xvisutil.c

早期freebsd实现

/* $XConsortium: XVisUtil.c,v 11.14 91/06/30 18:15:42 rws Exp $ */
/* Copyright    Massachusetts Institute of Technology    1986	*/

/*
Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation, and that the name of M.I.T. not be used in advertising or
publicity pertaining to distribution of the software without specific,
written prior permission.  M.I.T. makes no representations about the
suitability of this software for any purpose.  It is provided "as is"
without express or implied warranty.
*/

#include "Xlibint.h"
#include "Xutil.h"
#include <stdio.h>
/*
 *	This procedure returns a list of visual information structures
 *	that match the specified attributes given in the visual information 
 *	template.
 *
 *	If no visuals exist that match the specified attributes, a NULL is
 *	returned.
 *
 *	The choices for visual_info_mask are:
 *
 *		VisualNoMask
 *		VisualIDMask
 *		VisualScreenMask
 *		VisualDepthMask
 *		VisualClassMask
 *		VisualRedMaskMask
 *		VisualGreenMaskMask
 *		VisualBlueMaskMask
 *		VisualColormapSizeMask
 *		VisualBitsPerRGBMask
 *		VisualAllMask
 */

XVisualInfo *XGetVisualInfo( dpy, visual_info_mask, 
			    visual_info_template, nitems)
Display *dpy;
register long visual_info_mask; 
register XVisualInfo *visual_info_template;
int *nitems;	/* RETURN */
{

  register Visual *vp;
  register Depth *dp;
  Screen *sp;
  int ii,screen_s,screen_e,total,count;
  register XVisualInfo *vip,*vip_base;

  /* NOTE: NO HIGH PERFORMING CODE TO BE FOUND HERE */

  LockDisplay(dpy);

  /* ALLOCATE THE ORIGINAL BUFFER; REALLOCED LATER IF OVERFLOW OCCURS;
     FREED AT END IF NO VISUALS ARE FOUND */

  count = 0;
  total = 10;
  if (! (vip_base = vip = (XVisualInfo *) 
	 Xmalloc((unsigned) (sizeof(XVisualInfo) * total)))) {
      UnlockDisplay(dpy);
      return (XVisualInfo *) NULL;
  }

  /* DETERMINE IF WE DO ALL SCREENS OR ONLY ONE */

  screen_s = 0;
  screen_e = dpy->nscreens;
  if (visual_info_mask & VisualScreenMask)
    {
      screen_s = visual_info_template->screen;
      if (screen_s < 0 || screen_s >= screen_e)
	  screen_e = screen_s;
      else
	  screen_e = screen_s + 1;
    }

  /* LOOP THROUGH SCREENS */

  for (ii=screen_s; ii<screen_e; ii++)
    {
      sp = (Screen *)(&dpy->screens[ii]);

      /* LOOP THROUGH DEPTHS */

      for (dp=sp->depths; dp < (sp->depths + sp->ndepths); dp++)
        {
          if ((visual_info_mask & VisualDepthMask) &&
	      (dp->depth != visual_info_template->depth)) continue;

          /* LOOP THROUGH VISUALS */

	  if (dp->visuals) {
	    for (vp=dp->visuals; vp<(dp->visuals + dp->nvisuals); vp++) {
              if ((visual_info_mask & VisualIDMask) &&
                (vp->visualid != visual_info_template->visualid)) continue;
              if ((visual_info_mask & VisualClassMask) &&
                (vp->class != visual_info_template->class)) continue;
              if ((visual_info_mask & VisualRedMaskMask) &&
                (vp->red_mask != visual_info_template->red_mask)) continue;
              if ((visual_info_mask & VisualGreenMaskMask) &&
                (vp->green_mask != visual_info_template->green_mask)) continue;
              if ((visual_info_mask & VisualBlueMaskMask) &&
                (vp->blue_mask != visual_info_template->blue_mask)) continue;
              if ((visual_info_mask & VisualColormapSizeMask) &&
                (vp->map_entries != visual_info_template->colormap_size)) continue;
              if ((visual_info_mask & VisualBitsPerRGBMask) &&
                (vp->bits_per_rgb != visual_info_template->bits_per_rgb)) continue;

              /* YEA!!! WE FOUND A GOOD ONE */
 
              if (count+1 > total)
                {
		  XVisualInfo *old_vip_base = vip_base;
                  total += 10;
                  if (! (vip_base = (XVisualInfo *)
			 Xrealloc((char *) vip_base, 
				  (unsigned) (sizeof(XVisualInfo) * total)))) {
		      Xfree((char *) old_vip_base);
		      UnlockDisplay(dpy);
		      return (XVisualInfo *) NULL;
		  }
                  vip = &vip_base[count];
                }

              count++;

              vip->visual = vp;
              vip->visualid = vp->visualid;
              vip->screen = ii;
              vip->depth = dp->depth;
              vip->class = vp->class;
              vip->red_mask = vp->red_mask;
              vip->green_mask = vp->green_mask;
              vip->blue_mask = vp->blue_mask;
              vip->colormap_size = vp->map_entries;
              vip->bits_per_rgb = vp->bits_per_rgb;

              vip++;

            } /* END OF LOOP ON VISUALS */
	  } /* END OF IF THERE ARE ANY VISUALS AT THIS DEPTH */
          
        } /* END OF LOOP ON DEPTHS */

    } /* END OF LOOP ON SCREENS */

  UnlockDisplay(dpy);

  if (count)
    {
      *nitems = count;
      return vip_base;
    }

  Xfree((char *) vip_base);
  *nitems = 0;
  return NULL;
}


/*
 *	This procedure will return the visual information for a visual 
 *      that matches the specified depth and class for a screen.  Since 
 *	multiple visuals may exist that match the specified depth and 
 *	class, which visual chosen is undefined.
 *
 *	If a visual is found, True is returned as the function value,
 *	otherwise False is returned.
 */

Status XMatchVisualInfo( dpy, screen, depth, class, visual_info)
	Display *dpy;
	int screen;
	int depth;
	int class;
	XVisualInfo *visual_info; /* RETURNED */
{

  Visual *vp;
  Depth *dp;
  Screen *sp;
  int ii,jj;

  if (screen < 0 || screen >= dpy->nscreens)
      return False;

  LockDisplay(dpy);

  sp = (Screen *)(&dpy->screens[screen]);

  dp = sp->depths;

  for (ii=0; ii < sp->ndepths; ii++)
    {

    /* LOOK THROUGH DEPTHS FOR THE WANTED DEPTH */

    if (dp->depth == depth)
      {
        vp = dp->visuals;

        /* LOOK THROUGH VISUALS FOR THE WANTED CLASS */

	/* if nvisuals == 0 then vp will be NULL */
        for (jj=0; jj<dp->nvisuals; jj++)
          {
            if (vp->class == class) 
              {
		visual_info->visual = vp;
		visual_info->visualid = vp->visualid;
		visual_info->screen = screen;
		visual_info->depth = depth;
		visual_info->class = vp->class;
		visual_info->red_mask = vp->red_mask;
		visual_info->green_mask = vp->green_mask;
		visual_info->blue_mask = vp->blue_mask;
		visual_info->colormap_size = vp->map_entries;
		visual_info->bits_per_rgb = vp->bits_per_rgb;
                UnlockDisplay(dpy);
                return True;
              }
            vp++;
          }
      }

    dp++;

    }

  UnlockDisplay(dpy);

  return False;

}