view src/solaris/native/sun/awt/multiVis.c @ 13513:7d5d3659c9e0

8171000: Robot.createScreenCapture() crashes in wayland mode Reviewed-by: serb, mhalder
author kaddepalli
date Mon, 05 Feb 2018 13:44:41 +0530
parents 1a3de3cdc684
children 533a8dfd2ec5
line wrap: on
line source
/*
 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
/* $XConsortium: multiVis.c /main/4 1996/10/14 15:04:08 swick $ */
/** ------------------------------------------------------------------------
        This file contains functions to create a list of regions which
        tile a specified window.  Each region contains all visible
        portions of the window which are drawn with the same visual.
        If the window consists of subwindows of two different visual types,
        there will be two regions in the list.  The list can be traversed
        to correctly pull an image of the window using XGetImage or the
        Image Library.

 This file is available under and governed by the GNU General Public
 License version 2 only, as published by the Free Software Foundation.
 However, the following notice accompanied the original version of this
 file:

Copyright (c) 1994 Hewlett-Packard Co.
Copyright (c) 1996  X Consortium

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of the X Consortium shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from the X Consortium.

    ------------------------------------------------------------------------ **/
#include <stdlib.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/X.h>
#include <stdio.h>
#include "list.h"
#include "wsutils.h"
#include "multiVis.h"
#include "robot_common.h"

static char *vis_class_str[] = { "StaticGray" , "GrayScale" , "StaticColor",
                                 "PseudoColor","TrueColor","DirectColor" } ;
/* These structures are copied from X11/region.h.  For some reason
 * they're invisible from the outside.*/

typedef struct {
    short x1, x2, y1, y2;
} myBox, myBOX, myBoxRec, *myBoxPtr;

typedef struct my_XRegion {    /* 64-bit: Region is supposed to be opaque    */
    long size;                 /* but it is defined here anyway.  I'm going  */
    long numRects;             /* to leave those longs alone.                */
    myBOX *rects;
    myBOX extents;
} myREGION;

/* Items in long list of windows that have some part in the grabbed area */
typedef struct {
    Window win;
    Visual *vis;
    Colormap cmap;
    int32_t x_rootrel, y_rootrel;       /* root relative location of window */
    int32_t x_vis, y_vis;               /* rt rel x,y of vis part, not parent clipped */
    int32_t width, height;              /* width and height of visible part */
    int32_t border_width;               /* border width of the window */
    Window parent;              /* id of parent (for debugging) */
} image_win_type;

/*  Items in short list of regions that tile the grabbed area.  May have
    multiple windows in the region.
*/
typedef struct {
    Window win;                 /* lowest window of this visual */
    Visual *vis;
    Colormap cmap;
    int32_t x_rootrel, y_rootrel;       /* root relative location of bottom window */
    int32_t x_vis, y_vis;               /* rt rel x,y of vis part, not parent clipped */
    int32_t width, height;              /* w & h of visible rect of bottom window */
    int32_t border;                     /* border width of the window */
    Region visible_region;
} image_region_type;

/** ------------------------------------------------------------------------
        Returns TRUE if the two structs pointed to have the same "vis" &
        "cmap" fields and s2 lies completely within s1.  s1 and s2 can
        point to structs of image_win_type or image_region_type.
    ------------------------------------------------------------------------ **/
#define SAME_REGIONS( s1, s2)   \
        ((s1)->vis == (s2)->vis && (s1)->cmap == (s2)->cmap &&          \
         (s1)->x_vis <= (s2)->x_vis &&                              \
         (s1)->y_vis <= (s2)->y_vis &&                              \
         (s1)->x_vis + (s1)->width  >= (s2)->x_vis + (s2)->width && \
         (s1)->y_vis + (s1)->height >= (s2)->y_vis + (s2)->height)

#ifndef MIN
#define MIN( a, b)      ((a) < (b) ? a : b)
#define MAX( a, b)      ((a) > (b) ? a : b)
#endif

#define RED_SHIFT        16
#define GREEN_SHIFT       8
#define BLUE_SHIFT        0

/*
extern list_ptr new_list();
extern list_ptr dup_list_head();
extern void *   first_in_list();
extern void *   next_in_list();
extern int32_t  add_to_list();
extern void     zero_list();
extern void     delete_list();
extern void     delete_list_destroying();
extern uint32_t list_length();
*/

/* Prototype Declarations for Static Functions */
static void TransferImage(
#if NeedFunctionPrototypes
           Display *, XImage *,int32_t, int32_t , image_region_type*,
           XImage *,int32_t ,int32_t
#endif
           );
static XImage * ReadRegionsInList(
#if NeedFunctionPrototypes
           Display *, Visual *, int32_t ,int32_t ,int32_t ,
           int32_t , XRectangle, list_ptr
#endif
           );

static list_ptr make_region_list(
#if NeedFunctionPrototypes
                  Display*, Window, XRectangle*,
                  int32_t*, int32_t, XVisualInfo**, int32_t     *
#endif
         );

static void destroy_region_list(
#if NeedFunctionPrototypes
            list_ptr
#endif
            ) ;
static void subtr_rect_from_image_region(
#if NeedFunctionPrototypes
           image_region_type *, int32_t , int32_t , int32_t , int32_t
#endif
     );
static void add_rect_to_image_region(
#if NeedFunctionPrototypes
           image_region_type *,
           int32_t , int32_t , int32_t , int32_t
#endif
     );
static int32_t src_in_region_list(
#if NeedFunctionPrototypes
    image_win_type *, list_ptr
#endif
    );
static void add_window_to_list(
#if NeedFunctionPrototypes
    list_ptr, Window, int32_t, int32_t ,
    int32_t     , int32_t , int32_t , int32_t, int32_t,
    Visual*, Colormap, Window
#endif
    );
static int32_t src_in_image(
#if NeedFunctionPrototypes
    image_win_type      *, int32_t      , XVisualInfo**
#endif
    );
static int32_t src_in_overlay(
#if NeedFunctionPrototypes
    image_region_type *, int32_t, OverlayInfo *, int32_t*, int32_t*
#endif
    );

