1// Draws a progress bar with properties defined in CustomUiMaterial
2#import bevy_ui::ui_vertex_output::UiVertexOutput
3
4@group(1) @binding(0) var<uniform> color: vec4<f32>;
5@group(1) @binding(1) var<uniform> slider: vec4<f32>;
6@group(1) @binding(2) var material_color_texture: texture_2d<f32>;
7@group(1) @binding(3) var material_color_sampler: sampler;
8@group(1) @binding(4) var<uniform> border_color: vec4<f32>;
9
10
11@fragment
12fn fragment(in: UiVertexOutput) -> @location(0) vec4<f32> {
13    let output_color = textureSample(material_color_texture, material_color_sampler, in.uv) * color;
14
15    // half size of the UI node
16    let half_size = 0.5 * in.size;
17
18    // position relative to the center of the UI node
19    let p = in.uv * in.size - half_size;
20
21    // thickness of the border closest to the current position
22    let b = vec2(
23        select(in.border_widths.x, in.border_widths.z, 0. < p.x),
24        select(in.border_widths.y, in.border_widths.w, 0. < p.y)
25    );
26
27    // select radius for the nearest corner
28    let rs = select(in.border_radius.xy, in.border_radius.wz, 0.0 < p.y);
29    let radius = select(rs.x, rs.y, 0.0 < p.x);
30
31    // distance along each axis from the corner
32    let d = half_size - abs(p);
33
34    // if the distance to the edge from the current position on any axis 
35    // is less than the border width on that axis then the position is within 
36    // the border and we return the border color
37    if d.x < b.x || d.y < b.y {
38        // select radius for the nearest corner
39        let rs = select(in.border_radius.xy, in.border_radius.wz, 0.0 < p.y);
40        let radius = select(rs.x, rs.y, 0.0 < p.x);
41
42        // determine if the point is inside the curved corner and return the corresponding color
43        let q = radius - d;
44        if radius < min(max(q.x, q.y), 0.0) + length(vec2(max(q.x, 0.0), max(q.y, 0.0))) {
45            return vec4(0.0);
46        } else {
47            return border_color;
48        }
49    }
50
51    // sample the texture at this position if it's to the left of the slider value
52    // otherwise return a fully transparent color
53    if in.uv.x < slider.x {
54        let output_color = textureSample(material_color_texture, material_color_sampler, in.uv) * color;
55        return output_color;
56    } else {
57        return vec4(0.0);
58    }
59}