xref: /xsrc/external/mit/libXext/dist/src/Xdbe.c

/******************************************************************************
 *
 * Copyright (c) 1994, 1995  Hewlett-Packard Company
 *
 * 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/or 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 HEWLETT-PACKARD COMPANY 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 Hewlett-Packard
 * Company 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 Hewlett-Packard Company.
 *
 *     Xlib DBE code
 *
 *****************************************************************************/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <X11/Xlibint.h>
#include <X11/extensions/Xext.h>
#include <X11/extensions/extutil.h>
#include <X11/extensions/Xdbe.h>
#include <X11/extensions/dbeproto.h>
#include <limits.h>
#include "reallocarray.h"

static XExtensionInfo _dbe_info_data;
static XExtensionInfo *dbe_info = &_dbe_info_data;
static const char *dbe_extension_name = DBE_PROTOCOL_NAME;

#define DbeCheckExtension(dpy,i,val) \
  XextCheckExtension (dpy, i, dbe_extension_name, val)
#define DbeSimpleCheckExtension(dpy,i) \
  XextSimpleCheckExtension (dpy, i, dbe_extension_name)

#define DbeGetReq(name,req,info) GetReq (name, req); \
        req->reqType = info->codes->major_opcode; \
        req->dbeReqType = X_##name;


/*****************************************************************************
 *                                                                           *
 *			   private utility routines                          *
 *                                                                           *
 *****************************************************************************/

/*
 * find_display - locate the display info block
 */
static int close_display(Display *dpy, XExtCodes *codes);
static char *error_string(Display *dpy, int code, XExtCodes *codes,
			  char *buf, int n);
static XExtensionHooks dbe_extension_hooks = {
    NULL,                               /* create_gc */
    NULL,                               /* copy_gc */
    NULL,                               /* flush_gc */
    NULL,                               /* free_gc */
    NULL,                               /* create_font */
    NULL,                               /* free_font */
    close_display,                      /* close_display */
    NULL,                               /* wire_to_event */
    NULL,                               /* event_to_wire */
    NULL,                               /* error */
    error_string,                       /* error_string */
};

static const char *dbe_error_list[] = {
    "BadBuffer",			/* DbeBadBuffer */
};

static XEXT_GENERATE_FIND_DISPLAY (find_display, dbe_info,
				   dbe_extension_name,
				   &dbe_extension_hooks,
				   DbeNumberEvents, NULL)

static XEXT_GENERATE_CLOSE_DISPLAY (close_display, dbe_info)

static XEXT_GENERATE_ERROR_STRING (error_string, dbe_extension_name,
				   DbeNumberErrors,
				   dbe_error_list)


/*****************************************************************************
 *                                                                           *
 *		       Double-Buffering public interfaces                    *
 *                                                                           *
 *****************************************************************************/

/*
 * XdbeQueryExtension -
 *	Sets major_version_return and minor_verion_return to the major and
 *	minor DBE protocol version supported by the server.  If the DBE
 *	library is compatible with the version returned by the server, this
 *	function returns non-zero.  If dpy does not support the DBE
 *	extension, or if there was an error during communication with the
 *	server, or if the server and library protocol versions are
 *	incompatible, this functions returns zero.  No other Xdbe functions
 *	may be called before this function.   If a client violates this rule,
 *	the effects of all subsequent Xdbe calls are undefined.
 */
Status XdbeQueryExtension (
    Display *dpy,
    int *major_version_return,
    int *minor_version_return)
{
    XExtDisplayInfo *info = find_display (dpy);
    xDbeGetVersionReply rep;
    register xDbeGetVersionReq *req;

    if (!XextHasExtension (info))
        return (Status)0; /* failure */

    LockDisplay (dpy);
    DbeGetReq (DbeGetVersion, req, info);
    req->majorVersion = DBE_MAJOR_VERSION;
    req->minorVersion = DBE_MINOR_VERSION;

    if (!_XReply (dpy, (xReply *) &rep, 0, xTrue)) {
	UnlockDisplay (dpy);
	SyncHandle ();
	return (Status)0; /* failure */
    }
    *major_version_return = rep.majorVersion;
    *minor_version_return = rep.minorVersion;
    UnlockDisplay (dpy);

    SyncHandle ();

    if (*major_version_return != DBE_MAJOR_VERSION)
        return (Status)0; /* failure */
    else
        return (Status)1; /* success */
}


/*
 * XdbeAllocateBackBuffer -
 *	This function returns a drawable ID used to refer to the back buffer
 *	of the specified window.  The swap_action is a hint to indicate the
 *	swap action that will likely be used in subsequent calls to
 *	XdbeSwapBuffers.  The actual swap action used in calls to
 *	XdbeSwapBuffers does not have to be the same as the swap_action
 *	passed to this function, though clients are encouraged to provide
 *	accurate information whenever possible.
 */

