
|
---|
691 | GL_STATIC_DRAW_ARB);
|
---|
692 |
|
---|
693 | glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
|
---|
694 |
|
---|
695 | // data handled by graphics driver from now on
|
---|
696 | DEL_PTR(mVertices);
|
---|
697 |
|
---|
698 | cout << "******** created vbos for tighter bounds *********" << endl;
|
---|
699 | }
|
---|
700 |
|
---|
701 |
|
---|
702 | void Bvh::SetMaxDepthForTestingChildren(int maxDepth)
|
---|
703 | {
|
---|
704 | if (maxDepth != mMaxDepthForTestingChildren)
|
---|
705 | {
|
---|
706 | mMaxDepthForTestingChildren = maxDepth;
|
---|
707 | RecomputeBounds();
|
---|
708 | }
|
---|
709 | }
|
---|
710 |
|
---|
711 |
|
---|
712 | void Bvh::SetAreaRatioThresholdForTestingChildren(float ratio)
|
---|
713 | {
|
---|
714 | if (ratio != mAreaRatioThreshold)
|
---|
715 | {
|
---|
716 | mAreaRatioThreshold = ratio;
|
---|
717 | RecomputeBounds();
|
---|
718 | }
|
---|
719 | }
|
---|
720 |
|
---|
721 |
|
---|
722 | void Bvh::RecomputeBounds()
|
---|
723 | {
|
---|
724 | // collect all nodes
|
---|
725 | BvhNodeContainer nodes;
|
---|
726 | CollectNodes(mRoot, nodes);
|
---|
727 |
|
---|
728 | cout << "recomputing bounds, children will be tested in depth " << mMaxDepthForTestingChildren << endl;
|
---|
729 |
|
---|
730 | int success = 0;
|
---|
731 | BvhNodeContainer::const_iterator lit, lit_end = nodes.end();
|
---|
732 |
|
---|
733 | for (lit = nodes.begin(); lit != lit_end; ++ lit)
|
---|
734 | {
|
---|
735 | BvhNode *node = *lit;
|
---|
736 |
|
---|
737 | // recreate list of nodes that will be queried as a proxy
|
---|
738 | if (CreateNodeRenderList(node))
|
---|
739 | ++ success;
|
---|
740 | }
|
---|
741 |
|
---|
742 | float p = 100.0f * (float)success / nodes.size();
|
---|
743 | cout << "created tighter bounds for " << p << " percent of the nodes" << endl;
|
---|
744 |
|
---|
745 | // recreate indices used for indirect mode rendering
|
---|
746 | if (mIndices) CreateIndices();
|
---|
747 | }
|
---|
748 |
|
---|
749 |
|
---|
750 | bool Bvh::CreateNodeRenderList(BvhNode *node)
|
---|
751 | {
|
---|
752 | BvhNodeContainer children;
|
---|
753 |
|
---|
754 | // collect nodes that will be tested instead of the leaf node
|
---|
755 | // in order to get a tighter bounding box test
|
---|
756 | CollectNodes(node, children, mMaxDepthForTestingChildren);
|
---|
757 |
|
---|
758 |
|
---|
759 | // using the tighter bounds is not feasable in case
|
---|
760 | // that the tighter bounds represent nearly the same projected area
|
---|
761 | // as the old bounding box. Test this property using either
|
---|
762 | // volume or area heuristics
|
---|
763 |
|
---|
764 | float vol = 0;
|
---|
765 | float area = 0;
|
---|
766 |
|
---|
767 | BvhNodeContainer::const_iterator cit;
|
---|
768 |
|
---|
769 | for (cit = children.begin(); cit != children.end(); ++ cit)
|
---|
770 | area += (*cit)->GetBox().SurfaceArea();
|
---|
771 |
|
---|
772 | const float areaRatio = area / node->GetBox().SurfaceArea();
|
---|
773 |
|
---|
774 | bool success;
|
---|
775 |
|
---|
776 | if (areaRatio < mAreaRatioThreshold)
|
---|
777 | success = true;
|
---|
778 | else
|
---|
779 | {
|
---|
780 | // hack: only store node itself
|
---|
781 | children.clear();
|
---|
782 | children.push_back(node);
|
---|
783 |
|
---|
784 | success = false;
|
---|
785 | }
|
---|
786 |
|
---|
787 | // the new test nodes are added at the end of the vector
|
---|
788 | node->mTestNodesIdx = (int)mTestNodes.size();
|
---|
789 |
|
---|
790 | // use the found nodes as nodes during the occlusion tests