/* End of Prototype Declarations */

void initFakeVisual(Vis)
Visual *Vis ;
{
    Vis->ext_data=NULL;
    Vis->class = DirectColor ;
    Vis->red_mask =   0x00FF0000;
    Vis->green_mask = 0x0000FF00 ;
    Vis->blue_mask  = 0x000000FF ;
    Vis->map_entries = 256 ;
    Vis->bits_per_rgb = 8 ;
}

/* QueryColorMap has been moved into robot_common.c so it can be used by
 * awt_DataTransferer.c as well.
 */

int32_t
GetMultiVisualRegions(disp,srcRootWinid, x, y, width, height,
    transparentOverlays,numVisuals, pVisuals,numOverlayVisuals, pOverlayVisuals,
    numImageVisuals, pImageVisuals,vis_regions,vis_image_regions,allImage)
    Display             *disp;
    Window              srcRootWinid;   /* root win on which grab was done */
    int32_t             x;      /* root rel UL corner of bounding box of grab */
    int32_t             y;
    uint32_t            width;  /* size of bounding box of grab */
    uint32_t            height;
    int32_t             *transparentOverlays ;
    int32_t             *numVisuals;
    XVisualInfo         **pVisuals;
    int32_t             *numOverlayVisuals;
    OverlayInfo         **pOverlayVisuals;
    int32_t             *numImageVisuals;
    XVisualInfo         ***pImageVisuals;
    list_ptr            *vis_regions;    /* list of regions to read from */
    list_ptr            *vis_image_regions ;
    int32_t             *allImage ;
{
    int32_t             hasNonDefault;
    XRectangle          bbox;           /* bounding box of grabbed area */


    /* Java uses 32-bit ints for coordinates, but XRectangles use 16-bit shorts.
     * Hope nobody passes in too big a coordinate */

    bbox.x = (short) x;                 /* init X rect for bounding box */
    bbox.y = (short) y;
    bbox.width = (unsigned short) width;
    bbox.height = (unsigned short) height;

    GetXVisualInfo(disp,DefaultScreen(disp),
                    transparentOverlays,
                    numVisuals, pVisuals,
                    numOverlayVisuals, pOverlayVisuals,
                    numImageVisuals, pImageVisuals);

    *vis_regions = *vis_image_regions = NULL ;
    if ((*vis_regions = make_region_list( disp, srcRootWinid, &bbox,
                                         &hasNonDefault, *numImageVisuals,
                                         *pImageVisuals, allImage)) == NULL)
        return 0 ;

    if (*transparentOverlays)
    {
        *allImage = 1; /* until proven otherwise,
                         this flags that it to be an image only list */
        *vis_image_regions =
                make_region_list( disp, srcRootWinid, &bbox, &hasNonDefault,
                                        *numImageVisuals, *pImageVisuals, allImage);
    }

    /* if there is a second region in any of the two lists return 1 **/
    if ( ( *vis_regions && (*vis_regions)->next && (*vis_regions)->next->next ) ||
         ( *vis_image_regions && (*vis_image_regions)->next &&
           (*vis_image_regions)->next->next ) ) return 1 ;
    else return 0 ;

}

static void TransferImage(disp,reg_image,srcw,srch,reg,
                          target_image,dst_x,dst_y)
Display *disp;
XImage *reg_image,*target_image ;
image_region_type       *reg;
int32_t srcw,srch,dst_x , dst_y ;
{
    int32_t ncolors;
    int32_t i,j,old_pixel,new_pixel,red_ind,green_ind,blue_ind ;
    XColor *colors;
    int32_t rShift,gShift,bShift;
    int32_t targetBytesPerLine ;

    ncolors = QueryColorMap(disp,reg->cmap,reg->vis,&colors,
         &rShift,&gShift,&bShift) ;

    targetBytesPerLine = target_image->bytes_per_line;

    switch (reg->vis->class) {
    case TrueColor :
       for(i=0 ; i < srch ; i++)
       {
         for(j=0 ; j < srcw ;  j++)
         {
           old_pixel = (int32_t) XGetPixel(reg_image,j,i) ;

/* commented out since not using server RGB masks in all true color modes
 * causes the R and B values to be swapped around on some X servers
 *    - robi.khan@eng 9/7/1999
 *           if( reg->vis->map_entries == 16) {
 */
             red_ind   = (old_pixel & reg->vis->red_mask) >> rShift ;
                 green_ind = (old_pixel & reg->vis->green_mask) >> gShift ;
                 blue_ind  = (old_pixel & reg->vis->blue_mask) >> bShift ;

                 new_pixel = (
                              ((colors[red_ind].red >> 8) << RED_SHIFT)
                              |((colors[green_ind].green >> 8) << GREEN_SHIFT)
                              |((colors[blue_ind].blue >> 8) << BLUE_SHIFT)
                             );
/*         }
 *  else
 *    new_pixel = old_pixel;
 */

