use crate::core::renderer::Vertex;
use crate::core::scene::GpuVertexBuffer;
use crate::gpu::axis::{axis_storage_buffer, AxisData};
use crate::gpu::shaders;
use crate::gpu::{tuning, ScalarType};
use std::sync::Arc;
use wgpu::util::DeviceExt;
pub struct ContourGpuInputs<'a> {
pub x_axis: AxisData<'a>,
pub y_axis: AxisData<'a>,
pub z_buffer: Arc<wgpu::Buffer>,
pub color_table: &'a [[f32; 4]],
pub level_values: &'a [f32],
pub x_len: u32,
pub y_len: u32,
pub scalar: ScalarType,
}
pub struct ContourGpuParams {
pub min_z: f32,
pub max_z: f32,
pub base_z: f32,
pub level_count: u32,
}
#[repr(C)]
#[derive(Clone, Copy, bytemuck::Pod, bytemuck::Zeroable)]
struct ContourUniforms {
min_z: f32,
max_z: f32,
base_z: f32,
level_count: u32,
x_len: u32,
y_len: u32,
color_table_len: u32,
cell_count: u32,
}
const VERTICES_PER_INVOCATION: u64 = 4;
pub fn pack_contour_vertices(
device: &Arc<wgpu::Device>,
queue: &Arc<wgpu::Queue>,
inputs: &ContourGpuInputs<'_>,
params: &ContourGpuParams,
) -> Result<GpuVertexBuffer, String> {
if inputs.x_len < 2 || inputs.y_len < 2 {
return Err("contour: axis vectors must contain at least two elements".to_string());
}
if inputs.level_values.is_empty() {
return Err("contour: level buffer must not be empty".to_string());
}
if params.level_count == 0 {
return Err("contour: level count must be positive".to_string());
}
if inputs.level_values.len() != params.level_count as usize {
return Err("contour: level buffer length mismatch".to_string());
}
let cells_x = inputs.x_len - 1;
let cells_y = inputs.y_len - 1;
let cell_count = cells_x
.checked_mul(cells_y)
.ok_or_else(|| "contour: grid dimensions overflowed cell count".to_string())?;
if cell_count == 0 {
return Err("contour: no cells available for contour generation".to_string());
}
let total_invocations = cell_count
.checked_mul(params.level_count)
.ok_or_else(|| "contour: invocation count overflowed".to_string())?;
let vertex_count = total_invocations
.checked_mul(VERTICES_PER_INVOCATION as u32)
.ok_or_else(|| "contour: vertex count overflowed".to_string())?;
let workgroup_size = tuning::effective_workgroup_size();
let shader = compile_shader(device, workgroup_size, inputs.scalar);
let x_buffer = axis_storage_buffer(device, "contour-x-axis", &inputs.x_axis, inputs.scalar)?;
let y_buffer = axis_storage_buffer(device, "contour-y-axis", &inputs.y_axis, inputs.scalar)?;
let color_buffer = Arc::new(
device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
label: Some("contour-color-table"),
contents: bytemuck::cast_slice(inputs.color_table),
usage: wgpu::BufferUsages::STORAGE | wgpu::BufferUsages::COPY_DST,
}),
);
let level_buffer = Arc::new(
device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
label: Some("contour-level-values"),
contents: bytemuck::cast_slice(inputs.level_values),
usage: wgpu::BufferUsages::STORAGE | wgpu::BufferUsages::COPY_DST,
}),
);
let output_size = (vertex_count as u64) * std::mem::size_of::<Vertex>() as u64;
let output_buffer = Arc::new(device.create_buffer(&wgpu::BufferDescriptor {
label: Some("contour-gpu-vertices"),
size: output_size,
usage: wgpu::BufferUsages::STORAGE
| wgpu::BufferUsages::VERTEX
| wgpu::BufferUsages::COPY_DST,
mapped_at_creation: false,
}));
let uniforms = ContourUniforms {
min_z: params.min_z,
max_z: if params.max_z <= params.min_z {
params.min_z + 1e-6
} else {
params.max_z
},
base_z: params.base_z,
level_count: params.level_count,
x_len: inputs.x_len,
y_len: inputs.y_len,
color_table_len: inputs.color_table.len() as u32,
cell_count,
};
let uniform_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
label: Some("contour-pack-uniforms"),
contents: bytemuck::bytes_of(&uniforms),
usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
});
let bind_group_layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
label: Some("contour-pack-bind-layout"),
entries: &[
