initial wgpu backend impl

hui-wgpu/Cargo.toml

@@ -17,7 +17,7 @@ include = [
 
 [dependencies]
 hui = { version = "=0.1.0-alpha.5", path = "../hui", default-features = false }
-wgpu = "0.20"
+wgpu = { version = "0.20", default-features = false, features = ["wgsl"]}
 bytemuck = "1.15"
-glam = "0.27"
 log = "0.4"
+glam = "0.27"

hui-wgpu/shaders/ui.wgsl

@@ -0,0 +1,32 @@
+struct VertexInput {
+  @location(0) position: vec3<f32>,
+  @location(2) uv: vec2<f32>,
+  @location(3) color: vec4<f32>,
+}
+
+struct VertexOutput {
+  @builtin(position) clip_position: vec4<f32>,
+  @location(0) uv: vec2<f32>,
+  @location(1) color: vec4<f32>,
+};
+
+@vertex
+fn vs_main(
+  in: VertexInput,
+) -> VertexOutput {
+  var out: VertexOutput;
+  out.uv = in.uv;
+  out.clip_position = vec4<f32>(in.position, 1.0);
+  return out;
+}
+
+@group(0) @binding(0)
+var t_diffuse: texture_2d<f32>;
+
+@group(0) @binding(1)
+var s_diffuse: sampler;
+
+@fragment
+fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
+  return textureSample(t_diffuse, s_diffuse, in.uv);
+}

hui-wgpu/src/lib.rs

@@ -1,7 +1,314 @@
-pub struct WgpuUiRenderer {
+use glam::Vec2;
+use hui::{draw::{TextureAtlasMeta, UiDrawCall, UiVertex}, UiInstance};
 
+const DEFAULT_BUFFER_SIZE: u64 = 1024;
+const DEFAULT_TEXTURE_SIZE: u32 = 512;
+const SHADER_MODULE: &str = include_str!("../shaders/ui.wgsl");
+
+#[derive(Clone, Copy)]
+#[repr(C, packed)]
+struct WgpuVertex {
+  position: [f32; 2],
+  uv: [f32; 2],
+  color: [f32; 4],
+}
+unsafe impl bytemuck::Pod for WgpuVertex {}
+unsafe impl bytemuck::Zeroable for WgpuVertex {}
+
+impl WgpuVertex {
+  pub const LAYOUT: wgpu::VertexBufferLayout<'static> = wgpu::VertexBufferLayout {
+    array_stride: std::mem::size_of::<WgpuVertex>() as wgpu::BufferAddress,
+    step_mode: wgpu::VertexStepMode::Vertex,
+    attributes: &wgpu::vertex_attr_array![
+      0 => Float32x2,
+      1 => Float32x2,
+      2 => Float32x4,
+    ],
+  };
+}
+
+impl From<UiVertex> for WgpuVertex {
+  fn from(v: UiVertex) -> Self {
+    Self {
+      position: v.position.to_array(),
+      uv: v.uv.to_array(),
+      color: v.color.to_array(),
+    }
+  }
+}
+
+pub struct WgpuUiRenderer {
+  pub modified: bool,
+  pub vertex_buffer: wgpu::Buffer,
+  pub index_buffer: wgpu::Buffer,
+  pub vertex_count: usize,
+  pub index_count: usize,
+  pub bind_group_layout: wgpu::BindGroupLayout,
+  pub bind_group: wgpu::BindGroup,
+  pub pipeline: wgpu::RenderPipeline,
+  pub texture: wgpu::Texture,
+  pub texture_view: wgpu::TextureView,
+  pub texture_sampler: wgpu::Sampler,
 }
 
 impl WgpuUiRenderer {
+  pub fn new(
+    device: &wgpu::Device,
+    surface_format: wgpu::TextureFormat,
+  ) -> Self {
+    let vertex_buffer = device.create_buffer(&wgpu::BufferDescriptor {
+      label: Some("ui_vertex_buffer"),
+      size: std::mem::size_of::<WgpuVertex>() as u64 * DEFAULT_BUFFER_SIZE,
+      usage: wgpu::BufferUsages::VERTEX | wgpu::BufferUsages::COPY_DST,
+      mapped_at_creation: false,
+    });
 