           XPutPixel(target_image,dst_x+j, dst_y+i,new_pixel);

         }
       }
       break;
    case DirectColor :
       for(i=0 ; i < srch ; i++)
       {
         for(j=0 ; j < srcw ;  j++)
         {
           old_pixel = (int32_t) XGetPixel(reg_image,j,i) ;
           red_ind   = (old_pixel & reg->vis->red_mask) >> rShift ;
               green_ind = (old_pixel & reg->vis->green_mask) >> gShift ;
               blue_ind  = (old_pixel & reg->vis->blue_mask) >> bShift ;

               new_pixel = (
                         ((colors[red_ind].red >> 8) << RED_SHIFT)
                        |((colors[green_ind].green >> 8) << GREEN_SHIFT)
                        |((colors[blue_ind].blue >> 8) << BLUE_SHIFT)
                       );
           XPutPixel(target_image,dst_x+j, dst_y+i,new_pixel);

         }
       }
       break;
    default :
       for(i=0 ; i < srch ; i++)
       {
         for(j=0 ; j < srcw ;  j++)
         {
               old_pixel = (int32_t) XGetPixel(reg_image,j,i) ;

               new_pixel = (
                         ((colors[old_pixel].red >> 8) << RED_SHIFT)
                        |((colors[old_pixel].green >> 8) << GREEN_SHIFT)
                        |((colors[old_pixel].blue >> 8) << BLUE_SHIFT)
                       );
           XPutPixel(target_image,dst_x+j, dst_y+i,new_pixel);

         }
       }
       break;
    }

    /* Fix memory leak by freeing colors
     *  - robi.khan@eng 9/22/1999
     */
    free(colors);
}

static XImage *
ReadRegionsInList(disp,fakeVis,depth,format,width,height,bbox,regions)
Display *disp ;
Visual *fakeVis ;
int32_t depth , width , height ;
int32_t format ;
XRectangle      bbox;           /* bounding box of grabbed area */
list_ptr regions;/* list of regions to read from */
{
    XImage              *ximage ;

    ximage = XCreateImage(disp,fakeVis,(uint32_t) depth,format,0,NULL,
                          (uint32_t)width,(uint32_t)height,8,0);

    ximage->data = calloc(ximage->bytes_per_line*height*((format==ZPixmap)? 1 : depth), sizeof(char));
    ximage->bits_per_pixel = depth; /** Valid only if format is ZPixmap ***/

    for (image_region_type* reg = (image_region_type *) first_in_list( regions); reg;
         reg = (image_region_type *) next_in_list( regions))
    {
                struct my_XRegion *vis_reg = (struct my_XRegion *)(reg->visible_region);
                for (int32_t rect = 0; rect < vis_reg->numRects; rect++)
                {
                    /** ------------------------------------------------------------------------
                            Intersect bbox with visible part of region giving src rect & output
                            location.  Width is the min right side minus the max left side.
                            Similar for height.  Offset src rect so x,y are relative to
                            origin of win, not the root-relative visible rect of win.
                        ------------------------------------------------------------------------ **/
                        int32_t srcRect_width  = MIN( vis_reg->rects[rect].x2, bbox.width + bbox.x)
                                         - MAX( vis_reg->rects[rect].x1, bbox.x);

                        int32_t srcRect_height = MIN( vis_reg->rects[rect].y2, bbox.height + bbox.y)
                                         - MAX( vis_reg->rects[rect].y1, bbox.y);

                        int32_t diff = bbox.x - vis_reg->rects[rect].x1;
                        int32_t srcRect_x = MAX( 0, diff)  + (vis_reg->rects[rect].x1 - reg->x_rootrel - reg->border);
                        int32_t dst_x     = MAX( 0, -diff) ;

                        diff = bbox.y - vis_reg->rects[rect].y1;
                        int32_t srcRect_y = MAX( 0, diff)  + (vis_reg->rects[rect].y1 - reg->y_rootrel - reg->border);
                        int32_t dst_y     = MAX( 0, -diff) ;
                        XImage* reg_image = XGetImage(disp,reg->win,srcRect_x,srcRect_y,
                                            (uint32_t) srcRect_width, (uint32_t) srcRect_height,AllPlanes,format) ;

                        if (reg_image) {
                            TransferImage(disp,reg_image,srcRect_width,
                                            srcRect_height,reg,ximage,dst_x,dst_y) ;
                            XDestroyImage(reg_image);
                        }
                }
    }
    return ximage ;
}


/** ------------------------------------------------------------------------
    ------------------------------------------------------------------------ **/

