struct FragmentInput {
    @builtin(position) fragment_coordinate: vec4<f32>,
    @location(0) world_position: vec4<f32>,
    @location(1) world_normal: vec3<f32>,
    @location(2) uv: vec2<f32>,
};

struct TileLight {
    color: vec4<f32>,
    intensity: f32,
    position: vec2<f32>,
};

struct CanvasMaterial {
    ambient_color: vec4<f32>,
    tile_lights: array<TileLight, 256u>,
    number_of_lights: u32,
};


@group(1) @binding(0)
var<uniform> canvas_material: CanvasMaterial;

@fragment
fn fragment(input: FragmentInput) -> @location(0) vec4<f32> {
    var output_color = canvas_material.ambient_color;

    var lighting = vec4<f32>();
    for (var i: u32 = 0u; i < canvas_material.number_of_lights; i++) {
        var luminance = pow(length(canvas_material.tile_lights[i].position - input.world_position.xy), -2.0);
        luminance *= canvas_material.tile_lights[i].intensity * 2.5;
        lighting += vec4<f32>(luminance * canvas_material.tile_lights[i].color.rgb, 0.0);
    }

    output_color += lighting;

    return output_color;
}