use std::mem;
use crate::graphics::Transformation;
use zerocopy::AsBytes;
pub struct Pipeline {
pipeline: wgpu::RenderPipeline,
transform: wgpu::Buffer,
constants: wgpu::BindGroup,
vertices: wgpu::Buffer,
indices: wgpu::Buffer,
buffer_size: u32,
}
impl Pipeline {
const INITIAL_BUFFER_SIZE: u32 = 100_000;
pub fn new(device: &mut wgpu::Device) -> Pipeline {
let transform_layout =
device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
label: Some("coffee::backend::triangle transform"),
bindings: &[wgpu::BindGroupLayoutEntry {
binding: 0,
visibility: wgpu::ShaderStage::VERTEX,
ty: wgpu::BindingType::UniformBuffer { dynamic: false },
}],
});
let matrix: [f32; 16] = Transformation::identity().into();
let transform_buffer = device.create_buffer_with_data(
matrix.as_bytes(),
wgpu::BufferUsage::UNIFORM | wgpu::BufferUsage::COPY_DST,
);
let constant_bind_group =
device.create_bind_group(&wgpu::BindGroupDescriptor {
label: Some("coffee::backend::triangle constants"),
layout: &transform_layout,
bindings: &[wgpu::Binding {
binding: 0,
resource: wgpu::BindingResource::Buffer {
buffer: &transform_buffer,
range: 0..64,
},
}],
});
let layout =
device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
bind_group_layouts: &[&transform_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::Ccw,
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: wgpu::TextureFormat::Bgra8UnormSrgb,
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,
vertex_state: wgpu::VertexStateDescriptor {
index_format: wgpu::IndexFormat::Uint32,
vertex_buffers: &[wgpu::VertexBufferDescriptor {
stride: mem::size_of::<Vertex>() as u64,
step_mode: wgpu::InputStepMode::Vertex,
attributes: &[
wgpu::VertexAttributeDescriptor {
shader_location: 0,
format: wgpu::VertexFormat::Float2,
offset: 0,
},
wgpu::VertexAttributeDescriptor {
shader_location: 1,
format: wgpu::VertexFormat::Float4,
offset: 4 * 2,
},
],
}],
},
sample_count: 1,
sample_mask: !0,
alpha_to_coverage_enabled: false,
});
let vertices = device.create_buffer(&wgpu::BufferDescriptor {
label: Some("coffee::backend::triangle vertices"),
size: mem::size_of::<Vertex>() as u64
* Self::INITIAL_BUFFER_SIZE as u64,
usage: wgpu::BufferUsage::VERTEX | wgpu::BufferUsage::COPY_DST,
});
let indices = device.create_buffer(&wgpu::BufferDescriptor {
label: Some("coffee::backend::triangle indices"),
size: mem::size_of::<u32>() as u64
* Self::INITIAL_BUFFER_SIZE as u64,
usage: wgpu::BufferUsage::INDEX | wgpu::BufferUsage::COPY_DST,
});
Pipeline {
pipeline,
transform: transform_buffer,
constants: constant_bind_group,
vertices,
indices,
buffer_size: Self::INITIAL_BUFFER_SIZE,
}
}
pub fn draw(
&mut self,
device: &mut wgpu::Device,
encoder: &mut wgpu::CommandEncoder,
vertices: &[Vertex],
indices: &[u32],
transformation: &Transformation,
target: &wgpu::TextureView,
) {
if vertices.is_empty() || indices.is_empty() {
return;
}
let matrix: [f32; 16] = transformation.clone().into();
let transform_buffer = device.create_buffer_with_data(
matrix.as_bytes(),
wgpu::BufferUsage::COPY_SRC,
);
encoder.copy_buffer_to_buffer(
&transform_buffer,
0,
&self.transform,
0,
16 * 4,
);
if self.buffer_size < vertices.len() as u32
|| self.buffer_size < indices.len() as u32
{
let new_size = vertices.len().max(indices.len()) as u32;
self.vertices = device.create_buffer(&wgpu::BufferDescriptor {
label: Some("coffee::backend::triangle vertices"),
size: mem::size_of::<Vertex>() as u64 * new_size as u64,
usage: wgpu::BufferUsage::VERTEX | wgpu::BufferUsage::COPY_DST,
});
self.indices = device.create_buffer(&wgpu::BufferDescriptor {
label: Some("coffee::backend::triangle indices"),
size: mem::size_of::<u32>() as u64 * new_size as u64,
usage: wgpu::BufferUsage::INDEX | wgpu::BufferUsage::COPY_DST,
});
self.buffer_size = new_size;
}
let vertex_buffer = device.create_buffer_with_data(
vertices.as_bytes(),
wgpu::BufferUsage::COPY_SRC,
);
let index_buffer = device.create_buffer_with_data(
indices.as_bytes(),
wgpu::BufferUsage::COPY_SRC,
);
encoder.copy_buffer_to_buffer(
&vertex_buffer,
0,
&self.vertices,
0,
(mem::size_of::<Vertex>() * vertices.len()) as u64,
);
encoder.copy_buffer_to_buffer(
&index_buffer,
0,
&self.indices,
0,
(mem::size_of::<u32>() * indices.len()) as u64,
);
{
let mut render_pass =
encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
color_attachments: &[
wgpu::RenderPassColorAttachmentDescriptor {
attachment: target,
resolve_target: None,
load_op: wgpu::LoadOp::Load,
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_bind_group(0, &self.constants, &[]);
render_pass.set_index_buffer(&self.indices, 0, 0);
render_pass.set_vertex_buffer(0, &self.vertices, 0, 0);
render_pass.draw_indexed(0..indices.len() as u32, 0, 0..1);
}
}
}
#[derive(Debug, Clone, Copy, AsBytes)]
#[repr(C)]
pub struct Vertex {
_position: [f32; 2],
_color: [f32; 4],
}
impl Vertex {
pub fn new(position: [f32; 2], color: [f32; 4]) -> Vertex {
Vertex {
_position: position,
_color: color,
}
}
}