XdbeBackBuffer XdbeAllocateBackBufferName(
    Display *dpy,
    Window window,
    XdbeSwapAction swap_action)
{
    XExtDisplayInfo *info = find_display (dpy);
    register xDbeAllocateBackBufferNameReq *req;
    XdbeBackBuffer buffer;

    /* make sure extension is available; if not, return the
     * third parameter (0).
     */
    DbeCheckExtension (dpy, info, (XdbeBackBuffer)0);

    LockDisplay(dpy);
    DbeGetReq(DbeAllocateBackBufferName, req, info);
    req->window = window;
    req->swapAction = (unsigned char)swap_action;
    req->buffer = buffer = XAllocID (dpy);

    UnlockDisplay (dpy);
    SyncHandle ();
    return buffer;

} /* XdbeAllocateBackBufferName() */

/*
 * XdbeDeallocateBackBufferName -
 *	This function frees a drawable ID, buffer, that was obtained via
 *	XdbeAllocateBackBufferName.  The buffer must refer to the back buffer
 *	of the specified window, or a protocol error results.
 */
Status XdbeDeallocateBackBufferName (
    Display *dpy,
    XdbeBackBuffer buffer)
{
    XExtDisplayInfo *info = find_display (dpy);
    register xDbeDeallocateBackBufferNameReq *req;

    DbeCheckExtension (dpy, info, (Status)0 /* failure */);

    LockDisplay (dpy);
    DbeGetReq (DbeDeallocateBackBufferName, req, info);
    req->buffer = buffer;
    UnlockDisplay (dpy);
    SyncHandle ();

    return (Status)1; /* success */
}


/*
 * XdbeSwapBuffers -
 *	This function swaps the front and back buffers for a list of windows.
 *	The argument num_windows specifies how many windows are to have their
 *	buffers swapped; it is the number of elements in the swap_info array.
 *	The argument swap_info specifies the information needed per window
 *	to do the swap.
 */
Status XdbeSwapBuffers (
    Display *dpy,
    XdbeSwapInfo *swap_info,
    int num_windows)
{
    XExtDisplayInfo *info = find_display (dpy);
    register xDbeSwapBuffersReq *req;
    int i;

    DbeCheckExtension (dpy, info, (Status)0 /* failure */);

    LockDisplay (dpy);
    DbeGetReq (DbeSwapBuffers, req, info);
    req->length += 2*num_windows;
    req->n = num_windows;

    /* We need to handle 64-bit machines, where we can not use PackData32
     * directly because info would be lost in translating from 32- to 64-bit.
     * Instead we send data via a loop that accounts for the translation.
     */
    for (i = 0; i < num_windows; i++)
    {
        char tmp[4];
        Data32 (dpy, (long *)&swap_info[i].swap_window, 4);
        tmp[0] = swap_info[i].swap_action;
        Data (dpy, (char *)tmp, 4);
    }

    UnlockDisplay (dpy);
    SyncHandle ();


    return (Status)1; /* success */

} /* XdbeSwapBuffers() */


/*
 * XdbeBeginIdiom -
 *	This function marks the beginning of an idiom sequence.
 */
Status XdbeBeginIdiom (Display *dpy)
{
    XExtDisplayInfo *info = find_display(dpy);
    register xDbeBeginIdiomReq *req;

    DbeCheckExtension (dpy, info, (Status)0 /* failure */);

    LockDisplay (dpy);
    DbeGetReq (DbeBeginIdiom, req, info);
    UnlockDisplay (dpy);
    SyncHandle ();

    return (Status)1; /* success */
}


/*
 * XdbeEndIdiom -
 *	This function marks the end of an idiom sequence.
 */
Status XdbeEndIdiom (Display *dpy)
{
    XExtDisplayInfo *info = find_display(dpy);
    register xDbeEndIdiomReq *req;

    DbeCheckExtension (dpy, info, (Status)0 /* failure */);

    LockDisplay (dpy);
    DbeGetReq (DbeEndIdiom, req, info);
    UnlockDisplay (dpy);
    SyncHandle ();

    return (Status)1; /* success */
}


/*
 * XdbeGetVisualInfo -
 *	This function returns information about which visuals support
 *	double buffering.  The argument num_screens specifies how many
 *	elements there are in the screen_specifiers list.  Each drawable
 *	in screen_specifiers designates a screen for which the supported
 *	visuals are being requested.  If num_screens is zero, information
 *	for all screens is requested.  In this case, upon return from this
 *	function, num_screens will be set to the number of screens that were
 *	found.  If an error occurs, this function returns NULL, else it returns
 *	a pointer to a list of XdbeScreenVisualInfo structures of length
 *	num_screens.  The nth element in the returned list corresponds to the
 *	nth drawable in the screen_specifiers list, unless num_screens was
 *	passed in with the value zero, in which case the nth element in the
 *	returned list corresponds to the nth screen of the server, starting
 *	with screen zero.
 */
XdbeScreenVisualInfo *XdbeGetVisualInfo (
    Display        *dpy,
    Drawable       *screen_specifiers,
    int            *num_screens)  /* SEND and RETURN */
{
    XExtDisplayInfo *info = find_display(dpy);
    register xDbeGetVisualInfoReq *req;
    xDbeGetVisualInfoReply rep;
    XdbeScreenVisualInfo *scrVisInfo;
    int i;

