mirror of
https://github.com/patriciogonzalezvivo/thebookofshaders
synced 2024-11-01 21:40:27 +00:00
99 lines
2.5 KiB
GLSL
99 lines
2.5 KiB
GLSL
#ifdef GL_ES
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precision mediump float;
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#endif
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uniform sampler2D u_tex0;
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uniform float u_time;
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uniform vec2 u_mouse;
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uniform vec2 u_resolution;
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vec3 random3(vec3 c) {
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float j = 4096.0*sin(dot(c,vec3(17.0, 59.4, 15.0)));
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vec3 r;
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r.z = fract(512.0*j);
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j *= .125;
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r.x = fract(512.0*j);
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j *= .125;
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r.y = fract(512.0*j);
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return r-0.5;
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}
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const float F3 = 0.3333333;
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const float G3 = 0.1666667;
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float snoise(vec3 p) {
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vec3 s = floor(p + dot(p, vec3(F3)));
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vec3 x = p - s + dot(s, vec3(G3));
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vec3 e = step(vec3(0.0), x - x.yzx);
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vec3 i1 = e*(1.0 - e.zxy);
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vec3 i2 = 1.0 - e.zxy*(1.0 - e);
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vec3 x1 = x - i1 + G3;
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vec3 x2 = x - i2 + 2.0*G3;
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vec3 x3 = x - 1.0 + 3.0*G3;
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vec4 w, d;
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w.x = dot(x, x);
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w.y = dot(x1, x1);
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w.z = dot(x2, x2);
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w.w = dot(x3, x3);
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w = max(0.6 - w, 0.0);
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d.x = dot(random3(s), x);
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d.y = dot(random3(s + i1), x1);
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d.z = dot(random3(s + i2), x2);
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d.w = dot(random3(s + 1.0), x3);
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w *= w;
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w *= w;
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d *= w;
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return dot(d, vec4(52.0));
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}
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// Author: Matt DesLauriers
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// https://github.com/mattdesl/glsl-film-grain/blob/master/index.glsl
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//
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float grain(vec2 texCoord, vec2 resolution, float frame, float multiplier) {
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vec2 mult = texCoord * resolution;
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float offset = snoise(vec3(mult / multiplier, frame));
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float n1 = snoise(vec3(mult, offset));
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return n1 / 2.0 + 0.5;
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}
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float grain(vec2 texCoord, vec2 resolution, float frame) {
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return grain(texCoord, resolution, frame, 2.5);
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}
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float grain(vec2 texCoord, vec2 resolution) {
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return grain(texCoord, resolution, 0.0);
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}
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// Author: Hugh Kennedy
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// https://github.com/hughsk/glsl-luma/blob/master/index.glsl
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float luma(vec3 color) {
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return dot(color, vec3(0.299, 0.587, 0.114));
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}
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float luma(vec4 color) {
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return dot(color.rgb, vec3(0.299, 0.587, 0.114));
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}
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// Author: Matt DesLauriers
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// https://github.com/mattdesl/glsl-blend-soft-light/blob/master/index.glsl
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vec3 blendSoftLight(vec3 base, vec3 blend) {
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return mix(
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sqrt(base) * (2.0 * blend - 1.0) + 2.0 * base * (1.0 - blend),
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2.0 * base * blend + base * base * (1.0 - 2.0 * blend),
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step(base, vec3(0.5))
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);
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}
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void main (void) {
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vec2 st = gl_FragCoord.xy/u_resolution.xy;
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vec3 color = texture2D(u_tex0,st).rgb;
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vec3 grain = vec3( grain(st,u_resolution/7.) );
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color = blendSoftLight(color,grain);
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float luminance = luma(color);
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color = vec3(luminance);
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gl_FragColor = vec4(color,1.0);
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}
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