1 | #include "ShadowMapping.h"
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2 | #include "FrameBufferObject.h"
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3 | #include "RenderState.h"
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4 | #include "RenderTraverser.h"
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5 | #include "Light.h"
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6 | #include <IL/il.h>
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7 | #include <assert.h>
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8 |
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9 | using namespace std;
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10 |
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11 |
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12 | namespace CHCDemoEngine
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13 | {
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14 |
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15 |
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16 | static void PrintGLerror(char *msg)
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17 | {
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18 | GLenum errCode;
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19 | const GLubyte *errStr;
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20 |
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21 | if ((errCode = glGetError()) != GL_NO_ERROR)
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22 | {
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23 | errStr = gluErrorString(errCode);
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24 | fprintf(stderr,"OpenGL ERROR: %s: %s\n", errStr, msg);
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25 | }
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26 | }
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27 |
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28 |
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29 |
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30 | static CGprogram sCgShadowProgram;
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31 | static CGparameter sShadowParam;
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32 |
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33 |
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34 | static void GrabDepthBuffer(float *data, GLuint depthTexture)
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35 | {
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36 | glEnable(GL_TEXTURE_2D);
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37 | glBindTexture(GL_TEXTURE_2D, depthTexture);
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38 |
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39 | glGetTexImage(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, GL_FLOAT, data);
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40 |
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41 | glBindTexture(GL_TEXTURE_2D, 0);
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42 | glDisable(GL_TEXTURE_2D);
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43 | }
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44 |
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45 |
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46 | static void ExportDepthBuffer(float *data, int size)
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47 | {
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48 | ilInit();
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49 | assert(ilGetError() == IL_NO_ERROR);
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50 |
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51 | ILstring filename = ILstring("shadow.tga");
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52 | ilRegisterType(IL_FLOAT);
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53 |
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54 | const int depth = 1;
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55 | const int bpp = 1;
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56 |
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57 | if (!ilTexImage(size, size, depth, bpp, IL_LUMINANCE, IL_FLOAT, data))
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58 | {
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59 | cerr << "IL error " << ilGetError() << endl;
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60 |
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61 | ilShutDown();
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62 | assert(ilGetError() == IL_NO_ERROR);
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63 |
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64 | return;
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65 | }
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66 |
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67 | if (!ilSaveImage(filename))
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68 | {
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69 | cerr << "TGA write error " << ilGetError() << endl;
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70 | }
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71 |
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72 | ilShutDown();
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73 | assert(ilGetError() == IL_NO_ERROR);
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74 |
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75 | cout << "exported depth buffer" << endl;
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76 | }
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77 |
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78 |
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79 |
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80 | ShadowMap::ShadowMap(Light *light, int size, const AxisAlignedBox3 &sceneBox, Camera *cam):
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81 | mSceneBox(sceneBox), mSize(size), mCamera(cam), mLight(light)
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82 | {
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83 | mFbo = new FrameBufferObject(size, size, FrameBufferObject::DEPTH_32, true);
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84 | // the diffuse color buffer
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85 | mFbo->AddColorBuffer(ColorBufferObject::BUFFER_UBYTE, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_LINEAR, false);
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86 |
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87 | mShadowCam = new Camera(mSceneBox.Size().x * 0.5f, mSceneBox.Size().y * 0.5f);
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88 | mShadowCam->SetOrtho(true);
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89 | }
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90 |
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91 |
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92 | ShadowMap::~ShadowMap()
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93 | {
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94 | DEL_PTR(mFbo);
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95 | DEL_PTR(mShadowCam);
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96 | }
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97 |
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98 |
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99 | void ShadowMap::ComputeShadowMap(RenderTraverser *renderer)
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100 | {
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101 | const float xlen = Magnitude(mSceneBox.Diagonal() * 0.5f);
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102 | const float ylen = Magnitude(mSceneBox.Diagonal() * 0.5f);
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103 |
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104 | mShadowCam->SetDirection(mLight->GetDirection());
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105 |
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106 | // set position so that we can see the whole scene
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107 | Vector3 pos = mSceneBox.Center();
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108 |
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109 | pos -= mLight->GetDirection() * Magnitude(mSceneBox.Diagonal() * 0.5f);
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110 | mShadowCam->SetPosition(pos);
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111 |
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112 | mFbo->Bind();
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113 |
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114 | glDrawBuffers(1, mrt);
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115 |
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116 | glPushAttrib(GL_VIEWPORT_BIT);
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117 | glViewport(0, 0, mSize, mSize);
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118 |
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119 | glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
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120 |
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121 | glDisable(GL_LIGHTING);
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122 | glDisable(GL_TEXTURE_2D);
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123 | glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
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124 |
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125 | glPolygonOffset(1.0f, 2000.0f);
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126 | glEnable(GL_POLYGON_OFFSET_FILL);
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127 |
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128 | glShadeModel(GL_FLAT);
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129 | glEnable(GL_DEPTH_TEST);
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130 |
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131 | glMatrixMode(GL_PROJECTION);
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132 | glPushMatrix();
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133 | glLoadIdentity();
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134 |
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135 | // setup projection
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136 | glOrtho(+xlen, -xlen, +ylen, -ylen, 0.0f, Magnitude(mSceneBox.Diagonal()));
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137 |
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138 |
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139 | glMatrixMode(GL_MODELVIEW);
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140 | glPushMatrix();
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141 | glLoadIdentity();
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142 |
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143 | // setup shadow camera
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144 | mShadowCam->SetupCameraView();
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145 |
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146 |
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147 | //////////////
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148 | //-- compute texture matrix
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149 |
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150 | Matrix4x4 lightView, lightProj;
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151 |
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152 | mShadowCam->GetModelViewMatrix(lightView);
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153 | mShadowCam->GetProjectionMatrix(lightProj);
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154 |
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155 | static Matrix4x4 biasMatrix(0.5f, 0.0f, 0.0f, 0.5f,
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156 | 0.0f, 0.5f, 0.0f, 0.5f,
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157 | 0.0f, 0.0f, 0.5f, 0.5f,
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158 | 0.0f, 0.0f, 0.0f, 1.0f); //bias from [-1, 1] to [0, 1]
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159 |
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160 | Matrix4x4 lightProjView = lightView * lightProj;
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161 | mTextureMatrix = lightProjView * biasMatrix;
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162 |
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163 |
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164 | /////////////
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165 | //-- render scene into shadow map
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166 |
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167 | renderer->RenderScene();
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168 |
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169 |
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170 | glDisable(GL_POLYGON_OFFSET_FILL);
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171 | glMatrixMode(GL_MODELVIEW);
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172 | glPopMatrix();
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173 |
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174 | glMatrixMode(GL_PROJECTION);
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175 | glPopMatrix();
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176 |
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177 | glPopAttrib();
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178 |
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179 | /*float *data = new float[mSize * mSize];
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180 |
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181 | GrabDepthBuffer(data, mFbo->GetDepthTex());
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182 | ExportDepthBuffer(data, mSize);
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183 |
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184 | delete [] data;
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185 | */
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186 | PrintGLerror("shadow map");
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187 |
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188 | FrameBufferObject::Release();
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189 | }
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190 |
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191 |
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192 | void ShadowMap::GetTextureMatrix(Matrix4x4 &m) const
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193 | {
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194 | m = mTextureMatrix;
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195 | }
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196 |
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197 |
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198 | unsigned int ShadowMap::GetShadowTexture() const
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199 | {
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200 | return mFbo->GetDepthTex();
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201 | }
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202 |
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203 |
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204 | } // namespace
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