|
---|
791 | for (cit = children.begin(); cit != children.end(); ++ cit)
|
---|
792 | {
|
---|
793 | BvhNode *child = *cit;
|
---|
794 | mTestNodes.push_back(child);
|
---|
795 | }
|
---|
796 |
|
---|
797 | node->mNumTestNodes = (int)children.size();
|
---|
798 |
|
---|
799 | return success;
|
---|
800 | }
|
---|
801 |
|
---|
802 |
|
---|
803 | void Bvh::ResetNodeClassifications()
|
---|
804 | {
|
---|
805 | BvhNodeContainer nodes;
|
---|
806 |
|
---|
807 | nodes.reserve(GetNumNodes());
|
---|
808 | CollectNodes(mRoot, nodes);
|
---|
809 |
|
---|
810 | BvhNodeContainer::const_iterator lit, lit_end = nodes.end();
|
---|
811 |
|
---|
812 | for (lit = nodes.begin(); lit != lit_end; ++ lit)
|
---|
813 | {
|
---|
814 | (*lit)->ResetVisibility();
|
---|
815 | }
|
---|
816 | }
|
---|
817 |
|
---|
818 |
|
---|
819 | void Bvh::ComputeBvhStats(BvhNode *root, BvhStats &bvhStats)
|
---|
820 | {
|
---|
821 | bvhStats.Reset();
|
---|
822 | std::stack<BvhNode *> nodeStack;
|
---|
823 | nodeStack.push(root);
|
---|
824 |
|
---|
825 | int numVirtualLeaves = 0;
|
---|
826 | int numGeometry = 0;
|
---|
827 |
|
---|
828 | while (!nodeStack.empty())
|
---|
829 | {
|
---|
830 | BvhNode *node = nodeStack.top();
|
---|
831 | nodeStack.pop();
|
---|
832 |
|
---|
833 | if (node->IsVirtualLeaf())
|
---|
834 | {
|
---|
835 | ++ numVirtualLeaves;
|
---|
836 | numGeometry += node->CountPrimitives();
|
---|
837 |
|
---|
838 | BvhLeaf *leaf = static_cast<BvhLeaf *>(node);
|
---|
839 |
|
---|
840 | bvhStats.mTriangles += CountTriangles(leaf);
|
---|
841 | bvhStats.mLeafSA += leaf->mBox.SurfaceArea();
|
---|
842 | bvhStats.mLeafVol += leaf->mBox.GetVolume();
|
---|
843 | }
|
---|
844 | else
|
---|
845 | {
|
---|
846 | bvhStats.mInteriorSA += node->mBox.SurfaceArea();
|
---|
847 | bvhStats.mInteriorVol += node->mBox.GetVolume();
|
---|
848 |
|
---|
849 | BvhInterior *interior = static_cast<BvhInterior *>(node);
|
---|
850 |
|
---|
851 | nodeStack.push(interior->mBack);
|
---|
852 | nodeStack.push(interior->mFront);
|
---|
853 | }
|
---|
854 | }
|
---|
855 |
|
---|
856 | bvhStats.mGeometryRatio = (float)numGeometry / numVirtualLeaves;
|
---|
857 | bvhStats.mTriangleRatio = (float)bvhStats.mTriangles / numVirtualLeaves;
|
---|
858 | bvhStats.mLeaves = numVirtualLeaves;
|
---|
859 | }
|
---|
860 |
|
---|
861 |
|
---|
862 | void Bvh::PrintBvhStats(const BvhStats &bvhStats) const
|
---|
863 | {
|
---|
864 | cout << "\n============ BVH statistics =============" << endl;
|
---|
865 | cout << "interiorNodesSA = " << bvhStats.mInteriorSA / mRoot->mBox.SurfaceArea() << endl;
|
---|
866 | cout << "leafNodesSA = " << bvhStats.mLeafSA / mRoot->mBox.SurfaceArea() << endl;
|
---|
867 | cout << "interiorNodesVolume = " << bvhStats.mInteriorVol / mRoot->mBox.GetVolume() << endl;
|
---|
868 | cout << "leafNodesVolume = " << bvhStats.mLeafVol / mRoot->mBox.GetVolume() << endl;
|
---|
869 |
|
---|
870 | cout << "geometry per leaf: " << bvhStats.mGeometryRatio << endl;
|
---|
871 | cout << "triangles per leaf: " << bvhStats.mTriangleRatio << endl;
|
---|
872 | cout << "===========================================" << endl << endl;
|
---|
873 | }
|
---|
874 |
|
---|
875 |
|
---|
876 | int Bvh::CountTriangles(BvhNode *node) const
|
---|
877 | {
|
---|
878 | int numTriangles = 0;
|
---|
879 |
|
---|
880 | for (int i = node->mFirst; i <= node->mLast; ++ i)
|
---|
881 | {
|
---|
882 | numTriangles += mGeometry[i]->CountNumTriangles(0);
|
---|
883 | }
|
---|
884 |
|
---|
885 | return numTriangles;
