Initial revision

1 files changed, 2573 insertions, 0 deletions

diff --git a/mi/mibank.c b/mi/mibank.c
new file mode 100644
index 000000000..a6e1942c2
--- /dev/null
+++ b/mi/mibank.c
@@ -0,0 +1,2573 @@
+/*
+ * Copyright 1997 through 2003 by Marc Aurele La France (TSI @ UQV), tsi@xfree86.org
+ *
+ * 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 Marc Aurele La France not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  Marc Aurele La France makes no representations
+ * about the suitability of this software for any purpose.  It is provided
+ * "as-is" without express or implied warranty.
+ *
+ * MARC AURELE LA FRANCE DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.  IN NO
+ * EVENT SHALL MARC AURELE LA FRANCE BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * Copyright 1990,91,92,93 by Thomas Roell, Germany.
+ * Copyright 1991,92,93    by SGCS (Snitily Graphics Consulting Services), USA.
+ *
+ * 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 Thomas Roell nor
+ * SGCS be used in advertising or publicity pertaining to distribution
+ * of the software without specific, written prior permission.
+ * Thomas Roell nor SGCS makes no representations about the suitability
+ * of this software for any purpose. It is provided "as is" without
+ * express or implied warranty.
+ *
+ * THOMAS ROELL AND SGCS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL THOMAS ROELL OR SGCS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+ * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $XFree86: xc/programs/Xserver/mi/mibank.c,v 1.13 2003/01/01 19:16:42 tsi Exp $ */
+
+/*
+ * This thing originated from an idea of Edwin Goei and his bank switching
+ * code for the DEC TX board.
+ */
+
+/*
+ * Heavily modified for the XFree86 Project to turn this into an mi wrapper.
+ * ---  Marc Aurele La France (tsi@xfree86.org)
+ */
+
+/*
+ * "Heavily modified", indeed!  By the time this is finalized, there probably
+ * won't be much left of Roell's code...
+ *
+ * Miscellaneous notes:
+ * - Pixels with imbedded bank boundaries are required to be off-screen.  There
+ *   >might< be a way to fool the underlying framebuffer into dealing with
+ *   partial pixels.
+ * - Plans to generalise this to do (hardware) colour plane switching have been
+ *   dropped due to colour flashing concerns.
+ *
+ * TODO:
+ * - Allow miModifyBanking() to change BankSize and nBankDepth.
+ * - Re-instate shared and double banking for framebuffers whose pixmap formats
+ *   don't describe how the server "sees" the screen.
+ * - Remove remaining assumptions that a pixmap's devPrivate field points
+ *   directly to its pixel data.
+ */
+
+/* #define NO_ALLOCA 1 */
+
+#include "servermd.h"
+#include "gcstruct.h"
+#include "pixmapstr.h"
+#include "scrnintstr.h"
+#include "windowstr.h"
+#include "mi.h"
+#include "mibank.h"
+
+#define BANK_SINGLE 0
+#define BANK_SHARED 1
+#define BANK_DOUBLE 2
+#define BANK_NOBANK 3
+
+typedef struct _miBankScreen
+{
+    miBankInfoRec BankInfo;
+    unsigned int  nBankBPP;
+    unsigned int  type;
+
+    unsigned long nBitsPerBank;
+    unsigned long nBitsPerScanline;
+    unsigned long nPixelsPerScanlinePadUnit;
+
+    PixmapPtr     pScreenPixmap;
+    PixmapPtr     pBankPixmap;
+    GCPtr         pBankGC;
+
+    int           nBanks, maxRects;
+    RegionPtr     *pBanks;
+
+    pointer       pbits;
+
+    /*
+     * Screen Wrappers
+     */
+    CreateScreenResourcesProcPtr  CreateScreenResources;
+    ModifyPixmapHeaderProcPtr     ModifyPixmapHeader;
+    CloseScreenProcPtr            CloseScreen;
+    GetImageProcPtr               GetImage;
+    GetSpansProcPtr               GetSpans;
+    CreateGCProcPtr               CreateGC;
+    PaintWindowBackgroundProcPtr  PaintWindowBackground;
+    PaintWindowBorderProcPtr      PaintWindowBorder;
+    CopyWindowProcPtr             CopyWindow;
+    BSFuncRec                     BackingStoreFuncs;
+} miBankScreenRec, *miBankScreenPtr;
+
+typedef struct _miBankGC
+{
+    GCOps     *wrappedOps,   *unwrappedOps;
+    GCFuncs   *wrappedFuncs, *unwrappedFuncs;
+
+    Bool      fastCopy, fastPlane;
+
+    RegionPtr pBankedClips[1];
+} miBankGCRec, *miBankGCPtr;
+
+typedef struct _miBankQueue
+{
+    Bool           fastBlit;
+    unsigned short srcBankNo;
+    unsigned short dstBankNo;
+    short          x;
+    short          y;
+    short          w;
+    short          h;
+} miBankQueue;
+
+/*
+ * CAVEAT:  This banking scheme requires that the DDX store Pixmap data in the
+ *          server's address space.
+ */
+
+#define ModifyPixmap(_pPix, _width, _devKind, _pbits) \
+    (*pScreen->ModifyPixmapHeader)((_pPix), \
+        (_width), -1, -1, -1, (_devKind), (_pbits))
+
+#define SET_SINGLE_BANK(_pPix, _width, _devKind, _no) \
+    ModifyPixmap(_pPix, _width, _devKind, \
+        (char *)pScreenPriv->BankInfo.pBankA + \
+        (*pScreenPriv->BankInfo.SetSourceAndDestinationBanks)(pScreen, (_no)) - \
+        (pScreenPriv->BankInfo.BankSize * (_no)))
+
+#define SET_SOURCE_BANK(_pPix, _width, _devKind, _no) \
+    ModifyPixmap(_pPix, _width, _devKind, \
+        (char *)pScreenPriv->BankInfo.pBankA + \
+        (*pScreenPriv->BankInfo.SetSourceBank)(pScreen, (_no)) - \
+        (pScreenPriv->BankInfo.BankSize * (_no)))
+
+#define SET_DESTINATION_BANK(_pPix, _width, _devKind, _no) \
+    ModifyPixmap(_pPix, _width, _devKind, \
+        (char *)pScreenPriv->BankInfo.pBankB + \
+        (*pScreenPriv->BankInfo.SetDestinationBank)(pScreen, (_no)) - \
+        (pScreenPriv->BankInfo.BankSize * (_no)))
+
+#define ALLOCATE_LOCAL_ARRAY(atype, ntype) \
+    (atype *)ALLOCATE_LOCAL((ntype) * sizeof(atype))
+
+static int           miBankScreenIndex;
+static int           miBankGCIndex;
+static unsigned long miBankGeneration = 0;
+
+#define BANK_SCRPRIVLVAL pScreen->devPrivates[miBankScreenIndex].ptr
+
+#define BANK_SCRPRIVATE ((miBankScreenPtr)(BANK_SCRPRIVLVAL))
+
+#define BANK_GCPRIVLVAL(pGC) (pGC)->devPrivates[miBankGCIndex].ptr
+
+#define BANK_GCPRIVATE(pGC) ((miBankGCPtr)(BANK_GCPRIVLVAL(pGC)))
+
+#define PIXMAP_STATUS(_pPix) \
+    pointer pbits = (_pPix)->devPrivate.ptr
+
+#define PIXMAP_SAVE(_pPix) \
+    PIXMAP_STATUS(_pPix); \
+    if (pbits == (pointer)pScreenPriv) \
+        (_pPix)->devPrivate.ptr = pScreenPriv->pbits
+
+#define PIXMAP_RESTORE(_pPix) \
+    (_pPix)->devPrivate.ptr = pbits
+
+#define BANK_SAVE \
+    int width   = pScreenPriv->pBankPixmap->drawable.width; \
+    int devKind = pScreenPriv->pBankPixmap->devKind; \
+    PIXMAP_SAVE(pScreenPriv->pBankPixmap)
+
+#define BANK_RESTORE \
+    pScreenPriv->pBankPixmap->drawable.width = width; \
+    pScreenPriv->pBankPixmap->devKind = devKind; \
+    PIXMAP_RESTORE(pScreenPriv->pBankPixmap)
+
+#define SCREEN_STATUS \
+    PIXMAP_STATUS(pScreenPriv->pScreenPixmap)
+
+#define SCREEN_SAVE \
+    PIXMAP_SAVE(pScreenPriv->pScreenPixmap)
+
+#define SCREEN_RESTORE \
+    PIXMAP_RESTORE(pScreenPriv->pScreenPixmap)
+
+#define SCREEN_INIT \
+    miBankScreenPtr pScreenPriv = BANK_SCRPRIVATE
+
+#define SCREEN_UNWRAP(field) \
+    pScreen->field = pScreenPriv->field
+
+#define SCREEN_WRAP(field, wrapper) \
+    pScreenPriv->field = pScreen->field; \
+    pScreen->field     = wrapper
+
+#define GC_INIT(pGC) \
+    miBankGCPtr pGCPriv = BANK_GCPRIVATE(pGC)
+
+#define GC_UNWRAP(pGC) \
+    pGCPriv->unwrappedOps   = (pGC)->ops; \
+    pGCPriv->unwrappedFuncs = (pGC)->funcs; \
+    (pGC)->ops              = pGCPriv->wrappedOps; \
+    (pGC)->funcs            = pGCPriv->wrappedFuncs
+
+#define GC_WRAP(pGC) \
+    pGCPriv->wrappedOps   = (pGC)->ops; \
+    pGCPriv->wrappedFuncs = (pGC)->funcs; \