wgpu::BindGroupLayoutEntry {
binding: 0,
visibility: wgpu::ShaderStages::COMPUTE,
ty: wgpu::BindingType::Buffer {
ty: wgpu::BufferBindingType::Storage { read_only: true },
has_dynamic_offset: false,
min_binding_size: None,
},
count: None,
},
wgpu::BindGroupLayoutEntry {
binding: 1,
visibility: wgpu::ShaderStages::COMPUTE,
ty: wgpu::BindingType::Buffer {
ty: wgpu::BufferBindingType::Storage { read_only: true },
has_dynamic_offset: false,
min_binding_size: None,
},
count: None,
},
wgpu::BindGroupLayoutEntry {
binding: 2,
visibility: wgpu::ShaderStages::COMPUTE,
ty: wgpu::BindingType::Buffer {
ty: wgpu::BufferBindingType::Storage { read_only: true },
has_dynamic_offset: false,
min_binding_size: None,
},
count: None,
},
wgpu::BindGroupLayoutEntry {
binding: 3,
visibility: wgpu::ShaderStages::COMPUTE,
ty: wgpu::BindingType::Buffer {
ty: wgpu::BufferBindingType::Storage { read_only: true },
has_dynamic_offset: false,
min_binding_size: None,
},
count: None,
},
wgpu::BindGroupLayoutEntry {
binding: 4,
visibility: wgpu::ShaderStages::COMPUTE,
ty: wgpu::BindingType::Buffer {
ty: wgpu::BufferBindingType::Storage { read_only: false },
has_dynamic_offset: false,
min_binding_size: None,
},
count: None,
},
wgpu::BindGroupLayoutEntry {
binding: 5,
visibility: wgpu::ShaderStages::COMPUTE,
ty: wgpu::BindingType::Buffer {
ty: wgpu::BufferBindingType::Uniform,
has_dynamic_offset: false,
min_binding_size: None,
},
count: None,
},
wgpu::BindGroupLayoutEntry {
binding: 6,
visibility: wgpu::ShaderStages::COMPUTE,
ty: wgpu::BindingType::Buffer {
ty: wgpu::BufferBindingType::Storage { read_only: true },
has_dynamic_offset: false,
min_binding_size: None,
},
count: None,
},
],
});
let pipeline_layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
label: Some("contour-pack-pipeline-layout"),
bind_group_layouts: &[&bind_group_layout],
push_constant_ranges: &[],
});
let pipeline = device.create_compute_pipeline(&wgpu::ComputePipelineDescriptor {
label: Some("contour-pack-pipeline"),
layout: Some(&pipeline_layout),
module: &shader,
entry_point: "main",
});
let bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
label: Some("contour-pack-bind-group"),
layout: &bind_group_layout,
entries: &[
wgpu::BindGroupEntry {
binding: 0,
resource: x_buffer.as_ref().as_entire_binding(),
},
wgpu::BindGroupEntry {
binding: 1,
resource: y_buffer.as_ref().as_entire_binding(),
},
wgpu::BindGroupEntry {
binding: 2,
resource: inputs.z_buffer.as_ref().as_entire_binding(),
},
wgpu::BindGroupEntry {
binding: 3,
resource: color_buffer.as_ref().as_entire_binding(),
},
wgpu::BindGroupEntry {
binding: 4,
resource: output_buffer.as_ref().as_entire_binding(),
},
wgpu::BindGroupEntry {
binding: 5,
resource: uniform_buffer.as_entire_binding(),
},
wgpu::BindGroupEntry {
binding: 6,
resource: level_buffer.as_ref().as_entire_binding(),
},
],
});
let mut encoder = device.create_command_encoder(&wgpu::CommandEncoderDescriptor {
label: Some("contour-pack-encoder"),
});
{
let mut pass = encoder.begin_compute_pass(&wgpu::ComputePassDescriptor {
label: Some("contour-pack-pass"),
timestamp_writes: None,
});
pass.set_pipeline(&pipeline);
pass.set_bind_group(0, &bind_group, &[]);
let workgroups = total_invocations.div_ceil(workgroup_size);
pass.dispatch_workgroups(workgroups, 1, 1);
}
queue.submit(Some(encoder.finish()));
Ok(GpuVertexBuffer::new(output_buffer, vertex_count as usize))
}
fn compile_shader(
device: &Arc<wgpu::Device>,
workgroup_size: u32,
scalar: ScalarType,
) -> wgpu::ShaderModule {
let template = match scalar {
ScalarType::F32 => shaders::contour::F32,
ScalarType::F64 => shaders::contour::F64,
};
let source = template.replace("{{WORKGROUP_SIZE}}", &workgroup_size.to_string());
device.create_shader_module(wgpu::ShaderModuleDescriptor {
label: Some("contour-pack-shader"),
source: wgpu::ShaderSource::Wgsl(source.into()),
})
}