|
---|
886 | }
|
---|
887 |
|
---|
888 |
|
---|
889 | float Bvh::GetArea(BvhNode *node) const
|
---|
890 | {
|
---|
891 | return node->mArea;
|
---|
892 | }
|
---|
893 |
|
---|
894 |
|
---|
895 | void Bvh::UpdateNumLeaves(BvhNode *node) const
|
---|
896 | {
|
---|
897 | if (node->IsLeaf())
|
---|
898 | {
|
---|
899 | node->mNumLeaves = 1;
|
---|
900 | }
|
---|
901 | else
|
---|
902 | {
|
---|
903 | BvhNode *f = static_cast<BvhInterior *>(node)->GetFront();
|
---|
904 | BvhNode *b = static_cast<BvhInterior *>(node)->GetBack();
|
---|
905 |
|
---|
906 | UpdateNumLeaves(f);
|
---|
907 | UpdateNumLeaves(b);
|
---|
908 |
|
---|
909 | node->mNumLeaves = f->mNumLeaves + b->mNumLeaves;
|
---|
910 | }
|
---|
911 | }
|
---|
912 |
|
---|
913 |
|
---|
914 | void Bvh::CollectVirtualLeaves(BvhNode *node, BvhNodeContainer &leaves)
|
---|
915 | {
|
---|
916 | stack<BvhNode *> tStack;
|
---|
917 | tStack.push(node);
|
---|
918 |
|
---|
919 | while (!tStack.empty())
|
---|
920 | {
|
---|
921 | BvhNode *node = tStack.top();
|
---|
922 | tStack.pop();
|
---|
923 |
|
---|
924 | if (node->mIsVirtualLeaf)
|
---|
925 | {
|
---|
926 | leaves.push_back(node);
|
---|
927 | }
|
---|
928 | else if (!node->IsLeaf())
|
---|
929 | {
|
---|
930 | BvhInterior *interior = static_cast<BvhInterior *>(node);
|
---|
931 |
|
---|
932 | tStack.push(interior->mFront);
|
---|
933 | tStack.push(interior->mBack);
|
---|
934 | }
|
---|
935 | }
|
---|
936 | }
|
---|
937 |
|
---|
938 |
|
---|
939 | void Bvh::SetVirtualLeaves(int numTriangles)
|
---|
940 | {
|
---|
941 | // first invalidate old virtual leaves
|
---|
942 | BvhNodeContainer leaves;
|
---|
943 | CollectVirtualLeaves(mRoot, leaves);
|
---|
944 |
|
---|
945 | BvhNodeContainer::const_iterator bit, bit_end = leaves.end();
|
---|
946 |
|
---|
947 | for (bit = leaves.begin(); bit != bit_end; ++ bit)
|
---|
948 | {
|
---|
949 | (*bit)->mIsVirtualLeaf = false;
|
---|
950 | }
|
---|
951 |
|
---|
952 | mNumVirtualNodes = 0;
|
---|
953 | // assign new virtual leaves based on specified #triangles per leaf
|
---|
954 | std::stack<BvhNode *> nodeStack;
|
---|
955 | nodeStack.push(mRoot);
|
---|
956 |
|
---|
957 | while (!nodeStack.empty())
|
---|
958 | {
|
---|
959 | BvhNode *node = nodeStack.top();
|
---|
960 | nodeStack.pop();
|
---|
961 |
|
---|
962 | ++ mNumVirtualNodes;
|
---|
963 |
|
---|
964 | if (node->IsLeaf())
|
---|
965 | {
|
---|
966 | BvhLeaf *leaf = static_cast<BvhLeaf *>(node);
|
---|
967 | leaf->mIsVirtualLeaf = true;
|
---|
968 | }
|
---|
969 | else
|
---|
970 | {
|
---|
971 | BvhInterior *interior = static_cast<BvhInterior *>(node);
|
---|
972 |
|
---|
973 | BvhNode *f = interior->mFront;
|
---|
974 | BvhNode *b = interior->mBack;
|
---|
975 |
|
---|
976 | if (node->mIsMaxDepthForVirtualLeaf ||
|
---|
977 | (CountTriangles(node) <= numTriangles))
|
---|
978 | {
|
---|
979 | node->mIsVirtualLeaf = true;
|
---|
980 | }
|
---|
981 | else
|
---|
982 | {
|
---|
983 | nodeStack.push(interior->mBack);
|
---|
984 | nodeStack.push(interior->mFront);
|
---|
985 | }
|
---|
986 | }
|
---|
987 | }
|
---|
988 |
|
---|
989 | /// Reset the node states
|
---|
990 | ResetNodeClassifications();
|
---|
991 | }
|
---|
992 |
|
---|
993 |
|
---|
994 | void Bvh::PostProcess()
|
---|
995 | {
|
---|
996 | // this function must be called once after hierarchy creation
|
---|
997 |
|
---|
998 | // We initialize the virtual leaves
|
---|
999 | // of this bvh, i.e., the nodes that are used as
|
---|
1000 | // leaves of the hierarchy during traversal.
