path: root/rgb_image.c

/*----------------------------------------------------------------------------
** rgb_image.c
**  
**
**---------------------------------------------------------------------------
**  Copyright 2004 by CodeWeavers, Inc.
**
**     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 <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <stdlib.h>
#include <png.h>
#include "rgb_image.h"

/*----------------------------------------------------------------------------
** Initialize the pixel_format structure
**--------------------------------------------------------------------------*/
void pixel_format_init(pixel_format *var)
{
  var->r_mask = 0;
  var->g_mask = 0;
  var->b_mask = 0;
  var->r_count = 0;
  var->g_count = 0;
  var->b_count = 0;
  var->r_shift = -1;
  var->g_shift = -1;
  var->b_shift = -1;
}

/*----------------------------------------------------------------------------
** Destroy the ximage structure and free the win_image structure
**--------------------------------------------------------------------------*/
void win_image_destroy_ximage(win_image *var)
{
  if(var->ximage != NULL)
    XDestroyImage(var->ximage);
  
  var->ximage = (XImage*) NULL;
  var->origin_x = 0;
  var->origin_y = 0;
  var->width = 0;
  var->height = 0;
}

/*----------------------------------------------------------------------------
** Destroy the ximage structure and free the win_image structure
**--------------------------------------------------------------------------*/
void win_image_destroy(win_image *var)
{
  if(var != NULL)
  {
    win_image_destroy_ximage(var);
    free(var);
    var = NULL;
  }
}

/*----------------------------------------------------------------------------
** Allocate and initialize memory for the win_image structure
**--------------------------------------------------------------------------*/
win_image* win_image_init()
{
  win_image *var;
  
  var = malloc(sizeof(win_image));
  if(var == NULL)
  {
    fprintf(stderr,"Error: unable to allocate memory for win_image structure\n");
    return(NULL);
  }
  
  var->ximage = (XImage *)NULL;
  pixel_format_init(&var->pformat);
  var->origin_x = 0;
  var->origin_y = 0;
  var->width = 0;
  var->height = 0;
  
  return(var);
}

/*----------------------------------------------------------------------------
** Destroy the data memory allocated for the rgb_image
**--------------------------------------------------------------------------*/
void rgb_image_destroy_data(rgb_image *var)
{
  int x;
  
  /* free the columns of rgb */
  for(x = 0; x < var->width; x++)
    free(var->data[x]);
  
  /* remember to free the row of pointers */
  if(var->data != NULL)
    free(var->data);
  
  var->data = NULL;
  var->width = 0;
  var->height = 0;
}

/*----------------------------------------------------------------------------
** Destroy the memory allocated for the rgb_image
**--------------------------------------------------------------------------*/
void rgb_image_destroy(rgb_image *var)
{
  if(var != NULL)
  {
    rgb_image_destroy_data(var);
    free(var);
    var = NULL;
  }
}

/*----------------------------------------------------------------------------
** Allocate and initialize memory for the rgb_image structure
**--------------------------------------------------------------------------*/
rgb_image* rgb_image_init()
{
  rgb_image *var;
  
  var = malloc(sizeof(rgb_image));
  if(var == NULL)
  {
    fprintf(stderr,"Error: unable to allocate memory for rgb_image structure\n");
    return(NULL);
  }
  
  var->data = NULL;
  var->width = 0;
  var->height = 0;
  var->bit_depth = 0;
  
  return(var);
}

/*----------------------------------------------------------------------------
** Allocate and initialize memory for the rgb_hist structure
**--------------------------------------------------------------------------*/
rgb_hist* rgb_hist_init()
{
    rgb_hist *var;
    int i;
    
    var = malloc(sizeof(rgb_hist));
    if(var==NULL)
    {
        fprintf(stderr, "Error: unable to allocate memory for rgb_hist structure\n");
        return(NULL);
    }

    for(i=0; i<256; i++)
    {
        var->r[i]=0;
        var->g[i]=0;
        var->b[i]=0;
    }
    var->total_count=0;

    return(var);
}

/*----------------------------------------------------------------------------
** Destroy the memory allocated for the rgb_image
**--------------------------------------------------------------------------*/
void rgb_hist_destroy(rgb_hist *var)
{
  if(var != NULL)
  {
    free(var);
    var = NULL;
  }
}

