/*!
  @file    SFXVSMCommon.usf

  Copyright (c) 2010 BioWare ULC

  The source code included in this file is confidential,
  secret, or proprietary information of BioWare ULC. It
  may not be used in whole or in part without express
  written permission from BioWare ULC.

  Some common functions that are used within the VSM shadow implementation

  @author  Rob Krajcarski
  @date    August 16, 2010
*/

#if PS3

/** 
 * Reads a 4-component (ubyte) value (i.e one packed into A8R8G8B8) and retrieves
 * 2 half floats.
 */
half2 DecodeComponent( half4 inColour )
{
	float fPackedComponents = pack_4ubyte(inColour);
    half2 hComponents = unpack_2half(fPackedComponents);
    return hComponents;
}

/** 
 * Writes a 4-component (ubyte) value (i.e one packed into A8R8G8B8) given 2 half floats
 */
half4 EncodeComponent( half2 inComponents)
{
    float fPackedComponents = pack_2half(inComponents);
    half4 hColours = unpack_4ubyte(fPackedComponents);
    return hColours.bgra;
}

#else // PS3

/** 
 * Simple pass through implementation
 */
half2 DecodeComponent( half4 inColour )
{
	return inColour.xy;
}

/** 
 * Simple pass through implementation
 */
half4 EncodeComponent( half2 inValue)
{
	return half4( inValue, 0.0, 0.0 );
}

#endif // PS3