396 lines
13 KiB
Rust
396 lines
13 KiB
Rust
//! Draw meshes of triangles.
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use crate::{settings, Transformation};
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use iced_graphics::layer;
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use std::mem;
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use zerocopy::AsBytes;
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pub use iced_graphics::triangle::{Mesh2D, Vertex2D};
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mod msaa;
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const UNIFORM_BUFFER_SIZE: usize = 100;
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const VERTEX_BUFFER_SIZE: usize = 10_000;
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const INDEX_BUFFER_SIZE: usize = 10_000;
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#[derive(Debug)]
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pub(crate) struct Pipeline {
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pipeline: wgpu::RenderPipeline,
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blit: Option<msaa::Blit>,
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constants: wgpu::BindGroup,
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uniforms_buffer: Buffer<Uniforms>,
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vertex_buffer: Buffer<Vertex2D>,
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index_buffer: Buffer<u32>,
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}
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#[derive(Debug)]
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struct Buffer<T> {
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raw: wgpu::Buffer,
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size: usize,
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usage: wgpu::BufferUsage,
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_type: std::marker::PhantomData<T>,
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}
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impl<T> Buffer<T> {
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pub fn new(
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device: &wgpu::Device,
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size: usize,
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usage: wgpu::BufferUsage,
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) -> Self {
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let raw = device.create_buffer(&wgpu::BufferDescriptor {
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label: None,
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size: (std::mem::size_of::<T>() * size) as u64,
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usage,
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});
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Buffer {
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raw,
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size,
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usage,
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_type: std::marker::PhantomData,
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}
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}
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pub fn ensure_capacity(&mut self, device: &wgpu::Device, size: usize) {
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if self.size < size {
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self.raw = device.create_buffer(&wgpu::BufferDescriptor {
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label: None,
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size: (std::mem::size_of::<T>() * size) as u64,
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usage: self.usage,
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});
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self.size = size;
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}
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}
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}
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impl Pipeline {
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pub fn new(
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device: &wgpu::Device,
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format: wgpu::TextureFormat,
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antialiasing: Option<settings::Antialiasing>,
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) -> Pipeline {
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let constant_layout =
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device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
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label: None,
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bindings: &[wgpu::BindGroupLayoutEntry {
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binding: 0,
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visibility: wgpu::ShaderStage::VERTEX,
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ty: wgpu::BindingType::UniformBuffer { dynamic: true },
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}],
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});
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let constants_buffer = Buffer::new(
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device,
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UNIFORM_BUFFER_SIZE,
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wgpu::BufferUsage::UNIFORM | wgpu::BufferUsage::COPY_DST,
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);
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let constant_bind_group =
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device.create_bind_group(&wgpu::BindGroupDescriptor {
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label: None,
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layout: &constant_layout,
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bindings: &[wgpu::Binding {
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binding: 0,
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resource: wgpu::BindingResource::Buffer {
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buffer: &constants_buffer.raw,
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range: 0..std::mem::size_of::<Uniforms>() as u64,
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},
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}],
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});
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let layout =
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device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
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bind_group_layouts: &[&constant_layout],
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});
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let vs = include_bytes!("shader/triangle.vert.spv");
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let vs_module = device.create_shader_module(
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&wgpu::read_spirv(std::io::Cursor::new(&vs[..]))
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.expect("Read triangle vertex shader as SPIR-V"),
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);
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let fs = include_bytes!("shader/triangle.frag.spv");
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let fs_module = device.create_shader_module(
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&wgpu::read_spirv(std::io::Cursor::new(&fs[..]))