+    let index_buffer = device.create_buffer(&wgpu::BufferDescriptor {
+      label: Some("hui_index_buffer"),
+      size: std::mem::size_of::<u32>() as u64 * DEFAULT_BUFFER_SIZE,
+      usage: wgpu::BufferUsages::INDEX | wgpu::BufferUsages::COPY_DST,
+      mapped_at_creation: false,
+    });
+
+    let texture = device.create_texture(&wgpu::TextureDescriptor {
+      label: Some("ui_texture"),
+      size: wgpu::Extent3d {
+        width: DEFAULT_TEXTURE_SIZE,
+        height: DEFAULT_TEXTURE_SIZE,
+        depth_or_array_layers: 1,
+      },
+      mip_level_count: 1,
+      sample_count: 1,
+      dimension: wgpu::TextureDimension::D2,
+      format: wgpu::TextureFormat::Rgba8UnormSrgb,
+      usage: wgpu::TextureUsages::COPY_DST | wgpu::TextureUsages::TEXTURE_BINDING,
+      view_formats: &[],
+    });
+
+    let bind_group_layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
+      label: Some("ui_bind_group_layout"),
+      entries: &[
+        wgpu::BindGroupLayoutEntry {
+          binding: 0,
+          visibility: wgpu::ShaderStages::FRAGMENT,
+          ty: wgpu::BindingType::Texture {
+            sample_type: wgpu::TextureSampleType::Float { filterable: false },
+            view_dimension: wgpu::TextureViewDimension::D2,
+            multisampled: false,
+          },
+          count: None,
+        },
+        wgpu::BindGroupLayoutEntry {
+          binding: 1,
+          visibility: wgpu::ShaderStages::FRAGMENT,
+          ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::NonFiltering),
+          count: None,
+        },
+      ],
+    });
+
+    let texture_view = texture.create_view(&wgpu::TextureViewDescriptor {
+      label: Some("ui_texture_view"),
+      ..Default::default()
+    });
+
+    let texture_sampler = device.create_sampler(&wgpu::SamplerDescriptor {
+      label: Some("ui_texture_sampler"),
+      address_mode_u: wgpu::AddressMode::ClampToEdge,
+      address_mode_v: wgpu::AddressMode::ClampToEdge,
+      address_mode_w: wgpu::AddressMode::ClampToEdge,
+      mag_filter: wgpu::FilterMode::Nearest,
+      min_filter: wgpu::FilterMode::Nearest,
+      mipmap_filter: wgpu::FilterMode::Nearest,
+      ..Default::default()
+    });
+
+    let bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
+      label: Some("ui_bind_group"),
+      layout: &bind_group_layout,
+      entries: &[
+        wgpu::BindGroupEntry {
+          binding: 0,
+          resource: wgpu::BindingResource::TextureView(&texture_view),
+        },
+        wgpu::BindGroupEntry {
+          binding: 1,
+          resource: wgpu::BindingResource::Sampler(&texture_sampler),
+        },
+      ],
+    });
+
+    let shader_module = device.create_shader_module(wgpu::ShaderModuleDescriptor {
+      label: Some("ui_vertex_shader"),
+      source: wgpu::ShaderSource::Wgsl(SHADER_MODULE.into()),
+    });
+
+    let pipeline = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
+      label: Some("ui_pipeline_layout"),
+      bind_group_layouts: &[&bind_group_layout],
+      push_constant_ranges: &[],
+    });
+
+    let pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
+      label: Some("ui_pipeline"),
+      layout: Some(&pipeline),
+      vertex: wgpu::VertexState {
+        module: &shader_module,
+        compilation_options: wgpu::PipelineCompilationOptions::default(),
+        entry_point: "vs_main",
+        buffers: &[WgpuVertex::LAYOUT],
+      },
+      fragment: Some(wgpu::FragmentState {
+        module: &shader_module,
+        compilation_options: wgpu::PipelineCompilationOptions::default(),
+        entry_point: "fs_main",
+        targets: &[Some(wgpu::ColorTargetState {
+          format: surface_format,
+          blend: Some(wgpu::BlendState::ALPHA_BLENDING),
+          write_mask: wgpu::ColorWrites::COLOR,
+        })],
+      }),
+      primitive: wgpu::PrimitiveState {
+        topology: wgpu::PrimitiveTopology::TriangleList,
+        strip_index_format: None,
+        front_face: wgpu::FrontFace::Ccw,
+        cull_mode: None,
+        polygon_mode: wgpu::PolygonMode::Fill,
+        conservative: false,
+        unclipped_depth: false,
