float distx(float dist){
	return(far*(dist-near))/(dist*(far-near));
}

float getDepth(float depth){
	return 2.*near*far/(far+near-(2.*depth-1.)*(far-near));
}

vec4 distortShadow(vec4 shadowpos,float distortFactor){
	shadowpos.xy*=1./distortFactor;
	shadowpos.z=shadowpos.z*.2;
	shadowpos=shadowpos*.5+.5;
	
	return shadowpos;
}

vec4 getShadowSpace(float shadowdepth, vec2 texCoord) {
	vec4 viewPos = gbufferProjectionInverse * (vec4(texCoord, shadowdepth, 1.0) * 2.0 - 1.0);
	viewPos /= viewPos.w;

	vec4 wpos = gbufferModelViewInverse * viewPos;
	wpos = shadowModelView * wpos;
	wpos = shadowProjection * wpos;
	wpos /= wpos.w;
	
	float distb = sqrt(wpos.x * wpos.x + wpos.y * wpos.y);
	float distortFactor = 1.0 - shadowMapBias + distb * shadowMapBias;
	wpos = distortShadow(wpos,distortFactor);
	
	#if defined WATER_CAUSTICS && defined OVERWORLD && defined SMOKE_WATER_LIGHTSHAFTS
		if (isEyeInWater == 1.0) {
			vec3 worldPos = ToWorld(viewPos.xyz);
			vec3 causticpos = worldPos.xyz + cameraPosition.xyz;
			float caustic = getCausticWaves(causticpos.xyz * 0.25);
			wpos.xy *= 1.0 + caustic * 0.0125;
		}
	#endif
	
	return wpos;
}

vec3 getVolumetricRays(float pixeldepth0, float pixeldepth1, vec3 color, float dither) {
	vec3 vl = vec3(0.0);

	#if AA > 1
		dither = fract(dither + frameTimeCounter * 64.0);
	#endif
	
	#ifdef OVERWORLD
		#ifdef END
			vec4 viewPos = gbufferProjectionInverse * (vec4(texCoord, pixeldepth0, 1.0) * 2.0 - 1.0);
				 viewPos /= viewPos.w;
			vec3 nViewPos = normalize(viewPos.xyz);
			vec3 lightVec = sunVec * (1.0 - 2.0 * float(timeAngle > 0.5325 && timeAngle < 0.9675));
			float VoL = dot(nViewPos, lightVec);
			float visfactor = 0.01 * (3.0 * max(rainStrength - isEyeInWater, 0.0) + 1.0);
			float invvisfactor = 1.0 - visfactor;

			float visibility = clamp(VoL * 0.5 + 0.5, 0.0, 1.0);
				  visibility = clamp((visfactor / (1.0 - invvisfactor * visibility) - visfactor) * 1.015 / invvisfactor - 0.015, 0.0, 1.0);
				  visibility = visibility * 0.14285;
		#else
			float visibility = 0.055;
			if (isEyeInWater == 1) visibility = 0.10;

			vec4 viewPos = gbufferProjectionInverse * (vec4(texCoord, pixeldepth0, 1.0) * 2.0 - 1.0);
				 viewPos /= viewPos.w;
			vec3 nViewPos = normalize(viewPos.xyz);
			vec3 lightVec = sunVec * (1.0 - 2.0 * float(timeAngle > 0.5325 && timeAngle < 0.9675));
			float VoL = dot(nViewPos, lightVec);

			float endurance = LIGHTSHAFT_ENDURANCE;
			if (isEyeInWater == 0) endurance *= min(2.0 + rainStrength * rainStrength - sunVisibility * sunVisibility, 2.0);

			if (endurance < 5.40) {
				if (endurance >= 1.0) visibility *= max((VoL + endurance) / (endurance + 1.0), 0.0);
				else visibility *= pow(max((VoL + 1.0) / 2.0, 0.0), (11.0 - endurance * 10.0));
			}
		#endif
		
		if (eyeAltitude < 2.0) visibility *= clamp((eyeAltitude-1.0), 0.0, 1.0);
	#endif
	
	#ifdef END
	#ifdef LIGHTSHAFT_END
	float visibility=.14285* float(pixeldepth0 > 0.56);
	#else
	float visibility=0;
	#endif
	#endif

	if (visibility > 0.0) {
		#ifdef END
			float maxDist = 192.0 * (1.5 - isEyeInWater);
		#else
			float maxDist = LIGHTSHAFT_MAX_DISTANCE * 2.0 * (1.5);
		#endif
		
		float depth0 = getDepth(pixeldepth0);
		float depth1 = getDepth(pixeldepth1);
		vec4 worldposition = vec4(0.0);
		
		vec3 watercol = rawWaterColor.rgb * UNDERWATER_I;
		watercol *= watercol * 20;

		#ifdef END
			float minDistFactor = 5.0;
		#else
			float minDistFactor = 12.0 * LIGHTSHAFT_MIN_DISTANCE;

			float fovFactor = gbufferProjection[1][1] / 1.37;
			float x = abs(texCoord.x - 0.5);
			x = 1.0 - x*x;
			x = pow(x, max(3.0 - fovFactor, 0.0));
			minDistFactor *= x;
			maxDist *= x;
		#endif

		#ifdef END
			int sampleCount = 9;
		#else
			int sampleCount = LIGHTSHAFT_SAMPLE_COUNT;
		#endif

		for(int i = 0; i < sampleCount; i++) {
			#ifdef END
				float minDist = exp2(i + dither) - 0.9;
			#else
				float minDist = (i + dither) * minDistFactor;
				if (isEyeInWater == 1) minDist = (pow(i + dither + 0.5, 2.0)) * minDistFactor * 0.055;
			#endif

			float breakFactor = 0.0;

			if (minDist >= maxDist) breakFactor = 1.0;

			if (breakFactor > 0.5) break;

			if (depth1 < minDist || (depth0 < minDist && color == vec3(0.0))) break;

			worldposition = getShadowSpace(distx(minDist), texCoord.st);
			worldposition.z+=0.00002;

			if (length(worldposition.xy * 2.0 - 1.0) < 1.0)	{
				vec3 shadow0 = vec3(shadow2D(shadowtex0, worldposition.xyz).z);
				
				vec3 shadowCol = vec3(0.0);
				#ifdef SHADOW_COLOR
					if (shadow0.r < 0.9) {
						float shadow1 = shadow2D(shadowtex1, worldposition.xyz).z;
						if (shadow1 > 0.9) {
							shadowCol = texture2D(shadowcolor0, worldposition.xy).rgb;
							shadowCol *= shadowCol * shadow1 ;
							shadow0 = shadowCol * (1.0 - shadow0) + shadow0;
						}
					}
				#endif
				if (depth0 < minDist) shadow0 *= color;

				#ifdef END
					if (isEyeInWater == 1) shadow0 *= watercol.rgb;
					vl += shadow0;
				#else
					if (isEyeInWater == 1) {
						shadow0 *= watercol.rgb * 5.5;
						float sampleFactor = sqrt(minDist / maxDist) * 1.0 + 0.0 * 0.3;
						vl += shadow0 * sampleFactor * 1.55;
					}
					if (isEyeInWater == 0) {

						vl += shadow0 * LIGHTSHAFT_SAMPLE_INTENSITY * 0.25;
					}
				#endif
			} else {
				vl += 1.0;
			}
			if (breakFactor > 0.5) break;
		}
		vl = vl * visibility;
		if(isEyeInWater==1)	{
			vl = sqrt(vl);
		}
		vl *= 0.9;
		if (dot(vl, vl) > 0.0) vl += (dither - 0.25) / 256.0;
	}

	return vl;
}