ruffle/render/wgpu/shaders/gradient/mode/focal.wgsl

#import gradient
#import common

override fn gradient::find_t(focal_point: f32, uv: vec2<f32>) -> f32 {
    let uv = uv * 2.0 - 1.0;
    var d: vec2<f32> = vec2<f32>(focal_point, 0.0) - uv;
    let l = length(d);
    d = d / l;
    return l / (sqrt(1.0 - focal_point * focal_point * d.y * d.y) + focal_point * d.x);
}

@vertex
fn main_vertex(in: common::VertexInput) -> gradient::VertexOutput {
    return gradient::main_vertex(in);
}

@fragment
fn main_fragment(in: gradient::VertexOutput) -> @location(0) vec4<f32> {
    return gradient::main_fragment(in);
}