[2891] | 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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[2911] | 6 | #include "Polygon3.h"
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| 7 | #include "Polyhedron.h"
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| 8 |
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[2891] | 9 | #include <IL/il.h>
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| 10 | #include <assert.h>
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| 11 |
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[2911] | 12 |
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[2891] | 13 | using namespace std;
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| 14 |
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| 15 |
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| 16 | namespace CHCDemoEngine
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| 17 | {
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| 18 |
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[2931] | 19 | static CGprogram sCgShadowProgram;
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| 20 | static CGparameter sShadowParam;
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[2891] | 21 |
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[2931] | 22 |
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[2911] | 23 | static Polyhedron *polyhedron = NULL;
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[2929] | 24 | static Polyhedron *lightPoly = NULL;
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[2911] | 25 |
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| 26 |
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[2891] | 27 | static void PrintGLerror(char *msg)
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| 28 | {
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| 29 | GLenum errCode;
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| 30 | const GLubyte *errStr;
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| 31 |
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| 32 | if ((errCode = glGetError()) != GL_NO_ERROR)
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| 33 | {
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| 34 | errStr = gluErrorString(errCode);
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| 35 | fprintf(stderr,"OpenGL ERROR: %s: %s\n", errStr, msg);
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| 36 | }
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| 37 | }
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| 38 |
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| 39 |
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[2936] | 40 | static Polyhedron *CreatePolyhedron(const Matrix4x4 &lightMatrix,
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| 41 | const AxisAlignedBox3 &sceneBox)
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[2931] | 42 | {
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| 43 | Frustum frustum(lightMatrix);
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[2891] | 44 |
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[2931] | 45 | vector<Plane3> clipPlanes;
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[2891] | 46 |
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[2931] | 47 | for (int i = 0; i < 6; ++ i)
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| 48 | {
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| 49 | ////////////
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| 50 | //-- normalize the coefficients
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[2891] | 51 |
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[2931] | 52 | // the clipping planes look outward the frustum,
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| 53 | // so distances > 0 mean that a point is outside
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| 54 | const float invLength = -1.0f / Magnitude(frustum.mClipPlanes[i].mNormal);
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| 55 |
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| 56 | frustum.mClipPlanes[i].mD *= invLength;
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| 57 | frustum.mClipPlanes[i].mNormal *= invLength;
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| 58 | }
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| 59 |
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[2939] | 60 | // first create near plane because of precision issues
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| 61 | clipPlanes.push_back(frustum.mClipPlanes[4]);
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| 62 |
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[2931] | 63 | clipPlanes.push_back(frustum.mClipPlanes[0]);
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| 64 | clipPlanes.push_back(frustum.mClipPlanes[1]);
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| 65 | clipPlanes.push_back(frustum.mClipPlanes[2]);
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| 66 | clipPlanes.push_back(frustum.mClipPlanes[3]);
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[2936] | 67 | clipPlanes.push_back(frustum.mClipPlanes[5]);
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| 68 |
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[2931] | 69 | return Polyhedron::CreatePolyhedron(clipPlanes, sceneBox);
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| 70 | }
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| 71 |
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| 72 |
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[2891] | 73 | static void GrabDepthBuffer(float *data, GLuint depthTexture)
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| 74 | {
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| 75 | glEnable(GL_TEXTURE_2D);