+    (pGC)->ops            = pGCPriv->unwrappedOps; \
+    (pGC)->funcs          = pGCPriv->unwrappedFuncs
+
+#define IS_BANKED(pDrawable) \
+    ((pbits == (pointer)pScreenPriv) && \
+     (((DrawablePtr)(pDrawable))->type == DRAWABLE_WINDOW))
+
+#define CLIP_SAVE \
+    RegionPtr pOrigCompositeClip = pGC->pCompositeClip
+
+#define CLIP_RESTORE \
+    pGC->pCompositeClip = pOrigCompositeClip
+
+#define GCOP_INIT \
+    ScreenPtr pScreen = pGC->pScreen; \
+    SCREEN_INIT; \
+    GC_INIT(pGC)
+
+#define GCOP_UNWRAP \
+    GC_UNWRAP(pGC)
+
+#define GCOP_WRAP \
+    GC_WRAP(pGC)
+
+#define GCOP_TOP_PART \
+    for (i = 0;  i < pScreenPriv->nBanks;  i++) \
+    { \
+        if (!(pGC->pCompositeClip = pGCPriv->pBankedClips[i])) \
+            continue; \
+        GCOP_UNWRAP; \
+        SET_SINGLE_BANK(pScreenPriv->pScreenPixmap, -1, -1, i)
+
+#define GCOP_BOTTOM_PART \
+        GCOP_WRAP; \
+    }
+
+#define GCOP_SIMPLE(statement) \
+    if (nArray > 0) \
+    { \
+        GCOP_INIT; \
+        SCREEN_SAVE; \
+        if (!IS_BANKED(pDrawable)) \
+        { \
+            GCOP_UNWRAP; \
+            statement; \
+            GCOP_WRAP; \
+        } \
+        else \
+        { \
+            int i; \
+            CLIP_SAVE; \
+            GCOP_TOP_PART; \
+            statement; \
+            GCOP_BOTTOM_PART; \
+            CLIP_RESTORE; \
+        } \
+        SCREEN_RESTORE; \
+    }
+
+#define GCOP_0D_ARGS mode,
+#define GCOP_1D_ARGS
+#define GCOP_2D_ARGS shape, mode, 
+
+#define GCOP_COMPLEX(aop, atype) \
+    if (nArray > 0) \
+    { \
+        GCOP_INIT; \
+        SCREEN_SAVE; \
+        if (!IS_BANKED(pDrawable)) \
+        { \
+            GCOP_UNWRAP; \
+            (*pGC->ops->aop)(pDrawable, pGC, GCOP_ARGS nArray, pArray); \
+            GCOP_WRAP; \
+        } \
+        else \
+        { \
+            atype *aarg = pArray, *acopy; \
+            int   i; \
+            CLIP_SAVE; \
+            if ((acopy = ALLOCATE_LOCAL_ARRAY(atype, nArray))) \
+                aarg = acopy; \
+            GCOP_TOP_PART; \
+            if (acopy) \
+                memcpy(acopy, pArray, nArray * sizeof(atype)); \
+            (*pGC->ops->aop)(pDrawable, pGC, GCOP_ARGS nArray, aarg); \
+            GCOP_BOTTOM_PART; \
+            DEALLOCATE_LOCAL(acopy); \
+            CLIP_RESTORE; \
+        } \
+        SCREEN_RESTORE; \
+    }
+
+/*********************
+ * Utility functions *
+ *********************/
+
+static int
+miBankOf(
+    miBankScreenPtr pScreenPriv,
+    int             x,
+    int             y
+)
+{
+    int iBank = ((x * (int)pScreenPriv->nBankBPP) +
+                 (y * (long)pScreenPriv->nBitsPerScanline)) /
+                (long)pScreenPriv->nBitsPerBank;
+
+    if (iBank < 0)
+        iBank = 0;
+    else if (iBank >= pScreenPriv->nBanks)
+        iBank = pScreenPriv->nBanks - 1;
+
+    return iBank;
+}
+
+#define FirstBankOf(_x, _y) miBankOf(pScreenPriv, (_x), (_y))
+#define  LastBankOf(_x, _y) miBankOf(pScreenPriv, (_x) - 1, (_y))
+
+/* Determine banking type from the BankInfoRec */
+static unsigned int
+miBankDeriveType(
+    ScreenPtr     pScreen,
+    miBankInfoPtr pBankInfo
+)
+{
+    unsigned int type;
+
+    if (pBankInfo->pBankA == pBankInfo->pBankB)
+    {
+        if (pBankInfo->SetSourceBank == pBankInfo->SetDestinationBank)
+        {
+            if (pBankInfo->SetSourceAndDestinationBanks !=
+                pBankInfo->SetSourceBank)
+                return BANK_NOBANK;
+
+            type = BANK_SINGLE;
+        }
+        else
+        {
+            if (pBankInfo->SetSourceAndDestinationBanks ==
+                pBankInfo->SetDestinationBank)
+                return BANK_NOBANK;
+            if (pBankInfo->SetSourceAndDestinationBanks ==
+                pBankInfo->SetSourceBank)
+                return BANK_NOBANK;
+
+            type = BANK_SHARED;
+        }
+    }
+    else
+    {
+        if ((unsigned long)abs((char *)pBankInfo->pBankA -
+                               (char *)pBankInfo->pBankB) < pBankInfo->BankSize)
+            return BANK_NOBANK;
+
+        if (pBankInfo->SetSourceBank == pBankInfo->SetDestinationBank)
+        {
+            if (pBankInfo->SetSourceAndDestinationBanks !=
+                pBankInfo->SetSourceBank)
+                return BANK_NOBANK;
+        }
+        else
+        {
+            if (pBankInfo->SetSourceAndDestinationBanks ==
+                pBankInfo->SetDestinationBank)
+                return BANK_NOBANK;
+        }
+
+        type = BANK_DOUBLE;
+    }
+
+    /*
+     * Internal limitation:  Currently, only single banking is supported when
+     * the pixmap format and the screen's pixel format are different.  The
+     * following test is only partially successful at detecting this condition.
+     */
+    if (pBankInfo->nBankDepth != pScreen->rootDepth)
+        type = BANK_SINGLE;
+
+    return type;
+}
+
+/* Least common multiple */
+static unsigned int
+miLCM(
+    unsigned int x,
+    unsigned int y
+)
+{
+    unsigned int m = x, n = y, o;
+
+    while ((o = m % n))
+    {
+        m = n;
+        n = o;
+    }
+
+    return (x / n) * y;
+}
+
+/******************
+ * GCOps wrappers *
+ ******************/
+
+static void
+miBankFillSpans(
+    DrawablePtr pDrawable,
+    GCPtr       pGC,
+    int         nArray,
+    DDXPointPtr pptInit,
+    int         *pwidthInit,
+    int         fSorted
+)
+{
+    GCOP_SIMPLE((*pGC->ops->FillSpans)(pDrawable, pGC,
+        nArray, pptInit, pwidthInit, fSorted));
+}
+
+static void
+miBankSetSpans(
+    DrawablePtr pDrawable,
+    GCPtr       pGC,
+    char        *psrc,
+    DDXPointPtr ppt,
+    int         *pwidth,
+    int         nArray,
+    int         fSorted
+)
+{
+    GCOP_SIMPLE((*pGC->ops->SetSpans)(pDrawable, pGC, psrc,
+        ppt, pwidth, nArray, fSorted));
+}
+
+static void
+miBankPutImage(
+    DrawablePtr pDrawable,
+    GCPtr       pGC,
+    int         depth,
+    int         x,
+    int         y,
+    int         w,
+    int         h,
+    int         leftPad,
+    int         format,
+    char        *pImage
+)
+{
+    if ((w > 0) && (h > 0))
+    {
+        GCOP_INIT;
+        SCREEN_SAVE;
+
+        if (!IS_BANKED(pDrawable))
+        {
+            GCOP_UNWRAP;
+
+            (*pGC->ops->PutImage)(pDrawable, pGC, depth, x, y, w, h,
+                leftPad, format, pImage);
+
+            GCOP_WRAP;
+        }
+        else
+        {
+            int i, j;
+
+            CLIP_SAVE;
+
+            i = FirstBankOf(x + pDrawable->x,     y + pDrawable->y);
+            j =  LastBankOf(x + pDrawable->x + w, y + pDrawable->y + h);
+            for (;  i <= j;  i++)
+            {
+                if (!(pGC->pCompositeClip = pGCPriv->pBankedClips[i]))
+                    continue;
+
+                GCOP_UNWRAP;
+
+                SET_SINGLE_BANK(pScreenPriv->pScreenPixmap, -1, -1, i);
+
+                (*pGC->ops->PutImage)(pDrawable, pGC, depth, x, y, w, h,
+                    leftPad, format, pImage);
+
+                GCOP_WRAP;
+            }
+
+            CLIP_RESTORE;
+        }
+
+        SCREEN_RESTORE;
+    }
+}
+
+/*
+ * Here the CopyArea/CopyPlane wrappers.  First off, we have to clip against
+ * the source in order to make the minimal number of copies in case of slow
+ * systems.  Also the exposure handling is quite tricky.  Special attention
+ * is to be given to the way the copies are sequenced.  The list of boxes after
+ * the source clip is used to build a workqueue, that contains the atomic
+ * copies (i.e. only from one bank to one bank).  Doing so produces a minimal
+ * list of things to do.
