option HasDiffuseTexture: bool = false;
option HasAlphaTexture: bool = false;
option AlphaTest: bool = false;

[layout(std140)]
struct BasicSettings
{
	AlphaThreshold: f32,
	DiffuseColor: vec4<f32>
}

[layout(std140)]
struct InstanceData
{
	worldMatrix: mat4<f32>,
	invWorldMatrix: mat4<f32>
}

[layout(std140)]
struct ViewerData
{
	projectionMatrix: mat4<f32>,
	invProjectionMatrix: mat4<f32>,
	viewMatrix: mat4<f32>,
	invViewMatrix: mat4<f32>,
	viewProjMatrix: mat4<f32>,
	invViewProjMatrix: mat4<f32>,
	renderTargetSize: vec2<f32>,
	invRenderTargetSize: vec2<f32>,
	eyePosition: vec3<f32>
}

external
{
	[binding(0)] settings: uniform<BasicSettings>,
	[binding(1)] MaterialDiffuseMap: sampler2D<f32>,
	[binding(2)] MaterialAlphaMap: sampler2D<f32>,
	[binding(3)] TextureOverlay: sampler2D<f32>,
	[binding(4)] instanceData: uniform<InstanceData>,
	[binding(5)] viewerData: uniform<ViewerData>,
}

struct InputData
{
	[location(0)] normal: vec3<f32>,
	[location(1)] uv: vec2<f32>,
	[location(2)] pos: vec3<f32>
}

struct OutputData
{
	[location(0)] diffuseMap: vec4<f32>,
	[location(1)] normalMap: vec4<f32>,
	[location(2)] positionMap: vec4<f32>
}

[entry(frag)]
fn main(input: InputData) -> OutputData
{
	let diffuseColor = settings.DiffuseColor;
	const if (HasDiffuseTexture)
		diffuseColor *= MaterialDiffuseMap.Sample(input.uv);

	const if (HasAlphaTexture)
		diffuseColor.w *= MaterialAlphaMap.Sample(input.uv).x;

	const if (AlphaTest)
	{
		if (diffuseColor.w < settings.AlphaThreshold)
			discard;
	}

	let output: OutputData;
	output.diffuseMap = diffuseColor;
	output.normalMap = vec4<f32>((vec3<f32>(1.0, 1.0, 1.0) + input.normal) * 0.5, 1.0);
	output.positionMap = vec4<f32>(input.pos, 1.0);
	return output;
}