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.expect("Read triangle fragment shader as SPIR-V"),
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);
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let pipeline =
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device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
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layout: &layout,
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vertex_stage: wgpu::ProgrammableStageDescriptor {
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module: &vs_module,
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entry_point: "main",
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},
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fragment_stage: Some(wgpu::ProgrammableStageDescriptor {
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module: &fs_module,
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entry_point: "main",
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}),
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rasterization_state: Some(wgpu::RasterizationStateDescriptor {
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front_face: wgpu::FrontFace::Cw,
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cull_mode: wgpu::CullMode::None,
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depth_bias: 0,
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depth_bias_slope_scale: 0.0,
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depth_bias_clamp: 0.0,
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}),
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primitive_topology: wgpu::PrimitiveTopology::TriangleList,
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color_states: &[wgpu::ColorStateDescriptor {
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format,
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color_blend: wgpu::BlendDescriptor {
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src_factor: wgpu::BlendFactor::SrcAlpha,
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dst_factor: wgpu::BlendFactor::OneMinusSrcAlpha,
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operation: wgpu::BlendOperation::Add,
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},
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alpha_blend: wgpu::BlendDescriptor {
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src_factor: wgpu::BlendFactor::One,
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dst_factor: wgpu::BlendFactor::OneMinusSrcAlpha,
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operation: wgpu::BlendOperation::Add,
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},
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write_mask: wgpu::ColorWrite::ALL,
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}],
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depth_stencil_state: None,
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vertex_state: wgpu::VertexStateDescriptor {
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index_format: wgpu::IndexFormat::Uint32,
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vertex_buffers: &[wgpu::VertexBufferDescriptor {
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stride: mem::size_of::<Vertex2D>() as u64,
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step_mode: wgpu::InputStepMode::Vertex,
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attributes: &[
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// Position
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wgpu::VertexAttributeDescriptor {
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shader_location: 0,
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format: wgpu::VertexFormat::Float2,
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offset: 0,
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},
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// Color
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wgpu::VertexAttributeDescriptor {
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shader_location: 1,
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format: wgpu::VertexFormat::Float4,
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offset: 4 * 2,
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},
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],
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}],
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},
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sample_count: u32::from(
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antialiasing.map(|a| a.sample_count()).unwrap_or(1),
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),
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sample_mask: !0,
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alpha_to_coverage_enabled: false,
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});
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Pipeline {
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pipeline,
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blit: antialiasing.map(|a| msaa::Blit::new(device, format, a)),
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constants: constant_bind_group,
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uniforms_buffer: constants_buffer,
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vertex_buffer: Buffer::new(
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device,
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VERTEX_BUFFER_SIZE,
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wgpu::BufferUsage::VERTEX | wgpu::BufferUsage::COPY_DST,
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),
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index_buffer: Buffer::new(
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device,
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INDEX_BUFFER_SIZE,
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wgpu::BufferUsage::INDEX | wgpu::BufferUsage::COPY_DST,
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),
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}
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}
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pub fn draw(
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&mut self,
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device: &wgpu::Device,
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encoder: &mut wgpu::CommandEncoder,
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target: &wgpu::TextureView,
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target_width: u32,
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target_height: u32,
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transformation: Transformation,
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scale_factor: f32,
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meshes: &[layer::Mesh<'_>],
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) {
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// This looks a bit crazy, but we are just counting how many vertices
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// and indices we will need to handle.
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// TODO: Improve readability
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let (total_vertices, total_indices) = meshes
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.iter()
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.map(|layer::Mesh { buffers, .. }| {
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(buffers.vertices.len(), buffers.indices.len())
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})
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.fold((0, 0), |(total_v, total_i), (v, i)| {
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(total_v + v, total_i + i)
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});
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// Then we ensure the current buffers are big enough, resizing if
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// necessary
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self.uniforms_buffer.ensure_capacity(device, meshes.len());
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self.vertex_buffer.ensure_capacity(device, total_vertices);
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self.index_buffer.ensure_capacity(device, total_indices);
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let mut uniforms: Vec<Uniforms> = Vec::with_capacity(meshes.len());
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let mut offsets: Vec<(
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wgpu::BufferAddress,
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wgpu::BufferAddress,
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usize,
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)> = Vec::with_capacity(meshes.len());
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let mut last_vertex = 0;
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let mut last_index = 0;
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// We upload everything upfront
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for mesh in meshes {
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let transform = (transformation
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* Transformation::translate(mesh.origin.x, mesh.origin.y))
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.into();
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let vertex_buffer = device.create_buffer_with_data(
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bytemuck::cast_slice(&mesh.buffers.vertices),
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wgpu::BufferUsage::COPY_SRC,