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| 76 | glBindTexture(GL_TEXTURE_2D, depthTexture);
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| 77 |
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| 78 | glGetTexImage(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, GL_FLOAT, data);
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| 79 |
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| 80 | glBindTexture(GL_TEXTURE_2D, 0);
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| 81 | glDisable(GL_TEXTURE_2D);
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| 82 | }
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| 83 |
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| 84 |
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| 85 | static void ExportDepthBuffer(float *data, int size)
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| 86 | {
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| 87 | ilInit();
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| 88 | assert(ilGetError() == IL_NO_ERROR);
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| 89 |
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| 90 | ILstring filename = ILstring("shadow.tga");
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| 91 | ilRegisterType(IL_FLOAT);
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| 92 |
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| 93 | const int depth = 1;
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| 94 | const int bpp = 1;
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| 95 |
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| 96 | if (!ilTexImage(size, size, depth, bpp, IL_LUMINANCE, IL_FLOAT, data))
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| 97 | {
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| 98 | cerr << "IL error " << ilGetError() << endl;
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| 99 |
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| 100 | ilShutDown();
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| 101 | assert(ilGetError() == IL_NO_ERROR);
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| 102 |
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| 103 | return;
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| 104 | }
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| 105 |
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| 106 | if (!ilSaveImage(filename))
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| 107 | {
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| 108 | cerr << "TGA write error " << ilGetError() << endl;
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| 109 | }
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| 110 |
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| 111 | ilShutDown();
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| 112 | assert(ilGetError() == IL_NO_ERROR);
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| 113 |
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| 114 | cout << "exported depth buffer" << endl;
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| 115 | }
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| 116 |
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| 117 |
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| 118 |
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[2924] | 119 | static AxisAlignedBox3 GetExtremalPoints(const Matrix4x4 &m,
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| 120 | const VertexArray &pts)
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| 121 | {
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| 122 | AxisAlignedBox3 extremalPoints;
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| 123 | extremalPoints.Initialize();
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| 124 |
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| 125 | VertexArray::const_iterator it, it_end = pts.end();
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| 126 |
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| 127 | for (it = pts.begin(); it != it_end; ++ it)
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| 128 | {
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| 129 | Vector3 pt = *it;
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| 130 | pt = m * pt;
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| 131 |
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| 132 | extremalPoints.Include(pt);
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| 133 | }
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| 134 |
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| 135 | return extremalPoints;
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| 136 | }
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| 137 |
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| 138 |
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[2952] | 139 | ShadowMap::ShadowMap(DirectionalLight *light, int size, const AxisAlignedBox3 &sceneBox, Camera *cam):
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[2897] | 140 | mSceneBox(sceneBox), mSize(size), mCamera(cam), mLight(light)
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[2891] | 141 | {
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| 142 | mFbo = new FrameBufferObject(size, size, FrameBufferObject::DEPTH_32, true);
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[2947] | 143 | // need a color buffer to keep opengl happy
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[2891] | 144 | mFbo->AddColorBuffer(ColorBufferObject::BUFFER_UBYTE, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_LINEAR, false);
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| 145 |
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[2947] | 146 | mShadowCam = new Camera(mSize, mSize);
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[2891] | 147 | mShadowCam->SetOrtho(true);
