struct Uniforms {
    camera: vec2f,
    zooms: vec2f
}
@group(0) @binding(0) var<uniform> uniforms : Uniforms;

struct VertexOutput {
    @location(0) tex_pos: vec2f,
    @location(1) color: vec4f,
    @location(2) effect: u32,
    @builtin(position) pos: vec4f
}

@vertex
fn vs_main(
    @location(0) pos: vec2f,
    @location(1) color: vec4f,
    @location(2) tex_pos: vec2f,
    @location(3) effect: u32
) -> VertexOutput {
    var screen_pos: vec4f;
    if (effect & 1) == 0 {
        screen_pos = vec4f(pos, 0, 1);
    } else {
        screen_pos = vec4f((pos - uniforms.camera) * uniforms.zooms, 0, 1);
    }
    var out = VertexOutput(
        tex_pos,
        color,
        effect,
        screen_pos
    );
    return out;
}

@group(1) @binding(0)
var t_diffuse: texture_2d<f32>;
@group(1) @binding(1)
var s_diffuse: sampler;

@fragment
fn fs_main(in: VertexOutput) -> @location(0) vec4f {
    var tex_col = textureSample(t_diffuse, s_diffuse, in.tex_pos);
    var color = vec4f((tex_col.rgb * tex_col.a) + (in.color.rgb * in.color.a), tex_col.a + in.color.a);
    // Grayscale
    if (in.effect & 2) != 0 {
        var v = (color.r*0.299) + (color.g*0.587) + (color.b*0.114);
        color = vec4f(v, v, v, color.a);
    }
    return color;
}