struct VertexInput {
    @location(0) position: vec3<f32>,
    @location(1) tex_coord: vec2<f32>,

    @location(2) atlas_position: vec2<f32>,
    @location(3) size: vec2<f32>,
    @location(4) target_position: vec2<f32>,
    @location(5) y_offset: f32,

    @builtin(instance_index) glyph_id: u32,
}

struct VertexOutput {
    @builtin(position) position: vec4<f32>,
    @location(0) tex_coord: vec2<f32>,
}

// struct Params {
//     screen_size: vec4<f32>,
// }

fn to_device_position(position: vec2<f32>, size: vec2<f32>) -> vec4<f32> {
    return vec4<f32>((((position / size) * 2.) - 1.), 1., 1.);
}

@group(0) @binding(0)
var<uniform> screen_size: vec4<f32>;

@vertex
fn vs_main(input: VertexInput) -> VertexOutput {
    var out: VertexOutput;

    var vertex_pos = to_device_position(((input.position.xy + 1.) / 2.) * (input.size/2.0) + input.target_position + vec2<f32>(0., (input.y_offset/2.0)+32), screen_size.xy);
    // vertex_pos.y = -vertex_pos.y;
    var atlas_position = (((input.position.xy + 1.) / 2.) * input.size + input.atlas_position) / vec2<f32>(1024);

    out.position = vertex_pos;
    out.tex_coord = atlas_position;

    return out;
}