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| 148 | }
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| 149 |
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| 150 |
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[2894] | 151 | ShadowMap::~ShadowMap()
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[2891] | 152 | {
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| 153 | DEL_PTR(mFbo);
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[2897] | 154 | DEL_PTR(mShadowCam);
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[2891] | 155 | }
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| 156 |
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| 157 |
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[2943] | 158 | static void DrawPoly(Polyhedron *poly, const Vector3 &color)
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[2891] | 159 | {
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[2929] | 160 | if (!poly) return;
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[2911] | 161 |
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[2929] | 162 | for (size_t i = 0; i < poly->NumPolygons(); ++ i)
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[2911] | 163 | {
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[2929] | 164 | glColor3f(color.x, color.y, color.z);
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[2911] | 165 |
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| 166 | glBegin(GL_LINE_LOOP);
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| 167 |
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[2929] | 168 | Polygon3 *p = poly->GetPolygons()[i];
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[2911] | 169 |
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[2929] | 170 | for (size_t j = 0; j < p->mVertices.size(); ++ j)
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[2911] | 171 | {
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[2929] | 172 | Vector3 v = p->mVertices[j];
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[2911] | 173 | glVertex3d(v.x, v.y, v.z);
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| 174 | }
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| 175 |
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| 176 | glEnd();
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| 177 | }
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| 178 | }
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| 179 |
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| 180 |
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[2929] | 181 | void ShadowMap::DrawPolys()
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[2911] | 182 | {
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[2943] | 183 | DrawPoly(lightPoly, Vector3(1, 0, 1));
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| 184 | DrawPoly(polyhedron, Vector3(0, 1, 0));
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[2913] | 185 | }
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[2911] | 186 |
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[2913] | 187 |
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[2944] | 188 | // z0 is the point that lies on the parallel plane to the near plane through e (A)
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| 189 | //and on the near plane of the C frustum (the plane z = bZmax) and on the line x = e.x
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| 190 | Vector3 ShadowMap::GetLightSpaceZ0(const Matrix4x4 &lightSpace,
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| 191 | const Vector3 &e,
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| 192 | const float maxZ,
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| 193 | const Vector3 &eyeDir) const
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| 194 | {
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| 195 | // to calculate the parallel plane to the near plane through e we
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| 196 | // calculate the plane A with the three points
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| 197 | Plane3 planeA(e, eyeDir);
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| 198 |
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| 199 | planeA.Transform(lightSpace);
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| 200 |
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| 201 | // get the parameters of A from the plane equation n dot d = 0
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| 202 | const float d = planeA.mD;
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| 203 | const Vector3 n = planeA.mNormal;
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| 204 |
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| 205 | // transform to light space
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| 206 | const Vector3 e_ls = lightSpace * e;
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| 207 |
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| 208 | Vector3 z0;
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| 209 |
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| 210 | z0.x = e_ls.x;
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| 211 | z0.y = (d - n.z * maxZ - n.x * e_ls.x) / n.y;
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| 212 | z0.z = maxZ;
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| 213 |
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| 214 | return z0;
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| 215 | //return V3(e_ls.x(),(d-n.z()*b_lsZmax-n.x()*e_ls.x())/n.y(),b_lsZmax);
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| 216 | }
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| 217 |
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| 218 |