/*----------------------------------------------------------------------------
** Allocate the data array for the rgb_image w/given dimensions
**   --if the correct mem size has already been allocated, do nothing and 
**     return success
**--------------------------------------------------------------------------*/
int rgb_image_malloc(rgb_image *image, int width, int height)
{
  int x;
  
  /*--------------------------------------------------------------------------
  ** Make sure the dimensions passed are legitimate -- positive value
  **------------------------------------------------------------------------*/
  if(width < 1 || height < 1)
  {
    fprintf(stderr,"Error: invalid dimensions [%d x %d] passed to rgb_image_malloc\n",width,height);
    return(1);
  }
  
  /*--------------------------------------------------------------------------
  ** If the dimensions are the same, then return success, nothing to be done
  **------------------------------------------------------------------------*/
  if(width == image->width && height == image->height)
    return(0);
  
  /*--------------------------------------------------------------------------
  ** If the image already contains data, it needs to be destroyed
  **------------------------------------------------------------------------*/
  if(image->data != NULL)
    rgb_image_destroy_data(image);
      
  /*--------------------------------------------------------------------------
  ** Begin memory allocation -- allocate memory in columns s.t. it is easy
  ** to read coordinate values (ie. [x][y])
  **------------------------------------------------------------------------*/  
  image->data = malloc(width * sizeof(rgb*));
  if(image->data == NULL)
  {
    fprintf(stderr,"Unable to allocate memory for rgb_image struct\n");
    return(1);
  }
  
  /*--------------------------------------------------------------------------
  ** Allocate memory for each column
  **------------------------------------------------------------------------*/
  for(x = 0; x < width; x++)
  {
    image->data[x] = NULL;
    image->data[x] = malloc(height * sizeof(rgb));
    if(image->data[x] == NULL)
    {
      /*----------------------------------------------------------------------
      ** Unable to allocate memory, make sure to clean-up the memory that has
      ** already been allocated
      **--------------------------------------------------------------------*/
      image->width = x;
      rgb_image_destroy(image);
      fprintf(stderr,"Unable to allocate memory for rgb_image struct\n");
      return(1);
    }
  }
  
  /*--------------------------------------------------------------------------
  ** Set the image width and height before returning success
  **------------------------------------------------------------------------*/
  image->width = width;
  image->height = height;
  //image->bit_depth = 8;
  
  return(0);
}

/*----------------------------------------------------------------------------
** Convert an rgb_image to a png file.
**  Return values:
**    0 - success
**    1 - bad png file -- not able to open
**    2 - bad memory allocation
**--------------------------------------------------------------------------*/
int rgb_image_to_png(rgb_image *image, char *png_file)
{
  FILE *fp;
  int x, y;
  int rc = 0;
  png_structp png_ptr = (png_structp)NULL;
  png_infop info_ptr = (png_infop)NULL;
  png_bytepp write_data = (png_bytepp)NULL;
  
  /*--------------------------------------------------------------------------
  ** Open the png_file for writing
  **------------------------------------------------------------------------*/
  fp = fopen(png_file, "wb");
  if (!fp)
  {
    rc = ERR_PNG_FILE;
    goto ERREXIT;
  }
  
  /*--------------------------------------------------------------------------
  ** Create the png write structures
  **------------------------------------------------------------------------*/
  png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, NULL, NULL);
  if (!png_ptr)
  {
    rc = ERR_MALLOC;
    goto ERREXIT;
  }

  info_ptr = png_create_info_struct(png_ptr);
  if (!info_ptr)
  {
    rc = ERR_MALLOC;
    goto ERREXIT;
  }
  
  /*--------------------------------------------------------------------------
  ** Set the callback jump buffer
  **------------------------------------------------------------------------*/
  if (setjmp(png_jmpbuf(png_ptr)))
  {
    rc = ERR_MALLOC;
    goto ERREXIT;
  }
  
  /*--------------------------------------------------------------------------
  ** Initialize the io structures  
  **------------------------------------------------------------------------*/
  png_init_io(png_ptr, fp);
  
  /*--------------------------------------------------------------------------
  ** Set the image information 
  **------------------------------------------------------------------------*/
  png_set_IHDR(png_ptr, info_ptr, image->width, image->height, image->bit_depth, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
  