XImage *ReadAreaToImage(disp, srcRootWinid, x, y, width, height,
    numVisuals,pVisuals,numOverlayVisuals,pOverlayVisuals,numImageVisuals,
    pImageVisuals,vis_regions,vis_image_regions,format,allImage)
    Display             *disp;
    Window              srcRootWinid;   /* root win on which grab was done */
    int32_t                     x;   /* root rel UL corner of bounding box of grab */
    int32_t                     y;
    uint32_t            width;  /* size of bounding box of grab */
    uint32_t            height;
    /** int32_t                 transparentOverlays; ***/
    int32_t                     numVisuals;
    XVisualInfo         *pVisuals;
    int32_t                     numOverlayVisuals;
    OverlayInfo         *pOverlayVisuals;
    int32_t                     numImageVisuals;
    XVisualInfo         **pImageVisuals;
    list_ptr            vis_regions;    /* list of regions to read from */
    list_ptr            vis_image_regions ;/* list of regions to read from */
    int32_t                     format;
    int32_t             allImage ;
{
    image_region_type   *reg;
    XRectangle          bbox;           /* bounding box of grabbed area */
    int32_t             depth ;
    XImage              *ximage, *ximage_ipm ;
    Visual              fakeVis ;
    int32_t     x1, y1;
    XImage      *image;
    unsigned char       *pmData ,  *ipmData ;
    int32_t                 transparentColor, transparentType;
    int32_t                     srcRect_x,srcRect_y,srcRect_width,srcRect_height ;
    int32_t                     diff ;
    int32_t                     dst_x, dst_y;   /* where in pixmap to write (UL) */
    int32_t                     pixel;

    bbox.x = (short) x;                 /* init X rect for bounding box */
    bbox.y = (short) y;
    bbox.width = (unsigned short) width;
    bbox.height = (unsigned short) height;
    ximage_ipm = NULL;


    initFakeVisual(&fakeVis) ;

    depth = 24 ;
    ximage = ReadRegionsInList(disp,&fakeVis,depth,format,
             (int32_t) width, (int32_t) height, bbox,vis_regions) ;

    pmData = (unsigned char *)ximage -> data ;

/* if transparency possible do it again, but this time for image planes only */
    if (vis_image_regions && (vis_image_regions->next) && !allImage)
    {
            ximage_ipm = ReadRegionsInList(disp,&fakeVis,depth,format,
                         (int32_t) width, (int32_t) height,bbox,vis_image_regions) ;
        ipmData = (unsigned char *)ximage_ipm -> data ;
    }
/* Now tranverse the overlay visual windows and test for transparency index.  */
/* If you find one, subsitute the value from the matching image plane pixmap. */

    for (reg = (image_region_type *) first_in_list( vis_regions); reg;
         reg = (image_region_type *) next_in_list( vis_regions))
    {

        if (src_in_overlay( reg, numOverlayVisuals, pOverlayVisuals,
                                 &transparentColor, &transparentType))
        {
         int32_t test = 0 ;
             srcRect_width  = MIN( reg->width + reg->x_vis, bbox.width + bbox.x)
                                 - MAX( reg->x_vis, bbox.x);
             srcRect_height = MIN( reg->height + reg->y_vis, bbox.height
                                 + bbox.y) - MAX( reg->y_vis, bbox.y);
         diff = bbox.x - reg->x_vis;
         srcRect_x = MAX( 0, diff) + (reg->x_vis - reg->x_rootrel - reg->border);
         dst_x     = MAX( 0, -diff) ;
             diff = bbox.y - reg->y_vis;
             srcRect_y = MAX( 0, diff)  + (reg->y_vis - reg->y_rootrel - reg->border);
             dst_y     = MAX( 0, -diff) ;
        /* let's test some pixels for transparency */
         image = XGetImage(disp, reg->win, srcRect_x, srcRect_y,
                           (uint32_t) srcRect_width, (uint32_t) srcRect_height,
                           0xffffffff, ZPixmap);

        /* let's assume byte per pixel for overlay image for now */
             if ((image->depth == 8) && (transparentType == TransparentPixel))
             {
                 unsigned char *pixel_ptr;
                 unsigned char *start_of_line = (unsigned char *) image->data;

                 for (y1 = 0; y1 < srcRect_height; y1++) {
                    pixel_ptr = start_of_line;
                    for (x1 = 0; x1 < srcRect_width; x1++)
                    {
                        if (*pixel_ptr++ == transparentColor)
                        {
                        /*
                            *pmData++ = *ipmData++;
                            *pmData++ = *ipmData++;
                            *pmData++ = *ipmData++;
                        */
                        pixel = (int32_t) XGetPixel(ximage_ipm,dst_x+x1,dst_y+y1) ;
                    XPutPixel(ximage,dst_x+x1, dst_y+y1,(unsigned long)pixel);

                        if(!test){
                           test = 1 ;
                        }
                        }
                        /*
                        else {
                            pmData +=3;
                            ipmData +=3;
                        }
                        */
                    }
                    start_of_line += image->bytes_per_line;
                }
        } else {
                if (transparentType == TransparentPixel) {
                for (y1 = 0; y1 < srcRect_height; y1++) {
                      for (x1 = 0; x1 < srcRect_width; x1++)
                      {
                            int32_t pixel_value = (int32_t) XGetPixel(image, x1, y1);
                            if (pixel_value == transparentColor)
                            {
                            /*
                                *pmData++ = *ipmData++;
                                *pmData++ = *ipmData++;
                                *pmData++ = *ipmData++;
                            */
                        pixel = (int32_t) XGetPixel(ximage_ipm,dst_x+x1,dst_y+y1) ;
                    XPutPixel(ximage,dst_x+x1, dst_y+y1,(unsigned long)pixel);
                        if(!test){
                           test = 1 ;
                        }
                            }
                            /*
                            else {
                                pmData +=3;
                                ipmData +=3;
                            }
                            */
                        }
                    }
                } else {
                    for (y1 = 0; y1 < srcRect_height; y1++) {
                        for (x1 = 0; x1 < srcRect_width; x1++)
                        {
                            int32_t pixel_value = (int32_t) XGetPixel(image, x1, y1);
                            if (pixel_value & transparentColor)
                            {
                            /*
                                *pmData++ = *ipmData++;
                                *pmData++ = *ipmData++;
                                *pmData++ = *ipmData++;
                            */
                     pixel = (int32_t) XGetPixel(ximage_ipm,dst_x+x1,
                                    dst_y+y1) ;
                     XPutPixel(ximage,dst_x+x1, dst_y+y1,(unsigned long)pixel);
                        if(!test){
                           test = 1 ;
                        }
                            }
                            /*
                            else {
                                pmData +=3;
                                ipmData +=3;
                            }
                            */
                        }
                    }
                }
        }
        XDestroyImage (image);
      } /* end of src_in_overlay */
    } /** end transparency **/
    if (ximage_ipm != NULL) {
        XDestroyImage(ximage_ipm);
    }
    destroy_region_list( vis_regions);
    if (vis_image_regions) destroy_region_list( vis_image_regions );
    FreeXVisualInfo(pVisuals, pOverlayVisuals, pImageVisuals);
    XSync(disp, 0);