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| 219 | float ShadowMap::ComputeNOpt(const Matrix4x4 &lightSpace,
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| 220 | const AxisAlignedBox3 &extremalPoints,
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| 221 | const VertexArray &body) const
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| 222 | {
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| 223 | const Vector3 nearPt = GetNearCameraPointE(body);
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| 224 | const Vector3 eyeDir = mCamera->GetDirection();
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| 225 |
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| 226 | Matrix4x4 eyeView;
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| 227 | mCamera->GetModelViewMatrix(eyeView);
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| 228 |
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| 229 | const Matrix4x4 invLightSpace = Invert(lightSpace);
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| 230 |
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| 231 | const Vector3 z0_ls = GetLightSpaceZ0(lightSpace, nearPt, extremalPoints.Max().z, eyeDir);
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| 232 | const Vector3 z1_ls = Vector3(z0_ls.x, z0_ls.y, extremalPoints.Min().z);
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| 233 |
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| 234 | // transform back to world space
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| 235 | const Vector3 z0_ws = invLightSpace * z0_ls;
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| 236 | const Vector3 z1_ws = invLightSpace * z1_ls;
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| 237 |
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| 238 | // transform to eye space
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| 239 | const Vector3 z0_es = eyeView * z0_ws;
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| 240 | const Vector3 z1_es = eyeView * z1_ws;
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| 241 |
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| 242 | const float z0 = z0_es.z;
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| 243 | const float z1 = z1_es.z;
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| 244 |
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| 245 | cout << "z0 ls: " << z0_ls << " z1 ls: " << z1_ls << endl;
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| 246 | cout << "z0: " << z0_es << " z1: " << z1_es << endl;
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| 247 |
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| 248 | const float d = fabs(extremalPoints.Max()[2] - extremalPoints.Min()[2]);
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| 249 |
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| 250 | const float n = d / (sqrt(z1 / z0) - 1.0f);
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| 251 |
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| 252 | return n;
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| 253 | }
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| 254 |
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| 255 |
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[2920] | 256 | float ShadowMap::ComputeN(const AxisAlignedBox3 &extremalPoints) const
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[2913] | 257 | {
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[2944] | 258 | const float nearPlane = mCamera->GetNear();
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[2916] | 259 |
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[2920] | 260 | const float d = fabs(extremalPoints.Max()[2] - extremalPoints.Min()[2]);
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| 261 |
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[2916] | 262 | const float dotProd = DotProd(mCamera->GetDirection(), mShadowCam->GetDirection());
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| 263 | const float sinGamma = sin(fabs(acos(dotProd)));
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| 264 |
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[2944] | 265 | // test for values close to zero
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| 266 | if (sinGamma < 1e-6f) return 1e6f;
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| 267 |
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[2954] | 268 | const float scale = 2.0f;
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| 269 | return scale * (nearPlane + sqrt(nearPlane * (nearPlane + d * sinGamma))) / sinGamma;
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[2916] | 270 | }
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| 271 |
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| 272 |
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[2924] | 273 | Matrix4x4 ShadowMap::CalcLispSMTransform(const Matrix4x4 &lightSpace,
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[2920] | 274 | const AxisAlignedBox3 &extremalPoints,
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[2924] | 275 | const VertexArray &body
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[2920] | 276 | )
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[2917] | 277 | {
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[2928] | 278 | AxisAlignedBox3 bounds_ls = GetExtremalPoints(lightSpace, body);
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| 279 |
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[2913] | 280 | ///////////////
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[2915] | 281 | //-- We apply the lispsm algorithm in order to calculate an optimal light projection matrix
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[2924] | 282 | //-- first find the free parameter values n, and P (the projection center), and the projection depth