  /*--------------------------------------------------------------------------
  ** Allocate memory for the write buffer
  **------------------------------------------------------------------------*/
  write_data = (png_bytepp)malloc(image->height * sizeof(png_bytep));
  if(!write_data)
  {
    rc = ERR_MALLOC;
    goto ERREXIT;
  }
  for(y=0; y < image->height; y++)
  {
    write_data[y] = (png_bytep)malloc(image->width * 3);
    if(!write_data[y])
    {
      rc = ERR_MALLOC;
      goto ERREXIT;
    }
  }
  
  /*--------------------------------------------------------------------------
  ** Move information from the rgb_image structure into the write buffer
  **------------------------------------------------------------------------*/
  for(y=0; y < image->height; y++)
  {
    for(x=0; x < image->width; x++)
    {
      write_data[y][x*3] = image->data[x][y].r;
      write_data[y][(x*3)+1] = image->data[x][y].g;
      write_data[y][(x*3)+2] = image->data[x][y].b;
    }
  }
  
  /*--------------------------------------------------------------------------
  ** Insert data into info_ptr and write the information to the file
  **------------------------------------------------------------------------*/
  png_set_rows(png_ptr, info_ptr, write_data); 
  png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);

ERREXIT:
  
  for(y=0; y < image->height; y++)
    if(write_data[y])
      free(write_data[y]);
  
  if(write_data)
    free(write_data);
  
  if(png_ptr && info_ptr)
    png_destroy_write_struct(&png_ptr, &info_ptr);
  else if(png_ptr)
    png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
  
  if(fp)
    fclose(fp);
  
  return(rc);
}

/*----------------------------------------------------------------------------
** Combine two png images.  attach_image will be to the left of main_image.
** The resultant image will be set to main_image.  attach_image will be preserved.
**  Return values:
**    0 - success
**    1 - failure
**--------------------------------------------------------------------------*/
int rgb_image_attach(rgb_image **main_image, rgb_image **attach_image, int count)
{
  rgb_image *tmp_image = NULL;
  rgb_image *tmain = *main_image;
  int width, height;
  int rc = 0;
  int i, j, c, separator, x, y;
  int attach_width = 0, attach_height = 0;
  
  tmp_image = rgb_image_init();
  if(tmp_image == NULL)
  {
    fprintf(stderr,"Unable to allocate memory for rgb_image\n");
    rc = 1;
    goto EXIT;
  }
  
  // set the offset for the main image
  separator = 2; 
  
  // figure out the size needed for attachment portion
  for(i = 0; i < count; i++)
  {
    if(attach_height)
      attach_height += separator;
    attach_height += attach_image[i]->height;
    
    if(!attach_width || attach_image[i]->width > attach_width)
      attach_width = attach_image[i]->width;
  }
      
  
  // determine the height of the new image
  if(tmain->height > attach_height)
    height = tmain->height;
  else
    height = attach_height;
  height += separator*2;
  
  // determine the width of the new image
  width = attach_width + tmain->width + (separator*3);
  
  // allocate the memory for the new image
  if(rgb_image_malloc(tmp_image, width, height))
  {
    rc = 1;
    goto EXIT;
  }
  
  // more writing done, but more sensible approach
  // clear out the image first
  for(i = 0; i < width; i++)
  {
    for(j = 0; j < height; j++)
    {
      tmp_image->data[i][j].r = 0;
      tmp_image->data[i][j].g = 0;
      tmp_image->data[i][j].b = 0; 
    }
  }

  // write out the attached images
  x = separator;
  y = separator;
  for(c = 0; c < count; c++)
  {
    for(i = 0; i < attach_image[c]->width; i++)
    {
      for(j = 0; j < attach_image[c]->height; j++)
      {
        tmp_image->data[i+x][y+j].r = attach_image[c]->data[i][j].r;
        tmp_image->data[i+x][y+j].g = attach_image[c]->data[i][j].g;
        tmp_image->data[i+x][y+j].b = attach_image[c]->data[i][j].b; 
      }
    }
    y += attach_image[c]->height + separator;
  }