    return ximage;
}

/** ------------------------------------------------------------------------
        Creates a list of the subwindows of a given window which have a
        different visual than their parents.  The function is recursive.
        This list is used in make_region_list(), which coalesces the
        windows with the same visual into a region.
        image_wins must point to an existing list struct that's already
        been zeroed (zero_list()).
    ------------------------------------------------------------------------ **/
static void make_src_list( disp, image_wins, bbox, curr, x_rootrel, y_rootrel,
                    curr_attrs, pclip)
    Display             *disp;
    list_ptr            image_wins;
    XRectangle          *bbox;                  /* bnding box of area we want */
    Window              curr;
    int32_t                     x_rootrel;              /* pos of curr WRT root */
    int32_t                     y_rootrel;
    XWindowAttributes   *curr_attrs;
    XRectangle          *pclip;                 /* visible part of curr, not */
                                                /* obscurred by ancestors */
{
    XWindowAttributes child_attrs;
    Window root, parent, *child;        /* variables for XQueryTree() */
    Window *save_child_list;            /* variables for XQueryTree() */
    uint32_t nchild;            /* variables for XQueryTree() */
    XRectangle child_clip;              /* vis part of child */
    int32_t curr_clipX, curr_clipY, curr_clipRt, curr_clipBt;

    /* check that win is mapped & not outside bounding box */
    if (curr_attrs->map_state == IsViewable &&
        curr_attrs->class == InputOutput &&
        !( pclip->x >= (bbox->x + bbox->width)  ||
           pclip->y >= (bbox->y + bbox->height) ||
           (pclip->x + pclip->width)  <= bbox->x        ||
           (pclip->y + pclip->height) <= bbox->y)) {

        XQueryTree( disp, curr, &root, &parent, &child, &nchild );
        save_child_list = child;      /* so we can free list when we're done */
        add_window_to_list( image_wins, curr, x_rootrel, y_rootrel,
                            (int32_t) pclip->x, (int32_t) pclip->y,
                            (int32_t) pclip->width, (int32_t) pclip->height,
                            curr_attrs->border_width,curr_attrs->visual,
                            curr_attrs->colormap, parent);


/** ------------------------------------------------------------------------
        set RR coords of right (Rt), left (X), bottom (Bt) and top (Y)
        of rect we clip all children by.  This is our own clip rect (pclip)
        inflicted on us by our parent plus our own borders.  Within the
        child loop, we figure the clip rect for each child by adding in
        it's rectangle (not taking into account the child's borders).
    ------------------------------------------------------------------------ **/
        curr_clipX = MAX( pclip->x, x_rootrel + curr_attrs->border_width);
        curr_clipY = MAX( pclip->y, y_rootrel + curr_attrs->border_width);
        curr_clipRt = MIN(pclip->x + pclip->width,
                                  x_rootrel + curr_attrs->width + 2 * curr_attrs->border_width);

        curr_clipBt = MIN(pclip->y + pclip->height,
                                  y_rootrel + curr_attrs->height + 2 * curr_attrs->border_width);


        while (nchild--) {
            int32_t new_width, new_height;
            int32_t child_xrr, child_yrr;       /* root relative x & y of child */

            XGetWindowAttributes( disp, *child, &child_attrs);

            /* intersect parent & child clip rects */
            child_xrr = x_rootrel + child_attrs.x + curr_attrs->border_width;
            child_clip.x = (short) MAX( curr_clipX, child_xrr);
            new_width = MIN(curr_clipRt,
                        child_xrr + child_attrs.width +
                         2 * child_attrs.border_width) - child_clip.x;

            if (new_width >= 0) {
                child_clip.width = (unsigned short) new_width;

                child_yrr = y_rootrel + child_attrs.y +
                            curr_attrs->border_width;
                child_clip.y = (short) MAX( curr_clipY, child_yrr);
                new_height = MIN(curr_clipBt,
                                         child_yrr + (int32_t) child_attrs.height +
                                         2 * child_attrs.border_width) - child_clip.y;

                if (new_height >= 0) {
                    child_clip.height = (unsigned short) new_height;
                    make_src_list( disp, image_wins, bbox, *child,
                                   child_xrr, child_yrr,
                                   &child_attrs, &child_clip);
                }
            }
            child++;
        }
        XFree( save_child_list);
    }
}


