source/dng_filter_task.h

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// Copyright 2006 Adobe Systems Incorporated
// All Rights Reserved.
//
// NOTICE:  Adobe permits you to use, modify, and distribute this file in
// accordance with the terms of the Adobe license agreement accompanying it.
/*****************************************************************************/

/* $Id: //mondo/dng_sdk_1_4/dng_sdk/source/dng_filter_task.h#2 $ */ 
/* $DateTime: 2012/07/11 10:36:56 $ */
/* $Change: 838485 $ */
/* $Author: tknoll $ */

/** \file
 * Specialization of dng_area_task for processing an area from one dng_image to an
 * area of another.
 */ 

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#ifndef __dng_filter_task__
#define __dng_filter_task__

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#include "dng_area_task.h"
#include "dng_auto_ptr.h"
#include "dng_point.h"
#include "dng_rect.h"
#include "dng_sdk_limits.h"

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/// \brief Represents a task which filters an area of a source dng_image to an area
/// of a destination dng_image.

class dng_filter_task: public dng_area_task
	{
	
	protected:
	
		const dng_image &fSrcImage;
		
		dng_image &fDstImage;
		
		uint32 fSrcPlane;
		uint32 fSrcPlanes;
		uint32 fSrcPixelType;
		
		uint32 fDstPlane;
		uint32 fDstPlanes;
		uint32 fDstPixelType;
		
		dng_point fSrcRepeat;
		dng_point fSrcTileSize;
		
		AutoPtr<dng_memory_block> fSrcBuffer [kMaxMPThreads];
		AutoPtr<dng_memory_block> fDstBuffer [kMaxMPThreads];
		
	public:
	
		/// Construct a filter task given a source and destination images.
		/// \param srcImage Image from which source pixels are read.
		/// \param dstImage Image to which result pixels are written.

		dng_filter_task (const dng_image &srcImage,
						 dng_image &dstImage);
							   
		virtual ~dng_filter_task ();

		/// Compute the source area needed for a given destination area. Default
		/// implementation assumes destination area is equal to source area for all
		/// cases.
		///
		/// \param dstArea Area to for which pixels will be computed.
		///
		/// \retval The source area needed as input to calculate the requested
		/// destination area.

		virtual dng_rect SrcArea (const dng_rect &dstArea)
			{
			return dstArea;
			}

		/// Given a destination tile size, calculate input tile size. Simlar to
		/// SrcArea, and should seldom be overridden.
		///
		/// \param dstTileSize The destination tile size that is targeted for output.
		///
		/// \retval The source tile size needed to compute a tile of the destination
		/// size.

		virtual dng_point SrcTileSize (const dng_point &dstTileSize)
			{
			return SrcArea (dng_rect (dstTileSize)).Size ();
			}

		/// Implements filtering operation from one buffer to another. Source and
		/// destination pixels are set up in member fields of this class. Ideally, no
		/// allocation should be done in this routine.
		///
		/// \param threadIndex The thread on which this routine is being called,
		/// between 0 and threadCount - 1 for the threadCount passed to Start method.
		///
		/// \param srcBuffer Input area and source pixels.
		///
		/// \param dstBuffer Output area and destination pixels.

		virtual void ProcessArea (uint32 threadIndex,
								  dng_pixel_buffer &srcBuffer,
								  dng_pixel_buffer &dstBuffer) = 0;

		/// Called prior to processing on specific threads. Can be used to allocate
		/// per-thread memory buffers, etc.
		///
		/// \param threadCount Total number of threads that will be used for
		/// processing. Less than or equal to MaxThreads of dng_area_task.
		///
		/// \param tileSize Size of source tiles which will be processed. (Not all
		/// tiles will be this size due to edge conditions.)
		///
		/// \param allocator dng_memory_allocator to use for allocating temporary
		/// buffers, etc.
		///
		/// \param sniffer Sniffer to test for user cancellation and to set up
		/// progress.

		virtual void Start (uint32 threadCount,
							const dng_point &tileSize,
							dng_memory_allocator *allocator,
							dng_abort_sniffer *sniffer);
							
		/// Process one tile or partitioned area. Should not be overridden. Instead,
		/// override ProcessArea, which is where to implement filter processing for a
		/// specific type of dng_filter_task. There is no allocator parameter as all
		/// allocation should be done in Start.
		///
		/// \param threadIndex 0 to threadCount - 1 index indicating which thread
		/// this is. (Can be used to get a thread-specific buffer allocated in the
		/// Start method.)
		///
		/// \param area Size of tiles to be used for sizing buffers, etc. (Edges of
		/// processing can be smaller.)
		///
		/// \param sniffer dng_abort_sniffer to use to check for user cancellation
		/// and progress updates.

		virtual void Process (uint32 threadIndex,
							  const dng_rect &area,
							  dng_abort_sniffer *sniffer);
							  
	};

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#endif
	
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