rootvg_core/
pipeline.rs

1use std::error::Error;
2
3use crate::math::{PhysicalSizeI32, Point, ScaleFactor};
4
5pub type PrimitiveID = u32;
6
7#[derive(Debug, Clone, Copy, PartialEq)]
8pub struct CustomPrimitive {
9    pub id: PrimitiveID,
10    pub offset: Point,
11    pub pipeline_index: u8,
12}
13
14pub trait CustomPipeline {
15    fn needs_preparing(&self) -> bool;
16
17    fn prepare(
18        &mut self,
19        device: &wgpu::Device,
20        queue: &wgpu::Queue,
21        screen_size: PhysicalSizeI32,
22        scale_factor: ScaleFactor,
23        primitives: &[QueuedCustomPrimitive],
24    ) -> Result<(), Box<dyn Error>>;
25
26    fn render_primitives<'pass>(
27        &'pass self,
28        primitives: &[QueuedCustomPrimitive],
29        render_pass: &mut wgpu::RenderPass<'pass>,
30    ) -> Result<(), Box<dyn Error>>;
31}
32
33#[derive(Debug, Clone, Copy, PartialEq)]
34pub struct QueuedCustomPrimitive {
35    pub id: PrimitiveID,
36    pub offset: Point,
37}
38
39/// A default shader uniform struct containing the scale factor and a scaling vector
40/// used to convert from screen space to clip space.
41#[repr(C)]
42#[derive(Debug, Clone, Copy, bytemuck::Zeroable, bytemuck::Pod)]
43pub struct DefaultConstantUniforms {
44    pub screen_to_clip_scale: [f32; 2],
45    pub scale_factor: f32,
46    pub _padding: f32,
47}
48
49impl DefaultConstantUniforms {
50    pub fn new(screen_size: PhysicalSizeI32, scale_factor: ScaleFactor) -> Self {
51        Self {
52            screen_to_clip_scale: crate::math::screen_to_clip_scale(screen_size, scale_factor),
53            scale_factor: scale_factor.0,
54            _padding: 0.0,
55        }
56    }
57
58    pub fn layout_buffer_and_bind_group(
59        device: &wgpu::Device,
60    ) -> (wgpu::BindGroupLayout, wgpu::Buffer, wgpu::BindGroup) {
61        let layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
62            label: Some("rootvg-core constants layout"),
63            entries: &[Self::entry(0)],
64        });
65
66        let buffer = device.create_buffer(&wgpu::BufferDescriptor {
67            label: Some("rootvg-core constants buffer"),
68            size: std::mem::size_of::<Self>() as wgpu::BufferAddress,
69            usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
70            mapped_at_creation: false,
71        });
72
73        let bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
74            label: Some("rootvg-core constants bind group"),
75            layout: &layout,
76            entries: &[wgpu::BindGroupEntry {
77                binding: 0,
78                resource: buffer.as_entire_binding(),
79            }],
80        });
81
82        (layout, buffer, bind_group)
83    }
84
85    pub fn prepare_buffer(
86        buffer: &wgpu::Buffer,
87        screen_size: PhysicalSizeI32,
88        scale_factor: ScaleFactor,
89        queue: &wgpu::Queue,
90    ) {
91        let uniforms = Self::new(screen_size, scale_factor);
92        queue.write_buffer(buffer, 0, bytemuck::bytes_of(&uniforms));
93    }
94
95    pub fn entry(binding: u32) -> wgpu::BindGroupLayoutEntry {
96        wgpu::BindGroupLayoutEntry {
97            binding,
98            visibility: wgpu::ShaderStages::VERTEX,
99            ty: wgpu::BindingType::Buffer {
100                ty: wgpu::BufferBindingType::Uniform,
101                has_dynamic_offset: false,
102                min_binding_size: wgpu::BufferSize::new(
103                    std::mem::size_of::<Self>() as wgpu::BufferAddress
104                ),
105            },
106            count: None,
107        }
108    }
109}
rootvg_core/pipeline.rs

rootvg_core/
pipeline.rs
