#[set(everything)]
const constants: {
	SMVP: float4x4;
	envmap_data_world: float4; // angle, tonemap_strength, empty, strength
};

#[set(everything)]
const sampler_linear: sampler;

#[set(everything)]
const envmap: tex2d;

const PI: float = 3.1415926535;
const PI2: float = 6.283185307;

struct vert_in {
	pos: float3;
	nor: float3;
}

struct vert_out {
	pos: float4;
	nor: float3;
}

fun world_pass_vert(input: vert_in): vert_out {
	var output: vert_out;
	output.pos = constants.SMVP * float4(input.pos, 1.0);
	output.nor = input.nor;
	return output;
}

fun envmap_equirect(normal: float3, angle: float): float2 {
	var phi: float = acos(normal.z);
	var theta: float = atan2(normal.x, -normal.y) + PI + angle;
	return float2(theta / PI2, phi / PI);
}

fun tonemap_filmic(color: float3): float3 {
	// Based on Filmic Tonemapping Operators http://filmicgames.com/archives/75
	// var x: float3 = max(float3(0.0, 0.0, 0.0), color - 0.004);
	var x: float3;
	x.x = max(0.0, color.x - 0.004);
	x.y = max(0.0, color.y - 0.004);
	x.z = max(0.0, color.z - 0.004);
	return (x * (x * 6.2 + 0.5)) / (x * (x * 6.2 + 1.7) + 0.06);
}

fun world_pass_frag(input: vert_out): float4 {
	var n: float3 = normalize(input.nor);
	var color: float4;
	color.rgb = sample(envmap, sampler_linear, envmap_equirect(-n, constants.envmap_data_world.x)).rgb * constants.envmap_data_world.w;

	// Tonemap with gamma
	color.rgb = lerp3(color.rgb, tonemap_filmic(color.rgb), constants.envmap_data_world.y);

	color.a = 0.0; // Mark as non-opaque
	return color;
}

#[pipe]
struct pipe {
	vertex = world_pass_vert;
	fragment = world_pass_frag;
}