StratoSDK is a framework with a declarative approach similar to Flutter/React, written and designed entirely for Rust.
| 1 | use crate::fonts::RasterizedGlyph; |
| 2 | |
| 3 | use crate::rendering::atlas::AllocatedRegion; |
| 4 | use wgpu::{ |
| 5 | BindGroup, BindGroupDescriptor, BindGroupLayout, Extent3d, Queue, Sampler, |
| 6 | TexelCopyBufferLayout, Texture, TextureDescriptor, TextureFormat, TextureUsages, |
| 7 | }; |
| 8 | |
| 9 | /// Helper struct that includes a [`Texture`] and its corresponding [`BindGroup`] for use in the |
| 10 | /// `GlyphCache`. |
| 11 | pub(super) struct TextureWithBindGroup { |
| 12 | texture: Texture, |
| 13 | /// The [`BindGroup`] associated with the `texture`. We compute this whenever we need to create |
| 14 | /// a new texture as a performance optimization to ensure we don't create it on every render. |
| 15 | bind_group: BindGroup, |
| 16 | } |
| 17 | |
| 18 | impl TextureWithBindGroup { |
| 19 | pub(super) fn new( |
| 20 | size: usize, |
| 21 | device: &wgpu::Device, |
| 22 | bind_group_layout: &BindGroupLayout, |
| 23 | sampler: &Sampler, |
| 24 | ) -> Self { |
| 25 | let texture = device.create_texture(&TextureDescriptor { |
| 26 | label: Some("Glyph atlas texture"), |
| 27 | size: Extent3d { |
| 28 | width: size as u32, |
| 29 | height: size as u32, |
| 30 | depth_or_array_layers: 1, |
| 31 | }, |
| 32 | mip_level_count: 1, |
| 33 | sample_count: 1, |
| 34 | dimension: wgpu::TextureDimension::D2, |
| 35 | format: TextureFormat::Rgba8Unorm, |
| 36 | usage: TextureUsages::TEXTURE_BINDING | TextureUsages::COPY_DST, |
| 37 | view_formats: &[], |
| 38 | }); |
| 39 | |
| 40 | let view = texture.create_view(&wgpu::TextureViewDescriptor::default()); |
| 41 | let bind_group = device.create_bind_group(&BindGroupDescriptor { |
| 42 | layout: bind_group_layout, |
| 43 | entries: &[ |
| 44 | wgpu::BindGroupEntry { |
| 45 | binding: 0, |
| 46 | resource: wgpu::BindingResource::TextureView(&view), |
| 47 | }, |
| 48 | wgpu::BindGroupEntry { |
| 49 | binding: 1, |
| 50 | resource: wgpu::BindingResource::Sampler(sampler), |
| 51 | }, |
| 52 | ], |
| 53 | label: None, |
| 54 | }); |
| 55 | |
| 56 | Self { |
| 57 | texture, |
| 58 | bind_group, |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | pub(super) fn insert_glyph_into_texture( |
| 63 | &mut self, |
| 64 | region: AllocatedRegion, |
| 65 | glyph: &RasterizedGlyph, |
| 66 | queue: &Queue, |
| 67 | ) { |
| 68 | let bytes_per_row: u32 = 4 * (glyph.canvas.size.x() as u32); |
| 69 | queue.write_texture( |
| 70 | wgpu::TexelCopyTextureInfo { |
| 71 | texture: &self.texture, |
| 72 | mip_level: 0, |
| 73 | origin: wgpu::Origin3d { |
| 74 | x: region.pixel_region.origin_x() as u32, |
| 75 | y: region.pixel_region.origin_y() as u32, |
| 76 | z: 0, |
| 77 | }, |
| 78 | aspect: wgpu::TextureAspect::All, |
| 79 | }, |
| 80 | glyph.canvas.pixels.as_slice(), |
| 81 | TexelCopyBufferLayout { |
| 82 | offset: 0, |
| 83 | bytes_per_row: Some(bytes_per_row), |
| 84 | rows_per_image: None, |
| 85 | }, |
| 86 | Extent3d { |
| 87 | width: region.pixel_region.width() as u32, |
| 88 | height: region.pixel_region.height() as u32, |
| 89 | depth_or_array_layers: 1, |
| 90 | }, |
| 91 | ); |
| 92 | } |
| 93 | |
| 94 | pub(super) fn bind_group(&self) -> &BindGroup { |
| 95 | &self.bind_group |
| 96 | } |
| 97 | } |
| 98 |