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struct Globals {
transform: mat4x4<f32>,
scale: f32,
}
@group(0) @binding(0) var<uniform> globals: Globals;
fn distance_alg(
frag_coord: vec2<f32>,
position: vec2<f32>,
size: vec2<f32>,
radius: f32
) -> f32 {
var inner_size: vec2<f32> = size - vec2<f32>(radius, radius) * 2.0;
var top_left: vec2<f32> = position + vec2<f32>(radius, radius);
var bottom_right: vec2<f32> = top_left + inner_size;
var top_left_distance: vec2<f32> = top_left - frag_coord;
var bottom_right_distance: vec2<f32> = frag_coord - bottom_right;
var dist: vec2<f32> = vec2<f32>(
max(max(top_left_distance.x, bottom_right_distance.x), 0.0),
max(max(top_left_distance.y, bottom_right_distance.y), 0.0)
);
return sqrt(dist.x * dist.x + dist.y * dist.y);
}
// Based on the fragement position and the center of the quad, select one of the 4 radi.
// Order matches CSS border radius attribute:
// radi.x = top-left, radi.y = top-right, radi.z = bottom-right, radi.w = bottom-left
fn select_border_radius(radi: vec4<f32>, position: vec2<f32>, center: vec2<f32>) -> f32 {
var rx = radi.x;
var ry = radi.y;
rx = select(radi.x, radi.y, position.x > center.x);
ry = select(radi.w, radi.z, position.x > center.x);
rx = select(rx, ry, position.y > center.y);
return rx;
}
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