mirror of
https://github.com/Ttanasart-pt/Pixel-Composer.git
synced 2024-12-25 14:36:13 +01:00
39 lines
1 KiB
GLSL
39 lines
1 KiB
GLSL
//
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// Simple passthrough fragment shader
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//
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varying vec2 v_vTexcoord;
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varying vec4 v_vColour;
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#define PI 3.14159265359
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uniform float scale;
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uniform float strength;
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uniform float seed;
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float random (in vec2 st, float _seed) {
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return fract(sin(dot(st.xy, vec2(12.9898, 78.233))) * (43758.5453123 + (seed + _seed)));
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}
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float noise (in vec2 st, float _seed) {
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vec2 i = floor(st);
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vec2 f = fract(st);
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// Four corners in 2D of a tile
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float a = random(i, _seed);
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float b = random(i + vec2(1.0, 0.0), _seed);
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float c = random(i + vec2(0.0, 1.0), _seed);
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float d = random(i + vec2(1.0, 1.0), _seed);
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// Cubic Hermine Curve. Same as SmoothStep()
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vec2 u = f * f * (3.0 - 2.0 * f);
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// Mix 4 coorners percentages
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return mix(mix(a, b, u.x), mix(c, d, u.x), u.y);
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}
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void main() {
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float sX = noise(v_vTexcoord * scale, 1.986458) * 2. - 1.;
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float sY = noise(v_vTexcoord * scale, 5.648630) * 2. - 1.;
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gl_FragColor = vec4(128. / 255. + sX * 0.125 * strength, 128. / 255. + sY * 0.125 * strength, 0., 1.);
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}
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