/* 
 * Motif
 *
 * Copyright (c) 1987-2012, The Open Group. All rights reserved.
 *
 * These libraries and programs are free software; you can
 * redistribute them and/or modify them under the terms of the GNU
 * Lesser General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * These libraries and programs are distributed in the hope that
 * they 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 these librararies and programs; if not, write
 * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
 * Floor, Boston, MA 02110-1301 USA
*/ 
/* 
 * HISTORY
*/ 
#ifdef REV_INFO
#ifndef lint
static char rcsid[] = "$XConsortium: AllocNaColor.c /main/7 1995/07/14 11:45:33 drk $"
#endif
#endif
/***********************************************************************
  	@(#)AllocNaColor.c	1.5.1.1	Date:1/22/91
  	Author: TAT
	History:
	   03/30/90 SJS Add to sccs tree
	Calls:

	Summary:
            Allocate one unqiue named color from the locol color cache.

        NOTE: This routine, unlike mvsAllocColor() and mvsAllocColorStruct()
        does not add the pixel value to the mvsColorAllocInfo list.  So you
        must call mvsAllocColor() or mvsAllocColorStruct() after you return
        with the pixel value from this routine.                            

        INPUTS
            name  - requested RGB color name (one of the mvsColorTable names)

        OUTPUTS
            pixel - pixel color index value returned
 
        RETURNS
            Status where 0=failed, ~0=succeeded
************************************************************************/
#include <AutoMessages.h>
#include "vislib.h"

#define SQR(x) (temp=(x), temp*temp)

Status mvsAllocNamedColor(name, pixel)
char name[];
Pixel *pixel;
{
    int i,j;
    XColor nearest;
    Status status;
    unsigned long heuristic_val, lowest_heuristic_value = 0xFFFFFFFFL;
    int best_match_pixel_num;
    unsigned long temp;

    /* look up name in our color table */

    for (i=0; i<mvsNumTableColors && 
              mvsStringCompare(name,mvsColorTable[i].name1) != 0 &&
              mvsStringCompare(name,mvsColorTable[i].name2) != 0    ;
         i++);
    
    if (i == mvsNumTableColors) { /* if not found... */
        VIS_error("Color name '%s' not found in color table!\n",name);
        exit(1);
    }

    /* look-up which mvsColorAllocInfo slot will be used when we alloc it 
       later in mvsSetValuesNoCheck.                                       */

    nearest.red   = mvsColorTable[i].red<<8;
    nearest.green = mvsColorTable[i].green<<8;
    nearest.blue  = mvsColorTable[i].blue<<8;
    nearest.flags = (DoRed | DoGreen | DoBlue);

    status = XAllocColor(visDisplay,mvsVisualInfo.colormap_id,&nearest);

    if (status == 0) { /* XAllocColor failed! */

        /* In practice, this path should never occur if XServer implemented  */
        /* correctly (i.e., there is always a "nearest" color.               */

        AutoMessage(_AutoMessages[VISMSG18]);
	AutoMessage(_AutoMessages[VISMSG19]);
        

        /* find pixel in currently allocated set with nearest rgb */

        for (j=0; j<MAX_COLORS; j++) {

          if (mvsColorAllocInfo[j].alloc_cnt > 0) {
            heuristic_val = /* geometric distance in 3-space */
                SQR((mvsColorTable[i].red<<6)   - (mvsColorAllocInfo[j].red>>2))
              + SQR((mvsColorTable[i].green<<6) - (mvsColorAllocInfo[j].green>>2))
              + SQR((mvsColorTable[i].blue<<6)  - (mvsColorAllocInfo[j].blue>>2));

            /* NOTE: the above values have been scaled so that the result
               will always fit into an unsigned long variable.               */

            if (heuristic_val < lowest_heuristic_value) {
                lowest_heuristic_value = heuristic_val;
                best_match_pixel_num = j;
            }
          }
        }

        if (lowest_heuristic_value == 0xFFFFFFFFL) {
            *pixel = WhitePixel(visDisplay,DefaultScreen(visDisplay)); /* be safe */
            AutoMessage(_AutoMessages[VISMSG20]);
            return 0; /* could not find an allocated pixel close to request */
        }

        j = best_match_pixel_num;
        nearest.pixel = mvsColorAllocInfo[j].pixel;
        nearest.red = mvsColorAllocInfo[j].red;
        nearest.green = mvsColorAllocInfo[j].green;
        nearest.blue = mvsColorAllocInfo[j].blue;
    }

    *pixel = nearest.pixel;

    return 1;

} /* End mvsAllocNamedColor() */