// Bump distortion: magnifies the image inside a circular region.
//
// Parameters: center.x, center.y (uv space), radius (isotropic units,
// 1.0 = shorter output edge), scale. Distances are measured in isotropic
// space so the bump stays circular on non-square targets.
@compute @workgroup_size(WORKGROUP_X, WORKGROUP_Y)
fn main(@builtin(global_invocation_id) gid: vec3<u32>) {
let dims = vec2<u32>(uniforms.output_dimensions);
if gid.x >= dims.x || gid.y >= dims.y {
return;
}
let uv = output_uv(gid.xy);
let center = vec2<f32>(param(0u), param(1u));
let radius = max(param(2u), 0.001);
let scale = param(3u);
let center_iso = to_isotropic(center);
let delta = to_isotropic(uv) - center_iso;
let dist = length(delta);
var sample_uv = uv;
if dist < radius {
let t = 1.0 - dist / radius;
let factor = 1.0 + scale * t * t;
sample_uv = from_isotropic(center_iso + delta / factor);
}
textureStore(output_texture, vec2<i32>(gid.xy), sample_input_bilinear(sample_uv));
}