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| 283 |
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[2945] | 284 | const float n = ComputeN(bounds_ls);
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| 285 | //const float n = ComputeNOpt(lightSpace, extremalPoints, body); cout << "n: " << n << endl;
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[2924] | 286 |
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[2944] | 287 | if (n >= 1e6f) // light direction nearly parallel to view => switch to uniform
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| 288 | return IdentityMatrix();
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| 289 |
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[2924] | 290 | const Vector3 nearPt = GetNearCameraPointE(body);
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[2933] | 291 |
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[2915] | 292 | //get the coordinates of the near camera point in light space
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[2924] | 293 | const Vector3 lsNear = lightSpace * nearPt;
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[2915] | 294 |
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[2939] | 295 | // the start point has the x and y coordinate of e, the z coord of the near plane of the light volume
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[2924] | 296 | const Vector3 startPt = Vector3(lsNear.x, lsNear.y, bounds_ls.Max().z);
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[2943] | 297 |
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[2915] | 298 | // the new projection center
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[2936] | 299 | const Vector3 projCenter = startPt + Vector3::UNIT_Z() * n;
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[2915] | 300 |
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| 301 | //construct a translation that moves to the projection center
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| 302 | const Matrix4x4 projectionCenter = TranslationMatrix(-projCenter);
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| 303 |
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[2916] | 304 | // light space y size
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[2933] | 305 | const float d = fabs(bounds_ls.Max()[2] - bounds_ls.Min()[2]);
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[2922] | 306 |
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[2924] | 307 | const float dy = fabs(bounds_ls.Max()[1] - bounds_ls.Min()[1]);
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| 308 | const float dx = fabs(bounds_ls.Max()[0] - bounds_ls.Min()[0]);
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[2922] | 309 |
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[2924] | 310 |
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[2915] | 311 |
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[2928] | 312 | //////////
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[2924] | 313 | //-- now apply these values to construct the perspective lispsm matrix
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| 314 |
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| 315 | Matrix4x4 matLispSM;
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| 316 |
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[2939] | 317 | matLispSM = GetFrustum(-1.0, 1.0, -1.0, 1.0, n, n + d);
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[2924] | 318 |
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| 319 | // translate to the projection center
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[2920] | 320 | matLispSM = projectionCenter * matLispSM;
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[2915] | 321 |
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| 322 | // transform into OpenGL right handed system
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[2920] | 323 | Matrix4x4 refl = ScaleMatrix(1.0f, 1.0f, -1.0f);
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| 324 | matLispSM *= refl;
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[2924] | 325 |
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[2920] | 326 | return matLispSM;
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[2915] | 327 | }
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| 328 |
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[2925] | 329 | #if 0
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| 330 | Vector3 ShadowMap::GetNearCameraPointE(const VertexArray &pts) const
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| 331 | {
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| 332 | float maxDist = -1e25f;
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| 333 | Vector3 nearest = Vector3::ZERO();
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[2915] | 334 |
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[2925] | 335 | Matrix4x4 eyeView;
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| 336 | mCamera->GetModelViewMatrix(eyeView);
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| 337 |
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| 338 | VertexArray newPts;
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| 339 | polyhedron->CollectVertices(newPts);
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| 340 |
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| 341 | //the LVS volume is always in front of the camera
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| 342 | VertexArray::const_iterator it, it_end = pts.end();
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| 343 |
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| 344 | for (it = pts.begin(); it != it_end; ++ it)
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| 345 | {
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| 346 | Vector3 pt = *it;
