struct Uniforms
{
    view_proj: mat4x4<f32>,
}

@group(0) @binding(0)
var<uniform> u: Uniforms;

@group(0) @binding(1)
var glyph_atlas: texture_2d<f32>;

@group(0) @binding(2)
var glyph_sampler: sampler;

struct VertexIn
{
    @location(0) position: vec3<f32>,
    @location(1) uv:       vec2<f32>,
}

struct VertexOut
{
    @builtin(position) clip_pos: vec4<f32>,
    @location(0)       uv:       vec2<f32>,
}

@vertex
fn vs_main(in: VertexIn) -> VertexOut
{
    var out: VertexOut;
    out.clip_pos = u.view_proj * vec4<f32>(in.position, 1.0);
    out.uv       = in.uv;
    return out;
}

@fragment
fn fs_main(in: VertexOut) -> @location(0) vec4<f32>
{
    let coverage = textureSample(glyph_atlas, glyph_sampler, in.uv).r;
    if coverage < 0.004
    {
        discard;
    }
    return vec4<f32>(1.0, 1.0, 1.0, coverage);
}