// window.cpp
//
// Implements a simple graphics interface around the Watcom graphics
// library. Intended to make it easy to port programs with graphics,
// since you'll only have to port this module.
//
// by Dave Hershberger

#include <stdio.h>
#include <stdlib.h>
#include <graph.h>  // Watcom's graphics header
#include "window.h"

////////////////////////////////////////////////////////////
// Color functions.
////////////////////////////////////////////////////////////

int Color::next_avail_index = 0;
long Color::colors[NUM_COLORS];

Color::Color(long newcolor)
{
  int i;

  // check to see if this color has already been set up.

  for(i = 0; i < next_avail_index; i++){
    if(colors[i] == newcolor){
      index = i;
      return;
    }
  }

  if(next_avail_index >= NUM_COLORS){
    fprintf(stderr, "Warning: color allocation failed.\n");
    fprintf(stderr, "  Using closest existing color.\n");
    index = closest(newcolor);
  }
  else{
    // if not, set it up in the palette.

    index = next_avail_index;
    colors[index] = newcolor;
    next_avail_index++;

    _remappalette(index, newcolor);
  }
}

Color::Color(int red, int green, int blue)
{
  int i;
  long newcolor = (blue << 16) | (green << 8) | red;

  // check to see if this color has already been set up.

  for(i = 0; i < next_avail_index; i++){
    if(colors[i] == newcolor){
      index = i;
      return;
    }
  }

  if(next_avail_index >= NUM_COLORS){
    fprintf(stderr, "Warning: color allocation failed.\n");
    fprintf(stderr, "  Using closest existing color.\n");
    index = closest(newcolor);
  }
  else{
    // if not, set it up in the palette.

    index = next_avail_index;
    colors[index] = newcolor;
    next_avail_index++;
 
    _remappalette(index, newcolor);
  }
}


int Color::closest(long newcolor)
{
  int red, green, blue;
  int ired, igreen, iblue;
  int i, mini;
  int dist, mindist = 10000;

  blue = newcolor >> 16;
  green = (newcolor >> 8) & 0xff;
  red = newcolor & 0xff;

  for(i = 0; i < next_avail_index; i++){
    iblue = colors[i] >> 16;
    igreen = (colors[i] >> 8) & 0xff;
    ired = colors[i] & 0xff;

    dist = abs(red - ired) + abs(green - igreen) + abs(blue - iblue);

    if(dist < mindist){
      mindist = dist;
      mini = i;
    }
  }

  return mini;
}

////////////////////////////////////////////////////////////
// Window functions.
////////////////////////////////////////////////////////////

GraphMode Window::mode = UNKNOWN;

Window::Window(int x1, int y1, int x2, int y2)
{
  left = x1;
  top = y1;
  right = x2;
  bottom = y2;
}

void set_graphics_mode()
{
  if(Window::mode != GRAPHICS){
    // enter graphics mode (Watcom style)
    _setvideomode(_XRES256COLOR);

    Window::mode = GRAPHICS;
  }
}

void set_text_mode()
{
  if(Window::mode != TEXT){
    // set graphics mode to text (Watcom style)
    _setvideomode(_DEFAULTMODE);

    Window::mode = TEXT;
  }
}

void Window::set_color(Color color)
{
  cur_color = color;
}

void Window::clear()
{
  static Color black(0, 0, 0);
  
  _setcolor(black);
  _rectangle(_GFILLINTERIOR, left, top, right, bottom);
}

void Window::fill_ellipse(int x1, int y1, int x2, int y2)
{
  _setcolor(cur_color);
  _setcliprgn(left, top, right, bottom);
  _ellipse(_GFILLINTERIOR,
	   x1 + left, y1 + top,
	   x2 + left, y2 + top);
}

void Window::fill_rectangle(int x1, int y1, int x2, int y2)
{
  _setcolor(cur_color);
  _setcliprgn(left, top, right, bottom);
  _rectangle(_GFILLINTERIOR,
	     x1 + left, y1 + top,
	     x2 + left, y2 + top);
}

void Window::line(int x1, int y1, int x2, int y2)
{
  _setcolor(cur_color);
  _setcliprgn(left, top, right, bottom);
  _moveto(x1 + left, y1 + top);
  _lineto(x2 + left, y2 + top);
}

void Window::set_pixel(int x, int y)
{
  _setcolor(cur_color);
  _setcliprgn(left, top, right, bottom);
  _setpixel(left + x, top + y);
}

Color Window::get_pixel(int x, int y)
{
  _setcliprgn(left, top, right, bottom);
  return Color(_getpixel(left + x, top + y));
}

Image Window::get_image(int x1, int y1, int x2, int y2)
{
  Image image = (Image) malloc(_imagesize(x1, y1, x2, y2));

  _getimage(x1 + left, y1 + top, x2 + left, y2 + top, (char *) image);

  return image;
}

void Window::put_image(Image image, int x, int y)
{
  _setcliprgn(left, top, right, bottom);
  _putimage(x + left, y + top, (char *)image, _GPSET);
}