mach/examples/gkurve/vert.wgsl
Stephen Gutekanst e35b86ad25 examples/gkurve: calculate barycentric vertex coordinates in shader
Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
2022-05-15 02:55:23 -07:00

29 lines
859 B
WebGPU Shading Language

struct VertexUniform {
matrix: mat4x4<f32>,
}
@binding(0) @group(0) var<uniform> ubos: array<VertexUniform, 3>;
struct VertexOut {
@builtin(position) position_clip: vec4<f32>,
@location(0) frag_uv: vec2<f32>,
@location(1) frag_bary: vec3<f32>,
@interpolate(flat) @location(2) instance_index: u32,
}
@stage(vertex) fn main(
@builtin(instance_index) instanceIdx: u32,
@builtin(vertex_index) vertex_index: u32,
@location(0) position: vec4<f32>,
@location(1) uv: vec2<f32>,
) -> VertexOut {
var output : VertexOut;
output.position_clip = ubos[instanceIdx].matrix * position;
output.frag_uv = uv;
output.frag_bary = vec3<f32>(
f32(vertex_index % 3u == 1u),
f32(vertex_index % 3u == 2u),
f32(vertex_index % 3u == 0u),
);
output.instance_index = instanceIdx;
return output;
}