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

   1 in vec2 vertPosition;
   2 out vec2 uv;
   3 out vec4 particleColor;
   4 uniform vec3 headPos;
   5 uniform int batchSize;
   6 struct particle_t {
   7   vec4 positionAndSize;
   8   vec4 velocity;
   9   vec4 padding2; // for LÖVR's limited ShaderBlock type :(
  10   vec4 padding3; // for LÖVR's limited ShaderBlock type :(
  11 };
  12 layout(std430) buffer particleData { particle_t particles[]; };
  13
  14 vec4 position(mat4 projection, mat4 transform, vec4 vertex) {
  15   int index = gl_VertexID / 4 + gl_InstanceID * batchSize;
  16   particle_t particle = particles[index];
  17   vec3 pos = particle.positionAndSize.xyz;
  18   float size = particle.positionAndSize.w;
  19   particleColor = particle.velocity;
  20   uv = vertPosition * 0.5 + 0.5;
  21
  22   vec3 forward = normalize(pos - headPos);
  23   vec3 right = normalize(cross(forward, vec3(0, 1, 0)));
  24   vec3 up = cross(right, forward);
  25   vec3 offset = mat2x3(up, right) * (vertPosition * size);
  26
  27   return projection * transform * vec4(pos + offset, 1.0);
  28 }