  // write out the main image
  x = attach_width + (2*separator);
  y = separator;
  for(i = 0; i < tmain->width; i++)
  {
    for(j = 0; j < tmain->height; j++)
    {
      tmp_image->data[i+x][j+y].r = tmain->data[i][j].r;
      tmp_image->data[i+x][j+y].g = tmain->data[i][j].g;
      tmp_image->data[i+x][j+y].b = tmain->data[i][j].b; 
    }
  }

  // draw the border
  
  // don't forget to set the bit depth for the new rgb_image
  // todo: make sure bit depth of two images are compatible
  tmp_image->bit_depth = 8;
  
EXIT:
  if(tmp_image)
  {
    rgb_image_destroy(*main_image);
    *main_image = tmp_image;
  }
  
  return(rc);
}

/*----------------------------------------------------------------------------
** Convert a png file to an rgb_image structure.
**  Return values:
**    0 - success
**    1 - bad png file (either not able to open or bad format)
**    2 - bad memory allocation
**--------------------------------------------------------------------------*/
int png_to_rgb_image(char *png_file, rgb_image *image)
{
  FILE *fp;
  int read_num = 8, rc = SUCCESS;
  int width, height;
  int x,y;
  unsigned char header[read_num];
  png_structp png_ptr = (png_structp)NULL;
  png_infop info_ptr = (png_infop)NULL;
  png_bytepp row_pointers;
  
  /*--------------------------------------------------------------------------
  ** Make sure that png_file exists and that it is a png file
  **------------------------------------------------------------------------*/
  fp = fopen(png_file, "rb");
  if (!fp)
  {
      char *p = getenv("CXTEST_PICTURE_SEARCH_DIR");
      if (p && strlen(p))
      {
          char *q = malloc(strlen(p) + strlen(png_file) + 3);
          strcpy(q, p);
          if (*(q + strlen(q) - 1) != '/')
            strcat(q, "/");
          strcat(q, png_file);
          fp = fopen(q, "rb");
          free(q);
      }
  }

  if (!fp)
  {
      fprintf(stderr,"Error: unable to open file [%s]\n",png_file);
      rc = ERR_PNG_FILE;
      goto ERREXIT;
  }
  if(read_num != fread(header, 1, read_num, fp))
  {
      fprintf(stderr,"Error: unable to read header from file [%s]\n",png_file);
      rc = ERR_PNG_FILE;
      goto ERREXIT;
  }
  if(png_sig_cmp(header, 0, read_num) != 0)
  {
      fprintf(stderr,"Error: [%s] is not a png formatted imgae file\n",png_file);
      rc = ERR_PNG_FILE;
      goto ERREXIT;
  }

  /*--------------------------------------------------------------------------
  ** Initialize the png structures
  **------------------------------------------------------------------------*/
  png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, NULL, NULL);
  if (!png_ptr)
  {
      fprintf(stderr,"Error: unable to create png read struct\n");
      rc = ERR_MALLOC;
      goto ERREXIT;
  }

  info_ptr = png_create_info_struct(png_ptr);
  if (!info_ptr)
  {
      fprintf(stderr,"Error: unable to create png info struct\n");
      rc = ERR_MALLOC;
      goto ERREXIT;
  }
 
  /*--------------------------------------------------------------------------
  ** Initialize the IO structures
  **------------------------------------------------------------------------*/
  png_init_io(png_ptr, fp);
  png_set_sig_bytes(png_ptr, read_num);

  /*--------------------------------------------------------------------------
  ** Read the png file and with appropriate transformations -- convert to 
  ** 8 bit color depth and remove alpha component
  **------------------------------------------------------------------------*/
  png_read_png(png_ptr, info_ptr, (PNG_TRANSFORM_STRIP_16|PNG_TRANSFORM_STRIP_ALPHA|PNG_TRANSFORM_PACKING), NULL);

  /*--------------------------------------------------------------------------
  ** Get the height and width of the png image -- allocate appropriate memory
  ** for the rgb_image
  **------------------------------------------------------------------------*/
  height = png_get_image_height(png_ptr, info_ptr);
  width = png_get_image_width(png_ptr, info_ptr);
  if(rgb_image_malloc(image, width, height))
  {
      rc = ERR_MALLOC;
      goto ERREXIT;
  }