+ */
+static RegionPtr
+miBankCopy(
+    DrawablePtr   pSrc,
+    DrawablePtr   pDst,
+    GCPtr         pGC,
+    int           srcx,
+    int           srcy,
+    int           w,
+    int           h,
+    int           dstx,
+    int           dsty,
+    unsigned long plane,
+    Bool          SinglePlane
+)
+{
+    int         cx1, cy1, cx2, cy2;
+    int         ns, nd, nse, nde, dx, dy, xorg = 0, yorg = 0;
+    int         maxWidth = 0, maxHeight = 0, paddedWidth = 0;
+    int         nBox, nBoxClipSrc, nBoxClipDst, nQueue;
+    BoxPtr      pBox, pBoxClipSrc, pBoxClipDst;
+    BoxRec      fastBox, ccBox;
+    RegionPtr   ret = NULL, prgnSrcClip = NULL;
+    RegionRec   rgnDst;
+    char        *pImage = NULL;
+    miBankQueue *pQueue, *pQueueNew, *Queue;
+    miBankQueue *pQueueTmp, *pQueueNext, *pQueueBase;
+    Bool        fastBlit, freeSrcClip, fastClip;
+    Bool        fExpose = FALSE, fastExpose = FALSE;
+
+    GCOP_INIT;
+    SCREEN_SAVE;
+
+    if (!IS_BANKED(pSrc) && !IS_BANKED(pDst))
+    {
+        GCOP_UNWRAP;
+
+        if (SinglePlane)
+            ret = (*pGC->ops->CopyPlane)(pSrc, pDst, pGC,
+                srcx, srcy, w, h, dstx, dsty, plane);
+        else
+            ret = (*pGC->ops->CopyArea)(pSrc, pDst, pGC,
+                srcx, srcy, w, h, dstx, dsty);
+
+        GCOP_WRAP;
+    }
+    else if (!IS_BANKED(pDst))
+    {
+        fExpose = pGC->fExpose;
+        pGC->fExpose = FALSE;
+
+        xorg = pSrc->x;
+        yorg = pSrc->y;
+        dx   = dstx - srcx;
+        dy   = dsty - srcy;
+        srcx += xorg;
+        srcy += yorg;
+
+        ns = FirstBankOf(srcx,     srcy);
+        nse = LastBankOf(srcx + w, srcy + h);
+        for (;  ns <= nse;  ns++)
+        {
+            if (!pScreenPriv->pBanks[ns])
+                continue;
+
+            nBox = REGION_NUM_RECTS(pScreenPriv->pBanks[ns]);
+            pBox = REGION_RECTS(pScreenPriv->pBanks[ns]);
+
+            for (;  nBox--;  pBox++)
+            {
+                cx1 = max(pBox->x1, srcx);
+                cy1 = max(pBox->y1, srcy);
+                cx2 = min(pBox->x2, srcx + w);
+                cy2 = min(pBox->y2, srcy + h);
+
+                if ((cx1 >= cx2) || (cy1 >= cy2))
+                    continue;
+
+                GCOP_UNWRAP;
+
+                SET_SINGLE_BANK(pScreenPriv->pScreenPixmap, -1, -1, ns);
+
+                if (SinglePlane)
+                    (*pGC->ops->CopyPlane)(pSrc, pDst, pGC,
+                        cx1 - xorg, cy1 - yorg,
+                        cx2 - cx1, cy2 - cy1,
+                        cx1 + dx - xorg, cy1 + dy - yorg, plane);
+                else
+                    (*pGC->ops->CopyArea)(pSrc, pDst, pGC,
+                        cx1 - xorg, cy1 - yorg,
+                        cx2 - cx1, cy2 - cy1,
+                        cx1 + dx - xorg, cy1 + dy - yorg);
+
+                GCOP_WRAP;
+            }
+        }
+
+        pGC->fExpose = fExpose;
+        srcx -= xorg;
+        srcy -= yorg;
+    }
+    else if (!IS_BANKED(pSrc))
+    {
+        CLIP_SAVE;
+
+        if (pGC->miTranslate)
+        {
+            xorg = pDst->x;
+            yorg = pDst->y;
+        }
+        dx = srcx - dstx;
+        dy = srcy - dsty;
+        dstx += xorg;
+        dsty += yorg;
+
+        nd = FirstBankOf(dstx,     dsty);
+        nde = LastBankOf(dstx + w, dsty + h);
+        for (;  nd <= nde;  nd++)
+        {
+            if (!(pGC->pCompositeClip = pGCPriv->pBankedClips[nd]))
+                continue;
+
+            /*
+             * It's faster to let the lower-level CopyArea do the clipping
+             * within each bank.
+             */
+            nBox = REGION_NUM_RECTS(pScreenPriv->pBanks[nd]);
+            pBox = REGION_RECTS(pScreenPriv->pBanks[nd]);
+
+            for (;  nBox--;  pBox++)
+            {
+                cx1 = max(pBox->x1, dstx);
+                cy1 = max(pBox->y1, dsty);
+                cx2 = min(pBox->x2, dstx + w);
+                cy2 = min(pBox->y2, dsty + h);
+
+                if ((cx1 >= cx2) || (cy1 >= cy2))
+                    continue;
+
+                GCOP_UNWRAP;
+
+                SET_SINGLE_BANK(pScreenPriv->pScreenPixmap, -1, -1, nd);
+
+                if (SinglePlane)
+                    (*pGC->ops->CopyPlane)(pSrc, pDst, pGC,
+                        cx1 + dx - xorg, cy1 + dy - yorg,
+                        cx2 - cx1, cy2 - cy1,
+                        cx1 - xorg, cy1 - yorg, plane);
+                else
+                    (*pGC->ops->CopyArea)(pSrc, pDst, pGC,
+                        cx1 + dx - xorg, cy1 + dy - yorg,
+                        cx2 - cx1, cy2 - cy1,
+                        cx1 - xorg, cy1 - yorg);
+
+                GCOP_WRAP;
+            }
+        }
+
+        CLIP_RESTORE;
+    }
+    else /* IS_BANKED(pSrc) && IS_BANKED(pDst) */
+    {
+        CLIP_SAVE;
+
+        fExpose = pGC->fExpose;
+
+        fastBox.x1 = srcx + pSrc->x;
+        fastBox.y1 = srcy + pSrc->y;
+        fastBox.x2 = fastBox.x1 + w;
+        fastBox.y2 = fastBox.y1 + h;
+
+        dx = dstx - fastBox.x1;
+        dy = dsty - fastBox.y1;
+        if (pGC->miTranslate)
+        {
+            xorg = pDst->x;
+            yorg = pDst->y;
+        }
+
+        /*
+         * Clip against the source.  Otherwise we will blit too much for SINGLE
+         * and SHARED banked systems.
+         */
+        freeSrcClip = FALSE;
+        fastClip    = FALSE;
+        fastExpose  = FALSE;
+
+        if (pGC->subWindowMode != IncludeInferiors)
+            prgnSrcClip = &((WindowPtr)pSrc)->clipList;
+        else if (!((WindowPtr)pSrc)->parent)
+            fastClip = TRUE;
+        else if ((pSrc == pDst) && (pGC->clientClipType == CT_NONE))
+            prgnSrcClip = pGC->pCompositeClip;
+        else
+        {
+            prgnSrcClip = NotClippedByChildren((WindowPtr)pSrc);
+            freeSrcClip = TRUE;
+        }
+
+        if (fastClip)
+        {
+            fastExpose = TRUE;
+
+            /*
+             * Clip the source.  If regions extend beyond the source size, make
+             * sure exposure events get sent.
+             */
+            if (fastBox.x1 < pSrc->x)
+            {
+                fastBox.x1 = pSrc->x;
+                fastExpose = FALSE;
+            }
+            if (fastBox.y1 < pSrc->y)
+            {
+                fastBox.y1 = pSrc->y;
+                fastExpose = FALSE;
+            }
+            if (fastBox.x2 > pSrc->x + (int) pSrc->width)
+            {
+                fastBox.x2 = pSrc->x + (int) pSrc->width;
+                fastExpose = FALSE;
+            }
+            if (fastBox.y2 > pSrc->y + (int) pSrc->height)
+            {
+                fastBox.y2 = pSrc->y + (int) pSrc->height;
+                fastExpose = FALSE;
+            }
+
+            nBox = 1;
+            pBox = &fastBox;
+        }
+        else
+        {
+            REGION_INIT(pScreen, &rgnDst, &fastBox, 1);
+            REGION_INTERSECT(pScreen, &rgnDst, &rgnDst, prgnSrcClip);
+            pBox = REGION_RECTS(&rgnDst);
+            nBox = REGION_NUM_RECTS(&rgnDst);
+        }
+
+        /*
+         * fastBlit can only be TRUE if we don't need to worry about attempts
+         * to read partial pixels through the destination bank.
+         */
+        if (SinglePlane)
+            fastBlit = pGCPriv->fastPlane;
+        else
+            fastBlit = pGCPriv->fastCopy;
+
+        nQueue = nBox * pScreenPriv->maxRects * 2;
+        pQueue = Queue = ALLOCATE_LOCAL_ARRAY(miBankQueue, nQueue);
+
+        if (Queue)
+        {
+            for (;  nBox--;  pBox++)
+            {
+                ns = FirstBankOf(pBox->x1, pBox->y1);
+                nse = LastBankOf(pBox->x2, pBox->y2);
+                for (;  ns <= nse;  ns++)
+                {
+                    if (!pScreenPriv->pBanks[ns])
+                        continue;
+
+                    nBoxClipSrc = REGION_NUM_RECTS(pScreenPriv->pBanks[ns]);
+                    pBoxClipSrc = REGION_RECTS(pScreenPriv->pBanks[ns]);
+
+                    for (;  nBoxClipSrc--;  pBoxClipSrc++)
+                    {
+                        cx1 = max(pBox->x1, pBoxClipSrc->x1);
+                        cy1 = max(pBox->y1, pBoxClipSrc->y1);
+                        cx2 = min(pBox->x2, pBoxClipSrc->x2);
+                        cy2 = min(pBox->y2, pBoxClipSrc->y2);
+
+                        /* Check to see if the region is empty */
+                        if ((cx1 >= cx2) || (cy1 >= cy2))
+                            continue;
+
+                        /* Translate c[xy]* to destination coordinates */
+                        cx1 += dx + xorg;
+                        cy1 += dy + yorg;
+                        cx2 += dx + xorg;
+                        cy2 += dy + yorg;
+
+                        nd = FirstBankOf(cx1, cy1);
+                        nde = LastBankOf(cx2, cy2);
+                        for (;  nd <= nde;  nd++)
+                        {
+                            if (!pGCPriv->pBankedClips[nd])
+                                continue;
+
+                            /*
+                             * Clients can send quite large clip descriptions,
+                             * so use the bank clips here instead.
