22 lines
487 B
GLSL
22 lines
487 B
GLSL
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// Fragment shader for 2D texture with shadow attenuation
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// Brian Paul
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uniform sampler2D tex2d;
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uniform vec3 lightPos;
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void main()
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{
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// XXX should compute this from lightPos
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vec2 shadowCenter = vec2(-0.25, -0.25);
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// d = distance from center
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float d = distance(gl_TexCoord[0].xy, shadowCenter);
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// attenuate and clamp
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d = clamp(d * d * d, 0.0, 2.0);
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// modulate texture by d for shadow effect
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gl_FragColor = d * texture2D(tex2d, gl_TexCoord[0].xy, 0.0);
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}
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