Witch of Git - lovr-particles/blob - shaders/particles.comp

   1 uniform float dt;
   2 uniform vec3 handPos[2];
   3 uniform vec3 handVel[2];
   4
   5 struct particle_t {
   6   vec4 positionAndSize;
   7   vec4 velocity;
   8   vec4 padding2; // for LÖVR's limited ShaderBlock type :(
   9   vec4 padding3; // for LÖVR's limited ShaderBlock type :(
  10 };
  11 layout(std430) buffer particleData {
  12   float reloadFlag;
  13   particle_t particles[];
  14 };
  15
  16 vec3 wrap(vec3 v) { return mod(v, 2.0) - 1.0 + vec3(0.0, 1.0, 0.0); }
  17
  18 layout(local_size_x = 128) in;
  19 void compute() {
  20   uint id = gl_GlobalInvocationID.x;
  21   vec3 vel = particles[id].velocity.xyz;
  22   vec3 pos = particles[id].positionAndSize.xyz;
  23   for (int i = 0; i < 2; i++) {
  24     float speed = clamp(length(handVel[i]), 0.0, 3.0);
  25     float dist = distance(handPos[i], pos);
  26     float factor = 1.0 - smoothstep(0.0, speed * 0.1, dist);
  27     vel = mix(vel, handVel[i], factor * 0.01);
  28   }
  29   particles[id].positionAndSize.xyz = wrap(pos + vel * dt);
  30   particles[id].velocity.xyz = vel - vel * length(vel) * dt;
  31 }