+                             */
+                            nBoxClipDst =
+                                REGION_NUM_RECTS(pScreenPriv->pBanks[nd]);
+                            pBoxClipDst =
+                                REGION_RECTS(pScreenPriv->pBanks[nd]);
+
+                            for (;  nBoxClipDst--;  pBoxClipDst++)
+                            {
+                                ccBox.x1 = max(cx1, pBoxClipDst->x1);
+                                ccBox.y1 = max(cy1, pBoxClipDst->y1);
+                                ccBox.x2 = min(cx2, pBoxClipDst->x2);
+                                ccBox.y2 = min(cy2, pBoxClipDst->y2);
+
+                                /* Check to see if the region is empty */
+                                if ((ccBox.x1 >= ccBox.x2) ||
+                                    (ccBox.y1 >= ccBox.y2))
+                                    continue;
+
+                                pQueue->srcBankNo = ns;
+                                pQueue->dstBankNo = nd;
+                                pQueue->x         = ccBox.x1 - xorg;
+                                pQueue->y         = ccBox.y1 - yorg;
+                                pQueue->w         = ccBox.x2 - ccBox.x1;
+                                pQueue->h         = ccBox.y2 - ccBox.y1;
+
+                                if (maxWidth < pQueue->w)
+                                    maxWidth = pQueue->w;
+                                if (maxHeight < pQueue->h)
+                                    maxHeight = pQueue->h;
+
+                                /*
+                                 * When shared banking is used and the source
+                                 * and destination banks differ, prevent
+                                 * attempts to fetch partial scanline pad units
+                                 * through the destination bank.
+                                 */
+                                pQueue->fastBlit = fastBlit;
+                                if (fastBlit &&
+                                    (pScreenPriv->type == BANK_SHARED) &&
+                                    (ns != nd) &&
+                                    ((ccBox.x1 %
+                                      pScreenPriv->nPixelsPerScanlinePadUnit) ||
+                                     (ccBox.x2 %
+                                      pScreenPriv->nPixelsPerScanlinePadUnit) ||
+                                     (RECT_IN_REGION(pScreen,
+                                       pGCPriv->pBankedClips[nd], &ccBox) !=
+                                      rgnIN)))
+                                    pQueue->fastBlit = FALSE;
+                                pQueue++;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        if (!fastClip)
+        {
+            REGION_UNINIT(pScreen, &rgnDst);
+            if (freeSrcClip)
+                REGION_DESTROY(pScreen, prgnSrcClip);
+        }
+
+        pQueueNew = pQueue;
+        nQueue = pQueue - Queue;
+
+        if (nQueue > 0)
+        {
+            BANK_SAVE;
+
+            pQueue = Queue;
+
+            if ((nQueue > 1) &&
+                ((pSrc == pDst) || (pGC->subWindowMode == IncludeInferiors)))
+            {
+                if ((srcy + pSrc->y) < (dsty + yorg))
+                {
+                    /* Sort from bottom to top */
+                    pQueueBase = pQueueNext = pQueue + nQueue - 1;
+
+                    while (pQueueBase >= pQueue)
+                    {
+                        while ((pQueueNext >= pQueue) &&
+                               (pQueueBase->y == pQueueNext->y))
+                            pQueueNext--;
+
+                        pQueueTmp = pQueueNext + 1;
+                        while (pQueueTmp <= pQueueBase)
+                            *pQueueNew++ = *pQueueTmp++;
+
+                        pQueueBase = pQueueNext;
+                    }
+
+                    pQueueNew -= nQueue;
+                    pQueue = pQueueNew;
+                    pQueueNew = Queue;
+                }
+
+                if ((srcx + pSrc->x) < (dstx + xorg))
+                {
+                    /* Sort from right to left */
+                    pQueueBase = pQueueNext = pQueue;
+
+                    while (pQueueBase < pQueue + nQueue)
+                    {
+                        while ((pQueueNext < pQueue + nQueue) &&
+                               (pQueueNext->y == pQueueBase->y))
+                            pQueueNext++;
+
+                        pQueueTmp = pQueueNext;
+                        while (pQueueTmp != pQueueBase)
+                            *pQueueNew++ = *--pQueueTmp;
+
+                        pQueueBase = pQueueNext;
+                    }
+
+                    pQueueNew -= nQueue;
+                    pQueue = pQueueNew;
+                }
+            }
+
+            paddedWidth = PixmapBytePad(maxWidth,
+                pScreenPriv->pScreenPixmap->drawable.depth);
+            pImage = (char *)ALLOCATE_LOCAL(paddedWidth * maxHeight);
+
+            pGC->fExpose = FALSE;
+
+            while (nQueue--)
+            {
+                pGC->pCompositeClip = pGCPriv->pBankedClips[pQueue->dstBankNo];
+
+                GCOP_UNWRAP;
+
+                if (pQueue->srcBankNo == pQueue->dstBankNo)
+                {
+                    SET_SINGLE_BANK(pScreenPriv->pScreenPixmap,
+                        -1, -1, pQueue->srcBankNo);
+
+                    if (SinglePlane)
+                        (*pGC->ops->CopyPlane)(pSrc, pDst, pGC,
+                            pQueue->x - dx - pSrc->x, pQueue->y - dy - pSrc->y,
+                            pQueue->w, pQueue->h, pQueue->x, pQueue->y, plane);
+                    else
+                        (*pGC->ops->CopyArea)(pSrc, pDst, pGC,
+                            pQueue->x - dx - pSrc->x, pQueue->y - dy - pSrc->y,
+                            pQueue->w, pQueue->h, pQueue->x, pQueue->y);
+                }
+                else if (pQueue->fastBlit)
+                {
+                    SET_SOURCE_BANK     (pScreenPriv->pBankPixmap,
+                        pScreenPriv->pScreenPixmap->drawable.width,
+                        pScreenPriv->pScreenPixmap->devKind,
+                        pQueue->srcBankNo);
+                    SET_DESTINATION_BANK(pScreenPriv->pScreenPixmap,
+                        -1, -1, pQueue->dstBankNo);
+
+                    if (SinglePlane)
+                        (*pGC->ops->CopyPlane)(
+                            (DrawablePtr)pScreenPriv->pBankPixmap, pDst, pGC,
+                            pQueue->x - dx, pQueue->y - dy,
+                            pQueue->w, pQueue->h, pQueue->x, pQueue->y, plane);
+                    else
+                        (*pGC->ops->CopyArea)(
+                            (DrawablePtr)pScreenPriv->pBankPixmap, pDst, pGC,
+                            pQueue->x - dx, pQueue->y - dy,
+                            pQueue->w, pQueue->h, pQueue->x, pQueue->y);
+                }
+                else if (pImage)
+                {
+                    ModifyPixmap(pScreenPriv->pBankPixmap,
+                        maxWidth, paddedWidth, pImage);
+
+                    SET_SINGLE_BANK(pScreenPriv->pScreenPixmap,
+                        -1, -1, pQueue->srcBankNo);
+
+                    (*pScreenPriv->pBankGC->ops->CopyArea)(
+                        pSrc, (DrawablePtr)pScreenPriv->pBankPixmap,
+                        pScreenPriv->pBankGC,
+                        pQueue->x - dx - pSrc->x, pQueue->y - dy - pSrc->y,
+                        pQueue->w, pQueue->h, 0, 0);
+
+                    SET_SINGLE_BANK(pScreenPriv->pScreenPixmap,
+                        -1, -1, pQueue->dstBankNo);
+
+                    if (SinglePlane)
+                        (*pGC->ops->CopyPlane)(
+                            (DrawablePtr)pScreenPriv->pBankPixmap,
+                            pDst, pGC, 0, 0, pQueue->w, pQueue->h,
+                            pQueue->x, pQueue->y, plane);
+                    else
+                        (*pGC->ops->CopyArea)(
+                            (DrawablePtr)pScreenPriv->pBankPixmap,
+                            pDst, pGC, 0, 0, pQueue->w, pQueue->h,
+                            pQueue->x, pQueue->y);
+                }
+
+                GCOP_WRAP;
+
+                pQueue++;
+            }
+
+            DEALLOCATE_LOCAL(pImage);
+
+            BANK_RESTORE;
+        }
+
+        CLIP_RESTORE;
+
+        pGC->fExpose = fExpose;
+
+        DEALLOCATE_LOCAL(Queue);
+    }
+
+    SCREEN_RESTORE;
+
+    if (!fExpose || fastExpose)
+        return ret;
+
+    return miHandleExposures(pSrc, pDst, pGC, srcx, srcy, w, h, dstx, dsty, 0);
+}
+
+static RegionPtr
+miBankCopyArea(
+    DrawablePtr pSrc,
+    DrawablePtr pDst,
+    GCPtr       pGC,
+    int         srcx,
+    int         srcy,
+    int         w,
+    int         h,
+    int         dstx,
+    int         dsty
+)
+{
+    return miBankCopy(pSrc, pDst, pGC, srcx, srcy, w, h, dstx, dsty, 0, FALSE);
