//	DYNAMIC: "ALPHACLIP"					"0..1"
//  STATIC: "COLOR_DEPTH"					"0..1"


const float g_AlphaThreshold : register( c0 );

struct PS_INPUT
{
#ifdef _PS3
	float unused; // empty structures not supported on Cg??
#endif // _PS3
#if ALPHACLIP
	float2 texCoord0	:	TEXCOORD0;
#endif

#if 0
#if !defined( _X360 ) && !defined( _PS3 ) && defined(SHADER_MODEL_PS_3_0)
	float2 vScreenPos : VPOS;
#endif
#endif

#if COLOR_DEPTH
	float4 vWorldPos_projPosZ	: TEXCOORD1;
#endif

};

sampler BaseTextureSampler	: register( s0 );

float4 main( PS_INPUT i ) : COLOR
{
	float4 color = float4( 1, 0, 0, 1 );	// opaque alpha....the color doesn't matter for this shader

	#if ALPHACLIP
	{
		color = tex2D( BaseTextureSampler, i.texCoord0 );
		float threshold = g_AlphaThreshold;

#if 0
		// rg - shadow buffer dithering - experimental, but shows promise on large transparent shadow casters. May put this on a combo in CS:GO.
		#if !defined( _X360 ) && !defined( _PS3 ) && defined(SHADER_MODEL_PS_3_0)
		{
			float2 vScreenPos = frac( i.vScreenPos * .5f ) * 2.0f;
			threshold = ( ( vScreenPos.y * 3.0f + ( vScreenPos.y * 2.0f - 1.0f ) * vScreenPos.x * -2.0f ) - 2.0f ) * ( 1.0f / 4.0f );
			threshold = lerp( min( .4f, g_AlphaThreshold ), .9f, threshold );
		}
		#endif
#endif		

		clip( color.a - threshold );
	}	
	#endif

#if ( COLOR_DEPTH == 1 )

	return float4( i.vWorldPos_projPosZ.z / i.vWorldPos_projPosZ.w , 1.0, 1.0, 1.0 );

#else

	return color;

#endif
}