//    wearechat - generic multiplayer game with voip
//    Copyright (C) 2025 metamuffin
//
//    This program is free software: you can redistribute it and/or modify
//    it under the terms of the GNU Affero General Public License as published by
//    the Free Software Foundation, version 3 of the License only.
//
//    This program is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU Affero General Public License for more details.
//
//    You should have received a copy of the GNU Affero General Public License
//    along with this program.  If not, see <https://www.gnu.org/licenses/>.

struct VertexOut {
    @builtin(position) clip: vec4<f32>,
    @location(0) texcoord: vec2<f32>,
};

@group(0) @binding(0) var texture: texture_2d<f32>;
@group(0) @binding(1) var texture_sampler: sampler;

@vertex
fn vs_main(@builtin(vertex_index) vertex_index: u32) -> VertexOut {
    let x = i32(vertex_index) / 2;
    let y = i32(vertex_index) & 1;
    return VertexOut(
        vec4<f32>(f32(x) * 4.0 - 1.0, 1.0 - f32(y) * 4.0, 0.0, 1.0),
        vec2<f32>(f32(x) * 2.0, f32(y) * 2.0)
    );
}

@fragment
fn fs_main(vertex: VertexOut) -> @location(0) vec4<f32> {
    return textureSample(texture, texture_sampler, vertex.texcoord);
}