30 lines
692 B
GLSL
30 lines
692 B
GLSL
!!FP1.0
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# Eclipse shadow shader--this shader computes a black circle centered
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# at texcoord (0.5, 0.5) and multiplies this by texture zero and the
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# diffuse color.
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# Parameters:
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# p[5] - ambient light color
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# p[20] - shadow umbra/penumbra parameters (x = scale, y = bias)
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# Compute the square of the distance from the center of the shadow
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SUB R0, f[TEX0], { 0.5, 0.5, 0, 0 };
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DP3 R1.w, R0, R0;
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# Scale and bias the squared distance to get the right shadow umbra
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# and penumbra sizes.
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MAD_SAT R1.x, R1.w, p[20].x, p[20].y;
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#MUL R0.xyz, R1.x, 2.0;
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POW R0.xyz, R1.x, 0.5;
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#TEX R0.xyz, R1.x, TEX0, 2D;
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# Add the ambient light
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ADDX_SAT R0.xyz, R0, p[5];
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# Output it
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MOVX o[COLR], R0;
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END
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