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| 347 | Vector3 ptE = eyeView * pt;
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[2943] | 348 |
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[2925] | 349 | if (ptE.z > 0) cerr <<"should not happen " << ptE.z << endl;
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| 350 | else
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| 351 | if (ptE.z > maxDist)
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| 352 | {
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| 353 | cout << " d " << ptE.z;
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| 354 |
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| 355 | maxDist = ptE.z;
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| 356 | nearest = pt;
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| 357 | }
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| 358 | }
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| 359 |
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[2933] | 360 | // return Invert(eyeView) * nearest;
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[2925] | 361 | return nearest;
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| 362 | }
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| 363 |
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| 364 | #else
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| 365 |
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[2920] | 366 | Vector3 ShadowMap::GetNearCameraPointE(const VertexArray &pts) const
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[2919] | 367 | {
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[2925] | 368 | VertexArray newPts;
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| 369 | polyhedron->CollectVertices(newPts);
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| 370 |
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[2922] | 371 | Vector3 nearest = Vector3::ZERO();
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| 372 | float minDist = 1e25f;
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[2920] | 373 |
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[2924] | 374 | const Vector3 camPos = mCamera->GetPosition();
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[2920] | 375 |
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[2925] | 376 | VertexArray::const_iterator it, it_end = newPts.end();
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[2920] | 377 |
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[2925] | 378 | for (it = newPts.begin(); it != it_end; ++ it)
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[2920] | 379 | {
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| 380 | Vector3 pt = *it;
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| 381 |
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| 382 | const float dist = SqrDistance(pt, camPos);
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| 383 |
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| 384 | if (dist < minDist)
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| 385 | {
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| 386 | minDist = dist;
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| 387 | nearest = pt;
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| 388 | }
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| 389 | }
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| 390 |
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| 391 | return nearest;
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| 392 | }
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| 393 |
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[2925] | 394 | #endif
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[2920] | 395 |
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[2933] | 396 | Vector3 ShadowMap::GetProjViewDir(const Matrix4x4 &lightSpace,
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| 397 | const VertexArray &pts) const
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[2920] | 398 | {
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[2919] | 399 | //get the point in the LVS volume that is nearest to the camera
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[2920] | 400 | const Vector3 e = GetNearCameraPointE(pts);
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| 401 |
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[2919] | 402 | //construct edge to transform into light-space
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[2920] | 403 | const Vector3 b = e + mCamera->GetDirection();
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[2919] | 404 | //transform to light-space
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[2920] | 405 | const Vector3 e_lp = lightSpace * e;
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| 406 | const Vector3 b_lp = lightSpace * b;
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| 407 |
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| 408 | Vector3 projDir(b_lp - e_lp);
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| 409 |
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[2919] | 410 | //project the view direction into the shadow map plane
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[2932] | 411 | projDir.y = .0f;
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[2920] | 412 |
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| 413 | return Normalize(projDir);
|
---|
[2919] | 414 | }
|
---|
| 415 |
|
---|
| 416 |
|
---|
[2915] | 417 | bool ShadowMap::CalcLightProjection(Matrix4x4 &lightProj)
|
---|
| 418 | {
|
---|
| 419 | ///////////////////
|
---|
| 420 | //-- First step: calc frustum clipped by scene box
|
---|
| 421 |
|
---|
[2922] | 422 | DEL_PTR(polyhedron);
|
---|
[2915] | 423 | polyhedron = CalcClippedFrustum(mSceneBox);
|
---|
| 424 |
