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Diffstat (limited to 'wgpu/src/triangle.rs')
| -rw-r--r-- | wgpu/src/triangle.rs | 391 |
1 files changed, 391 insertions, 0 deletions
diff --git a/wgpu/src/triangle.rs b/wgpu/src/triangle.rs new file mode 100644 index 00000000..85ed4bd5 --- /dev/null +++ b/wgpu/src/triangle.rs @@ -0,0 +1,391 @@ +//! Draw meshes of triangles. +use crate::{settings, Transformation}; +use iced_native::{Point, Rectangle}; +use std::{mem, sync::Arc}; + +mod msaa; + +const UNIFORM_BUFFER_SIZE: usize = 100; +const VERTEX_BUFFER_SIZE: usize = 100_000; +const INDEX_BUFFER_SIZE: usize = 100_000; + +#[derive(Debug)] +pub(crate) struct Pipeline { + pipeline: wgpu::RenderPipeline, + blit: Option<msaa::Blit>, + constants: wgpu::BindGroup, + uniforms_buffer: Buffer<Uniforms>, + vertex_buffer: Buffer<Vertex2D>, + index_buffer: Buffer<u32>, +} + +#[derive(Debug)] +struct Buffer<T> { + raw: wgpu::Buffer, + size: usize, + usage: wgpu::BufferUsage, + _type: std::marker::PhantomData<T>, +} + +impl<T> Buffer<T> { + pub fn new( + device: &wgpu::Device, + size: usize, + usage: wgpu::BufferUsage, + ) -> Self { + let raw = device.create_buffer(&wgpu::BufferDescriptor { + size: (std::mem::size_of::<T>() * size) as u64, + usage, + }); + + Buffer { + raw, + size, + usage, + _type: std::marker::PhantomData, + } + } + + pub fn ensure_capacity(&mut self, device: &wgpu::Device, size: usize) { + if self.size < size { + self.raw = device.create_buffer(&wgpu::BufferDescriptor { + size: (std::mem::size_of::<T>() * size) as u64, + usage: self.usage, + }); + + self.size = size; + } + } +} + +impl Pipeline { + pub fn new( + device: &mut wgpu::Device, + format: wgpu::TextureFormat, + antialiasing: Option<settings::Antialiasing>, + ) -> Pipeline { + let constant_layout = + device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor { + bindings: &[wgpu::BindGroupLayoutBinding { + binding: 0, + visibility: wgpu::ShaderStage::VERTEX, + ty: wgpu::BindingType::UniformBuffer { dynamic: true }, + }], + }); + + let constants_buffer = Buffer::new( + device, + UNIFORM_BUFFER_SIZE, + wgpu::BufferUsage::UNIFORM | wgpu::BufferUsage::COPY_DST, + ); + + let constant_bind_group = + device.create_bind_group(&wgpu::BindGroupDescriptor { + layout: &constant_layout, + bindings: &[wgpu::Binding { + binding: 0, + resource: wgpu::BindingResource::Buffer { + buffer: &constants_buffer.raw, + range: 0..std::mem::size_of::<Uniforms>() as u64, + }, + }], + }); + + let layout = + device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor { + bind_group_layouts: &[&constant_layout], + }); + + let vs = include_bytes!("shader/triangle.vert.spv"); + let vs_module = device.create_shader_module( + &wgpu::read_spirv(std::io::Cursor::new(&vs[..])) + .expect("Read triangle vertex shader as SPIR-V"), + ); + + let fs = include_bytes!