#version 430
layout(local_size_x = 1, local_size_y = 1) in;

#include <utils>
#include <noise>

uniform float seconds = 0;
layout(rgba8) uniform readonly image2D noise_texture;
layout(rgba8) uniform writeonly image2D output_image;

uniform float antialiasing = 0.28;
uniform bool enable_antialiasing = false;

float sample_noise(in vec2 p) {
  vec4 noise = imageLoad(noise_texture, ivec2(p * imageSize(noise_texture)));
  return noise.x;
}

vec3 image(vec2 uv) {
  const vec3 bg_color = srgb(0.10, 0.10, 0.14);
  const vec3 line1_color = srgb(0.2, 0.25, 0.4);
  const vec3 line2_color = srgb(0.8, 0.3, 0.4);

  vec3 color = bg_color;

  float line_thickness = 0.04;
  vec2 p = (vec2(uv.y, uv.x)) * 50;
  int max = 40;
  float t = mod(seconds, 12) * 0.7;

  vec3 l1c = line1_color;
  vec3 l2c = line2_color;

  for (int i = 0; i < max; i++) {
    float a = i * PI * (1 + t / 10) / 62;
    float r = 5 * sin(a + t / 6) * sin(a + t / 6);
    vec2 off = r * vec2(cos(a), sin(a)) + (1 + t / 1000.) * i * 0.2;
    vec2 pos = (p + off) * mat2x2(cos(a), -sin(a), sin(a), cos(a));
    float line = abs(sin(pos.x * (0.7 + 0.3 * fbm(p / 10)) + t * 2) / 3 - pos.y) - line_thickness;
    vec3 line_color = mix(l1c, l2c, smoothstep(0, 1, float(i - 1) / (2. * max)));
    color = mix(color, line_color, step(line, 0));
  }

  // color = mix(color, vec3(1), step(mixer, 0));

  return color;
}

vec3 antialiased_image(vec2 uv) {
  vec2 resolution = vec2(imageSize(output_image).xy);
  float s = antialiasing / max(resolution.x, resolution.y);
  vec3 sum = vec3(0);
  int count = 0;
  for (int i = -2; i < 2; i++)
    for (int j = -2; j < 2; j++, count++)
      sum += image(uv + vec2(i, j) * s);
  return sum / count;
}

void main() {
  vec2 resolution = vec2(imageSize(output_image).xy);
  float aspect_ratio = resolution.y / resolution.x;
  vec2 uv = (gl_GlobalInvocationID.xy - resolution / 2) * vec2(1.0, aspect_ratio) / resolution;

  vec3 color = enable_antialiasing ? antialiased_image(uv) : image(uv);

  imageStore(output_image, ivec2(gl_GlobalInvocationID.xy), vec4(color, 1));
}