|
---|
1001 |
|
---|
1002 | // Initially they are set either
|
---|
1003 | // a) to the real leaves of the hierarchy or
|
---|
1004 | // b) the point where the subdivision on object level ends
|
---|
1005 | // and the subsequent nodes are just used to provide tighter bounds
|
---|
1006 | // (see article for the notations)
|
---|
1007 |
|
---|
1008 | std::stack<BvhNode *> nodeStack;
|
---|
1009 | nodeStack.push(mRoot);
|
---|
1010 |
|
---|
1011 | while (!nodeStack.empty())
|
---|
1012 | {
|
---|
1013 | BvhNode *node = nodeStack.top();
|
---|
1014 | nodeStack.pop();
|
---|
1015 |
|
---|
1016 | if (node->IsLeaf())
|
---|
1017 | {
|
---|
1018 | node->mIsMaxDepthForVirtualLeaf = true;
|
---|
1019 | }
|
---|
1020 | else
|
---|
1021 | {
|
---|
1022 | BvhInterior *interior = static_cast<BvhInterior *>(node);
|
---|
1023 |
|
---|
1024 | BvhNode *f = interior->mFront;
|
---|
1025 | BvhNode *b = interior->mBack;
|
---|
1026 |
|
---|
1027 | if ((f->mFirst == b->mFirst) && (f->mLast == b->mLast))
|
---|
1028 | {
|
---|
1029 | // point reached where beyond there would be no further reduction
|
---|
1030 | // as both subtrees contain the same objects => stop here
|
---|
1031 | // The tree beyond the current node is used to describe
|
---|
1032 | // tighter bounds on the geometry contained in it
|
---|
1033 | node->mIsMaxDepthForVirtualLeaf = true;
|
---|
1034 | }
|
---|
1035 | else
|
---|
1036 | {
|
---|
1037 | nodeStack.push(f);
|
---|
1038 | nodeStack.push(b);
|
---|
1039 | }
|
---|
1040 | }
|
---|
1041 | }
|
---|
1042 | }
|
---|
1043 |
|
---|
1044 |
|
---|
1045 | void Bvh::RenderBoundingBoxImmediate(const AxisAlignedBox3 &box)
|
---|
1046 | {
|
---|
1047 | const Vector3 l = box.Min();
|
---|
1048 | const Vector3 u = box.Max();
|
---|
1049 |
|
---|
1050 | ///////////
|
---|
1051 | //-- render AABB as triangle strips
|
---|
1052 |
|
---|
1053 | glBegin(GL_TRIANGLE_STRIP);
|
---|
1054 |
|
---|
1055 | // render first half of AABB
|
---|
1056 | glVertex3f(l.x, l.y, u.z);
|
---|
1057 | glVertex3f(u.x, l.y, u.z);
|
---|
1058 | glVertex3f(l.x, u.y, u.z);
|
---|
1059 | glVertex3f(u.x, u.y, u.z);
|
---|
1060 | glVertex3f(l.x, u.y, l.z);
|
---|
1061 | glVertex3f(u.x, u.y, l.z);
|
---|
1062 | glVertex3f(l.x, l.y, l.z);
|
---|
1063 | glVertex3f(u.x, l.y, l.z);
|
---|
1064 |
|
---|
1065 | glPrimitiveRestartNV();
|
---|
1066 |
|
---|
1067 | // render second half of AABB
|
---|
1068 | glVertex3f(l.x, u.y, u.z);
|
---|
1069 | glVertex3f(l.x, u.y, l.z);
|
---|
1070 | glVertex3f(l.x, l.y, u.z);
|
---|
1071 | glVertex3f(l.x, l.y, l.z);
|
---|
1072 | glVertex3f(u.x, l.y, u.z);
|
---|
1073 | glVertex3f(u.x, l.y, l.z);
|
---|
1074 | glVertex3f(u.x, u.y, u.z);
|
---|
1075 | glVertex3f(u.x, u.y, l.z);
|
---|
1076 |
|
---|
1077 | glEnd();
|
---|
1078 | }
|
---|
1079 |
|
---|
1080 |
|
---|
1081 | static void RenderBoxForViz(const AxisAlignedBox3 &box)
|
---|
1082 | {
|
---|
1083 | glBegin(GL_LINE_LOOP);
|
---|
1084 | glVertex3d(box.Min().x, box.Max().y, box.Min().z);
|
---|
1085 | glVertex3d(box.Max().x, box.Max().y, box.Min().z);
|
---|
1086 | glVertex3d(box.Max().x, box.Min().y, box.Min().z);
