Crude wide lines

src/bin/wireframe/main.rs

@@ -22,21 +22,6 @@ struct Vertex {
 	position: [f32; 3],
 }
 
-impl Vertex {
-	fn desc() -> wgpu::VertexBufferLayout<'static> {
-		use std::mem;
-		wgpu::VertexBufferLayout {
-			array_stride: mem::size_of::<Vertex>() as wgpu::BufferAddress,
-			step_mode: wgpu::VertexStepMode::Vertex,
-			attributes: &[wgpu::VertexAttribute {
-				offset: mem::offset_of!(Self, position) as u64,
-				shader_location: 0,
-				format: wgpu::VertexFormat::Float32x3,
-			}],
-		}
-	}
-}
-
 struct Wireframe {
 	color: Vec3,
 	data: wgpu::Buffer,
@@ -311,7 +296,23 @@ impl<'a> State<'a> {
 			vertex: wgpu::VertexState {
 				module: &shader,
 				entry_point: "vs_main",
-				buffers: &[Vertex::desc()],
+				buffers: &[wgpu::VertexBufferLayout {
+					array_stride: mem::size_of::<Vertex>() as wgpu::BufferAddress,
+					step_mode: wgpu::VertexStepMode::Instance,
+					attributes: &[
+						wgpu::VertexAttribute {
+							offset: mem::offset_of!(Vertex, position) as u64,
+							shader_location: 0,
+							format: wgpu::VertexFormat::Float32x3,
+						},
+						wgpu::VertexAttribute {
+							offset: (mem::size_of::<Vertex>() + mem::offset_of!(Vertex, position))
+								as u64,
+							shader_location: 1,
+							format: wgpu::VertexFormat::Float32x3,
+						},
+					],
+				}],
 				compilation_options: Default::default(),
 			},
 			fragment: Some(wgpu::FragmentState {
@@ -328,7 +329,7 @@ impl<'a> State<'a> {
 				compilation_options: Default::default(),
 			}),
 			primitive: wgpu::PrimitiveState {
-				topology: wgpu::PrimitiveTopology::LineStrip,
+				topology: wgpu::PrimitiveTopology::TriangleStrip,
 				..Default::default()
 			},
 			depth_stencil: None,
@@ -447,7 +448,7 @@ impl<'a> State<'a> {
 				};
 				render_pass.set_push_constants(ShaderStages::VERTEX, 0, bytemuck::bytes_of(&line));
 				render_pass.set_vertex_buffer(0, wireframe.data.slice(..));
-				render_pass.draw(0..wireframe.size, 0..1);
+				render_pass.draw(0..4, 0..wireframe.size - 1);
 			}
 		}
 

src/bin/wireframe/ray.wgsl

@@ -7,10 +7,15 @@ var<uniform> camera: CameraUniform;
 struct LineUniform {
 	color: vec3<f32>,
 }
+const width = 0.1;
 var<push_constant> line: LineUniform;
 
-struct VertexInput {
+struct SegmentInput {
-	@location(0) position: vec3<f32>,
+	@location(0) a: vec3<f32>,
+	@location(1) b: vec3<f32>,
+}
+struct OffsetInput {
+	@builtin(vertex_index) idx: u32,
 }
 
 struct VertexOutput {
@@ -19,15 +24,24 @@ struct VertexOutput {
 }
 
 @vertex
-fn vs_main(model: VertexInput) -> VertexOutput {
+fn vs_main(seg: SegmentInput, off: OffsetInput) -> VertexOutput {
 	var out: VertexOutput;
 	out.vertex_color = line.color;
-	out.clip_position = camera.mvp * vec4(model.position, 1.0);
+	let a = camera.mvp * vec4(seg.a, 1.);
+	let b = camera.mvp * vec4(seg.b, 1.);
+	let dir = normalize(b.xy / b.w - a.xy / a.w);
+	let d = width * vec4(-dir.y, dir.x, 0., 0.);
+	switch (off.idx) {
+	case 0u: { out.clip_position = a - d; }
+	case 1u: { out.clip_position = a + d; }
+	case 2u: { out.clip_position = b - d; }
+	case 3u: { out.clip_position = b + d; }
+	default: {}
+	}
 	return out;
 }
 
 @fragment
 fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
-	let opacity = pow(0.5 - 0.5 * in.clip_position.z, 0.25);
+	return 0.5 * vec4(in.vertex_color, 1.0);
-	return opacity * vec4(in.vertex_color, 1.0);
 }