separate global (light) and per-object (position) parameters

src/lib.rs

@@ -3,7 +3,7 @@ use std::{
 	f32::consts::{FRAC_PI_2, PI},
 };
 
-use glam::{Affine3A, FloatExt, Mat4, Quat, UVec2, Vec3, Vec4, vec3, vec4};
+use glam::{FloatExt, Mat4, Quat, UVec2, Vec3, Vec4, vec3, vec4};
 
 use crate::render::mesh::GpuParams;
 
@@ -188,37 +188,42 @@ impl Core {
 		.to_mat4();
 		let view = Mat4::from_mat3(camera::rotation(-args.cam_yaw, -args.cam_pitch));
 		let light = vec3(0.7, 0.5, 1.0).normalize();
-		let set_params = |target: &GpuParams, color, tfm| {
-			target.set(
+
+		self.mesh_pipeline.set_params(
 			&self.queue,
-				render::mesh::Params {
-					mvp: proj * view * tfm,
+			render::mesh::SceneParams {
+				projection: proj * view,
 				light,
 				_zero: 0.,
-					color: srgba_to_linear(color),
 			},
 		);
-		};
 
 		let turn_teeth = self.t;
-		let bevel_turns = turn_teeth / self.bevel_gear_desc.teeth as f32;
+		let bevel_turns = -turn_teeth / self.bevel_gear_desc.teeth as f32;
 		let crown_skip_teeth = self.crown_gear_desc.pitch_radius.floor();
 		let crown_turns =
 			(turn_teeth.fract_gl() + crown_skip_teeth) / (2. * self.crown_gear_desc.pitch_radius);
 
-		set_params(
-			&self.params_gear,
-			vec4(0.2, 0.8, 0.1, 1.0),
-			Affine3A::IDENTITY,
+		self.params_gear.set(
+			&self.queue,
+			render::mesh::ObjectParams {
+				transform: Mat4::from_rotation_translation(
+					Quat::from_rotation_z(2. * PI * bevel_turns),
+					Vec3::ZERO,
+				),
+				color: srgba_to_linear(vec4(0.2, 0.8, 0.1, 1.0)),
+			},
 		);
-		set_params(
-			&self.params_cutter,
-			vec4(0.8, 0.2, 0.1, 1.0),
-			Affine3A::from_rotation_translation(
+		self.params_cutter.set(
+			&self.queue,
+			render::mesh::ObjectParams {
+				transform: Mat4::from_rotation_translation(
 					Quat::from_rotation_y(FRAC_PI_2 + self.bevel_gear_desc.cone_halfangle)
 						* Quat::from_rotation_z(2. * PI * crown_turns),
 					vec3(0., 0., self.bevel_gear_desc.pitch_distance()),
 				),
+				color: srgba_to_linear(vec4(0.8, 0.2, 0.1, 1.0)),
+			},
 		);
 
 		let view = output.create_view(&wgpu::TextureViewDescriptor::default());

src/render/mesh.rs

@@ -19,15 +19,23 @@ pub struct Vertex {
 
 #[derive(Debug, Clone, Copy, Zeroable, Pod)]
 #[repr(C)]
-pub struct Params {
-	pub mvp: Mat4,
+pub struct SceneParams {
+	pub projection: Mat4,
 	pub light: Vec3,
 	pub _zero: f32,
+}
+
+#[derive(Debug, Clone, Copy, Zeroable, Pod)]
+#[repr(C)]
+pub struct ObjectParams {
+	pub transform: Mat4,
 	pub color: Vec4,
 }
 
 pub struct Pipeline {
 	pipeline: wgpu::RenderPipeline,
+	params: wgpu::Buffer,
+	bindings: wgpu::BindGroup,
 }
 
 pub struct GpuMesh {
@@ -153,7 +161,29 @@ impl Pipeline {
 			multiview: None,
 			cache: None,
 		});
-		Self { pipeline }
+		let params = device.create_buffer(&wgpu::BufferDescriptor {
+			label: None,
+			size: size_of::<SceneParams>() as u64,
+			usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
+			mapped_at_creation: false,
+		});
+		let bindings = device.create_bind_group(&wgpu::BindGroupDescriptor {
+			label: None,
+			layout: &pipeline.get_bind_group_layout(0),
+			entries: &[wgpu::BindGroupEntry {
+				binding: 0,
+				resource: params.as_entire_binding(),
+			}],
+		});
+		Self {
+			params,
+			bindings,
+			pipeline,
+		}
+	}
+
+	pub fn set_params(&self, queue: &wgpu::Queue, params: SceneParams) {
+		queue.write_buffer(&self.params, 0, bytes_of(&params));
 	}
 }
 