|
---|
1087 | glVertex3d(box.Min().x, box.Min().y, box.Min().z);
|
---|
1088 | glEnd();
|
---|
1089 |
|
---|
1090 | glBegin(GL_LINE_LOOP);
|
---|
1091 | glVertex3d(box.Min().x, box.Min().y, box.Max().z);
|
---|
1092 | glVertex3d(box.Max().x, box.Min().y, box.Max().z);
|
---|
1093 | glVertex3d(box.Max().x, box.Max().y, box.Max().z);
|
---|
1094 | glVertex3d(box.Min().x, box.Max().y, box.Max().z);
|
---|
1095 | glEnd();
|
---|
1096 |
|
---|
1097 | glBegin(GL_LINE_LOOP);
|
---|
1098 | glVertex3d(box.Max().x, box.Min().y, box.Min().z);
|
---|
1099 | glVertex3d(box.Max().x, box.Min().y, box.Max().z);
|
---|
1100 | glVertex3d(box.Max().x, box.Max().y, box.Max().z);
|
---|
1101 | glVertex3d(box.Max().x, box.Max().y, box.Min().z);
|
---|
1102 | glEnd();
|
---|
1103 |
|
---|
1104 | glBegin(GL_LINE_LOOP);
|
---|
1105 | glVertex3d(box.Min().x, box.Min().y, box.Min().z);
|
---|
1106 | glVertex3d(box.Min().x, box.Min().y, box.Max().z);
|
---|
1107 | glVertex3d(box.Min().x, box.Max().y, box.Max().z);
|
---|
1108 | glVertex3d(box.Min().x, box.Max().y, box.Min().z);
|
---|
1109 | glEnd();
|
---|
1110 |
|
---|
1111 | glBegin(GL_LINE_LOOP);
|
---|
1112 | glVertex3d(box.Min().x, box.Min().y, box.Min().z);
|
---|
1113 | glVertex3d(box.Max().x, box.Min().y, box.Min().z);
|
---|
1114 | glVertex3d(box.Max().x, box.Min().y, box.Max().z);
|
---|
1115 | glVertex3d(box.Min().x, box.Min().y, box.Max().z);
|
---|
1116 | glEnd();
|
---|
1117 |
|
---|
1118 | glBegin(GL_LINE_LOOP);
|
---|
1119 | glVertex3d(box.Min().x, box.Max().y, box.Min().z);
|
---|
1120 | glVertex3d(box.Max().x, box.Max().y, box.Min().z);
|
---|
1121 | glVertex3d(box.Max().x, box.Max().y, box.Max().z);
|
---|
1122 | glVertex3d(box.Min().x, box.Max().y, box.Max().z);
|
---|
1123 |
|
---|
1124 | glEnd();
|
---|
1125 | }
|
---|
1126 |
|
---|
1127 |
|
---|
1128 | static Technique GetVizTechnique()
|
---|
1129 | {
|
---|
1130 | Technique tech;
|
---|
1131 | tech.Init();
|
---|
1132 |
|
---|
1133 | //tech.SetLightingEnabled(false);
|
---|
1134 | //tech.SetDepthWriteEnabled(false);
|
---|
1135 |
|
---|
1136 | tech.SetEmmisive(RgbaColor(1.0f, 1.0f, 1.0f, 1.0f));
|
---|
1137 | tech.SetDiffuse(RgbaColor(1.0f, 1.0f, 1.0f, 1.0f));
|
---|
1138 | tech.SetAmbient(RgbaColor(1.0f, 1.0f, 1.0f, 1.0f));
|
---|
1139 |
|
---|
1140 | return tech;
|
---|
1141 | }
|
---|
1142 |
|
---|
1143 |
|
---|
1144 | void Bvh::RenderBoundsForViz(BvhNode *node,
|
---|
1145 | RenderState *state,
|
---|
1146 | bool useTightBounds)
|
---|
1147 | {
|
---|
1148 | Technique *oldTech = state->GetState();
|
---|
1149 | // we set a simple material
|
---|
1150 | static Technique boxMat = GetVizTechnique();
|
---|
1151 | boxMat.Render(state);
|
---|
1152 |
|
---|
1153 | if (!useTightBounds)
|
---|
1154 | {
|
---|
1155 | RenderBoxForViz(node->GetBox());
|
---|
1156 | /*glPolygonMode(GL_FRONT, GL_LINE);
|
---|
1157 | RenderBoundingBoxImmediate(node->GetBox());
|
---|
1158 | glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);*/
|
---|
1159 | }
|
---|
1160 | else
|
---|
1161 | {
|
---|
1162 | for (int i = 0; i < node->mNumTestNodes; ++ i)
