// Vertex shader
struct InstanceInput {
	@location(2) transform_matrix_0: vec4<f32>,
	@location(3) transform_matrix_1: vec4<f32>,
	@location(4) transform_matrix_2: vec4<f32>,
	@location(5) transform_matrix_3: vec4<f32>,
	@location(6) texture_idx: u32,
};

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

struct VertexOutput {
	@builtin(position) clip_position: vec4<f32>,
	@location(0) texture_coords: vec2<f32>,
	@location(1) index: u32,
}

@vertex
fn vertex_shader_main(
	model: VertexInput,
	instance: InstanceInput,
) -> VertexOutput {
	let transform_matrix = mat4x4<f32>(
		instance.transform_matrix_0,
		instance.transform_matrix_1,
		instance.transform_matrix_2,
		instance.transform_matrix_3,
	);

	var out: VertexOutput;
	out.texture_coords = model.texture_coords;
	out.clip_position = transform_matrix * vec4<f32>(model.position, 1.0);
	out.index = instance.texture_idx;
	return out;
}


// Fragment shader
@group(0) @binding(0)
var texture_array: binding_array<texture_2d<f32>>;
@group(0) @binding(1)
var sampler_array: binding_array<sampler>;


@fragment
fn fragment_shader_main(in: VertexOutput) -> @location(0) vec4<f32> {
	return textureSampleLevel(
		texture_array[in.index],
		sampler_array[in.index],
		in.texture_coords,
		0.0
	).rgba;
}