b333386271
# Objective - Add reusable shader functions for transforming positions / normals / tangents between local and world / clip space for 2D and 3D so that they are done in a simple and correct way - The next step in #3969 so check there for more details. ## Solution - Add `bevy_pbr::mesh_functions` and `bevy_sprite::mesh2d_functions` shader imports - These contain `mesh_` and `mesh2d_` versions of the following functions: - `mesh_position_local_to_world` - `mesh_position_world_to_clip` - `mesh_position_local_to_clip` - `mesh_normal_local_to_world` - `mesh_tangent_local_to_world` - Use them everywhere where it is appropriate - Notably not in the sprite and UI shaders where `mesh2d_position_world_to_clip` could have been used, but including all the functions depends on the mesh binding so I chose to not use the function there - NOTE: The `mesh_` and `mesh2d_` functions are currently identical. However, if I had defined only `bevy_pbr::mesh_functions` and used that in bevy_sprite, then bevy_sprite would have a runtime dependency on bevy_pbr, which seems undesirable. I also expect that when we have a proper 2D rendering API, these functions will diverge between 2D and 3D. --- ## Changelog - Added: `bevy_pbr::mesh_functions` and `bevy_sprite::mesh2d_functions` shader imports containing `mesh_` and `mesh2d_` versions of the following functions: - `mesh_position_local_to_world` - `mesh_position_world_to_clip` - `mesh_position_local_to_clip` - `mesh_normal_local_to_world` - `mesh_tangent_local_to_world` ## Migration Guide - The `skin_tangents` function from the `bevy_pbr::skinning` shader import has been replaced with the `mesh_tangent_local_to_world` function from the `bevy_pbr::mesh_functions` shader import
37 lines
1.2 KiB
WebGPU Shading Language
37 lines
1.2 KiB
WebGPU Shading Language
#define_import_path bevy_sprite::mesh2d_functions
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fn mesh2d_position_local_to_world(model: mat4x4<f32>, vertex_position: vec4<f32>) -> vec4<f32> {
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return model * vertex_position;
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}
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fn mesh2d_position_world_to_clip(world_position: vec4<f32>) -> vec4<f32> {
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return view.view_proj * world_position;
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}
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// NOTE: The intermediate world_position assignment is important
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// for precision purposes when using the 'equals' depth comparison
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// function.
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fn mesh2d_position_local_to_clip(model: mat4x4<f32>, vertex_position: vec4<f32>) -> vec4<f32> {
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let world_position = mesh2d_position_local_to_world(model, vertex_position);
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return mesh2d_position_world_to_clip(world_position);
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}
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fn mesh2d_normal_local_to_world(vertex_normal: vec3<f32>) -> vec3<f32> {
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return mat3x3<f32>(
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mesh.inverse_transpose_model[0].xyz,
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mesh.inverse_transpose_model[1].xyz,
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mesh.inverse_transpose_model[2].xyz
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) * vertex_normal;
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}
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fn mesh2d_tangent_local_to_world(model: mat4x4<f32>, vertex_tangent: vec4<f32>) -> vec4<f32> {
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return vec4<f32>(
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mat3x3<f32>(
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model[0].xyz,
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model[1].xyz,
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model[2].xyz
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) * vertex_tangent.xyz,
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vertex_tangent.w
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);
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}
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