Created
November 22, 2019 15:10
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Playing around with better random values in GPU.js
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| // language=GLSL | |
| const source = `// https://www.shadertoy.com/view/4t2SDh | |
| //note: uniformly distributed, normalized rand, [0,1] | |
| highp float randomSeedShift = 0.0; | |
| highp float previousRandomSeedShift = 0.0; | |
| bool flip = false; | |
| const highp float factor = 9999.0; | |
| uniform highp float randomSeed1; | |
| uniform highp float randomSeed2; | |
| highp float nrand(highp vec2 n) { | |
| previousRandomSeedShift = randomSeedShift; | |
| if (previousRandomSeedShift > 0.0) { | |
| if (flip) { | |
| flip = false; | |
| return randomSeedShift = fract(sin(dot(n.xy * vec2(randomSeedShift * factor, previousRandomSeedShift * factor), vec2(12.9898, 78.233))) * 43758.5453); | |
| } | |
| flip = true; | |
| return randomSeedShift = fract(sin(dot(n.xy * vec2(previousRandomSeedShift * factor, randomSeedShift * factor), vec2(12.9898, 78.233))) * 43758.5453); | |
| } | |
| if (randomSeedShift > 0.0) { | |
| return randomSeedShift = fract(sin(dot(n.xy * vec2(randomSeed1 * factor, randomSeedShift * factor), vec2(12.9898, 78.233))) * 43758.5453); | |
| } | |
| return randomSeedShift = fract(sin(dot(n.xy * vec2(randomSeed1 * factor, randomSeed2 * factor), vec2(12.9898, 78.233))) * 43758.5453); | |
| }`; | |
| const name = 'math-random-uniformly-distributed'; | |
| // language=JavaScript | |
| const functionMatch = `Math.random()`; | |
| const functionReplace = `nrand(vTexCoord)`; | |
| const functionReturnType = 'Number'; | |
| /** | |
| * | |
| * @param {Kernel} kernel | |
| */ | |
| const onBeforeRun = (kernel) => { | |
| kernel.setUniform1f('randomSeed1', Math.random()); | |
| kernel.setUniform1f('randomSeed2', Math.random()); | |
| }; | |
| /** | |
| * | |
| * @type IPlugin | |
| */ | |
| module.exports = { | |
| name, | |
| onBeforeRun, | |
| functionMatch, | |
| functionReplace, | |
| functionReturnType, | |
| source | |
| }; |
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