playcanvas

Version:
Open-source WebGL/WebGPU 3D engine for the web
36 lines (35 loc) • 1.5 kB
JavaScript
var particleInputRgba8_default = `
const PI2: f32 = 6.283185307179586;
uniform inBoundsSize: vec3f;
uniform inBoundsCenter: vec3f;
uniform maxVel: f32;
fn decodeFloatRG(rg: vec2f) -> f32 {
	return rg.y * (1.0 / 255.0) + rg.x;
}
fn decodeFloatRGBA( rgba: vec4f ) -> f32 {
	return dot(rgba, vec4f(1.0, 1.0 / 255.0, 1.0 / 65025.0, 1.0 / 160581375.0));
}
fn readInput(uv: f32) {
	let textureSize = textureDimensions(particleTexIN, 0);
	let texel0: vec2i = vec2i(vec2f(uv, 0.125) * vec2f(textureSize));
	let texel1: vec2i = vec2i(vec2f(uv, 0.375) * vec2f(textureSize));
	let texel2: vec2i = vec2i(vec2f(uv, 0.625) * vec2f(textureSize));
	let texel3: vec2i = vec2i(vec2f(uv, 0.875) * vec2f(textureSize));
	let tex0 = textureLoad(particleTexIN, texel0, 0);
	let tex1 = textureLoad(particleTexIN, texel1, 0);
	let tex2 = textureLoad(particleTexIN, texel2, 0);
	let tex3 = textureLoad(particleTexIN, texel3, 0);
	inPos = vec3f(decodeFloatRG(tex0.rg), decodeFloatRG(tex0.ba), decodeFloatRG(tex1.rg));
	inPos = (inPos - vec3f(0.5)) * uniform.inBoundsSize + uniform.inBoundsCenter;
	inVel = tex2.xyz;
	inVel = (inVel - vec3f(0.5)) * uniform.maxVel;
	inAngle = decodeFloatRG(tex1.ba) * PI2;
	inShow = tex2.a > 0.5;
	let life_decoded = decodeFloatRGBA(tex3);
	let maxNegLife = max(uniform.lifetime, uniform.numParticles * (uniform.rate + uniform.rateDiv));
	let maxPosLife = uniform.lifetime + 1.0;
	inLife = life_decoded * (maxNegLife + maxPosLife) - maxNegLife;
}`;
export {
	particleInputRgba8_default as default
};