c1f083a67e
git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/branches/OpenSceneGraph-3.2@15105 16af8721-9629-0410-8352-f15c8da7e697
103 lines
4.8 KiB
C++
103 lines
4.8 KiB
C++
char volume_frag[] = "uniform sampler3D baseTexture;\n"
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"uniform float SampleDensityValue;\n"
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"uniform float TransparencyValue;\n"
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"uniform float AlphaFuncValue;\n"
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"\n"
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"varying vec4 cameraPos;\n"
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"varying vec4 vertexPos;\n"
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"varying mat4 texgen;\n"
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"varying vec4 baseColor;\n"
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"\n"
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"void main(void)\n"
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"{\n"
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" vec4 t0 = vertexPos;\n"
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" vec4 te = cameraPos;\n"
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"\n"
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" if (te.x>=0.0 && te.x<=1.0 &&\n"
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" te.y>=0.0 && te.y<=1.0 &&\n"
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" te.z>=0.0 && te.z<=1.0)\n"
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" {\n"
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" // do nothing... te inside volume\n"
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" }\n"
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" else\n"
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" {\n"
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" if (te.x<0.0)\n"
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" {\n"
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" float r = -te.x / (t0.x-te.x);\n"
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" te = te + (t0-te)*r;\n"
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" }\n"
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"\n"
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" if (te.x>1.0)\n"
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" {\n"
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" float r = (1.0-te.x) / (t0.x-te.x);\n"
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" te = te + (t0-te)*r;\n"
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" }\n"
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"\n"
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" if (te.y<0.0)\n"
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" {\n"
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" float r = -te.y / (t0.y-te.y);\n"
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" te = te + (t0-te)*r;\n"
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" }\n"
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"\n"
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" if (te.y>1.0)\n"
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" {\n"
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" float r = (1.0-te.y) / (t0.y-te.y);\n"
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" te = te + (t0-te)*r;\n"
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" }\n"
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"\n"
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" if (te.z<0.0)\n"
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" {\n"
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" float r = -te.z / (t0.z-te.z);\n"
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" te = te + (t0-te)*r;\n"
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" }\n"
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"\n"
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" if (te.z>1.0)\n"
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" {\n"
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" float r = (1.0-te.z) / (t0.z-te.z);\n"
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" te = te + (t0-te)*r;\n"
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" }\n"
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" }\n"
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"\n"
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" t0 = t0 * texgen;\n"
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" te = te * texgen;\n"
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"\n"
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" const float min_iterations = 2.0;\n"
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" const float max_iterations = 2048.0;\n"
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" float num_iterations = ceil(length((te-t0).xyz)/SampleDensityValue);\n"
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" if (num_iterations<min_iterations) num_iterations = min_iterations;\n"
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" else if (num_iterations>max_iterations) num_iterations = max_iterations;\n"
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" else if (num_iterations!=num_iterations) num_iterations = max_iterations;\n"
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"\n"
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" vec3 deltaTexCoord=(te-t0).xyz/(num_iterations-1.0);\n"
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" vec3 texcoord = t0.xyz;\n"
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"\n"
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" vec4 fragColor = vec4(0.0, 0.0, 0.0, 0.0);\n"
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" while(num_iterations>0.0)\n"
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" {\n"
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" vec4 color = texture3D( baseTexture, texcoord);\n"
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" float r = color[3]*TransparencyValue;\n"
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" if (r>AlphaFuncValue)\n"
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" {\n"
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" fragColor.xyz = fragColor.xyz*(1.0-r)+color.xyz*r;\n"
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" fragColor.w += r;\n"
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" }\n"
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"\n"
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" if (fragColor.w<color.w)\n"
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" {\n"
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" fragColor = color;\n"
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" }\n"
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" texcoord += deltaTexCoord;\n"
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"\n"
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" --num_iterations;\n"
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" }\n"
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"\n"
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" fragColor.w *= TransparencyValue;\n"
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" if (fragColor.w>1.0) fragColor.w = 1.0;\n"
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"\n"
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" fragColor *= baseColor;\n"
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"\n"
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" if (fragColor.w<AlphaFuncValue) discard;\n"
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" gl_FragColor = fragColor;\n"
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"}\n"
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"\n";
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