41 lines
1.4 KiB
Factor
41 lines
1.4 KiB
Factor
! Copyright (C) 2010 Erik Charlebois.
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! See http://factorcode.org/license.txt for BSD license.
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USING: destructors gpu.render gpu.shaders gpu.state gpu.textures
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gpu.util images kernel locals math.rectangles ;
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IN: gpu.effects.step
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GLSL-SHADER: step-fragment-shader fragment-shader
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const vec4 luminance = vec4(0.3, 0.59, 0.11, 0.0);
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uniform sampler2D texture;
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uniform sampler2D ramp;
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varying vec2 texcoord;
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void main()
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{
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vec4 col = texture2D(texture, texcoord);
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float l = dot(col, luminance);
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gl_FragColor = texture2D(ramp, vec2(l, 0.0));
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}
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;
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UNIFORM-TUPLE: step-uniforms
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{ "texture" texture-uniform f }
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{ "ramp" texture-uniform f } ;
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GLSL-PROGRAM: step-program window-vertex-shader step-fragment-shader window-vertex-format ;
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: (step-texture) ( texture ramp texture dim -- )
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{ 0 0 } swap <rect> <viewport-state> set-gpu-state
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[ step-uniforms boa ] dip {
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{ "primitive-mode" [ 2drop triangle-strip-mode ] }
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{ "uniforms" [ drop ] }
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{ "vertex-array" [ 2drop <window-vertex-buffer> step-program <program-instance> <vertex-array> ] }
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{ "indexes" [ 2drop T{ index-range f 0 4 } ] }
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{ "framebuffer" [ nip ] }
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} 2<render-set> render ;
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:: step-texture ( texture ramp dim -- texture )
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dim RGB float-components <2d-render-texture> :> ( target-framebuffer target-texture )
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texture ramp target-framebuffer dim (step-texture)
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target-framebuffer dispose
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target-texture ;
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