Files
marathon/crates/libmarathon/src/render/oit/oit_draw.wgsl
Sienna Meridian Satterwhite f3f8094530 Vendor Bevy rendering crates (Phase 1 complete)
Closes #6, #7, #8, #9, #10
Refs #2, #122

Vendored bevy_render, bevy_core_pipeline, and bevy_pbr from Bevy v0.17.2
(commit 566358363126dd69f6e457e47f306c68f8041d2a) into libmarathon.

- ~51K LOC vendored to crates/libmarathon/src/render/
- Merged bevy_render_macros into crates/macros/
- Fixed 773→0 compilation errors
- Updated dependencies (encase 0.10→0.11, added 4 new deps)
- Removed bevy_render/pbr/core_pipeline from app Cargo features

All builds passing, macOS smoke test successful.

Signed-off-by: Sienna Meridian Satterwhite <sienna@r3t.io>
2025-12-24 00:04:24 +00:00

49 lines
2.0 KiB
WebGPU Shading Language

#define_import_path bevy_core_pipeline::oit
#import bevy_pbr::mesh_view_bindings::{view, oit_layers, oit_layer_ids, oit_settings}
#ifdef OIT_ENABLED
// Add the fragment to the oit buffer
fn oit_draw(position: vec4f, color: vec4f) {
// Don't add fully transparent fragments to the list
// because we don't want to have to sort them in the resolve pass
if color.a < oit_settings.alpha_threshold {
return;
}
// get the index of the current fragment relative to the screen size
let screen_index = i32(floor(position.x) + floor(position.y) * view.viewport.z);
// get the size of the buffer.
// It's always the size of the screen
let buffer_size = i32(view.viewport.z * view.viewport.w);
// gets the layer index of the current fragment
var layer_id = atomicAdd(&oit_layer_ids[screen_index], 1);
// exit early if we've reached the maximum amount of fragments per layer
if layer_id >= oit_settings.layers_count {
// force to store the oit_layers_count to make sure we don't
// accidentally increase the index above the maximum value
atomicStore(&oit_layer_ids[screen_index], oit_settings.layers_count);
// TODO for tail blending we should return the color here
return;
}
// get the layer_index from the screen
let layer_index = screen_index + layer_id * buffer_size;
let rgb9e5_color = bevy_pbr::rgb9e5::vec3_to_rgb9e5_(color.rgb);
let depth_alpha = pack_24bit_depth_8bit_alpha(position.z, color.a);
oit_layers[layer_index] = vec2(rgb9e5_color, depth_alpha);
}
#endif // OIT_ENABLED
fn pack_24bit_depth_8bit_alpha(depth: f32, alpha: f32) -> u32 {
let depth_bits = u32(saturate(depth) * f32(0xFFFFFFu) + 0.5);
let alpha_bits = u32(saturate(alpha) * f32(0xFFu) + 0.5);
return (depth_bits & 0xFFFFFFu) | ((alpha_bits & 0xFFu) << 24u);
}
fn unpack_24bit_depth_8bit_alpha(packed: u32) -> vec2<f32> {
let depth_bits = packed & 0xFFFFFFu;
let alpha_bits = (packed >> 24u) & 0xFFu;
return vec2(f32(depth_bits) / f32(0xFFFFFFu), f32(alpha_bits) / f32(0xFFu));
}