|
---|
1163 | {
|
---|
1164 | RenderBoxForViz(mTestNodes[node->mTestNodesIdx + i]->GetBox());
|
---|
1165 | }
|
---|
1166 | }
|
---|
1167 |
|
---|
1168 | if (oldTech) oldTech->Render(state);
|
---|
1169 | }
|
---|
1170 |
|
---|
1171 |
|
---|
1172 |
|
---|
1173 | ////////////////////////
|
---|
1174 | //-- functions for construction of the dynamic hierarchy
|
---|
1175 |
|
---|
1176 | int Bvh::SortTriangles(BvhLeaf *leaf,
|
---|
1177 | int axis,
|
---|
1178 | float position
|
---|
1179 | )
|
---|
1180 | {
|
---|
1181 | int i = leaf->mFirst;
|
---|
1182 | int j = leaf->mLast;
|
---|
1183 |
|
---|
1184 | while (1)
|
---|
1185 | {
|
---|
1186 | while (mGeometry[i]->GetWorldCenter()[axis] < position) ++ i;
|
---|
1187 | while (position < mGeometry[j]->GetWorldCenter()[axis]) -- j;
|
---|
1188 |
|
---|
1189 | // sorting finished
|
---|
1190 | if (i >= j) break;
|
---|
1191 |
|
---|
1192 | // swap entities
|
---|
1193 | swap(mGeometry[i], mGeometry[j]);
|
---|
1194 |
|
---|
1195 | ++ i;
|
---|
1196 | -- j;
|
---|
1197 | }
|
---|
1198 |
|
---|
1199 | return j;
|
---|
1200 | }
|
---|
1201 |
|
---|
1202 |
|
---|
1203 | int Bvh::SortTrianglesSpatialMedian(BvhLeaf *leaf,
|
---|
1204 | int axis
|
---|
1205 | )
|
---|
1206 | {
|
---|
1207 | // spatial median
|
---|
1208 | float m = leaf->mBox.Center()[axis];
|
---|
1209 | return SortTriangles(leaf, axis, m);
|
---|
1210 | }
|
---|
1211 |
|
---|
1212 |
|
---|
1213 | BvhNode *Bvh::SubdivideLeaf(BvhLeaf *leaf,
|
---|
1214 | int parentAxis
|
---|
1215 | )
|
---|
1216 | {
|
---|
1217 | if (TerminationCriteriaMet(leaf))
|
---|
1218 | {
|
---|
1219 | leaf->mIsVirtualLeaf = true;
|
---|
1220 | leaf->mIsMaxDepthForVirtualLeaf = true;
|
---|
1221 | cout << "leaf contructed:" << leaf->mBox << " " << leaf->mFirst << " " << leaf->mLast << endl;
|
---|
1222 | return leaf;
|
---|
1223 | }
|
---|
1224 |
|
---|
1225 | //const int axis = (parentAxis + 1) % 3;
|
---|
1226 | const int axis = leaf->mBox.MajorAxis();
|
---|
1227 |
|
---|
1228 |
|
---|
1229 | const int scale = 20;
|
---|
1230 |
|
---|
1231 | // position of the split in the partailly sorted array of triangles
|
---|
1232 | // corresponding to this leaf
|
---|
1233 | int split = -1;
|
---|
1234 | float pos = -1.0f;
|
---|
1235 |
|
---|
1236 | // Spatial median subdivision
|
---|
1237 | split = SortTrianglesSpatialMedian(leaf, axis);
|
---|
1238 | pos = leaf->mBox.Center()[axis];
|
---|
1239 |
|
---|
1240 | if (split == leaf->mLast)
|
---|
1241 | {
|
---|
1242 | // no split could be achieved => just halve number of objects
|
---|
1243 | split = (leaf->mLast - leaf->mFirst) / 2;
|
---|
1244 | cerr << "no reduction " << leaf->CountPrimitives() << " " << leaf->mFirst << " " << leaf->mLast << endl;
|
---|
1245 | }
|
---|
1246 |
|
---|
1247 | // create two more nodes
|
---|
1248 | mNumNodes += 2;
|
---|
1249 | BvhInterior *parent = new BvhInterior(leaf->GetParent());
|
---|
1250 | BvhLeaf *front = new BvhLeaf(parent);
|
---|
1251 |
|
---|
1252 | parent->mAxis = axis;
|
---|
1253 | parent->mBox = leaf->mBox;
|
---|
1254 | parent->mDepth = leaf->mDepth;
