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Image.cxx

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/*
 * @(#)src/Image.cxx  1.0  2002-08-27 13:47
 *
 * Copyright (C)  2002  Daniel Léonard
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#include <algorithm>
#include <cstring>
#include <string>
#include "Image.h"

namespace halftoner
{

//---------------------------
// Constructor
//---------------------------

   Image::Image(int width, int height) throw(std::invalid_argument) :
      pixels(0),
      width(width),
      height(height)
   {
   // check parameters
      if ((0 >= width) || (0 >= height))
      {
         std::string message("Cannot create image with a negative width or height");
         throw std::invalid_argument(message);
      }

   // create the raw data
      int size = width * height;
      this->pixels = new unsigned char[size];
      memset(this->pixels, 0, size * sizeof(unsigned char));
   }


//---------------------------
// Destructor
//---------------------------

   Image::~Image() throw()
   {
      delete [] this->pixels;
   }


//---------------------------
// Instance methods
//---------------------------

   unsigned char* Image::getPixels() const throw()
   {
      return this->pixels;
   }

   int Image::getWidth() const throw()
   {
      return this->width;
   }

   int Image::getHeight() const throw()
   {
      return this->height;
   }

   int Image::getColorAt(int x, int y) const throw (std::out_of_range)
   {
      unsigned char* pixel = this->getPixel(x, y);
      int color = *pixel;
      return color;
   }

   void Image::setColorAt(int x, int y, int color) throw (std::out_of_range)
   {
      unsigned char* pixel = this->getPixel(x, y);
      *pixel = color;
   }

   void Image::setLine(int line, int* colors, int colors_size) throw (std::out_of_range)
   {
      int width = this->getWidth();
      if (colors_size != width)
      {
         std::string message("Given size is not equal to image width");
         throw std::out_of_range(message);
      }

      int x = 0;
      int y = line;
      unsigned char* pixels = this->getPixel(x, y);

      std::copy_n(colors, colors_size, pixels);
   }

   unsigned char* Image::getPixel(int x, int y) const throw (std::out_of_range)
   {
      int w = this->getWidth();
      int h = this->getHeight();

      if ((0 > x) || (0 > y) || (x > w) || (y > h))
      {
         std::string message("Given coordinates are out of bounds");
         throw std::out_of_range(message);
      }

      unsigned char* data = this->getPixels();
      int position = Image::calculateOffset(x, y, w);
      unsigned char* pixel = &data[position];

      return pixel;
   }

   unsigned char* Image::getCopy() const throw()
   {
      int width = this->getWidth();
      int height = this->getHeight();
      int size = width * height;

      unsigned char* pixels = this->getPixels();
      unsigned char* copy = new unsigned char[size];

      memcpy(copy, pixels, size);

      return copy;
   }

//---------------------------
// Class methods
//---------------------------

   int Image::calculateOffset(int x, int y, int line_width) throw()
   {
      int offset = x + (y * line_width);
      return offset;
   }

}

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