cyborg/src/commands.rs

56 lines
2.0 KiB
Rust

use super::{MeshInstance, MeshPool};
use std::collections::HashMap;
pub struct MeshCommands {
transforms: Vec<[f32; 16]>,
transform_ranges: Vec<(usize, std::ops::Range<u32>)>,
}
impl MeshCommands {
pub fn build(instances: &Vec<MeshInstance>) -> Self {
let mut sorted_meshes = HashMap::<usize, Vec<MeshInstance>>::new();
for mesh in instances.iter() {
let group_id = mesh.handle.group_id;
if let Some(by_group) = sorted_meshes.get_mut(&group_id) {
by_group.push(*mesh);
} else {
sorted_meshes.insert(group_id, vec![*mesh]);
}
}
let mut transforms = Vec::new();
let mut transform_ranges = Vec::new();
// this code assumes MeshHandle only uses group_id (which it does for now)
// TODO bucket by sub_id too before MeshHandle supports it
for (group_id, meshes) in sorted_meshes.iter() {
let start_idx = transforms.len() as u32;
let as_arrays = meshes.iter().map(|i| i.transform.to_cols_array());
transforms.extend(as_arrays);
let end_idx = transforms.len() as u32;
transform_ranges.push((*group_id, start_idx..end_idx));
}
Self {
transforms,
transform_ranges,
}
}
pub fn get_storage(&self) -> &[u8] {
bytemuck::cast_slice(&self.transforms)
}
pub fn dispatch<'a>(&self, rp: &mut wgpu::RenderPass<'a>, mesh_pool: &'a MeshPool) {
// TODO one group per mesh, still...
// TODO this could be implemented without accessing private members
for (group_id, meshes_range) in self.transform_ranges.iter() {
let group = mesh_pool.groups.get(*group_id).unwrap();
rp.set_vertex_buffer(0, group.vertices.slice(..));
rp.set_index_buffer(group.indices.slice(..), wgpu::IndexFormat::Uint32);
let indices = 0..(group.index_capacity as u32);
rp.draw_indexed(indices, 0, meshes_range.to_owned());
}
}
}