+}
+
+static RegionPtr
+miBankCopyPlane(
+    DrawablePtr   pSrc,
+    DrawablePtr   pDst,
+    GCPtr         pGC,
+    int           srcx,
+    int           srcy,
+    int           w,
+    int           h,
+    int           dstx,
+    int           dsty,
+    unsigned long plane
+)
+{
+    return
+        miBankCopy(pSrc, pDst, pGC, srcx, srcy, w, h, dstx, dsty, plane, TRUE);
+}
+
+static void
+miBankPolyPoint(
+    DrawablePtr pDrawable,
+    GCPtr       pGC,
+    int         mode,
+    int         nArray,
+    xPoint      *pArray
+)
+{
+#   define GCOP_ARGS GCOP_0D_ARGS
+    GCOP_COMPLEX(PolyPoint, xPoint);
+#   undef GCOP_ARGS
+}
+
+static void
+miBankPolylines(
+    DrawablePtr pDrawable,
+    GCPtr       pGC,
+    int         mode,
+    int         nArray,
+    DDXPointPtr pArray
+)
+{
+#   define GCOP_ARGS GCOP_0D_ARGS
+    GCOP_COMPLEX(Polylines, DDXPointRec);
+#   undef GCOP_ARGS
+}
+
+static void
+miBankPolySegment(
+    DrawablePtr pDrawable,
+    GCPtr       pGC,
+    int         nArray,
+    xSegment    *pArray
+)
+{
+#   define GCOP_ARGS GCOP_1D_ARGS
+    GCOP_COMPLEX(PolySegment, xSegment);
+#   undef GCOP_ARGS
+}
+
+static void
+miBankPolyRectangle(
+    DrawablePtr pDrawable,
+    GCPtr       pGC,
+    int         nArray,
+    xRectangle  *pArray
+)
+{
+#   define GCOP_ARGS GCOP_1D_ARGS
+    GCOP_COMPLEX(PolyRectangle, xRectangle);
+#   undef GCOP_ARGS
+}
+
+static void
+miBankPolyArc(
+    DrawablePtr pDrawable,
+    GCPtr       pGC,
+    int         nArray,
+    xArc        *pArray
+)
+{
+#   define GCOP_ARGS GCOP_1D_ARGS
+    GCOP_COMPLEX(PolyArc, xArc);
+#   undef GCOP_ARGS
+}
+
+static void
+miBankFillPolygon(
+    DrawablePtr pDrawable,
+    GCPtr       pGC,
+    int         shape,
+    int         mode,
+    int         nArray,
+    DDXPointRec *pArray
+)
+{
+#   define GCOP_ARGS GCOP_2D_ARGS
+    GCOP_COMPLEX(FillPolygon, DDXPointRec);
+#   undef GCOP_ARGS
+}
+
+static void
+miBankPolyFillRect(
+    DrawablePtr pDrawable,
+    GCPtr       pGC,
+    int         nArray,
+    xRectangle  *pArray
+)
+{
+#   define GCOP_ARGS GCOP_1D_ARGS
+    GCOP_COMPLEX(PolyFillRect, xRectangle);
+#   undef GCOP_ARGS
+}
+
+static void
+miBankPolyFillArc(
+    DrawablePtr pDrawable,
+    GCPtr       pGC,
+    int         nArray,
+    xArc        *pArray
+)
+{
+#   define GCOP_ARGS GCOP_1D_ARGS
+    GCOP_COMPLEX(PolyFillArc, xArc);
+#   undef GCOP_ARGS
+}
+
+static int
+miBankPolyText8(
+    DrawablePtr pDrawable,
+    GCPtr       pGC,
+    int         x,
+    int         y,
+    int         nArray,
+    char        *pchar
+)
+{
+    int retval = x;
+
+    GCOP_SIMPLE(retval =
+        (*pGC->ops->PolyText8)(pDrawable, pGC, x, y, nArray, pchar));
+
+    return retval;
+}
+
+static int
+miBankPolyText16(
+    DrawablePtr    pDrawable,
+    GCPtr          pGC,
+    int            x,
+    int            y,
+    int            nArray,
+    unsigned short *pchar
+)
+{
+    int retval = x;
+
+    GCOP_SIMPLE(retval =
+        (*pGC->ops->PolyText16)(pDrawable, pGC, x, y, nArray, pchar));
+
+    return retval;
+}
+
+static void
+miBankImageText8(
+    DrawablePtr pDrawable,
+    GCPtr       pGC,
+    int         x,
+    int         y,
+    int         nArray,
+    char        *pchar
+)
+{
+    GCOP_SIMPLE((*pGC->ops->ImageText8)(pDrawable, pGC, x, y, nArray, pchar));
+}
+
+static void
+miBankImageText16(
+    DrawablePtr    pDrawable,
+    GCPtr          pGC,
+    int            x,
+    int            y,
+    int            nArray,
+    unsigned short *pchar
+)
+{
+    GCOP_SIMPLE((*pGC->ops->ImageText16)(pDrawable, pGC, x, y, nArray, pchar));
+}
+
+static void
+miBankImageGlyphBlt(
+    DrawablePtr  pDrawable,
+    GCPtr        pGC,
+    int          x,
+    int          y,
+    unsigned int nArray,
+    CharInfoPtr  *ppci,
+    pointer      pglyphBase
+)
+{
+    GCOP_SIMPLE((*pGC->ops->ImageGlyphBlt)(pDrawable, pGC,
+        x, y, nArray, ppci, pglyphBase));
+}
+
+static void
+miBankPolyGlyphBlt(
+    DrawablePtr  pDrawable,
+    GCPtr        pGC,
+    int          x,
+    int          y,
+    unsigned int nArray,
+    CharInfoPtr  *ppci,
+    pointer      pglyphBase
+)
+{
+    GCOP_SIMPLE((*pGC->ops->PolyGlyphBlt)(pDrawable, pGC,
+        x, y, nArray, ppci, pglyphBase));
+}
+
+static void
+miBankPushPixels(
+    GCPtr       pGC,
+    PixmapPtr   pBitmap,
+    DrawablePtr pDrawable,
+    int         w,
+    int         h,
+    int         x,
+    int         y
+)
+{
+    if ((w > 0) && (h > 0))
+    {
+        GCOP_INIT;
+        SCREEN_SAVE;
+
+        if (!IS_BANKED(pDrawable))
+        {
+            GCOP_UNWRAP;
+
+            (*pGC->ops->PushPixels)(pGC, pBitmap, pDrawable, w, h, x, y);
+
+            GCOP_WRAP;
+        }
+        else
+        {
+            int i, j;
+
+            CLIP_SAVE;
+
+            i = FirstBankOf(x,     y);
+            j =  LastBankOf(x + w, y + h);
+            for (;  i <= j;  i++)
+            {
+                if (!(pGC->pCompositeClip = pGCPriv->pBankedClips[i]))
+                    continue;
+
+                GCOP_UNWRAP;
+
+                SET_SINGLE_BANK(pScreenPriv->pScreenPixmap, -1, -1, i);
+
+                (*pGC->ops->PushPixels)(pGC, pBitmap, pDrawable, w, h, x, y);
+
+                GCOP_WRAP;
+            }
+
+            CLIP_RESTORE;
+        }
+
+        SCREEN_RESTORE;
+    }
+}
+
+static GCOps miBankGCOps =
+{
+    miBankFillSpans,
+    miBankSetSpans,
+    miBankPutImage,
+    miBankCopyArea,
+    miBankCopyPlane,
+    miBankPolyPoint,
+    miBankPolylines,
+    miBankPolySegment,
+    miBankPolyRectangle,
+    miBankPolyArc,
+    miBankFillPolygon,
+    miBankPolyFillRect,
+    miBankPolyFillArc,
+    miBankPolyText8,
+    miBankPolyText16,
+    miBankImageText8,
+    miBankImageText16,
+    miBankImageGlyphBlt,
+    miBankPolyGlyphBlt,
+    miBankPushPixels,
+#ifdef NEED_LINEHELPER
+    NULL,               /* LineHelper */
+#endif
+    {NULL}              /* devPrivate */
+};
+
+/********************
+ * GCFuncs wrappers *
+ ********************/
+
+static void
+miBankValidateGC(
+    GCPtr         pGC,
+    unsigned long changes,
+    DrawablePtr   pDrawable
+)
+{
+    GC_INIT(pGC);
+    GC_UNWRAP(pGC);
+
+    (*pGC->funcs->ValidateGC)(pGC, changes, pDrawable);
+
+    if ((changes & (GCClipXOrigin|GCClipYOrigin|GCClipMask|GCSubwindowMode)) ||
+        (pDrawable->serialNumber != (pGC->serialNumber & DRAWABLE_SERIAL_BITS)))
+    {
+        ScreenPtr     pScreen = pGC->pScreen;
+        RegionPtr     prgnClip;
+        unsigned long planemask;
+        int           i;
+
+        SCREEN_INIT;
+        SCREEN_SAVE;
+
+        if (IS_BANKED(pDrawable))
+        {
+            for (i = 0;  i < pScreenPriv->nBanks;  i++)
+            {
+                if (!pScreenPriv->pBanks[i])
+                    continue;
+
+                if (!(prgnClip = pGCPriv->pBankedClips[i]))
+                    prgnClip = REGION_CREATE(pScreen, NULL, 1);
+
+                REGION_INTERSECT(pScreen, prgnClip,
+                    pScreenPriv->pBanks[i], pGC->pCompositeClip);
+
+                if ((REGION_NUM_RECTS(prgnClip) <= 1) &&
+                    ((prgnClip->extents.x1 == prgnClip->extents.x2) ||
+                     (prgnClip->extents.y1 == prgnClip->extents.y2)))
+                {
+                    REGION_DESTROY(pScreen, prgnClip);
+                    pGCPriv->pBankedClips[i] = NULL;
+                }
+                else
+                    pGCPriv->pBankedClips[i] = prgnClip;
+            }
+
+            /*
+             * fastCopy and fastPlane can only be TRUE if we don't need to
+             * worry about attempts to read partial pixels through the
+             * destination bank.
+             */
+            switch (pScreenPriv->type)
+            {
+                case BANK_SHARED:
+                    pGCPriv->fastCopy = pGCPriv->fastPlane = FALSE;
+
+                    if ((pGC->alu != GXclear) && (pGC->alu != GXcopy) &&
+                        (pGC->alu != GXcopyInverted) && (pGC->alu != GXset))
+                        break;
+
+                    if (pScreen->rootDepth == 1)
+                        pGCPriv->fastPlane = TRUE;
+
+                    /* This is probably paranoia */
+                    if ((pDrawable->depth != pScreen->rootDepth) ||
+                        (pDrawable->depth != pGC->depth))
+                        break;
+
+                    planemask = (1 << pGC->depth) - 1;
+                    if ((pGC->planemask & planemask) == planemask)
+                        pGCPriv->fastCopy = TRUE;
+
+                    break;
+
+                case BANK_DOUBLE:
+                    pGCPriv->fastCopy = pGCPriv->fastPlane = TRUE;
+                    break;
+
+                default:
+                    pGCPriv->fastCopy = pGCPriv->fastPlane = FALSE;
+                    break;
+            }
+        }
+        else
+        {
+            /*
+             * Here we are on a pixmap and don't need all that special clipping
+             * stuff, hence free it.