@@ -161,13 +191,13 @@ impl GpuParams {
 	pub fn new(device: &wgpu::Device, pipeline: &Pipeline) -> Self {
 		let params = device.create_buffer(&wgpu::BufferDescriptor {
 			label: None,
-			size: size_of::<Params>() as u64,
+			size: size_of::<ObjectParams>() as u64,
 			usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
 			mapped_at_creation: false,
 		});
 		let bindings = device.create_bind_group(&wgpu::BindGroupDescriptor {
 			label: None,
-			layout: &pipeline.pipeline.get_bind_group_layout(0),
+			layout: &pipeline.pipeline.get_bind_group_layout(1),
 			entries: &[wgpu::BindGroupEntry {
 				binding: 0,
 				resource: params.as_entire_binding(),
@@ -176,7 +206,7 @@ impl GpuParams {
 		Self { params, bindings }
 	}
 
-	pub fn set(&self, queue: &wgpu::Queue, params: Params) {
+	pub fn set(&self, queue: &wgpu::Queue, params: ObjectParams) {
 		queue.write_buffer(&self.params, 0, bytes_of(&params));
 	}
 }
@@ -184,7 +214,8 @@ impl GpuParams {
 impl GpuMesh {
 	pub fn render(&self, pass: &mut wgpu::RenderPass, pipeline: &Pipeline, params: &GpuParams) {
 		pass.set_pipeline(&pipeline.pipeline);
-		pass.set_bind_group(0, &params.bindings, &[]);
+		pass.set_bind_group(0, &pipeline.bindings, &[]);
+		pass.set_bind_group(1, &params.bindings, &[]);
 		pass.set_vertex_buffer(0, self.vertices.slice(..));
 		pass.draw(0..self.vertex_count, 0..1);
 	}
@@ -193,7 +224,8 @@ impl GpuMesh {
 impl GpuMeshIndexed {
 	pub fn render(&self, pass: &mut wgpu::RenderPass, pipeline: &Pipeline, params: &GpuParams) {
 		pass.set_pipeline(&pipeline.pipeline);
-		pass.set_bind_group(0, &params.bindings, &[]);
+		pass.set_bind_group(0, &pipeline.bindings, &[]);
+		pass.set_bind_group(1, &params.bindings, &[]);
 		pass.set_vertex_buffer(0, self.vertices.slice(..));
 		pass.set_index_buffer(self.indices.slice(..), wgpu::IndexFormat::Uint16);
 		pass.draw_indexed(0..self.index_count, 0, 0..1);

src/render/mesh.wgsl

@@ -1,7 +1,11 @@
-struct Params {
-	mvp: mat4x4f,
+struct SceneParams {
+	projection: mat4x4f,
 	light: vec3f,
 	_zero: f32,
+}
+
+struct ObjectParams {
+	transform: mat4x4f,
 	color: vec4f,
 }
 
@@ -15,20 +19,21 @@ struct Varying {
 	@location(0) normal: vec3f,
 }
 
-@group(0) @binding(0) var<uniform> params: Params;
+@group(0) @binding(0) var<uniform> scene_params: SceneParams;
+@group(1) @binding(0) var<uniform> object_params: ObjectParams;
 
 @vertex
 fn on_vertex(in: Vertex) -> Varying {
-	let position = params.mvp * vec4f(in.position, 1.0);
-	let normal = in.normal;
+	let position = scene_params.projection * object_params.transform * vec4f(in.position, 1.0);
+	let normal = normalize((object_params.transform * vec4(in.normal, 0.0)).xyz);
 	return Varying(position, normal);
 }
 
 @fragment
 fn on_fragment(in: Varying) -> @location(0) vec4f {
 	let normal = normalize(in.normal);
-	let light = dot(params.light, normal);
+	let light = dot(scene_params.light, normal);
 	let u = 0.5 + 0.5 * light;
-	let color = vec4f(u * params.color.xyz, params.color.w);
+	let color = vec4f(u * object_params.color.xyz, object_params.color.w);
 	return color;
 }