let CURVATURE: vec2<f32> = vec2<f32>(3.0, 3.0);
let RESOLUTION: vec2<f32> = vec2<f32>(100.0, 100.0);
let BRIGHTNESS: f32 = 4.0;
let PI: f32 = 3.14159;
fn curveRemapUV(uv_in: vec2<f32>) -> vec2<f32> {
var uv_out: vec2<f32>;
// as we near the edge of our screen apply greater distortion using a cubic function
uv_out = uv_in * 2.0 - 1.0;
var offset: vec2<f32> = abs(uv_out.yx) / CURVATURE;
uv_out = uv_out + uv_out * offset * offset;
return uv_out * 0.5 + 0.5;
}
fn scanLineIntensity(uv_in: f32, resolution: f32, opacity: f32) -> vec4<f32> {
var intensity: f32 = sin(uv_in * resolution * PI * 2.0);
intensity = ((0.5 * intensity) + 0.5) * 0.9 + 0.1;
return vec4<f32>(vec3<f32>(pow(intensity, opacity)), 1.0);
}
fn vignetteIntensity(uv_in: vec2<f32>, resolution: vec2<f32>, opacity: f32, roundness: f32) -> vec4<f32> {
var intensity: f32 = uv_in.x * uv_in.y * (1.0 - uv_in.x) * (1.0 - uv_in.y);
return vec4<f32>(vec3<f32>(clamp(pow((resolution.x / roundness) * intensity, opacity), 0.0, 1.0)), 1.0);
}
@vertex
...snip...
@fragment
fn fs_main(
vs_out: VertexOutput
) -> @location(0) vec4<f32> {
var remapped_tex_coords = curveRemapUV(vs_out.tex_coords);
var color: vec4<f32> = textureSample(r_texture, r_sampler, remapped_tex_coords);
color *= vignetteIntensity(remapped_tex_coords, RESOLUTION, 1.0, 2.0);
color *= scanLineIntensity(remapped_tex_coords.x, RESOLUTION.y, 1.0);
color *= scanLineIntensity(remapped_tex_coords.y, RESOLUTION.x, 1.0);
return vec4<f32>(color.rgb * BRIGHTNESS, 1.0);
}