|
---|
| 425 | if (!polyhedron) return false; // something is wrong
|
---|
| 426 |
|
---|
| 427 | // include the part of the light volume that "sees" the frustum
|
---|
| 428 | // we only require frustum vertices
|
---|
| 429 |
|
---|
| 430 | VertexArray frustumPoints;
|
---|
[2939] | 431 | IncludeLightVolume(*polyhedron, frustumPoints, mLight->GetDirection(), mSceneBox);
|
---|
[2915] | 432 |
|
---|
| 433 |
|
---|
| 434 | ///////////////
|
---|
| 435 | //-- transform points from world view to light view and calculate extremal points
|
---|
| 436 |
|
---|
| 437 | Matrix4x4 lightView;
|
---|
| 438 | mShadowCam->GetModelViewMatrix(lightView);
|
---|
| 439 |
|
---|
[2920] | 440 | const AxisAlignedBox3 extremalPoints = GetExtremalPoints(lightView, frustumPoints);
|
---|
[2913] | 441 |
|
---|
[2920] | 442 | // we use directional lights, so the projection can be set to identity
|
---|
| 443 | lightProj = IdentityMatrix();
|
---|
[2913] | 444 |
|
---|
[2922] | 445 | // switch coordinate system to that used in the lispsm algorithm for calculations
|
---|
| 446 | Matrix4x4 transform2LispSM = ZeroMatrix();
|
---|
| 447 |
|
---|
| 448 | transform2LispSM.x[0][0] = 1.0f;
|
---|
[2934] | 449 | transform2LispSM.x[1][2] = -1.0f; // y => -z
|
---|
[2924] | 450 | transform2LispSM.x[2][1] = 1.0f; // z => y
|
---|
[2922] | 451 | transform2LispSM.x[3][3] = 1.0f;
|
---|
| 452 |
|
---|
[2936] | 453 |
|
---|
[2922] | 454 | //switch to the lightspace used in the article
|
---|
[2936] | 455 | lightProj *= transform2LispSM;
|
---|
[2922] | 456 |
|
---|
[2924] | 457 | const Vector3 projViewDir = GetProjViewDir(lightView * lightProj, frustumPoints);
|
---|
[2916] | 458 |
|
---|
[2952] | 459 | //do DirectionalLight Space Perspective shadow mapping
|
---|
[2922] | 460 | //rotate the lightspace so that the projected light view always points upwards
|
---|
| 461 | //calculate a frame matrix that uses the projViewDir[lightspace] as up vector
|
---|
[2917] | 462 | //look(from position, into the direction of the projected direction, with unchanged up-vector)
|
---|
[2938] | 463 | //const Matrix4x4 frame = MyLookAt2(Vector3::ZERO(), projViewDir, Vector3::UNIT_Y());
|
---|
[2944] | 464 | const Matrix4x4 frame = LookAt(Vector3::ZERO(), projViewDir, Vector3::UNIT_Y());
|
---|
[2917] | 465 |
|
---|
[2936] | 466 | lightProj *= frame;
|
---|
[2924] | 467 |
|
---|
[2917] | 468 | const Matrix4x4 matLispSM =
|
---|
[2920] | 469 | CalcLispSMTransform(lightView * lightProj, extremalPoints, frustumPoints);
|
---|
[2917] | 470 |
|
---|
[2936] | 471 | lightProj *= matLispSM;
|
---|
[2917] | 472 |
|
---|
[2922] | 473 | // change back to GL coordinate system
|
---|
| 474 | Matrix4x4 transformToGL = ZeroMatrix();
|
---|
| 475 |
|
---|
[2940] | 476 | transformToGL.x[0][0] = 1.0f;
|
---|
| 477 | transformToGL.x[1][2] = 1.0f; // z => y
|
---|
[2934] | 478 | transformToGL.x[2][1] = -1.0f; // y => -z
|
---|
[2940] | 479 | transformToGL.x[3][3] = 1.0f;
|
---|
[2922] | 480 |
|
---|
[2936] | 481 | lightProj *= transformToGL;
|
---|
[2922] | 482 |
|
---|
[2920] | 483 | AxisAlignedBox3 lightPts = GetExtremalPoints(lightView * lightProj, frustumPoints);
|
---|
| 484 |
|
---|
[2917] | 485 | // focus projection matrix on the extremal points => scale to unit cube
|
---|
[2922] | 486 | Matrix4x4 scaleTranslate = GetFittingProjectionMatrix(lightPts);
|
---|
[2917] | 487 |
|
---|
[2939] | 488 | lightProj = lightProj * scaleTranslate;
|
---|
| 489 |
|
---|
| 490 | Matrix4x4 mymat = lightView * lightProj;
|
---|
| 491 |
|
---|
| 492 | AxisAlignedBox3 lightPtsNew = GetExtremalPoints(mymat, frustumPoints);
|
---|
| 493 |
|
---|
[2920] | 494 | // we have to flip the signs in order to tranform to opengl right handed system
|
---|
| 495 | Matrix4x4 refl = ScaleMatrix(1, 1, -1);
|
---|
| 496 | lightProj *= refl;
|
---|
[2916] | 497 |
|
---|
[2913] | 498 | return true;
|
---|
[2911] | 499 | }
|
---|
| 500 |
|
---|
| 501 |
|
---|
[2913] | 502 | Polyhedron *ShadowMap::CalcClippedFrustum(const AxisAlignedBox3 &box) const
|
---|
| 503 | {
|
---|
[2931] | 504 | Polyhedron *p = mCamera->ComputeFrustum();
|
---|
| 505 |
|
---|
| 506 | Polyhedron *clippedPolyhedron = box.CalcIntersection(*p);
|
---|
[2913] | 507 |
|
---|
[2931] | 508 | DEL_PTR(p);
|
---|
[2913] | 509 |
|
---|
[2931] | 510 | return clippedPolyhedron;
|
---|
| 511 | }
|
---|
[2913] | 512 |
|
---|
| 513 |
|
---|
[2931] | 514 | //calculates the up vector for the light coordinate frame
|
---|
| 515 | static Vector3 CalcUpVec(const Vector3 viewDir, const Vector3 lightDir)
|
---|
| 516 | {
|
---|
| 517 | //we do what gluLookAt does...
|
---|
| 518 | //left is the normalized vector perpendicular to lightDir and viewDir
|
---|
| 519 | //this means left is the normalvector of the yz-plane from the paper
|
---|
| 520 | Vector3 left = CrossProd(lightDir, viewDir);
|
---|
[2913] | 521 |
|
---|
[2931] | 522 | //we now can calculate the rotated(in the yz-plane) viewDir vector
|
---|
| 523 | //and use it as up vector in further transformations
|
---|
| 524 | Vector3 up = CrossProd(left, lightDir);
|
---|
[2913] | 525 |
|
---|
[2931] | 526 | return Normalize(up);
|
---|
[2913] | 527 | }
|
---|
| 528 |
|
---|
| 529 |
|
---|
[2932] | 530 | void ShadowMap::GetTextureMatrix(Matrix4x4 &m) const
|
---|
| 531 | {
|
---|
| 532 | m = mTextureMatrix;
|
---|
| 533 | }
|
---|
| 534 |
|
---|
| 535 |
|
---|
| 536 | unsigned int ShadowMap::GetDepthTexture() const
|
---|
| 537 | {
|
---|
| 538 | return mFbo->GetDepthTex();
|
---|
| 539 | }
|
---|
| 540 |
|
---|
| 541 | unsigned int ShadowMap::GetShadowColorTexture() const
|
---|
| 542 | {
|
---|
| 543 | return mFbo->GetColorBuffer(0)->GetTexture();
|
---|
| 544 |
|
---|
| 545 | }
|
---|
| 546 |
|
---|
| 547 |
|
---|
| 548 | void ShadowMap::IncludeLightVolume(const Polyhedron &polyhedron,
|
---|
| 549 | VertexArray &frustumPoints,
|
---|
| 550 | const Vector3 lightDir,
|
---|
| 551 | const AxisAlignedBox3 &sceneBox
|