|
---|
1255 |
|
---|
1256 | parent->mBack = leaf;
|
---|
1257 | parent->mFront = front;
|
---|
1258 | //parent->mPosition = pos;
|
---|
1259 |
|
---|
1260 | // now assign the triangles to the subnodes
|
---|
1261 | front->mFirst = split + 1;
|
---|
1262 | front->mLast = leaf->mLast;
|
---|
1263 | front->mDepth = leaf->mDepth + 1;
|
---|
1264 |
|
---|
1265 | leaf->mLast = split;
|
---|
1266 | leaf->mDepth = front->mDepth;
|
---|
1267 | leaf->mParent = parent;
|
---|
1268 |
|
---|
1269 | // reset box
|
---|
1270 | //leaf->mBox.Initialize();
|
---|
1271 |
|
---|
1272 | front->mBox = ComputeBoundingBox(mGeometry + front->mFirst, front->CountPrimitives());
|
---|
1273 | leaf->mBox = ComputeBoundingBox(mGeometry + leaf->mFirst, leaf->CountPrimitives());
|
---|
1274 |
|
---|
1275 | // recursively continue subdivision
|
---|
1276 | parent->mBack = SubdivideLeaf(static_cast<BvhLeaf *>(parent->mBack), axis);
|
---|
1277 | parent->mFront = SubdivideLeaf(static_cast<BvhLeaf *>(parent->mFront), axis);
|
---|
1278 |
|
---|
1279 | return parent;
|
---|
1280 | }
|
---|
1281 |
|
---|
1282 |
|
---|
1283 | bool Bvh::TerminationCriteriaMet(BvhLeaf *leaf) const
|
---|
1284 | {
|
---|
1285 | const bool criteriaMet =
|
---|
1286 | (leaf->mDepth > mMaxDepthForDynamicBranch) ||
|
---|
1287 | (leaf->CountPrimitives() == 1);
|
---|
1288 |
|
---|
1289 | return criteriaMet;
|
---|
1290 | }
|
---|
1291 |
|
---|
1292 |
|
---|
1293 | void Bvh::UpdateDynamicBranch(BvhNode *node)
|
---|
1294 | {
|
---|
1295 | if (node->IsLeaf())
|
---|
1296 | {
|
---|
1297 | int numEntities;
|
---|
1298 | SceneEntity **entities = GetGeometry(node, numEntities);
|
---|
1299 |
|
---|
1300 | node->mBox = ComputeBoundingBox(entities, numEntities);
|
---|
1301 | //cout << "box: " << node->mBox << endl;
|
---|
1302 | }
|
---|
1303 | else
|
---|
1304 | {
|
---|
1305 | BvhNode *f = static_cast<BvhInterior *>(node)->GetFront();
|
---|
1306 | BvhNode *b = static_cast<BvhInterior *>(node)->GetBack();
|
---|
1307 |
|
---|
1308 | UpdateDynamicBranch(f);
|
---|
1309 | UpdateDynamicBranch(b);
|
---|
1310 |
|
---|
1311 | node->mBox = f->mBox;
|
---|
1312 | node->mBox.Include(b->mBox);
|
---|
1313 | }
|
---|
1314 | }
|
---|
1315 |
|
---|
1316 |
|
---|
1317 | void Bvh::CreateDynamicBranch()
|
---|
1318 | {
|
---|
1319 | // the bvh has two main branches
|
---|
1320 | // a static branch (the old root), and adynamic branch
|
---|
1321 | // we create a 'dynamic' leaf which basically is a container
|
---|
1322 | // for all dynamic objects underneath
|
---|
1323 |
|
---|
1324 | // the bounding boxes of the dynamic tree must be updated
|
---|
1325 | // once each frame in order to be able to incorporate
|
---|
1326 | // the movements of the objects within
|
---|
1327 |
|
---|
1328 | DEL_PTR(mDynamicRoot);
|
---|
1329 |
|
---|
1330 | BvhLeaf *l = new BvhLeaf(mRoot);
|
---|
1331 |
|
---|
1332 | l->mBox.Initialize();
|
---|
1333 |
|
---|
1334 | SceneEntityContainer::const_iterator sit, sit_end = mDynamicEntities.end();
|
---|
1335 |
|
---|
1336 | for (sit = mDynamicEntities.begin(); sit != sit_end; ++ sit)
