//: image.h : Grafik-Bibliothek ohne Grafiktreiber - R.Richter 2011-01-15
/////////////////////////////////////////////////////////////////////////

#ifndef IMAGE_H
#define IMAGE_H

#include <algorithm>
#include <vector>
#include "color.h"

class Image
{
public:
  Image(unsigned int width, unsigned int height, Color background = 0)
  : width_(width), height_(height), pixels_(width * height, background)
  {
  }

  unsigned int width()  const { return width_;  }
  unsigned int height() const { return height_; }

  Color& pixel(unsigned int x, unsigned int y) 
  {
    return x>=width() || y>=height() ? outside() : pixels_[y*width() + x];
  }
  
  Color const& pixel(unsigned int x, unsigned int y) const 
  {
    return x>=width() || y>=height() ? outside() : pixels_[y*width() + x];
  }
private:
  unsigned int width_, height_;
  std::vector<Color> pixels_; // width_ x height_ pixels

  static Color& outside() { static Color c; return c = Color::NONE; }
};

// ===[ Speichern als BMP 24bit unkomprimiert, ohne Transparenz ]===========

#include <fstream>
#include <iostream>
#include <iomanip>
#include <string>

// Achtung, nicht portabel: Intel Byte-order vorausgesetzt

inline  // a bit too long for ...
void saveBMP(std::string filename, Image const& image)
{
  unsigned long const linesize  = 3*image.width();  // 24 bit per pixel
  unsigned long const fillbytes = (4-linesize%4)%4; // at end of line to quad boundary
  unsigned long Image constsize = (linesize+fillbytes)*image.height();

  // byte alignment, no padding
  // #if defined( _MSC_VER ) || defined( __MINGW32__ )
  #pragma pack(1)
  // #endif
  struct BMPheader
  {
    // file info
    char ID[2];
    unsigned long filesize, reserved, offset;

    // BMP info
    unsigned long  infosize, width, height;
    unsigned short planes, bitsperpixel;
    unsigned long  compression, imagesize,
                   xPixelPerMeter, yPixelPerMeter,
                   colorsUsed, colorsImportant;
  } header =
  { 
    // file info
    { 'B', 'M' },
    unsigned(sizeof(header)) + imagesize, // 24 bits per pixel
    0, sizeof(header),          // 0x36

    // BMP info
    40, image.width(), image.height(),
    1, 24,
    0, imagesize,
    1000, 1000,
    0, 0
  };
  // #if defined( _MSC_VER ) || defined( __MINGW32__ )
  #pragma pack()
  // #endif

  std::ofstream file(filename.c_str(), std::ios::out|std::ios::binary);
  file.write( (char*)&header, sizeof(header)); // Intel byte order

  for (unsigned y = 0; y < image.height(); ++y)
  {
    for (unsigned x = 0; x < image.width(); ++x)
    {
      Color c= image.pixel(x,y);
      unsigned char b = c.blue(), g = c.green(), r = c.red();
      file.write( (char*) &b, 1);
      file.write( (char*) &g, 1);
      file.write( (char*) &r, 1);
    }
    if (fillbytes)
    {
      int zero = 0;
      file.write( (char*) &zero, fillbytes);
    }
  }
}

#endif // IMAGE_H
//~