("shader/triangle.frag.spv"); + let fs_module = device.create_shader_module( + &wgpu::read_spirv(std::io::Cursor::new(&fs[..])) + .expect("Read triangle fragment shader as SPIR-V"), + ); + + let pipeline = + device.create_render_pipeline(&wgpu::RenderPipelineDescriptor { + layout: &layout, + vertex_stage: wgpu::ProgrammableStageDescriptor { + module: &vs_module, + entry_point: "main", + }, + fragment_stage: Some(wgpu::ProgrammableStageDescriptor { + module: &fs_module, + entry_point: "main", + }), + rasterization_state: Some(wgpu::RasterizationStateDescriptor { + front_face: wgpu::FrontFace::Cw, + cull_mode: wgpu::CullMode::None, + depth_bias: 0, + depth_bias_slope_scale: 0.0, + depth_bias_clamp: 0.0, + }), + primitive_topology: wgpu::PrimitiveTopology::TriangleList, + color_states: &[wgpu::ColorStateDescriptor { + format, + color_blend: wgpu::BlendDescriptor { + src_factor: wgpu::BlendFactor::SrcAlpha, + dst_factor: wgpu::BlendFactor::OneMinusSrcAlpha, + operation: wgpu::BlendOperation::Add, + }, + alpha_blend: wgpu::BlendDescriptor { + src_factor: wgpu::BlendFactor::One, + dst_factor: wgpu::BlendFactor::OneMinusSrcAlpha, + operation: wgpu::BlendOperation::Add, + }, + write_mask: wgpu::ColorWrite::ALL, + }], + depth_stencil_state: None, + index_format: wgpu::IndexFormat::Uint32, + vertex_buffers: &[wgpu::VertexBufferDescriptor { + stride: mem::size_of::<Vertex2D>() as u64, + step_mode: wgpu::InputStepMode::Vertex, + attributes: &[ + // Position + wgpu::VertexAttributeDescriptor { + shader_location: 0, + format: wgpu::VertexFormat::Float2, + offset: 0, + }, + // Color + wgpu::VertexAttributeDescriptor { + shader_location: 1, + format: wgpu::VertexFormat::Float4, + offset: 4 * 2, + }, + ], + }], + sample_count: antialiasing + .map(|a| a.sample_count()) + .unwrap_or(1), + sample_mask: !0, + alpha_to_coverage_enabled: false, + }); + + Pipeline { + pipeline, + blit: antialiasing.map(|a| msaa::Blit::new(device, format, a)), + constants: constant_bind_group, + uniforms_buffer: constants_buffer, + vertex_buffer: Buffer::new( + device, + VERTEX_BUFFER_SIZE, + wgpu::BufferUsage::VERTEX | wgpu::BufferUsage::COPY_DST, + ), + index_buffer: Buffer::new( + device, + INDEX_BUFFER_SIZE, + wgpu::BufferUsage::INDEX | wgpu::BufferUsage::COPY_DST, + ), + } + } + + pub fn draw( + &mut self, + device: &mut wgpu::Device, + encoder: &mut wgpu::CommandEncoder, + target: &wgpu::TextureView, + target_width: u32, + target_height: u32, + transformation: Transformation, + meshes: &Vec<(Point, Arc<Mesh2D>)>, + bounds: Rectangle<u32>, + ) { + // This looks a bit crazy, but we are just counting how many vertices + // and indices we will need to handle. + // TODO: Improve readability + let (total_vertices, total_indices) = meshes + .iter() + .map(|(_, mesh)| (mesh.vertices.len(), mesh.indices.len())) + .fold((0, 0), |(total_v, total_i), (v, i)| { + (total_v + v, total_i + i) + }); + + // Then we ensure the current buffers are big enough, resizing if + // necessary + self.uniforms_buffer.ensure_capacity(device, meshes.len()); + self.vertex_buffer.ensure_capacity(device, total_vertices); + self.index_buffer.ensure_capacity(device, total_indices); + + let mut uniforms: Vec<Uniforms> = Vec::with_capacity(meshes.len()); + let mut offsets: Vec<( + wgpu::BufferAddress, + wgpu::BufferAddress, + usize, + )> = Vec::with_capacity(meshes.len()); + let mut last_vertex = 0; + let mut last_index = 0; + + // We upload everything upfront + for (origin, mesh) in meshes { + let transform = Uniforms { + transform: (transformation + * Transformation::translate(origin.x, origin.y)) + .into(), + }; + + let vertex_buffer = device + .create_buffer_mapped( + mesh.vertices.len(), + wgpu::BufferUsage::COPY_SRC, + ) + .fill_from_slice(&mesh.vertices); + + let index_buffer = device + .create_buffer_mapped( + mesh.indices.len(), + wgpu::BufferUsage::COPY_SRC, + ) + .fill_from_slice(&mesh.indices); + + encoder.copy_buffer_to_buffer( + &vertex_buffer, + 0, + &self.vertex_buffer.raw, + (std::mem::size_of::<Vertex2D>() * last_vertex) as u64, + (std::mem::size_of::<Vertex2D>() * mesh.vertices.len()) as u64, + ); + + encoder.copy_buffer_to_buffer( + &index_buffer, + 0, + &self.index_buffer.raw, + (std::mem::size_of::<u32>() * last_index) as u64, + (std::mem::size_of::<u32>() * mesh.indices.len()) as u64, + ); + + uniforms.push(transform); + offsets.push(( + last_vertex as u64, + last_index as u64, + mesh.indices.len(), + )); + + last_vertex += mesh.vertices.len(); + last_index += mesh.indices.len(); + } + + let uniforms_buffer = device + .create_buffer_mapped(uniforms.len(), wgpu::BufferUsage::COPY_SRC) + .fill_from_slice(&uniforms); + + encoder.copy_buffer_to_buffer( + &uniforms_buffer, + 0, + &self.uniforms_buffer.raw, + 0, + (std::mem::size_of::<Uniforms>() * uniforms.len()) as u64, + ); + + { + let (attachment, resolve_target, load_op) = + if let Some(blit) = &mut self.blit { + let (attachment, resolve_target) = + blit.targets(device, target_width, target_height); + + (attachment, Some(resolve_target), wgpu::LoadOp::Clear) + } else { + (target, None, wgpu::LoadOp::Load) + }; + + let mut render_pass = + encoder.begin_render_pass(&wgpu::RenderPassDescriptor { + color_attachments: &[ + wgpu::RenderPassColorAttachmentDescriptor { + attachment, + resolve_target, + load_op, + store_op: wgpu::StoreOp::Store, + clear_color: wgpu::Color { + r: 0.0, + g: 0.0, + b: 0.0, + a: 0.0, + }, + }, + ], + depth_stencil_attachment: None, + }); + + render_pass.set_pipeline(&self.pipeline); + render_pass.set_scissor_rect( + bounds.x, + bounds.y, + bounds.width, + bounds.height, + ); + + for (i, (vertex_offset, index_offset, indices)) in + offsets.into_iter().enumerate() + { + render_pass.set_bind_group( + 0, + &self.constants, + &[(std::mem::size_of::<Uniforms>() * i) as u64], + ); + + render_pass.set_index_buffer( + &self.index_buffer.raw, + index_offset * std::mem::size_of::<u32>() as u64, + ); + + render_pass.set_vertex_buffers( + 0, + &[( + &self.vertex_buffer.raw, + vertex_offset * std::mem::size_of::<Vertex2D>() as u64, + )], + ); + + render_pass.draw_indexed(0..indices as u32, 0, 0..1); + } + } + + if let Some(blit) = &mut self.blit { + blit.draw(encoder, target); + } + } +} + +#[repr(C)] +#[derive(Debug, Clone, Copy)] +struct Uniforms { + transform: [f32; 16], +} + +impl Default for Uniforms { + fn default() -> Self { + Self { + transform: *Transformation::identity().as_ref(), + } + } +} + +/// A two-dimensional vertex with some color in __linear__ RGBA. +#[repr(C)] +#[derive(Copy, Clone, Debug)] +pub struct Vertex2D { + /// The vertex position + pub position: [f32; 2], + /// The vertex color in __linear__ RGBA. + pub color: [f32; 4], +} + +/// A set of [`Vertex2D`] and indices representing a list of triangles. +/// +/// [`Vertex2D`]: struct.Vertex2D.html +#[derive(Clone, Debug)] +pub struct Mesh2D { + /// The vertices of the mesh + pub vertices: Vec<Vertex2D>, + /// The list of vertex indices that defines the triangles of the mesh. + /// + /// Therefore, this list should always have a length that is a multiple of 3. + pub indices: Vec<u32>, +} |