---|
| 552 | )
|
---|
| 553 | {
|
---|
| 554 | // we don't need closed form anymore => just store vertices
|
---|
| 555 | VertexArray vertices;
|
---|
| 556 | polyhedron.CollectVertices(vertices);
|
---|
| 557 |
|
---|
| 558 | // we 'look' at each point and calculate intersections of rays with scene bounding box
|
---|
| 559 | VertexArray::const_iterator it, it_end = vertices.end();
|
---|
| 560 |
|
---|
| 561 | for (it = vertices.begin(); it != it_end; ++ it)
|
---|
| 562 | {
|
---|
| 563 | Vector3 v = *it;
|
---|
| 564 |
|
---|
| 565 | frustumPoints.push_back(v);
|
---|
| 566 |
|
---|
[2939] | 567 | // hack: start at point which is guaranteed to be outside of box
|
---|
[2932] | 568 | v -= Magnitude(mSceneBox.Diagonal()) * lightDir;
|
---|
| 569 |
|
---|
| 570 | SimpleRay ray(v, lightDir);
|
---|
| 571 |
|
---|
| 572 | float tNear, tFar;
|
---|
| 573 |
|
---|
| 574 | if (sceneBox.Intersects(ray, tNear, tFar))
|
---|
| 575 | {
|
---|
| 576 | Vector3 newpt = ray.Extrap(tNear);
|
---|
| 577 | frustumPoints.push_back(newpt);
|
---|
| 578 | }
|
---|
| 579 | }
|
---|
| 580 | }
|
---|
| 581 |
|
---|
| 582 |
|
---|
[2911] | 583 | void ShadowMap::ComputeShadowMap(RenderTraverser *renderer, const Matrix4x4 &projView)
|
---|
| 584 | {
|
---|
[2891] | 585 | mFbo->Bind();
|
---|
[2892] | 586 |
|
---|
[2891] | 587 | glDrawBuffers(1, mrt);
|
---|
| 588 |
|
---|
| 589 | glPushAttrib(GL_VIEWPORT_BIT);
|
---|
| 590 | glViewport(0, 0, mSize, mSize);
|
---|
| 591 |
|
---|
| 592 | glDisable(GL_LIGHTING);
|
---|
| 593 | glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
|
---|
| 594 |
|
---|
| 595 | glShadeModel(GL_FLAT);
|
---|
| 596 |
|
---|
| 597 |
|
---|
[2942] | 598 | /////////////
|
---|
| 599 | //-- render scene into shadow map
|
---|
[2894] | 600 |
|
---|
[2942] | 601 | _Render(renderer);
|
---|
[2911] | 602 |
|
---|
[2939] | 603 |
|
---|
[2913] | 604 | //////////////
|
---|
| 605 | //-- compute texture matrix
|
---|
[2925] | 606 |
|
---|
[2894] | 607 | static Matrix4x4 biasMatrix(0.5f, 0.0f, 0.0f, 0.5f,
|
---|
| 608 | 0.0f, 0.5f, 0.0f, 0.5f,
|
---|
| 609 | 0.0f, 0.0f, 0.5f, 0.5f,
|
---|
[2911] | 610 | 0.0f, 0.0f, 0.0f, 1.0f);
|
---|
[2894] | 611 |
|
---|
[2911] | 612 | mTextureMatrix = mLightProjView * biasMatrix;
|
---|
[2894] | 613 |
|
---|
[2891] | 614 | glPopAttrib();
|
---|
[2928] | 615 |
|
---|
[2943] | 616 | glShadeModel(GL_SMOOTH);
|
---|
[2928] | 617 | glEnable(GL_LIGHTING);
|
---|
| 618 | glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
|
---|
| 619 |
|
---|
[2913] | 620 | #if 0
|
---|
[2911] | 621 | float *data = new float[mSize * mSize];
|
---|
[2891] | 622 |
|
---|
| 623 | GrabDepthBuffer(data, mFbo->GetDepthTex());
|
---|
| 624 | ExportDepthBuffer(data, mSize);
|
---|
| 625 |
|
---|
[2892] | 626 | delete [] data;
|
---|
[2911] | 627 |
|
---|
[2892] | 628 | PrintGLerror("shadow map");
|
---|
[2913] | 629 | #endif
|
---|
[2942] | 630 |
|
---|
[2891] | 631 | FrameBufferObject::Release();
|
---|
| 632 | }
|
---|
| 633 |
|
---|
| 634 |
|
---|
[2931] | 635 | void ShadowMap::RenderShadowView(RenderTraverser *renderer, const Matrix4x4 &projView)
|
---|
| 636 | {
|
---|
[2942] | 637 | glEnable(GL_LIGHTING);
|
---|
[2943] | 638 |
|
---|
[2942] | 639 | _Render(renderer);
|
---|
| 640 |
|
---|
[2943] | 641 | /*glDisable(GL_LIGHTING);
|
---|
| 642 | glDisable(GL_DEPTH_TEST);
|
---|
| 643 |
|
---|
| 644 | //glLineWidth(2);
|
---|
| 645 | Polyhedron *hpoly = CreatePolyhedron(projView, mSceneBox);
|
---|
| 646 | DrawPoly(hpoly, Vector3(1, 1, 1));
|
---|
| 647 |
|
---|
| 648 | DEL_PTR(hpoly);
|
---|
| 649 |
|
---|
| 650 | glEnable(GL_LIGHTING);
|
---|
| 651 | glEnable(GL_DEPTH_TEST);*/
|
---|
| 652 |
|
---|
[2942] | 653 | glDisable(GL_POLYGON_OFFSET_FILL);
|
---|
| 654 | }
|
---|
| 655 |
|
---|
| 656 |
|
---|
| 657 | void ShadowMap::_Render(RenderTraverser *renderer)
|
---|
| 658 | {
|
---|
[2939] | 659 | const Vector3 dir = mLight->GetDirection();
|
---|
[2931] | 660 |
|
---|
| 661 | mShadowCam->SetDirection(dir);
|
---|
| 662 |
|
---|
| 663 | // set position so that we can see the whole scene
|
---|
| 664 | Vector3 pos = mSceneBox.Center();
|
---|
| 665 | pos -= dir * Magnitude(mSceneBox.Diagonal() * 0.5f);
|
---|
| 666 |
|
---|
[2932] | 667 | mShadowCam->SetPosition(mCamera->GetPosition());
|
---|
| 668 |
|
---|
| 669 | Vector3 upVec = CalcUpVec(mCamera->GetDirection(), dir);
|
---|
[2944] | 670 | Matrix4x4 lightView = LookAt(mShadowCam->GetPosition(), dir, upVec);
|
---|
[2932] | 671 |
|
---|
| 672 | mShadowCam->mViewOrientation = lightView;
|
---|
| 673 |
|
---|
[2931] | 674 | glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
|
---|
| 675 |
|
---|
[2944] | 676 | glPolygonOffset(5.0f, 100.0f);
|
---|
[2931] | 677 | glEnable(GL_POLYGON_OFFSET_FILL);
|
---|
[2932] | 678 |
|
---|
| 679 | Matrix4x4 lightProj;
|
---|
[2931] | 680 | CalcLightProjection(lightProj);
|
---|
| 681 |
|
---|
| 682 | glMatrixMode(GL_PROJECTION);
|
---|
| 683 | glPushMatrix();
|
---|
| 684 | glLoadMatrixf((float *)lightProj.x);
|
---|
| 685 |
|
---|
| 686 | mLightProjView = lightView * lightProj;
|
---|
[2932] | 687 |
|
---|
[2931] | 688 | DEL_PTR(lightPoly);
|
---|
| 689 | lightPoly = CreatePolyhedron(mLightProjView, mSceneBox);
|
---|
| 690 |
|
---|
| 691 | glMatrixMode(GL_MODELVIEW);
|
---|
| 692 | glPushMatrix();
|
---|
[2951] | 693 |
|
---|
[2932] | 694 | mShadowCam->SetupCameraView();
|
---|
[2931] | 695 |
|
---|
[2942] | 696 |
|
---|
[2931] | 697 | /////////////
|
---|
| 698 | //-- render scene into shadow map
|
---|
| 699 |
|
---|
| 700 | renderer->RenderScene();
|
---|
| 701 |
|
---|
[2943] | 702 |
|
---|
[2931] | 703 | glMatrixMode(GL_PROJECTION);
|
---|
| 704 | glPopMatrix();
|
---|
| 705 |
|
---|
[2951] | 706 | glMatrixMode(GL_MODELVIEW);
|
---|
| 707 | glPopMatrix();
|
---|
| 708 |
|
---|
[2931] | 709 |
|
---|
[2942] | 710 | glDisable(GL_POLYGON_OFFSET_FILL);
|
---|
[2931] | 711 | }
|
---|
[2891] | 712 | } // namespace
|
---|