  /*--------------------------------------------------------------------------
  ** Get the data row pointers and copy image into rgb_image -- png_get_rows
  ** is a high level function call, png takes care of malloc and free
  **------------------------------------------------------------------------*/
  row_pointers = png_get_rows(png_ptr, info_ptr);
  for(y=0; y < height; y++)
  {
    for(x=0; x < width; x++)
    {
      image->data[x][y].r = row_pointers[y][x*3];
      image->data[x][y].g = row_pointers[y][(x*3)+1];
      image->data[x][y].b = row_pointers[y][(x*3)+2];
    }
  }

  /*--------------------------------------------------------------------------
  ** Set the bit_depth for the image
  **--------------------------------------------------------------------------*/
  image->bit_depth = 8;

ERREXIT:

  if(fp)
    fclose(fp);

  if(png_ptr && info_ptr)
    png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
  else if(png_ptr)
    png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);

  return(rc);
}

/*----------------------------------------------------------------------------
** Set the pixel format for ximage
** precondition: win_image_init() has been called for w_image
**               and w_image->ximage has been set (no longer null)
**--------------------------------------------------------------------------*/
void win_image_set_pixel_format(win_image *w_image)
{
  /*--------------------------------------------------------------------------
  ** Initialize temp r, g, and b masks, to be used to determine the
  ** r, g, and b counts and shifts 
  **------------------------------------------------------------------------*/
  unsigned long tmp_rmask = w_image->ximage->red_mask;
  unsigned long tmp_gmask = w_image->ximage->green_mask;
  unsigned long tmp_bmask = w_image->ximage->blue_mask;
  int i;

  /*--------------------------------------------------------------------------
  ** Figure out the shift and count for r, g, and b
  ** Find the Red shift and count
  **------------------------------------------------------------------------*/
  for(i = 0; i < 32; i++)
  {
    if((tmp_rmask & 1) == 1)
    {
      if(w_image->pformat.r_shift == -1)
        w_image->pformat.r_shift = i;
      w_image->pformat.r_count++;
    }
    else if(w_image->pformat.r_shift != -1)
      break;
    
    tmp_rmask = tmp_rmask >> 1;
  }
  
  /*--------------------------------------------------------------------------
  ** Find the Green shift and count
  **------------------------------------------------------------------------*/
  for(i = 0; i < 32; i++)
  {
    if((tmp_gmask & 1) == 1)
    {
      if(w_image->pformat.g_shift == -1)
        w_image->pformat.g_shift = i;
      w_image->pformat.g_count++;
    }
    else if(w_image->pformat.g_shift != -1)
      break;
    
    tmp_gmask = tmp_gmask >> 1;
  }
  
  /*--------------------------------------------------------------------------
  ** Find the Blue shift and count
  **------------------------------------------------------------------------*/
  for(i = 0; i < 32; i++)
  {
    if((tmp_bmask & 1) == 1)
    {
      if(w_image->pformat.b_shift == -1)
        w_image->pformat.b_shift = i;
      w_image->pformat.b_count++;
    }
    else if(w_image->pformat.b_shift != -1)
      break;
    
    tmp_bmask = tmp_bmask >> 1;
  }
  
  /*--------------------------------------------------------------------------
  ** Assign the r, g, and b masks
  **------------------------------------------------------------------------*/
  w_image->pformat.r_mask = w_image->ximage->red_mask;
  w_image->pformat.g_mask = w_image->ximage->green_mask;
  w_image->pformat.b_mask = w_image->ximage->blue_mask;
}

/*----------------------------------------------------------------------------
** Set the viewable parameters for an ximage
**--------------------------------------------------------------------------*/
void find_viewable_coords(int global_coord, int dpy_dimension, int win_dimension, int *origin_coord, int *adjusted_dimension)
{
  /*--------------------------------------------------------------------------
  ** If the dimensions are already set, then adjust them accordingly
  **------------------------------------------------------------------------*/
  if(*adjusted_dimension > 0)
  {
    if(*adjusted_dimension + *origin_coord >= dpy_dimension)
      *adjusted_dimension -= ((*adjusted_dimension + *origin_coord) - dpy_dimension);

    if(*origin_coord < 0)
    {
      *adjusted_dimension += *origin_coord;
      *origin_coord = 0;
    }
  }
  else
  {
    /*------------------------------------------------------------------------
    ** Adjust the dimension around the dimension axis origin
    **----------------------------------------------------------------------*/
    *adjusted_dimension = win_dimension;
    if( global_coord < 0 )
    {
      *origin_coord -= global_coord;
      *adjusted_dimension += global_coord;
    }
    
