use crate::Transformation;
use iced_graphics::layer;
use iced_native::Rectangle;
use std::mem;
use zerocopy::AsBytes;
#[derive(Debug)]
pub struct Pipeline {
pipeline: wgpu::RenderPipeline,
constants: wgpu::BindGroup,
constants_buffer: wgpu::Buffer,
vertices: wgpu::Buffer,
indices: wgpu::Buffer,
instances: wgpu::Buffer,
}
impl Pipeline {
pub fn new(device: &wgpu::Device, format: wgpu::TextureFormat) -> Pipeline {
let constant_layout =
device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
label: None,
bindings: &[wgpu::BindGroupLayoutEntry {
binding: 0,
visibility: wgpu::ShaderStage::VERTEX,
ty: wgpu::BindingType::UniformBuffer { dynamic: false },
}],
});
let constants_buffer = device.create_buffer_with_data(
Uniforms::default().as_bytes(),
wgpu::BufferUsage::UNIFORM | wgpu::BufferUsage::COPY_DST,
);
let constants = device.create_bind_group(&wgpu::BindGroupDescriptor {
label: None,
layout: &constant_layout,
bindings: &[wgpu::Binding {
binding: 0,
resource: wgpu::BindingResource::Buffer {
buffer: &constants_buffer,
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/quad.vert.spv");
let vs_module = device.create_shader_module(
&wgpu::read_spirv(std::io::Cursor::new(&vs[..]))
.expect("Read quad vertex shader as SPIR-V"),
);
let fs = include_bytes!("shader/quad.frag.spv");
let fs_module = device.create_shader_module(
&wgpu::read_spirv(std::io::Cursor::new(&fs[..]))
.expect("Read quad 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,
vertex_state: wgpu::VertexStateDescriptor {
index_format: wgpu::IndexFormat::Uint16,
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::VertexBufferDescriptor {
stride: mem::size_of::<layer::Quad>() as u64,
step_mode: wgpu::InputStepMode::Instance,
attributes: &[
wgpu::VertexAttributeDescriptor {
shader_location: 1,
format: wgpu::VertexFormat::Float2,
offset: 0,
},
wgpu::VertexAttributeDescriptor {
shader_location: 2,
format: wgpu::VertexFormat::Float2,
offset: 4 * 2,
},
wgpu::VertexAttributeDescriptor {
shader_location: 3,
format: wgpu::VertexFormat::Float4,
offset: 4 * (2 + 2),
},
wgpu::VertexAttributeDescriptor {
shader_location: 4,
format: wgpu::VertexFormat::Float4,
offset: 4 * (2 + 2 + 4),
},
wgpu::VertexAttributeDescriptor {
shader_location: 5,
format: wgpu::VertexFormat::Float,
offset: 4 * (2 + 2 + 4 + 4),
},
wgpu::VertexAttributeDescriptor {
shader_location: 6,
format: wgpu::VertexFormat::Float,
offset: 4 * (2 + 2 + 4 + 4 + 1),
},
],
},
],
},
sample_count: 1,
sample_mask: !0,
alpha_to_coverage_enabled: false,
});
let vertices = device.create_buffer_with_data(
QUAD_VERTS.as_bytes(),
wgpu::BufferUsage::VERTEX,
);
let indices = device.create_buffer_with_data(
QUAD_INDICES.as_bytes(),
wgpu::BufferUsage::INDEX,
);
let instances = device.create_buffer(&wgpu::BufferDescriptor {
label: None,
size: mem::size_of::<layer::Quad>() as u64 * MAX_INSTANCES as u64,
usage: wgpu::BufferUsage::VERTEX | wgpu::BufferUsage::COPY_DST,
});
Pipeline {
pipeline,
constants,
constants_buffer,
vertices,
indices,
instances,
}
}
pub fn draw(
&mut self,
device: &wgpu::Device,
encoder: &mut wgpu::CommandEncoder,
instances: &[layer::Quad],
transformation: Transformation,
scale: f32,
bounds: Rectangle<u32>,
target: &wgpu::TextureView,
) {
let uniforms = Uniforms::new(transformation, scale);
let constants_buffer = device.create_buffer_with_data(
uniforms.as_bytes(),
wgpu::BufferUsage::COPY_SRC,
);
encoder.copy_buffer_to_buffer(
&constants_buffer,
0,
&self.constants_buffer,
0,
std::mem::size_of::<Uniforms>() as u64,
);
let mut i = 0;
let total = instances.len();
while i < total {
let end = (i + MAX_INSTANCES).min(total);
let amount = end - i;
let instance_buffer = device.create_buffer_with_data(
bytemuck::cast_slice(&instances[i..end]),
wgpu::BufferUsage::COPY_SRC,
);
encoder.copy_buffer_to_buffer(
&instance_buffer,
0,
&self.instances,
0,
(mem::size_of::<layer::Quad>() * amount) 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.set_vertex_buffer(1, &self.instances, 0, 0);
render_pass.set_scissor_rect(
bounds.x,
bounds.y,
bounds.width,
bounds.height + 1,
);
render_pass.draw_indexed(
0..QUAD_INDICES.len() as u32,
0,
0..amount as u32,
);
}
i += MAX_INSTANCES;
}
}
}
#[repr(C)]
#[derive(Clone, Copy, AsBytes)]
pub struct Vertex {
_position: [f32; 2],
}
const QUAD_INDICES: [u16; 6] = [0, 1, 2, 0, 2, 3];
const QUAD_VERTS: [Vertex; 4] = [
Vertex {
_position: [0.0, 0.0],
},
Vertex {
_position: [1.0, 0.0],
},
Vertex {
_position: [1.0, 1.0],
},
Vertex {
_position: [0.0, 1.0],
},
];
const MAX_INSTANCES: usize = 100_000;
#[repr(C)]
#[derive(Debug, Clone, Copy, AsBytes)]
struct Uniforms {
transform: [f32; 16],
scale: f32,
}
impl Uniforms {
fn new(transformation: Transformation, scale: f32) -> Uniforms {
Self {
transform: *transformation.as_ref(),
scale,
}
}
}
impl Default for Uniforms {
fn default() -> Self {
Self {
transform: *Transformation::identity().as_ref(),
scale: 1.0,
}
}
}