#include "/Lib/Settings.glsl"
#include "/Lib/Utilities.glsl"
#include "/Lib/BasicFunctions/LightingConstants.glsl"
// MinecraftPT — Planar Clouds
// Simple 2D cloud layer rendered as a plane at altitude.

#ifndef PLANAR_CLOUDS_GLSL
#define PLANAR_CLOUDS_GLSL

// Sample cloud density at a world XZ position (2D noise + coverage)
float GetPlanarCloudDensity(vec2 xz, float time, out vec3 cloudColor){
	// Coverage by weather
	float coverage = mix(PC_CLEAR_COVERAGE, PC_RAIN_COVERAGE, wetness);
	float density = mix(PC_CLEAR_DENSITY, PC_RAIN_DENSITY, wetness);
	float sunlighting = mix(PC_CLEAR_SUNLIGHTING, PC_RAIN_SUNLIGHTING, wetness);
	float skylighting = mix(PC_CLEAR_SKYLIGHTING, PC_RAIN_SKYLIGHTING, wetness);

	// FBM noise
	vec2 p = xz * PC_NOISE_SCALE + vec2(time * 0.01, 0.0);
	float n = 0.0;
	float amp = 0.5;
	for (int i = 0; i < 3; i++){
		n += textureLod(CloudNoise3D, vec3(p, 0.5), 0.0).r * amp;
		p *= 2.0;
		amp *= 0.5;
	}

	float clouds = saturate((n - (1.0 - coverage)) * (1.0 / max(coverage, 0.01)));

	// Cloud color: lit by sun and sky
	float sunFactor = sunlighting;
	cloudColor = mix(GetCloudAtmoIrradiance(), GetCloudSunIrradiance(), sunFactor) * clouds
		+ vec3(1.0) * skylighting * clouds;

	return clouds * density;
}

#endif