/** ------------------------------------------------------------------------
        This function creates a list of regions which tile a specified
        window.  Each region contains all visible portions of the window
        which are drawn with the same visual.  For example, if the
        window consists of subwindows of two different visual types,
        there will be two regions in the list.
        Returns a pointer to the list.
    ------------------------------------------------------------------------ **/
static list_ptr make_region_list( disp, win, bbox, hasNonDefault,
                             numImageVisuals, pImageVisuals, allImage)
    Display             *disp;
    Window              win;
    XRectangle          *bbox;
    int32_t             *hasNonDefault;
    int32_t                     numImageVisuals;
    XVisualInfo         **pImageVisuals;
    int32_t                     *allImage;
{
    XWindowAttributes   win_attrs;
    list                image_wins;
    list_ptr            image_regions;
    list_ptr            srcs_left;
    image_region_type   *new_reg;
    image_win_type      *base_src, *src;
    Region              bbox_region = XCreateRegion();
    XRectangle          clip;
    int32_t                     image_only;

    int32_t                 count=0 ;

    *hasNonDefault = False;
    XUnionRectWithRegion( bbox, bbox_region, bbox_region);
    XGetWindowAttributes( disp, win, &win_attrs);

    zero_list( &image_wins);
    clip.x = 0;
    clip.y = 0;
    clip.width  = (unsigned short) win_attrs.width;
    clip.height = (unsigned short) win_attrs.height;
    make_src_list( disp, &image_wins, bbox, win,
                   0 /* x_rootrel */, 0 /* y_rootrel */, &win_attrs, &clip);

    image_regions = new_list();
    image_only = (*allImage) ? True:False;

    for (base_src = (image_win_type *) first_in_list( &image_wins); base_src;
         base_src = (image_win_type *) next_in_list( &image_wins))
    {
        /* test for image visual */
        if (!image_only || src_in_image(base_src, numImageVisuals, pImageVisuals))
        {
            /* find a window whose visual hasn't been put in list yet */
            if (!src_in_region_list( base_src, image_regions))
            {
                if (! (new_reg = (image_region_type *)
                                        malloc( sizeof( image_region_type)))) {
                    return (list_ptr) NULL;
                }
                count++;

                new_reg->visible_region = XCreateRegion();
                new_reg->win            = base_src->win;
                new_reg->vis            = base_src->vis;
                new_reg->cmap           = base_src->cmap;
                new_reg->x_rootrel      = base_src->x_rootrel;
                new_reg->y_rootrel      = base_src->y_rootrel;
                new_reg->x_vis          = base_src->x_vis;
                new_reg->y_vis          = base_src->y_vis;
                new_reg->width          = base_src->width;
                new_reg->height         = base_src->height;
                new_reg->border         = base_src->border_width;

                srcs_left = (list_ptr) dup_list_head( &image_wins, START_AT_CURR);
                for (src = (image_win_type *) first_in_list( srcs_left); src;
                     src = (image_win_type *) next_in_list( srcs_left)) {
                    if (SAME_REGIONS( base_src, src)) {
                        add_rect_to_image_region( new_reg, src->x_vis, src->y_vis,
                                                  src->width, src->height);
                    }
                    else {
                        if (!image_only || src_in_image(src, numImageVisuals, pImageVisuals))
                        {
                            subtr_rect_from_image_region( new_reg, src->x_vis,
                                          src->y_vis, src->width, src->height);
                        }
                    }
                }
                XIntersectRegion( bbox_region, new_reg->visible_region,
                                  new_reg->visible_region);
                if (! XEmptyRegion( new_reg->visible_region)) {
                    add_to_list( image_regions, new_reg);
                    if (new_reg->vis != DefaultVisualOfScreen( win_attrs.screen) ||
                        new_reg->cmap != DefaultColormapOfScreen(
                                                            win_attrs.screen)) {
                        *hasNonDefault = True;
                    }
                }
                else {
                    XDestroyRegion( new_reg->visible_region);
                    free( (void *) new_reg);
                }
            }
        } else *allImage = 0;
    }
    delete_list( &image_wins, True);
    XDestroyRegion( bbox_region);
    return image_regions;
}
/** ------------------------------------------------------------------------
        Destructor called from destroy_region_list().
    ------------------------------------------------------------------------ **/
void destroy_image_region( image_region)
    image_region_type *image_region;
{
    XDestroyRegion( image_region->visible_region);
    free( (void *) image_region);
}

/** ------------------------------------------------------------------------
        Destroys the region list, destroying all the regions contained in it.
    ------------------------------------------------------------------------ **/
static void destroy_region_list( rlist)
    list_ptr rlist;
{
    delete_list_destroying( rlist, (DESTRUCT_FUNC_PTR)destroy_image_region);
}


/** ------------------------------------------------------------------------
        Subtracts the specified rectangle from the region in image_region.
        First converts the rectangle to a region of its own, since X
        only provides a way to subtract one region from another, not a
        rectangle from a region.
    ------------------------------------------------------------------------ **/
static void subtr_rect_from_image_region( image_region, x, y, width, height)
    image_region_type *image_region;
    int32_t x;
    int32_t y;
    int32_t width;
    int32_t height;
{
    XRectangle rect;
    Region rect_region;

    rect_region = XCreateRegion();
    rect.x = (short)x;
    rect.y = (short)y;
    rect.width = (unsigned short)width;
    rect.height = (unsigned short)height;
    XUnionRectWithRegion( &rect, rect_region, rect_region);
    XSubtractRegion( image_region->visible_region, rect_region,
                     image_region->visible_region);
    XDestroyRegion( rect_region);
}


