rgbimageiter.h

barcode readers [ from Image]

//
// Class for easy indexing of an image.
// Using ()[R,G,B] gets current pixel.
// Using ++ advances to next pixel.
// End() tests for end.
//
// Copyright (C) 2003, 2006 by Jon A. Webb (Contact via GMail; username is jonawebb)
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// 
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
//

#ifndef RgbImageIter_h
#define RgbImageIter_h

#include "RgbIndex.h" // for enum TRgbVal

namespace Core
{
	class IRgbImageIter
	{
	public:
		// Lifecycle
		inline IRgbImageIter(CImage& image) :
			inHeight(0),
			inRowBytes(0),
			inWidth(0),
			ipBegin(NULL),
			ipCurrent(NULL),
			ipEnd(NULL),
			ipREnd(NULL)
			 {
				_LIT(LRgbIterErr, "IRgbImageIter: Not a color 24-bit image");
				__ASSERT_ALWAYS(image.iBitmap.DisplayMode() == EColor16M, User::Panic(LRgbIterErr, KErrGeneral));
				inWidth = image.iBitmap.SizeInPixels().iWidth;
				inHeight = image.iBitmap.SizeInPixels().iHeight;
				inRowBytes = CFbsBitmap::ScanLineLength(image.iBitmap.SizeInPixels().iWidth, EColor16M);
				ipBegin = (unsigned char*) image.iBitmap.DataAddress();
				ipCurrent = ipBegin;
				ipREnd = ipCurrent + inWidth * 3;
				ipEnd = ipCurrent + inRowBytes * (inHeight-1) + inWidth* 3;
			 }
		inline IRgbImageIter(const IRgbImageIter& other)
			 {
				inWidth = other.inWidth;
				inHeight = other.inHeight;
				inRowBytes = other.inRowBytes;
				ipBegin = other.ipBegin;
				ipCurrent = other.ipCurrent;
				ipREnd = other.ipREnd;
				ipEnd = other.ipEnd;
			 }
		inline ~IRgbImageIter(void) 
		{
		};

		// Operations
	public:

		// Prefix ++
		inline IRgbImageIter& operator++() {
			ASSERT(!REnd());
			ipCurrent += 3;
			return *this;
		}
		// Postfix ++
		inline IRgbImageIter operator++(int) {
			ASSERT(!REnd());
			IRgbImageIter prev = *this;
			ipCurrent += 3;
			return prev;
		}
		// Start over
		inline void Reset() {
			ipCurrent = ipBegin;
			ipREnd = ipBegin + inWidth * 3;
		}
		// Next row
		// if we are at the last row we make sure End() and REnd() are asserted
		inline void NextRow() {
			if (ipREnd != ipEnd) {
				ipREnd += inRowBytes;
				ipCurrent = ipREnd - inWidth * 3;
			} else {
				ipCurrent = ipEnd; // asserting End()
				ipREnd = ipCurrent; // asserting REnd
			}
		}

		// Operators
	public:
		inline IRgbImageIter& operator=(const IRgbImageIter& other) {
			if (this != &other) {
				inWidth = other.inWidth;
				inHeight = other.inHeight;
				inRowBytes = other.inRowBytes;
				ipBegin = other.ipBegin;
				ipCurrent = other.ipCurrent;
				ipREnd = other.ipREnd;
				ipEnd = other.ipEnd;
			}
			return *this;
		}


		// Accessors
	public:
		inline const unsigned char operator[](int color) const {
			return ipCurrent[color];
		}
		inline unsigned char& operator[](int color) {
			return ipCurrent[color];
		}
		inline bool End() const {
			return ipCurrent == ipEnd;
		}
		inline bool REnd() const {
			return ipCurrent == ipREnd;
		}

	private:
		// Attributes
		int inHeight;
		int inRowBytes;
		int inWidth;
		unsigned char *ipBegin;
		unsigned char *ipCurrent;
		unsigned char *ipEnd;
		unsigned char *ipREnd;
	};

};

#endif // RgbImageIter_h