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);
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let index_buffer = device.create_buffer_with_data(
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mesh.buffers.indices.as_bytes(),
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wgpu::BufferUsage::COPY_SRC,
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);
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encoder.copy_buffer_to_buffer(
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&vertex_buffer,
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0,
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&self.vertex_buffer.raw,
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(std::mem::size_of::<Vertex2D>() * last_vertex) as u64,
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(std::mem::size_of::<Vertex2D>() * mesh.buffers.vertices.len())
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as u64,
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);
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encoder.copy_buffer_to_buffer(
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&index_buffer,
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0,
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&self.index_buffer.raw,
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(std::mem::size_of::<u32>() * last_index) as u64,
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(std::mem::size_of::<u32>() * mesh.buffers.indices.len())
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as u64,
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);
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uniforms.push(transform);
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offsets.push((
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last_vertex as u64,
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last_index as u64,
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mesh.buffers.indices.len(),
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));
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last_vertex += mesh.buffers.vertices.len();
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last_index += mesh.buffers.indices.len();
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}
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let uniforms_buffer = device.create_buffer_with_data(
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uniforms.as_bytes(),
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wgpu::BufferUsage::COPY_SRC,
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);
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encoder.copy_buffer_to_buffer(
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&uniforms_buffer,
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0,
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&self.uniforms_buffer.raw,
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0,
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(std::mem::size_of::<Uniforms>() * uniforms.len()) as u64,
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);
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{
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let (attachment, resolve_target, load_op) =
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if let Some(blit) = &mut self.blit {
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let (attachment, resolve_target) =
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blit.targets(device, target_width, target_height);
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(attachment, Some(resolve_target), wgpu::LoadOp::Clear)
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} else {
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(target, None, wgpu::LoadOp::Load)
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};
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let mut render_pass =
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encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
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color_attachments: &[
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wgpu::RenderPassColorAttachmentDescriptor {
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attachment,
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resolve_target,
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load_op,
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store_op: wgpu::StoreOp::Store,
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clear_color: wgpu::Color {
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r: 0.0,
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g: 0.0,
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b: 0.0,
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a: 0.0,
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},
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},
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],
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depth_stencil_attachment: None,
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});
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render_pass.set_pipeline(&self.pipeline);
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for (i, (vertex_offset, index_offset, indices)) in
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offsets.into_iter().enumerate()
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{
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let clip_bounds =
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(meshes[i].clip_bounds * scale_factor).round();
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render_pass.set_scissor_rect(
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clip_bounds.x,
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clip_bounds.y,
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clip_bounds.width,
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clip_bounds.height,
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);
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render_pass.set_bind_group(
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0,
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&self.constants,
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&[(std::mem::size_of::<Uniforms>() * i) as u32],
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);
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render_pass.set_index_buffer(
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&self.index_buffer.raw,
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index_offset * std::mem::size_of::<u32>() as u64,
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0,
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);
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render_pass.set_vertex_buffer(
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0,
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&self.vertex_buffer.raw,
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vertex_offset * std::mem::size_of::<Vertex2D>() as u64,
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0,
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);
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render_pass.draw_indexed(0..indices as u32, 0, 0..1);
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}
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}
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if let Some(blit) = &mut self.blit {
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blit.draw(encoder, target);
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}
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}
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}
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#[repr(C)]
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#[derive(Debug, Clone, Copy, AsBytes)]
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struct Uniforms {
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transform: [f32; 16],
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// We need to align this to 256 bytes to please `wgpu`...
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// TODO: Be smarter and stop wasting memory!
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_padding_a: [f32; 32],
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_padding_b: [f32; 16],
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}
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impl Default for Uniforms {
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fn default() -> Self {
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Self {
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transform: *Transformation::identity().as_ref(),
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_padding_a: [0.0; 32],
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_padding_b: [0.0; 16],
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}
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}
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}
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impl From<Transformation> for Uniforms {
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fn from(transformation: Transformation) -> Uniforms {
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Self {
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transform: transformation.into(),
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_padding_a: [0.0; 32],
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_padding_b: [0.0; 16],
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}
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}
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}
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