+             */
+            for (i = 0;  i < pScreenPriv->nBanks;  i++)
+            {
+                if (!pGCPriv->pBankedClips[i])
+                    continue;
+
+                REGION_DESTROY(pScreen, pGCPriv->pBankedClips[i]);
+                pGCPriv->pBankedClips[i] = NULL;
+            }
+        }
+
+        SCREEN_RESTORE;
+    }
+
+    GC_WRAP(pGC);
+}
+
+static void
+miBankChangeGC(
+    GCPtr         pGC,
+    unsigned long mask
+)
+{
+    GC_INIT(pGC);
+    GC_UNWRAP(pGC);
+
+    (*pGC->funcs->ChangeGC)(pGC, mask);
+
+    GC_WRAP(pGC);
+}
+
+static void
+miBankCopyGC(
+    GCPtr         pGCSrc,
+    unsigned long mask,
+    GCPtr         pGCDst
+)
+{
+    GC_INIT(pGCDst);
+    GC_UNWRAP(pGCDst);
+
+    (*pGCDst->funcs->CopyGC)(pGCSrc, mask, pGCDst);
+
+    GC_WRAP(pGCDst);
+}
+
+static void
+miBankDestroyGC(
+    GCPtr pGC
+)
+{
+    ScreenPtr pScreen = pGC->pScreen;
+    int       i;
+
+    SCREEN_INIT;
+    GC_INIT(pGC);
+    GC_UNWRAP(pGC);
+
+    (*pGC->funcs->DestroyGC)(pGC);
+
+    for (i = 0;  i < pScreenPriv->nBanks;  i++)
+    {
+        if (!pGCPriv->pBankedClips[i])
+            continue;
+
+        REGION_DESTROY(pScreen, pGCPriv->pBankedClips[i]);
+        pGCPriv->pBankedClips[i] = NULL;
+    }
+
+    GC_WRAP(pGC);
+}
+
+static void
+miBankChangeClip(
+    GCPtr   pGC,
+    int     type,
+    pointer pvalue,
+    int     nrects
+)
+{
+    GC_INIT(pGC);
+    GC_UNWRAP(pGC);
+
+    (*pGC->funcs->ChangeClip)(pGC, type, pvalue, nrects);
+
+    GC_WRAP(pGC);
+}
+
+static void
+miBankDestroyClip(
+    GCPtr pGC
+)
+{
+    GC_INIT(pGC);
+    GC_UNWRAP(pGC);
+
+    (*pGC->funcs->DestroyClip)(pGC);
+
+    GC_WRAP(pGC);
+}
+
+static void
+miBankCopyClip(
+    GCPtr pGCDst,
+    GCPtr pGCSrc
+)
+{
+    GC_INIT(pGCDst);
+    GC_UNWRAP(pGCDst);
+
+    (*pGCDst->funcs->CopyClip)(pGCDst, pGCSrc);
+
+    GC_WRAP(pGCDst);
+}
+
+static GCFuncs miBankGCFuncs =
+{
+    miBankValidateGC,
+    miBankChangeGC,
+    miBankCopyGC,
+    miBankDestroyGC,
+    miBankChangeClip,
+    miBankDestroyClip,
+    miBankCopyClip
+};
+
+/*******************
+ * Screen Wrappers *
+ *******************/
+
+static Bool
+miBankCreateScreenResources(
+    ScreenPtr pScreen
+)
+{
+    Bool retval;
+
+    SCREEN_INIT;
+    SCREEN_UNWRAP(CreateScreenResources);
+
+    if ((retval = (*pScreen->CreateScreenResources)(pScreen)))
+    {
+        /* Set screen buffer address to something recognizable */
+        pScreenPriv->pScreenPixmap = (*pScreen->GetScreenPixmap)(pScreen);
+        pScreenPriv->pbits = pScreenPriv->pScreenPixmap->devPrivate.ptr;
+        pScreenPriv->pScreenPixmap->devPrivate.ptr = (pointer)pScreenPriv;
+
+        /* Get shadow pixmap;  width & height of 0 means no pixmap data */
+        pScreenPriv->pBankPixmap = (*pScreen->CreatePixmap)(pScreen, 0, 0,
+            pScreenPriv->pScreenPixmap->drawable.depth);
+        if (!pScreenPriv->pBankPixmap)
+            retval = FALSE;
+    }
+
+    /* Shadow the screen */
+    if (retval)
+        retval = (*pScreen->ModifyPixmapHeader)(pScreenPriv->pBankPixmap,
+            pScreenPriv->pScreenPixmap->drawable.width,
+            pScreenPriv->pScreenPixmap->drawable.height,
+            pScreenPriv->pScreenPixmap->drawable.depth,
+            pScreenPriv->pScreenPixmap->drawable.bitsPerPixel,
+            pScreenPriv->pScreenPixmap->devKind, NULL);
+
+    /* Create shadow GC */
+    if (retval)
+    {
+        pScreenPriv->pBankGC = CreateScratchGC(pScreen,
+            pScreenPriv->pBankPixmap->drawable.depth);
+        if (!pScreenPriv->pBankGC)
+            retval = FALSE;
+    }
+
+    /* Validate shadow GC */
+    if (retval)
+    {
+        pScreenPriv->pBankGC->graphicsExposures = FALSE;
+        pScreenPriv->pBankGC->subWindowMode = IncludeInferiors;
+        ValidateGC((DrawablePtr)pScreenPriv->pBankPixmap,
+            pScreenPriv->pBankGC);
+    }
+
+    SCREEN_WRAP(CreateScreenResources, miBankCreateScreenResources);
+
+    return retval;
+}
+
+static Bool
+miBankModifyPixmapHeader(
+    PixmapPtr pPixmap,
+    int       width,
+    int       height,
+    int       depth,
+    int       bitsPerPixel,
+    int       devKind,
+    pointer   pPixData
+)
+{
+    Bool retval = FALSE;
+
+    if (pPixmap)
+    {
+        ScreenPtr pScreen = pPixmap->drawable.pScreen;
+
+        SCREEN_INIT;
+        PIXMAP_SAVE(pPixmap);
+        SCREEN_UNWRAP(ModifyPixmapHeader);
+
+        retval = (*pScreen->ModifyPixmapHeader)(pPixmap, width, height,
+            depth, bitsPerPixel, devKind, pPixData);
+
+        SCREEN_WRAP(ModifyPixmapHeader, miBankModifyPixmapHeader);
+
+        if (pbits == (pointer)pScreenPriv)
+        {
+            pScreenPriv->pbits = pPixmap->devPrivate.ptr;
+            pPixmap->devPrivate.ptr = pbits;
+        }
+    }
+
+    return retval;
+}
+
+static Bool
+miBankCloseScreen(
+    int       nIndex,
+    ScreenPtr pScreen
+)
+{
+    int i;
+
+    SCREEN_INIT;
+
+    /* Free shadow GC */
+    FreeScratchGC(pScreenPriv->pBankGC);
+
+    /* Free shadow pixmap */
+    (*pScreen->DestroyPixmap)(pScreenPriv->pBankPixmap);
+
+    /* Restore screen pixmap devPrivate pointer */
+    pScreenPriv->pScreenPixmap->devPrivate.ptr = pScreenPriv->pbits;
+
+    /* Delete bank clips */
+    for (i = 0;  i < pScreenPriv->nBanks;  i++)
+        if (pScreenPriv->pBanks[i])
+            REGION_DESTROY(pScreen, pScreenPriv->pBanks[i]);
+
+    Xfree(pScreenPriv->pBanks);
+
+    SCREEN_UNWRAP(CreateScreenResources);
+    SCREEN_UNWRAP(ModifyPixmapHeader);
+    SCREEN_UNWRAP(CloseScreen);
+    SCREEN_UNWRAP(GetImage);
+    SCREEN_UNWRAP(GetSpans);
+    SCREEN_UNWRAP(CreateGC);
+    SCREEN_UNWRAP(PaintWindowBackground);
+    SCREEN_UNWRAP(PaintWindowBorder);
+    SCREEN_UNWRAP(CopyWindow);
+    SCREEN_UNWRAP(BackingStoreFuncs);
+
+    Xfree(pScreenPriv);
+    return (*pScreen->CloseScreen)(nIndex, pScreen);
+}
+
+static void
+miBankGetImage(
+    DrawablePtr   pDrawable,
+    int           sx,
+    int           sy,
+    int           w,
+    int           h,
+    unsigned int  format,
+    unsigned long planemask,
+    char          *pImage
+)
+{
+    if ((w > 0) && (h > 0))
+    {
+        ScreenPtr pScreen = pDrawable->pScreen;
+
+        SCREEN_INIT;
+        SCREEN_STATUS;
+        SCREEN_UNWRAP(GetImage);
+
+        if (!IS_BANKED(pDrawable))
+        {
+            (*pScreen->GetImage)(pDrawable, sx, sy, w, h,
+                format, planemask, pImage);
+        }
+        else
+        {
+            int  paddedWidth;
+            char *pBankImage;
+
+            paddedWidth = PixmapBytePad(w,
+                pScreenPriv->pScreenPixmap->drawable.depth);
+            pBankImage = (char *)ALLOCATE_LOCAL(paddedWidth * h);
+
+            if (pBankImage)
+            {
+                BANK_SAVE;
+
+                ModifyPixmap(pScreenPriv->pBankPixmap, w, paddedWidth,
+                    pBankImage);
+
+                (*pScreenPriv->pBankGC->ops->CopyArea)(
+                    (DrawablePtr)WindowTable[pScreen->myNum],
+                    (DrawablePtr)pScreenPriv->pBankPixmap,
+                    pScreenPriv->pBankGC,
+                    sx + pDrawable->x, sy + pDrawable->y, w, h, 0, 0);
+
+                (*pScreen->GetImage)((DrawablePtr)pScreenPriv->pBankPixmap,
+                    0, 0, w, h, format, planemask, pImage);
+
+                BANK_RESTORE;
+
+                DEALLOCATE_LOCAL(pBankImage);
+            }
+        }
+
+        SCREEN_WRAP(GetImage, miBankGetImage);
+    }
+}
+
+static void
+miBankGetSpans(
+    DrawablePtr pDrawable,