    DbeCheckExtension (dpy, info, (XdbeScreenVisualInfo *)NULL);

    LockDisplay (dpy);

    DbeGetReq(DbeGetVisualInfo, req, info);
    req->length = 2 + *num_screens;
    req->n      = *num_screens;
    Data32 (dpy, screen_specifiers, (*num_screens * sizeof (CARD32)));

    if (!_XReply (dpy, (xReply *) &rep, 0, xFalse)) {
        UnlockDisplay (dpy);
        SyncHandle ();
        return NULL;
    }

    /* return the number of screens actually found if we
     * requested information about all screens (*num_screens == 0)
     */
    if (*num_screens == 0)
       *num_screens = rep.m;

    /* allocate list of visual information to be returned */
    if ((*num_screens > 0) && (*num_screens < 65536))
        scrVisInfo = Xcalloc(*num_screens, sizeof(XdbeScreenVisualInfo));
    else
        scrVisInfo = NULL;
    if (scrVisInfo == NULL) {
        _XEatDataWords(dpy, rep.length);
        UnlockDisplay (dpy);
        SyncHandle ();
        return NULL;
    }

    for (i = 0; i < *num_screens; i++)
    {
        int j;
        unsigned long c;

        _XRead32 (dpy, (long *) &c, sizeof(CARD32));

        if (c < 65536) {
            scrVisInfo[i].count = c;
            scrVisInfo[i].visinfo = Xmallocarray(c, sizeof(XdbeVisualInfo));
        } else
            scrVisInfo[i].visinfo = NULL;

        /* if we can not allocate the list of visual/depth info
         * then free the lists that we already allocated as well
         * as the visual info list itself
         */
        if (scrVisInfo[i].visinfo == NULL) {
            for (j = 0; j < i; j++) {
                Xfree (scrVisInfo[j].visinfo);
            }
            Xfree (scrVisInfo);
            _XEatDataWords(dpy, rep.length);
            UnlockDisplay (dpy);
            SyncHandle ();
            return NULL;
        }

        /* Read the visual info item into the wire structure.  Then copy each
         * element into the library structure.  The element sizes and/or
         * padding may be different in the two structures.
         */
        for (j = 0; j < scrVisInfo[i].count; j++) {
            xDbeVisInfo xvi;

            _XRead (dpy, (char *)&xvi, sizeof(xDbeVisInfo));
            scrVisInfo[i].visinfo[j].visual    = xvi.visualID;
            scrVisInfo[i].visinfo[j].depth     = xvi.depth;
            scrVisInfo[i].visinfo[j].perflevel = xvi.perfLevel;
        }

    }

    UnlockDisplay (dpy);
    SyncHandle ();
    return scrVisInfo;

} /* XdbeGetVisualInfo() */


/*
 * XdbeFreeVisualInfo -
 *	This function frees the list of XdbeScreenVisualInfo returned by the
 *	function XdbeGetVisualInfo.
 */
void XdbeFreeVisualInfo(XdbeScreenVisualInfo *visual_info)
{
    if (visual_info == NULL) {
        return;
    }

    if (visual_info->visinfo) {
        XFree(visual_info->visinfo);
    }

    XFree(visual_info);
}


/*
 * XdbeGetBackBufferAttributes -
 *	This function returns the attributes associated with the specified
 *	buffer.
 */
XdbeBackBufferAttributes *XdbeGetBackBufferAttributes(
    Display *dpy,
    XdbeBackBuffer buffer)
{
    XExtDisplayInfo *info = find_display(dpy);
    register xDbeGetBackBufferAttributesReq *req;
    xDbeGetBackBufferAttributesReply rep;
    XdbeBackBufferAttributes *attr;

    DbeCheckExtension(dpy, info, (XdbeBackBufferAttributes *)NULL);

    if (!(attr = Xmalloc(sizeof(XdbeBackBufferAttributes)))) {
        return NULL;
    }

    LockDisplay(dpy);
    DbeGetReq(DbeGetBackBufferAttributes, req, info);
    req->buffer = buffer;

    if (!_XReply (dpy, (xReply *) &rep, 0, xTrue)) {
        UnlockDisplay (dpy);
        SyncHandle ();
	Xfree(attr);
        return NULL;
    }
    attr->window = rep.attributes;

    UnlockDisplay (dpy);
    SyncHandle ();

    return attr;
}