    /*------------------------------------------------------------------------
    ** Adjust the dimension at the other edge of the window
    **----------------------------------------------------------------------*/
    if( global_coord + *adjusted_dimension >= dpy_dimension )
      *adjusted_dimension -= ((*adjusted_dimension + global_coord) - dpy_dimension);
  }
  
  /*------------------------------------------------------------------------
  ** Aditional control if we are in broken X, i.e CrossOver Mac 6.1 branch
  ** with bundled X implemenation
  **----------------------------------------------------------------------*/
  if(*adjusted_dimension > dpy_dimension)
    *adjusted_dimension = dpy_dimension; 
}

/*----------------------------------------------------------------------------
** Set the viewable parameters for an ximage
**--------------------------------------------------------------------------*/
void win_image_set_viewable_params(win_image *w_image, int global_x, int global_y, int display_width, int display_height, int win_width, int win_height)
{
  /*--------------------------------------------------------------------------
  ** Find the viewable origin coord and width for the x axis
  **------------------------------------------------------------------------*/
  find_viewable_coords(global_x, display_width, win_width, &w_image->origin_x, &w_image->width);
  
  /*--------------------------------------------------------------------------
  ** Find the viewable origin coord and width for the y axis
  **------------------------------------------------------------------------*/
  find_viewable_coords(global_y, display_height, win_height, &w_image->origin_y, &w_image->height);
}

/*----------------------------------------------------------------------------
** Get the ximage
**  -- might want to think about changing operations for win == root_win
**  return 0 on success, 1 on failure
**--------------------------------------------------------------------------*/
int win_image_set_ximage(win_image *wimage, Display *display, Window win)
{
  Window root_win = 0, dummy;
  XWindowAttributes win_attr;
  int global_x, global_y;
  int display_width = -1, display_height = -1;
  
  /*--------------------------------------------------------------------------
  ** Make sure to reset wimage if it already has an XImage
  **--------------------------------------------------------------------------*/
  if(wimage->ximage != (XImage *)NULL)
    win_image_destroy_ximage(wimage);
  
  /*--------------------------------------------------------------------------
  ** Get the root window
  **--------------------------------------------------------------------------*/
  root_win = DefaultRootWindow(display);
  if(!root_win)
  {
    fprintf(stderr, "Unable to get default root window\n");
    return(1);
  }
  
  /*--------------------------------------------------------------------------
  ** Get the window attributes
  **--------------------------------------------------------------------------*/
  if( !XGetWindowAttributes(display, win, &win_attr))
  {
    fprintf(stderr,"Unable to get window attributes\n");
    return(1);
  }
  
  /*--------------------------------------------------------------------------
  ** Find the global coordinates of the upper left corner of the window
  **--------------------------------------------------------------------------*/
  if( !XTranslateCoordinates(display, win, root_win, 0, 0, &global_x, &global_y, &dummy))
  {
    fprintf(stderr,"Unable to translate coordinates\n");
    return(1);
  }
  
  /*--------------------------------------------------------------------------
  ** Get the display width and height
  **--------------------------------------------------------------------------*/
  display_width =  DisplayWidth(display, DefaultScreen(display));
  display_height = DisplayHeight(display, DefaultScreen(display));
  if ( display_width == -1 || display_height == -1)
  {
    fprintf(stderr,"Unable to retrieve display width and/or height\n");
    return(1);
  }
   
  /*--------------------------------------------------------------------------
  ** Find and set the viewable window parameters for win and capture the ximage
  **--------------------------------------------------------------------------*/  
  win_image_set_viewable_params(wimage, global_x, global_y, display_width, display_height, win_attr.width, win_attr.height);
  wimage->ximage = XGetImage(display, win, wimage->origin_x, wimage->origin_y, wimage->width, wimage->height, AllPlanes, ZPixmap);

  if( wimage->ximage == (XImage *)NULL)
  {
    fprintf(stderr, "Unable to allocate ximage\n");
    
