1 ! Copyright (C) 2010 Erik Charlebois.
2 ! See https://factorcode.org/license.txt for BSD license.
3 USING: destructors gpu.render gpu.shaders gpu.state gpu.util
4 images kernel math.rectangles ;
7 GLSL-SHADER: step-fragment-shader fragment-shader
8 const vec4 luminance = vec4(0.3, 0.59, 0.11, 0.0);
9 uniform sampler2D texture;
10 uniform sampler2D ramp;
11 varying vec2 texcoord;
14 vec4 col = texture2D(texture, texcoord);
15 float l = dot(col, luminance);
16 gl_FragColor = texture2D(ramp, vec2(l, 0.0));
20 UNIFORM-TUPLE: step-uniforms
21 { "texture" texture-uniform f }
22 { "ramp" texture-uniform f } ;
24 GLSL-PROGRAM: step-program window-vertex-shader step-fragment-shader window-vertex-format ;
26 : (step-texture) ( texture ramp texture dim -- )
27 { 0 0 } swap <rect> <viewport-state> set-gpu-state
28 [ step-uniforms boa ] dip {
29 { "primitive-mode" [ 2drop triangle-strip-mode ] }
30 { "uniforms" [ drop ] }
31 { "vertex-array" [ 2drop <window-vertex-buffer> step-program <program-instance> <vertex-array> ] }
32 { "indexes" [ 2drop T{ index-range f 0 4 } ] }
33 { "framebuffer" [ nip ] }
34 } 2<render-set> render ;
36 :: step-texture ( texture ramp dim -- texture )
37 dim RGB float-components <2d-render-texture> :> ( target-framebuffer target-texture )
38 texture ramp target-framebuffer dim (step-texture)
39 target-framebuffer dispose