fa068d7810
git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@14919 178a84e3-b1eb-0310-8ba1-8eac791a3b58
46 lines
875 B
GLSL
46 lines
875 B
GLSL
#version 130
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uniform sampler2D halft; // half is a reserved word
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uniform sampler2D quarter;
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uniform sampler2D eighth;
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void main()
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{
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vec3 val[3];
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val[0] = texture2D(halft, gl_TexCoord[0].xy).xyz;
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val[1] = texture2D(quarter, gl_TexCoord[0].xy).xyz;
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val[2] = texture2D(eighth, gl_TexCoord[0].xy).xyz;
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// Find the first level with a penumbra value
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int i;
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float q = 0.0;
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float outval = 1.0;
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float hasshadow = dot(vec3(1.0), vec3(val[0].z, val[1].z, val[2].z));
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if (hasshadow > 0.9)
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{
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for (i = 0; i < 3; i++)
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{
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if (val[i].z > 0.9)
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{
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q = val[i].y;
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break;
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}
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}
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q *= 8.0;
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q = max(1.0, q);
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q = log2(q);
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q = min(1.9, q);
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// q is now between 0 and 1.9.
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int down = int(floor(q));
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int up = down + 1;
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float interp = q - float(down);
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outval = 1.0 - mix(val[down].x, val[up].x, interp);
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}
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gl_FragColor = vec4(vec3(outval), 1.0);
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}
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