+    int         wMax,
+    DDXPointPtr ppt,
+    int         *pwidth,
+    int         nspans,
+    char        *pImage
+)
+{
+    if (nspans > 0)
+    {
+        ScreenPtr pScreen = pDrawable->pScreen;
+
+        SCREEN_INIT;
+        SCREEN_STATUS;
+        SCREEN_UNWRAP(GetSpans);
+
+        if (!IS_BANKED(pDrawable))
+        {
+            (*pScreen->GetSpans)(pDrawable, wMax, ppt, pwidth, nspans, pImage);
+        }
+        else
+        {
+            char        *pBankImage;
+            int         paddedWidth;
+            DDXPointRec pt;
+
+            pt.x = pt.y = 0;
+
+            paddedWidth =
+                PixmapBytePad(pScreenPriv->pScreenPixmap->drawable.width,
+                    pScreenPriv->pScreenPixmap->drawable.depth);
+            pBankImage = (char *)ALLOCATE_LOCAL(paddedWidth);
+
+            if (pBankImage)
+            {
+                BANK_SAVE;
+
+                ModifyPixmap(pScreenPriv->pBankPixmap,
+                    pScreenPriv->pScreenPixmap->drawable.width,
+                    paddedWidth, pBankImage);
+
+                for (;  nspans--;  ppt++, pwidth++)
+                {
+                    if (*pwidth <= 0)
+                        continue;
+
+                    (*pScreenPriv->pBankGC->ops->CopyArea)(
+                        (DrawablePtr)WindowTable[pScreen->myNum],
+                        (DrawablePtr)pScreenPriv->pBankPixmap,
+                        pScreenPriv->pBankGC,
+                        ppt->x, ppt->y, *pwidth, 1, 0, 0);
+
+                    (*pScreen->GetSpans)((DrawablePtr)pScreenPriv->pBankPixmap,
+                        wMax, &pt, pwidth, 1, pImage);
+
+                    pImage = pImage + PixmapBytePad(*pwidth, pDrawable->depth);
+                }
+
+                BANK_RESTORE;
+
+                DEALLOCATE_LOCAL(pBankImage);
+            }
+        }
+
+        SCREEN_WRAP(GetSpans, miBankGetSpans);
+    }
+}
+
+static Bool
+miBankCreateGC(
+    GCPtr pGC
+)
+{
+    ScreenPtr   pScreen = pGC->pScreen;
+    miBankGCPtr pGCPriv = BANK_GCPRIVATE(pGC);
+    Bool        ret;
+
+    SCREEN_INIT;
+    SCREEN_UNWRAP(CreateGC);
+
+    if ((ret = (*pScreen->CreateGC)(pGC)))
+    {
+        pGCPriv->unwrappedOps = &miBankGCOps;
+        pGCPriv->unwrappedFuncs = &miBankGCFuncs;
+        GC_WRAP(pGC);
+
+        memset(&pGCPriv->pBankedClips, 0,
+            pScreenPriv->nBanks * sizeof(pGCPriv->pBankedClips));
+    }
+
+    SCREEN_WRAP(CreateGC, miBankCreateGC);
+
+    return ret;
+}
+
+static void
+miBankPaintWindow(
+    WindowPtr pWin,
+    RegionPtr pRegion,
+    int       what
+)
+{
+    ScreenPtr          pScreen = pWin->drawable.pScreen;
+    RegionRec          tmpReg;
+    int                i;
+    PaintWindowProcPtr PaintWindow;
+
+    SCREEN_INIT;
+    SCREEN_SAVE;
+
+    if (what == PW_BORDER)
+    {
+        SCREEN_UNWRAP(PaintWindowBorder);
+        PaintWindow = pScreen->PaintWindowBorder;
+    }
+    else
+    {
+        SCREEN_UNWRAP(PaintWindowBackground);
+        PaintWindow = pScreen->PaintWindowBackground;
+    }
+
+    if (!IS_BANKED(pWin))
+    {
+        (*PaintWindow)(pWin, pRegion, what);
+    }
+    else
+    {
+        REGION_INIT(pScreen, &tmpReg, NullBox, 0);
+
+        for (i = 0;  i < pScreenPriv->nBanks;  i++)
+        {
+            if (!pScreenPriv->pBanks[i])
+                continue;
+
+            REGION_INTERSECT(pScreen, &tmpReg, pRegion,
+                pScreenPriv->pBanks[i]);
+
+            if (REGION_NIL(&tmpReg))
+                continue;
+
+            SET_SINGLE_BANK(pScreenPriv->pScreenPixmap, -1, -1, i);
+
+            (*PaintWindow)(pWin, &tmpReg, what);
+        }
+
+        REGION_UNINIT(pScreen, &tmpReg);
+    }
+
+    if (what == PW_BORDER)
+    {
+        SCREEN_WRAP(PaintWindowBorder, miBankPaintWindow);
+    }
+    else
+    {
+        SCREEN_WRAP(PaintWindowBackground, miBankPaintWindow);
+    }
+
+    SCREEN_RESTORE;
+}
+
+static void
+miBankCopyWindow(
+    WindowPtr   pWindow,
+    DDXPointRec ptOldOrg,
+    RegionPtr   pRgnSrc
+)
+{
+    ScreenPtr   pScreen = pWindow->drawable.pScreen;
+    GCPtr       pGC;
+    int         dx, dy, nBox;
+    DrawablePtr pDrawable = (DrawablePtr)WindowTable[pScreen->myNum];
+    RegionPtr   pRgnDst;
+    BoxPtr      pBox, pBoxTmp, pBoxNext, pBoxBase, pBoxNew1, pBoxNew2;
+    XID         subWindowMode = IncludeInferiors;
+
+    pGC = GetScratchGC(pDrawable->depth, pScreen);
+
+    ChangeGC(pGC, GCSubwindowMode, &subWindowMode);
+    ValidateGC(pDrawable, pGC);
+
+    pRgnDst = REGION_CREATE(pScreen, NULL, 1);
+
+    dx = ptOldOrg.x - pWindow->drawable.x;
+    dy = ptOldOrg.y - pWindow->drawable.y;
+    REGION_TRANSLATE(pScreen, pRgnSrc, -dx, -dy);
+    REGION_INTERSECT(pScreen, pRgnDst, &pWindow->borderClip, pRgnSrc);
+
+    pBox = REGION_RECTS(pRgnDst);
+    nBox = REGION_NUM_RECTS(pRgnDst);
+
+    pBoxNew1 = NULL;
+    pBoxNew2 = NULL;
+
+    if (nBox > 1)
+    {
+        if (dy < 0)
+        {
+            /* Sort boxes from bottom to top */
+            pBoxNew1 = ALLOCATE_LOCAL_ARRAY(BoxRec, nBox);
+
+            if (pBoxNew1)
+            {
+                pBoxBase = pBoxNext = pBox + nBox - 1;
+
+                while (pBoxBase >= pBox)
+                {
+                    while ((pBoxNext >= pBox) &&
+                           (pBoxBase->y1 == pBoxNext->y1))
+                        pBoxNext--;
+
+                    pBoxTmp = pBoxNext + 1;
+
+                    while (pBoxTmp <= pBoxBase)
+                        *pBoxNew1++ = *pBoxTmp++;
+
+                    pBoxBase = pBoxNext;
+                }
+
+                pBoxNew1 -= nBox;
+                pBox = pBoxNew1;
+            }
+        }
+
+        if (dx < 0)
+        {
+            /* Sort boxes from right to left */
+            pBoxNew2 = ALLOCATE_LOCAL_ARRAY(BoxRec, nBox);
+
+            if (pBoxNew2)
+            {
+                pBoxBase = pBoxNext = pBox;
+
+                while (pBoxBase < pBox + nBox)
+                {
+                    while ((pBoxNext < pBox + nBox) &&
+                           (pBoxNext->y1 == pBoxBase->y1))
+                        pBoxNext++;
+
+                    pBoxTmp = pBoxNext;
+
+                    while (pBoxTmp != pBoxBase)
+                        *pBoxNew2++ = *--pBoxTmp;
+
+                    pBoxBase = pBoxNext;
+                }
+
+                pBoxNew2 -= nBox;
+                pBox = pBoxNew2;
+            }
+        }
+    }
+
+    while (nBox--)
+    {
+        (*pGC->ops->CopyArea)(pDrawable, pDrawable, pGC,
+            pBox->x1 + dx, pBox->y1 + dy,
+            pBox->x2 - pBox->x1, pBox->y2 - pBox->y1,
+            pBox->x1, pBox->y1);
+
+        pBox++;
+    }
+
+    FreeScratchGC(pGC);
+
+    REGION_DESTROY(pScreen, pRgnDst);
+
+    DEALLOCATE_LOCAL(pBoxNew2);
+    DEALLOCATE_LOCAL(pBoxNew1);
+}
+
+/**************************
+ * Backing store wrappers *
+ **************************/
+
+static void
+miBankSaveAreas(
+    PixmapPtr pPixmap,
+    RegionPtr prgnSave,
+    int       xorg,
+    int       yorg,
+    WindowPtr pWin
+)
+{
+    ScreenPtr   pScreen   = pPixmap->drawable.pScreen;
+    RegionRec   rgnClipped;
+    int         i;
+
+    SCREEN_INIT;
+    SCREEN_SAVE;
+    SCREEN_UNWRAP(BackingStoreFuncs.SaveAreas);
+
+    if (!IS_BANKED(pWin))
+    {
+        (*pScreen->BackingStoreFuncs.SaveAreas)(pPixmap, prgnSave, xorg, yorg,
+            pWin);
+    }
+    else
+    {
+        REGION_INIT(pScreen, &rgnClipped, NullBox, 0);
+        REGION_TRANSLATE(pScreen, prgnSave, xorg, yorg);
+