    return(1);
  }
  
  /*--------------------------------------------------------------------------
  ** Get the pixel format for w_image.ximage, but only if it has not previously
  ** been set... pixel format will not change on fly
  **--------------------------------------------------------------------------*/
  if(wimage->pformat.r_shift == -1)
    win_image_set_pixel_format(wimage);
  
  return(0);
}

/*----------------------------------------------------------------------------
** Convert to 8 bit depth
**--------------------------------------------------------------------------*/
short convert_to_8bit(short pixel_component, int component_size)
{
  short return_val;
  switch(component_size)
  {
    case 5:
      return_val = pixel_component << 3 | pixel_component >> 2;
    break;
    
    case 6:
      return_val = pixel_component << 2 | pixel_component >> 4;
    break;
    
    default:
      return_val = pixel_component;
    break;
  }
  
  return(return_val);
}

/*----------------------------------------------------------------------------
** Convert a win_image to a rgb_image
**--------------------------------------------------------------------------*/
int win_image_to_rgb_image(win_image *w_image, rgb_image *r_image)
{
  int x, y;
  unsigned long pixel;
  short r, g, b;
  
  /*--------------------------------------------------------------------------
  ** Allocate memory for r_image
  **--------------------------------------------------------------------------*/
  if(rgb_image_malloc(r_image, w_image->width, w_image->height))
    return(1);
  
  /*--------------------------------------------------------------------------
  ** Go through the ximage and assign r_image values, x first
  **--------------------------------------------------------------------------*/
  for(x = 0; x < w_image->width; x++)  
  {
    /*------------------------------------------------------------------------
    ** Go through the y values for each x value of ximage
    **------------------------------------------------------------------------*/
    for(y = 0; y < w_image->height; y++)
    {
      pixel = XGetPixel(w_image->ximage, x, y);
      
      /*----------------------------------------------------------------------
      ** Find the r, g, and b values
      **----------------------------------------------------------------------*/
      r = (pixel & w_image->pformat.r_mask) >> w_image->pformat.r_shift;
      g = (pixel & w_image->pformat.g_mask) >> w_image->pformat.g_shift;
      b = (pixel & w_image->pformat.b_mask) >> w_image->pformat.b_shift;

      /*----------------------------------------------------------------------
      ** Convert the pixels to 8 bit per r, g, b and assign values
      **----------------------------------------------------------------------*/
      r_image->data[x][y].r = convert_to_8bit(r, w_image->pformat.r_count);
      r_image->data[x][y].g = convert_to_8bit(g, w_image->pformat.g_count);
      r_image->data[x][y].b = convert_to_8bit(b, w_image->pformat.b_count);
    }
  }
  
  /*--------------------------------------------------------------------------
  ** Record the bit depth that is being used
  **--------------------------------------------------------------------------*/
  r_image->bit_depth = 8;

  return(0);
}

/*----------------------------------------------------------------------------
** Convert an rgb image to an rgb histogram
**--------------------------------------------------------------------------*/
int rgb_image_to_rgb_hist(rgb_image *r_image, rgb_hist *r_hist)
{
    int i=0;
    int j=0;
    
  /*--------------------------------------------------------------------------
 ** Allocate memory for r_hist
 **--------------------------------------------------------------------------*/
 // r_hist=rgb_hist_init();
  //if( r_hist==NULL )
   // return(1);
   
   // printf("width: %d, height: %d\n",r_image->width,r_image->height);
  for(i=0; i<r_image->width; i++)
  {
    for(j=0; j<r_image->height; j++)
    {
      /*-----------------------------------------------------------------------
   ** At each pixel, get the rgb image's r,g and b values 
   **---------------------------------------------------------------------*/
      int r_val=r_image->data[i][j].r;
      int g_val=r_image->data[i][j].g;
      int b_val=r_image->data[i][j].b;
            
      /*----------------------------------------------------------------------------
   ** Increment the spots in the arrays that correspond to the image's rgb values 
   **--------------------------------------------------------------------------*/
      r_hist->r[r_val]++;
      r_hist->g[g_val]++;
      r_hist->b[b_val]++;
            