/** ------------------------------------------------------------------------
        Adds the specified rectangle to the region in image_region.
    ------------------------------------------------------------------------ **/
static void add_rect_to_image_region( image_region, x, y, width, height)
    image_region_type *image_region;
    int32_t x;
    int32_t y;
    int32_t width;
    int32_t height;
{
    XRectangle rect;

    rect.x = (short) x;
    rect.y = (short) y;
    rect.width = (unsigned short) width;
    rect.height = (unsigned short) height;
    XUnionRectWithRegion( &rect, image_region->visible_region,
                          image_region->visible_region);
}


/** ------------------------------------------------------------------------
        Returns TRUE if the given src's visual is already represented in
        the image_regions list, FALSE otherwise.
    ------------------------------------------------------------------------ **/
static int32_t src_in_region_list( src, image_regions)
    image_win_type *src;
    list_ptr image_regions;
{
    image_region_type   *ir;

    for (ir = (image_region_type *) first_in_list( image_regions); ir;
         ir = (image_region_type *) next_in_list( image_regions)) {
        if (SAME_REGIONS( ir, src)) {

            return 1;
        }
    }

    return 0;
}


/** ------------------------------------------------------------------------
        Makes a new entry in image_wins with the given fields filled in.
    ------------------------------------------------------------------------ **/
static void add_window_to_list( image_wins, w, xrr, yrr, x_vis, y_vis,
                                width, height, border_width,vis, cmap, parent)
    list_ptr    image_wins;
    Window      w;
    int32_t             xrr;
    int32_t     yrr;
    int32_t             x_vis;
    int32_t     y_vis;
    int32_t     width;
    int32_t     height;
    int32_t     border_width;
    Visual      *vis;
    Colormap    cmap;
    Window      parent;
{
    image_win_type      *new_src;

    if ((new_src = (image_win_type *) malloc( sizeof( image_win_type))) == NULL)

        return;

    new_src->win = w;
    new_src->x_rootrel = xrr;
    new_src->y_rootrel = yrr;
    new_src->x_vis = x_vis;
    new_src->y_vis = y_vis;
    new_src->width = width;
    new_src->height = height;
    new_src->border_width = border_width;
    new_src->vis = vis;
    new_src->cmap = cmap;
    new_src->parent = parent;
    add_to_list( image_wins, new_src);
}

/** ------------------------------------------------------------------------
        Returns TRUE if the given src's visual is in the image planes,
        FALSE otherwise.
    ------------------------------------------------------------------------ **/
static int32_t src_in_image( src, numImageVisuals, pImageVisuals)
    image_win_type      *src;
    int32_t                     numImageVisuals;
    XVisualInfo         **pImageVisuals;
{
    int32_t             i;

    for (i = 0 ; i < numImageVisuals ; i++)
    {
        if (pImageVisuals[i]->visual == src->vis)
            return 1;
    }
    return 0;
}


/** ------------------------------------------------------------------------
        Returns TRUE if the given src's visual is in the overlay planes
        and transparency is possible, FALSE otherwise.
    ------------------------------------------------------------------------ **/
static int32_t src_in_overlay( src, numOverlayVisuals, pOverlayVisuals,
                        transparentColor, transparentType)
    image_region_type   *src;
    int32_t                     numOverlayVisuals;
    OverlayInfo         *pOverlayVisuals;
    int32_t                     *transparentColor;
    int32_t                     *transparentType;
{
    int32_t             i;

    for (i = 0 ; i < numOverlayVisuals ; i++)
    {
        if (((pOverlayVisuals[i].pOverlayVisualInfo)->visual == src->vis)
                && (pOverlayVisuals[i].transparentType != None))
        {
            *transparentColor = pOverlayVisuals[i].value;
            *transparentType = pOverlayVisuals[i].transparentType;
            return 1;
        }

        else {
        }

    }
    return 0;
}


/********************** from wsutils.c ******************************/

/******************************************************************************
 *
 * This file contains a set of example utility procedures; procedures that can
 * help a "window-smart" Starbase or PHIGS program determine information about
 * a device, and create image and overlay plane windows.  To use these
 * utilities, #include "wsutils.h" and compile this file and link the results
 * with your program.
 *
 ******************************************************************************/



#define STATIC_GRAY     0x01
#define GRAY_SCALE      0x02
#define PSEUDO_COLOR    0x04
#define TRUE_COLOR      0x10
#define DIRECT_COLOR    0x11


static int32_t  weCreateServerOverlayVisualsProperty = False;


/******************************************************************************
 *
 * GetXVisualInfo()
 *
 * This routine takes an X11 Display, screen number, and returns whether the
 * screen supports transparent overlays and three arrays:
 *
 *      1) All of the XVisualInfo struct's for the screen.
 *      2) All of the OverlayInfo struct's for the screen.
 *      3) An array of pointers to the screen's image plane XVisualInfo
 *         structs.
 *
 * The code below obtains the array of all the screen's visuals, and obtains
 * the array of all the screen's overlay visual information.  It then processes
 * the array of the screen's visuals, determining whether the visual is an
 * overlay or image visual.
 *
 * If the routine sucessfully obtained the visual information, it returns zero.
 * If the routine didn't obtain the visual information, it returns non-zero.
 *
 ******************************************************************************/

int32_t GetXVisualInfo(display, screen, transparentOverlays,
                   numVisuals, pVisuals,
                   numOverlayVisuals, pOverlayVisuals,
                   numImageVisuals, pImageVisuals)

