Add antialiasing to template

1 files changed, 21 insertions, 2 deletions

diff --git a/templates/glsl/shaders/shader.glsl b/templates/glsl/shaders/shader.glsl
index a271146..0fc172a 100644
--- a/templates/glsl/shaders/shader.glsl
+++ b/templates/glsl/shaders/shader.glsl
@@ -5,18 +5,37 @@ 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) {
+  float v = sample_noise(uv);
+  vec3 color = mix(vec3(0), vec3(1), v);
+  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 * vec2(1.0, aspect_ratio) / resolution;
 
-  float v = sample_noise(uv);
-  vec3 color = mix(vec3(0), vec3(1), v);
+  vec3 color = enable_antialiasing ? antialiased_image(uv) : image(uv);
 
   imageStore(output_image, ivec2(gl_GlobalInvocationID.xy), vec4(color, 1));
 }