#include "/Lib/Settings.glsl"
#include "/Lib/Utilities.glsl"
#include "/Lib/BasicFunctions/LightingConstants.glsl"
// MinecraftPT — Cloud Shadow
// Cloud shadow projection onto the ground from the cloud layer.

#ifndef CLOUD_SHADOW_GLSL
uniform sampler3D CloudNoise3D;
#define CLOUD_SHADOW_GLSL

float GetCloudShadow(vec3 worldPos){
	float cloudAlt = mix(CLOUD_CLEAR_ALTITUDE, CLOUD_RAIN_ALTITUDE, wetness);
	float cloudDensity = mix(CLOUD_CLEAR_DENSITY, CLOUD_RAIN_DENSITY, wetness);

	// Project ground position onto cloud layer
	vec3 shadowDir = normalize(GetSunDirWorld());
	vec3 cloudPos = worldPos + shadowDir * (cloudAlt - worldPos.y) / shadowDir.y;

	// Sample cloud density at that position
	vec2 p = cloudPos.xz * CLOUD_BASE_NOISE_SCALE + frameTimeCounter * 0.001 * CLOUD_SPEED;
	float n = textureLod(CloudNoise3D, vec3(p, 0.2), 0.0).r;

	float shadow = 1.0 - saturate((n - 0.5) * cloudDensity * 2.0 * CLOUD_SHADOW);

	return shadow;
}

#endif