    Display     *display;                   /* Which X server (aka "display"). */
    int32_t             screen;                 /* Which screen of the "display". */
    int32_t             *transparentOverlays;   /* Non-zero if there's at least one
                                         * overlay visual and if at least one
                                         * of those supports a transparent
                                         * pixel. */
    int32_t             *numVisuals;            /* Number of XVisualInfo struct's
                                         * pointed to to by pVisuals. */
    XVisualInfo **pVisuals;             /* All of the device's visuals. */
    int32_t             *numOverlayVisuals;     /* Number of OverlayInfo's pointed
                                         * to by pOverlayVisuals.  If this
                                         * number is zero, the device does
                                         * not have overlay planes. */
    OverlayInfo **pOverlayVisuals;      /* The device's overlay plane visual
                                         * information. */
    int32_t             *numImageVisuals;       /* Number of XVisualInfo's pointed
                                         * to by pImageVisuals. */
    XVisualInfo ***pImageVisuals;       /* The device's image visuals. */
{
    XVisualInfo getVisInfo;             /* Parameters of XGetVisualInfo */
    int32_t             mask;
    XVisualInfo *pVis, **pIVis;         /* Faster, local copies */
    OverlayInfo *pOVis;
    OverlayVisualPropertyRec    *pOOldVis;
    int32_t             nVisuals, nOVisuals;
    Atom        overlayVisualsAtom;     /* Parameters for XGetWindowProperty */
    Atom        actualType;
    unsigned long numLongs, bytesAfter;
    int32_t             actualFormat;
    int32_t             nImageVisualsAlloced;   /* Values to process the XVisualInfo */
    int32_t             imageVisual;            /* array */


    /* First, get the list of visuals for this screen. */
    getVisInfo.screen = screen;
    mask = VisualScreenMask;

    *pVisuals = XGetVisualInfo(display, mask, &getVisInfo, numVisuals);
    if ((nVisuals = *numVisuals) <= 0)
    {
        /* Return that the information wasn't sucessfully obtained: */
        return(1);
    }
    pVis = *pVisuals;


    /* Now, get the overlay visual information for this screen.  To obtain
     * this information, get the SERVER_OVERLAY_VISUALS property.
     */
    overlayVisualsAtom = XInternAtom(display, "SERVER_OVERLAY_VISUALS", True);
    if (overlayVisualsAtom != None)
    {
        /* Since the Atom exists, we can request the property's contents.  The
         * do-while loop makes sure we get the entire list from the X server.
         */
        bytesAfter = 0;
        numLongs = sizeof(OverlayVisualPropertyRec) / 4;
        do
        {
            numLongs += bytesAfter * 4;
            XGetWindowProperty(display, RootWindow(display, screen),
                               overlayVisualsAtom, 0, numLongs, False,
                               overlayVisualsAtom, &actualType, &actualFormat,
                               &numLongs, &bytesAfter, (unsigned char**) pOverlayVisuals);
        } while (bytesAfter > 0);


        /* Calculate the number of overlay visuals in the list. */
        /* *numOverlayVisuals = numLongs / (sizeof(OverlayVisualPropertyRec) / 4); */
        *numOverlayVisuals = numLongs / (sizeof(OverlayVisualPropertyRec) / sizeof(long));
    }
    else
    {
        /* This screen doesn't have overlay planes. */
        *numOverlayVisuals = 0;
        *pOverlayVisuals = NULL;
        *transparentOverlays = 0;
    }


    /* Process the pVisuals array. */
    *numImageVisuals = 0;
    nImageVisualsAlloced = 1;
    pIVis = *pImageVisuals = (XVisualInfo **) malloc(sizeof(XVisualInfo *));
    while (--nVisuals >= 0)
    {
        nOVisuals = *numOverlayVisuals;
        pOVis = *pOverlayVisuals;
        imageVisual = True;
        while (--nOVisuals >= 0)
        {
            pOOldVis = (OverlayVisualPropertyRec *) pOVis;
            if (pVis->visualid == pOOldVis->visualID)
            {
                imageVisual = False;
                pOVis->pOverlayVisualInfo = pVis;
                if (pOVis->transparentType == TransparentPixel)
                    *transparentOverlays = 1;
            }
            pOVis++;
        }
        if (imageVisual)
        {
            if ((*numImageVisuals += 1) > nImageVisualsAlloced)
            {
                nImageVisualsAlloced++;
                *pImageVisuals = (XVisualInfo **)
                    realloc(*pImageVisuals, (nImageVisualsAlloced * sizeof(XVisualInfo *)));
                pIVis = *pImageVisuals + (*numImageVisuals - 1);
            }
            *pIVis++ = pVis;
        }
        pVis++;
    }


    /* Return that the information was sucessfully obtained: */
    return(0);

} /* GetXVisualInfo() */


/******************************************************************************
 *
 * FreeXVisualInfo()
 *
 * This routine frees the data that was allocated by GetXVisualInfo().
 *
 ******************************************************************************/

void FreeXVisualInfo(pVisuals, pOverlayVisuals, pImageVisuals)

    XVisualInfo *pVisuals;
    OverlayInfo *pOverlayVisuals;
    XVisualInfo **pImageVisuals;
{
    XFree(pVisuals);
    if (weCreateServerOverlayVisualsProperty)
        free(pOverlayVisuals);
    else
        XFree(pOverlayVisuals);
    free(pImageVisuals);

} /* FreeXVisualInfo() */