|
---|
1337 | {
|
---|
1338 | l->mBox.Include((*sit)->GetWorldBoundingBox());
|
---|
1339 | }
|
---|
1340 |
|
---|
1341 | l->mFirst = (int)(mGeometrySize - mDynamicEntities.size());
|
---|
1342 | l->mLast = (int)mGeometrySize - 1;
|
---|
1343 | l->mArea = l->mBox.SurfaceArea();
|
---|
1344 |
|
---|
1345 | cout << "updating dynamic branch " << l->mFirst << " " << l->mLast << endl;
|
---|
1346 |
|
---|
1347 | mDynamicRoot = SubdivideLeaf(l, 0);
|
---|
1348 |
|
---|
1349 | BvhStats bvhStats;
|
---|
1350 | ComputeBvhStats(mDynamicRoot, bvhStats);
|
---|
1351 |
|
---|
1352 | cout << "\n=========== Dynamic BVH statistics: =========" << endl;
|
---|
1353 | cout << "leaves = " << bvhStats.mLeaves << endl;
|
---|
1354 | cout << "interiorNodesSA = " << bvhStats.mInteriorSA << endl;
|
---|
1355 | cout << "leafNodesSA = " << bvhStats.mLeafSA << endl;
|
---|
1356 | cout << "interiorNodesVolume = " << bvhStats.mInteriorVol << endl;
|
---|
1357 | cout << "leafNodesVolume = " << bvhStats.mLeafVol << endl;
|
---|
1358 |
|
---|
1359 | cout << "geometry per leaf: " << bvhStats.mGeometryRatio << endl;
|
---|
1360 | cout << "triangles per leaf: " << bvhStats.mTriangleRatio << endl;
|
---|
1361 | cout << "=============================================" << endl << endl;
|
---|
1362 | }
|
---|
1363 |
|
---|
1364 |
|
---|
1365 | void Bvh::AddDynamicObjects(const SceneEntityContainer &entities)
|
---|
1366 | {
|
---|
1367 | // copy old entities
|
---|
1368 | SceneEntity **newGeom = new SceneEntity*[mGeometrySize + (int)entities.size()];
|
---|
1369 |
|
---|
1370 | memcpy(newGeom, mGeometry, mGeometrySize * sizeof(SceneEntity *));
|
---|
1371 |
|
---|
1372 | delete [] mGeometry;
|
---|
1373 | mGeometry = newGeom;
|
---|
1374 |
|
---|
1375 | // now add new entities
|
---|
1376 | SceneEntityContainer::const_iterator it, it_end = entities.end();
|
---|
1377 |
|
---|
1378 | size_t i = mGeometrySize;
|
---|
1379 | for (it = entities.begin(); it != it_end; ++ it, ++ i)
|
---|
1380 | {
|
---|
1381 | mGeometry[i] = (*it);
|
---|
1382 | mDynamicEntities.push_back(*it);
|
---|
1383 | }
|
---|
1384 |
|
---|
1385 |
|
---|
1386 | mGeometrySize += entities.size();
|
---|
1387 | }
|
---|
1388 |
|
---|
1389 |
|
---|
1390 | bool Bvh::IntersectsNearPlane(BvhNode *node) const
|
---|
1391 | {
|
---|
1392 | // note: we have problems with large scale object penetrating the near plane
|
---|
1393 | // (e.g., objects in the distance which are always handled to be visible)
|
---|
1394 | // especially annoying is this problem when using the frustum
|
---|
1395 | // fitting on the visible objects for shadow mapping
|
---|
1396 | // but don't see how to solve this issue without using much costlier calculations
|
---|
1397 |
|
---|
1398 | // we stored the near plane distance => we can use it also here
|
---|
1399 | float distanceToNearPlane = node->GetDistance();
|
---|
1400 | //float distanceToNearPlane = node->GetBox().GetMinDistance(sNearPlane);
|
---|
1401 |
|
---|
1402 | return (distanceToNearPlane < sNear);
|
---|
1403 | }
|
---|
1404 |
|
---|
1405 |
|
---|
1406 | } |
---|