//! Very simple shader used to demonstrate how to get the world position and pass data //! between the vertex and fragment shader. Also shows the custom vertex layout. // First we import everything we need from bevy_pbr // A 2d shader would be vevry similar but import from bevy_sprite instead #import bevy_pbr::{ mesh_functions, view_transformations::position_world_to_clip } struct Vertex { // This is needed if you are using batching and/or gpu preprocessing // It's a built in so you don't need to define it in the vertex layout @builtin(instance_index) instance_index: u32, // Like we defined for the vertex layout // position is at location 0 @location(0) position: vec3<f32>, // and color at location 1 @location(1) color: vec4<f32>, }; // This is the output of the vertex shader and we also use it as the input for the fragment shader struct VertexOutput { @builtin(position) clip_position: vec4<f32>, @location(0) world_position: vec4<f32>, @location(1) color: vec3<f32>, }; @vertex fn vertex(vertex: Vertex) -> VertexOutput { var out: VertexOutput; // This is how bevy computes the world position // The vertex.instance_index is very important. Esepecially if you are using batching and gpu preprocessing var world_from_local = mesh_functions::get_world_from_local(vertex.instance_index); out.world_position = mesh_functions::mesh_position_local_to_world(world_from_local, vec4(vertex.position, 1.0)); out.clip_position = position_world_to_clip(out.world_position.xyz); // We just use the raw vertex color out.color = vertex.color.rgb; return out; } @fragment fn fragment(in: VertexOutput) -> @location(0) vec4<f32> { // output the color directly return vec4(in.color, 1.0); }