vue-cesium
Version:
Vue 3.x components for CesiumJS.
60 lines (47 loc) • 1.94 kB
JavaScript
"use strict";
const text = `
uniform sampler2D nextParticlesPosition;
uniform sampler2D particlesSpeed; // (u, v, w, norm)
// range (min, max)
uniform vec2 lonRange;
uniform vec2 latRange;
uniform float randomCoefficient; // use to improve the pseudo-random generator
uniform float dropRate; // drop rate is a chance a particle will restart at random position to avoid degeneration
uniform float dropRateBump;
in vec2 v_textureCoordinates;
// pseudo-random generator
const vec3 randomConstants = vec3(12.9898, 78.233, 4375.85453);
const vec2 normalRange = vec2(0.0, 1.0);
float rand(vec2 seed, vec2 range) {
vec2 randomSeed = randomCoefficient * seed;
float temp = dot(randomConstants.xy, randomSeed);
temp = fract(sin(temp) * (randomConstants.z + temp));
return temp * (range.y - range.x) + range.x;
}
vec3 generateRandomParticle(vec2 seed, float lev) {
// ensure the longitude is in [0, 360]
float randomLon = mod(rand(seed, lonRange), 360.0);
float randomLat = rand(-seed, latRange);
return vec3(randomLon, randomLat, lev);
}
bool particleOutbound(vec3 particle) {
return particle.y < -90.0 || particle.y > 90.0;
}
void main() {
vec3 nextParticle = texture(nextParticlesPosition, v_textureCoordinates).rgb;
vec4 nextSpeed = texture(particlesSpeed, v_textureCoordinates);
float speedNorm = nextSpeed.a;
float particleDropRate = dropRate + dropRateBump * speedNorm;
vec2 seed1 = nextParticle.xy + v_textureCoordinates;
vec2 seed2 = nextSpeed.xy + v_textureCoordinates;
vec3 randomParticle = generateRandomParticle(seed1, nextParticle.z);
float randomNumber = rand(seed2, normalRange);
if (randomNumber < particleDropRate || particleOutbound(nextParticle)) {
out_FragColor = vec4(randomParticle, 1.0); // 1.0 means this is a random particle
} else {
out_FragColor = vec4(nextParticle, 0.0);
}
}
`;
export { text as default };
//# sourceMappingURL=postProcessingPosition.frag.mjs.map