Implement compute-shader simulation of particles!

[lovr-particles] / shaders / particles.frag

in vec2 uv;

vec4 color(vec4 graphicsColor, sampler2D image, vec2 _uv) {
  float alpha = 1.0 - (distance(uv, vec2(0.5)) * 2.0);
  graphicsColor.a *= sqrt(clamp(alpha, 0.0, 1.0));
  return graphicsColor;
}