// __multiversion__
// This signals the loading code to prepend either #version 100 or #version 300 es as apropriate.

#include "shaders/fragmentVersionSimple.h"

uniform sampler2D TEXTURE_0;
uniform sampler2D TEXTURE_1;
uniform sampler2D TEXTURE_2;

varying vec2 uv;
varying vec4 color;
varying vec4 worldPosition;
varying vec4 fogColor;

void main()
{
	vec4 albedo = texture2D( TEXTURE_0, uv);

#ifdef ALPHA_TEST
	if (albedo.a < 0.5)
		discard;
#endif

	albedo.a *= color.a;

	vec2 occlusionUV = worldPosition.xz;
	vec4 occlusionTexture = texture2D( TEXTURE_1, occlusionUV);

#ifndef FLIP_OCCLUSION
#define OCCLUSION_OPERATOR <
#else
#define OCCLUSION_OPERATOR >
#endif

#ifdef SNOW
#define OCCLUSION_HEIGHT occlusionTexture.g
#define OCCLUSION_LUMINANCE occlusionTexture.r
#else
#define OCCLUSION_HEIGHT occlusionTexture.a
#define OCCLUSION_LUMINANCE occlusionTexture.b
#endif

	// clamp the uvs
	if ( occlusionUV.x >= 0.0 && occlusionUV.x <= 1.0 && 
		 occlusionUV.y >= 0.0 && occlusionUV.y <= 1.0 && 
		 worldPosition.y OCCLUSION_OPERATOR OCCLUSION_HEIGHT) {
		albedo.a = 0.0;
	}

	float mixAmount = (worldPosition.y - OCCLUSION_HEIGHT)*25.0;
	vec2 lightingUVs = vec2(OCCLUSION_LUMINANCE, 1.0);
	lightingUVs.x = mix(lightingUVs.x, 0.0, mixAmount);

	vec3 lighting = texture2D( TEXTURE_2, lightingUVs ).rgb;
	vec4 finalOutput = albedo;
	finalOutput.rgb *= lighting.rgb;

	//apply fog
	gl_FragColor.rgb = mix( finalOutput.rgb, fogColor.rgb, fogColor.a );
	gl_FragColor.a = finalOutput.a;
}