+      },
+      depth_stencil: None,
+      multisample: wgpu::MultisampleState::default(),
+      multiview: None,
+    });
+
+    Self {
+      modified: true,
+      vertex_buffer,
+      index_buffer,
+      vertex_count: 0,
+      index_count: 0,
+      bind_group_layout,
+      bind_group,
+      texture,
+      texture_view,
+      texture_sampler,
+      pipeline,
+    }
+  }
+
+  fn update_buffers(&mut self, call: &UiDrawCall, queue: &wgpu::Queue, device: &wgpu::Device, resolution: Vec2) {
+    let data_vtx = call.vertices.iter()
+      .copied()
+      .map(|x| {
+        let mut v = x;
+        v.position = (v.position / resolution) * 2.0 - 1.0;
+        v
+      })
+      .map(WgpuVertex::from)
+      .collect::<Vec<_>>();
+    let data_idx = &call.indices[..];
+
+    self.vertex_count = call.vertices.len();
+    self.index_count = call.indices.len();
+
+    if data_vtx.is_empty() || data_idx.is_empty() {
+      return
+    }
+
+    if data_vtx.len() as u64 > self.vertex_buffer.size() {
+      self.vertex_buffer = device.create_buffer(&wgpu::BufferDescriptor {
+        label: Some("ui_vertex_buffer"),
+        size: (data_vtx.len() as u64).next_power_of_two(),
+        usage: wgpu::BufferUsages::VERTEX | wgpu::BufferUsages::COPY_DST,
+        mapped_at_creation: false,
+      });
+    }
+
+    if data_idx.len() as u64 > self.index_buffer.size() {
+      self.index_buffer = device.create_buffer(&wgpu::BufferDescriptor {
+        label: Some("ui_index_buffer"),
+        size: (data_idx.len() as u64).next_power_of_two(),
+        usage: wgpu::BufferUsages::INDEX | wgpu::BufferUsages::COPY_DST,
+        mapped_at_creation: false,
+      });
+    }
+
+    queue.write_buffer(&self.vertex_buffer, 0, bytemuck::cast_slice(&data_vtx));
+    queue.write_buffer(&self.index_buffer, 0, bytemuck::cast_slice(data_idx));
+  }
+
+  fn update_texture(&self, meta: TextureAtlasMeta, queue: &wgpu::Queue) {
+    //TODO URGENCY:HIGH resize texture if needed
+    if meta.data.len() as u32 > (self.texture.size().width * self.texture.size().height * 4) {
+      unimplemented!("texture resize not implemented");
+    }
+    queue.write_texture(
+      wgpu::ImageCopyTexture {
+        texture: &self.texture,
+        mip_level: 0,
+        origin: wgpu::Origin3d::ZERO,
+        aspect: wgpu::TextureAspect::All,
+      },
+      meta.data,
+      wgpu::ImageDataLayout {
+        offset: 0,
+        bytes_per_row: Some(meta.size.x * 4),
+        rows_per_image: Some(meta.size.y),
+      },
+      wgpu::Extent3d {
+        width: meta.size.x,
+        height: meta.size.y,
+        depth_or_array_layers: 1,
+      }
+    );
+  }
+
+  pub fn update(
+    &mut self,
+    instance: &UiInstance,
+    queue: &wgpu::Queue,
+    device: &wgpu::Device,
+    resolution: Vec2,
+  ) {
+    let (modified, call) = instance.draw_call();
+    if self.modified || modified {
+      self.update_buffers(call, queue, device, resolution);
+    }
+
+    let meta = instance.atlas();
+    if self.modified || meta.modified {
+      self.update_texture(meta, queue);
+    }
+
+    self.modified = false;
+  }
+
+  pub fn draw(
+    &self,
+    encoder: &mut wgpu::CommandEncoder,
+    surface_view: &wgpu::TextureView,
+  ) {
+    let mut rpass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+      label: Some("ui_render_pass"),
+      color_attachments: &[Some(wgpu::RenderPassColorAttachment {
+        view: surface_view,
+        resolve_target: None,
+        ops: wgpu::Operations {
+          load: wgpu::LoadOp::Load,
+          store: wgpu::StoreOp::Store,
+        },
+      })],
+      ..Default::default()
+    });
+
+    let vtx_size = self.vertex_count as u64 * std::mem::size_of::<WgpuVertex>() as u64;
+    let idx_size = self.index_count as u64 * std::mem::size_of::<u32>() as u64;
+
+    rpass.set_pipeline(&self.pipeline);
+    rpass.set_bind_group(0, &self.bind_group, &[]);
+    rpass.set_vertex_buffer(0, self.vertex_buffer.slice(0..vtx_size));
+    rpass.set_index_buffer(self.index_buffer.slice(..idx_size), wgpu::IndexFormat::Uint32);
+    rpass.draw_indexed(0..self.index_count as u32, 0, 0..1);
+  }
 }