|  | // Copyright 2020 The Tint Authors. | 
|  | // | 
|  | // Licensed under the Apache License, Version 2.0 (the "License"); | 
|  | // you may not use this file except in compliance with the License. | 
|  | // You may obtain a copy of the License at | 
|  | // | 
|  | //     http://www.apache.org/licenses/LICENSE-2.0 | 
|  | // | 
|  | // Unless required by applicable law or agreed to in writing, software | 
|  | // distributed under the License is distributed on an "AS IS" BASIS, | 
|  | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | 
|  | // See the License for the specific language governing permissions and | 
|  | // limitations under the License. | 
|  |  | 
|  | // Vertex shader | 
|  | let pos : array<vec2<f32>, 3> = array<vec2<f32>, 3>( | 
|  | vec2<f32>(0.0, 0.5), | 
|  | vec2<f32>(-0.5, -0.5), | 
|  | vec2<f32>(0.5, -0.5)); | 
|  |  | 
|  | [[stage(vertex)]] | 
|  | fn vtx_main([[builtin(vertex_index)]] VertexIndex : i32) | 
|  | -> [[builtin(position)]] vec4<f32> { | 
|  | return vec4<f32>(pos[VertexIndex], 0.0, 1.0); | 
|  | } | 
|  |  | 
|  | // Fragment shader | 
|  | [[stage(fragment)]] | 
|  | fn frag_main() -> [[location(0)]] vec4<f32> { | 
|  | return vec4<f32>(1.0, 0.0, 0.0, 1.0); | 
|  | } |