      /*------------------------------------------------------------------
   ** Increment the variable that stores how many pixels there are 
   **----------------------------------------------------------------*/
      r_hist->total_count++;
    }
  }
  r_hist->width=r_image->width;
  r_hist->height=r_image->height;
    
  return(0);
}

/*----------------------------------------------------------------------------
** Convert a win image to an rgb histogram
**--------------------------------------------------------------------------*/
int win_image_to_rgb_hist(win_image *w_image, rgb_hist *r_hist)
{
  
  rgb_image *r_image=NULL;
    
  /*--------------------------------------------------------------------------
 ** Convert the win image to an rgb image
 **--------------------------------------------------------------------------*/
  if (!win_image_to_rgb_image(w_image, r_image))
      return(1);
  
  /*--------------------------------------------------------------------------
 ** Call rgb_image_to_rgb_hist on the newly created rgb image
 **--------------------------------------------------------------------------*/
   if (!rgb_image_to_rgb_hist(r_image, r_hist))
       return(1);

  /*--------------------------------------------------------------------------
 ** If we are here, both function calls worked; we exit successfully
 **--------------------------------------------------------------------------*/
  return(0);
}

/*----------------------------------------------------------------------------
** Compare two pixels
** return 0 if they are within the error margin, 1 if they are not
**  -- might want to think about making percentage
**--------------------------------------------------------------------------*/
int rgb_pixel_comparison(rgb *p1, rgb *p2, int err_margin)
{
  /*--------------------------------------------------------------------------
  ** Compare each component of the pixel separately
  **--------------------------------------------------------------------------*/
  if( err_margin < abs(p1->r - p2->r))
    return 1;
  
  if( err_margin < abs(p1->g - p2->g))
    return 1;
    
  if( err_margin < abs(p1->b - p2->b))
    return 1;

  /*--------------------------------------------------------------------------
  ** All components w/in error margin... success
  **--------------------------------------------------------------------------*/
  return 0;
}

/*----------------------------------------------------------------------------
** Move through the subimage, comparing each pixel with a set location
** from the image
**--------------------------------------------------------------------------*/
int rgb_image_subimage_search (rgb_image *image, rgb_image *subimage, int err_margin, int x, int y)
{
  int i, j;

  for (i = 0; i < subimage->width; i++)
  {
    for (j = 0; j < subimage->height; j++)
    {
      /*------------------------------------------------------------------------
      ** Do a comparison of each pixel
      **----------------------------------------------------------------------*/
      if ( rgb_pixel_comparison( &image->data[i+x][j+y], &subimage->data[i][j], err_margin)) 
        return(1);
    }
  }
    
  /*--------------------------------------------------------------------------
  ** All pixels in the subimage are within the error margin, success
  **--------------------------------------------------------------------------*/
  return(0);
}

/*----------------------------------------------------------------------------
** Find one rgb_image inside of another
**  --return 0 on success, 1 on image not found, 2 on error
**--------------------------------------------------------------------------*/
int rgb_image_find_subimage(rgb_image *image, rgb_image *subimage, int err_margin, int *x, int *y)
{
  int x_diff, y_diff;
  int i = 0, j = 0;
  int rc = 1;
  
  /*--------------------------------------------------------------------------
  ** Make sure that the subimage is smaller than the image & that they have
  ** the same bit depth
  **--------------------------------------------------------------------------*/
  x_diff = image->width - subimage->width;
  y_diff = image->height - subimage->height;
  if (x_diff < 0 || y_diff < 0 || image->bit_depth != subimage->bit_depth)
    return(2);
  
  /*--------------------------------------------------------------------------
  ** Loop through the image, sending a search at each potential location of
  ** the subimage's upper-left corner
  **--------------------------------------------------------------------------*/
  for (i = 0; i <= x_diff && rc; i++)
  {
    for (j = 0; j <= y_diff && rc; j++)
    {
      rc = rgb_image_subimage_search(image, subimage, err_margin, i, j);
    }
  }
  
  /*--------------------------------------------------------------------------
  ** Adjust the coordinates, x and y, to be coordinates of the image
  **  -- if no coords are passed in, or if they are not applicable to the
  **     subimage (ie. too large), then use the middle of the subimage
  **--------------------------------------------------------------------------*/
  if(!rc)
  {
    if(*x < 0 || *x > subimage->width || *y < 0 || *y > subimage->height)
    {
      *x = subimage->width/2;
      *y = subimage->height/2;
    }
    *x += i;
    *y += j;
  }
  
  return(rc);
}