+        for (i = 0;  i < pScreenPriv->nBanks;  i++)
+        {
+            if (!pScreenPriv->pBanks[i])
+                continue;
+
+            REGION_INTERSECT(pScreen, &rgnClipped,
+                prgnSave, pScreenPriv->pBanks[i]);
+
+            if (REGION_NIL(&rgnClipped))
+                continue;
+
+            SET_SINGLE_BANK(pScreenPriv->pScreenPixmap, -1, -1, i);
+
+            REGION_TRANSLATE(pScreen, &rgnClipped, -xorg, -yorg);
+
+            (*pScreen->BackingStoreFuncs.SaveAreas)(pPixmap, &rgnClipped,
+                xorg, yorg, pWin);
+        }
+
+        REGION_TRANSLATE(pScreen, prgnSave, -xorg, -yorg);
+        REGION_UNINIT(pScreen, &rgnClipped);
+    }
+
+    SCREEN_WRAP(BackingStoreFuncs.SaveAreas, miBankSaveAreas);
+    SCREEN_RESTORE;
+}
+
+static void
+miBankRestoreAreas(
+    PixmapPtr pPixmap,
+    RegionPtr prgnRestore,
+    int       xorg,
+    int       yorg,
+    WindowPtr pWin
+)
+{
+    ScreenPtr   pScreen   = pPixmap->drawable.pScreen;
+    RegionRec   rgnClipped;
+    int         i;
+
+    SCREEN_INIT;
+    SCREEN_SAVE;
+    SCREEN_UNWRAP(BackingStoreFuncs.RestoreAreas);
+
+    if (!IS_BANKED(pWin))
+    {
+        (*pScreen->BackingStoreFuncs.RestoreAreas)(pPixmap, prgnRestore,
+            xorg, yorg, pWin);
+    }
+    else
+    {
+        REGION_INIT(pScreen, &rgnClipped, NullBox, 0);
+
+        for (i = 0;  i < pScreenPriv->nBanks;  i++)
+        {
+            if (!pScreenPriv->pBanks[i])
+                continue;
+
+            REGION_INTERSECT(pScreen, &rgnClipped,
+                prgnRestore, pScreenPriv->pBanks[i]);
+
+            if (REGION_NIL(&rgnClipped))
+                continue;
+
+            SET_SINGLE_BANK(pScreenPriv->pScreenPixmap, -1, -1, i);
+
+            (*pScreen->BackingStoreFuncs.RestoreAreas)(pPixmap, &rgnClipped,
+                xorg, yorg, pWin);
+        }
+
+        REGION_UNINIT(pScreen, &rgnClipped);
+    }
+
+    SCREEN_WRAP(BackingStoreFuncs.RestoreAreas, miBankRestoreAreas);
+    SCREEN_RESTORE;
+}
+
+Bool
+miInitializeBanking(
+    ScreenPtr     pScreen,
+    unsigned int  xsize,
+    unsigned int  ysize,
+    unsigned int  width,
+    miBankInfoPtr pBankInfo
+)
+{
+    miBankScreenPtr pScreenPriv;
+    unsigned long   nBitsPerBank, nBitsPerScanline, nPixelsPerScanlinePadUnit;
+    unsigned long   BankBase, ServerPad;
+    unsigned int    type, iBank, nBanks, maxRects, we, nBankBPP;
+    int             i;
+
+    if (!pBankInfo || !pBankInfo->BankSize)
+        return TRUE;            /* No banking required */
+
+    /* Sanity checks */
+
+    if (!pScreen || !xsize || !ysize || (xsize > width) ||
+        !pBankInfo->SetSourceBank || !pBankInfo->SetDestinationBank ||
+        !pBankInfo->SetSourceAndDestinationBanks ||
+        !pBankInfo->pBankA || !pBankInfo->pBankB ||
+        !pBankInfo->nBankDepth)
+        return FALSE;
+
+    /*
+     * DDX *must* have registered a pixmap format whose depth is
+     * pBankInfo->nBankDepth.  This is not necessarily the rootDepth
+     * pixmap format.
+     */
+    i = 0;
+    while (screenInfo.formats[i].depth != pBankInfo->nBankDepth)
+        if (++i >= screenInfo.numPixmapFormats)
+            return FALSE;
+    nBankBPP = screenInfo.formats[i].bitsPerPixel;
+
+    i = 0;
+    while (screenInfo.formats[i].depth != pScreen->rootDepth)
+        if (++i >= screenInfo.numPixmapFormats)
+            return FALSE;
+
+    if (nBankBPP > screenInfo.formats[i].bitsPerPixel)
+        return FALSE;
+
+    /* Determine banking type */
+    if ((type = miBankDeriveType(pScreen, pBankInfo)) == BANK_NOBANK)
+        return FALSE;
+
+    /* Internal data */
+
+    nBitsPerBank = pBankInfo->BankSize * 8;
+    ServerPad = PixmapBytePad(1, pBankInfo->nBankDepth) * 8;
+    if (nBitsPerBank % ServerPad)
+        return FALSE;
+    nBitsPerScanline = PixmapBytePad(width, pBankInfo->nBankDepth) * 8;
+    nBanks = ((nBitsPerScanline * (ysize - 1)) +
+              (nBankBPP * xsize) + nBitsPerBank - 1) / nBitsPerBank;
+    nPixelsPerScanlinePadUnit = miLCM(ServerPad, nBankBPP) / nBankBPP;
+
+    /* Private areas */
+
+    if (miBankGeneration != serverGeneration)
+    {
+        if (((miBankScreenIndex = AllocateScreenPrivateIndex()) < 0) ||
+            ((miBankGCIndex = AllocateGCPrivateIndex()) < 0))
+            return FALSE;
+
+        miBankGeneration = serverGeneration;
+    }
+
+    if (!AllocateGCPrivate(pScreen, miBankGCIndex,
+        (nBanks * sizeof(RegionPtr)) +
+            (sizeof(miBankGCRec) - sizeof(RegionPtr))))
+        return FALSE;
+
+    if (!(pScreenPriv = (miBankScreenPtr)Xcalloc(sizeof(miBankScreenRec))))
+        return FALSE;
+
+    if (!(pScreenPriv->pBanks =                 /* Allocate and clear */
+        (RegionPtr *)Xcalloc(nBanks * sizeof(RegionPtr))))
+    {
+        Xfree(pScreenPriv);
+        return FALSE;
+    }
+
+    /*
+     * Translate banks into clipping regions which are themselves clipped
+     * against the screen.  This also ensures that pixels with imbedded bank
+     * boundaries are off-screen.
+     */
+
+    BankBase = 0;
+    maxRects = 0;
+    we = 0;
+    for (iBank = 0;  iBank < nBanks;  iBank++)
+    {
+        xRectangle   pRects[3], *pRect = pRects;
+        unsigned int xb, yb, xe, ye;
+
+        xb = ((BankBase + nBankBPP - 1) % nBitsPerScanline) / nBankBPP;
+        yb =  (BankBase + nBankBPP - 1) / nBitsPerScanline;
+        if (xb >= xsize)
+        {
+            xb = we = 0;
+            yb++;
+        }
+        if (yb >= ysize)
+        {
+            we = 0;
+            break;
+        }
+
+        if (we)
+            break;
+
+        BankBase += nBitsPerBank;
+
+        we = (BankBase % nBitsPerScanline) % nBankBPP;
+        xe = (BankBase % nBitsPerScanline) / nBankBPP;
+        ye =  BankBase / nBitsPerScanline;
+        if (xe >= xsize)
+        {
+            we = xe = 0;
+            ye++;
+        }
+        if (ye >= ysize)
+        {
+            we = xe = 0;
+            ye = ysize;
+        }
+
+        if (yb == ye)
+        {
+            if (xb >= xe)
+                continue;
+
+            pRect->x      = xb;
+            pRect->y      = yb;
+            pRect->width  = xe - xb;
+            pRect->height = 1;
+            maxRects += 2;
+            pRect++;
+        }
+        else
+        {
+            if (xb)
+            {
+                pRect->x      = xb;
+                pRect->y      = yb++;
+                pRect->width  = xsize - xb;
+                pRect->height = 1;
+                maxRects += 2;
+                pRect++;
+            }
+
+            if (yb < ye)
+            {
+                pRect->x      = 0;
+                pRect->y      = yb;
+                pRect->width  = xsize;
+                pRect->height = ye - yb;
+                maxRects += min(pRect->height, 3) + 1;
+                pRect++;
+            }
+
+            if (xe)
+            {
+                pRect->x      = 0;
+                pRect->y      = ye;
+                pRect->width  = xe;
+                pRect->height = 1;
+                maxRects += 2;
+                pRect++;
+            }
+        }
+
+        pScreenPriv->pBanks[iBank] =
+            RECTS_TO_REGION(pScreen, pRect - pRects, pRects, 0);
+        if (!pScreenPriv->pBanks[iBank] ||
+            REGION_NAR(pScreenPriv->pBanks[iBank]))
+        {
+            we = 1;
+            break;
+        }
+    }
+
+    if (we && (iBank < nBanks))
+    {
+        for (i = iBank;  i >= 0;  i--)
+            if (pScreenPriv->pBanks[i])
+                REGION_DESTROY(pScreen, pScreenPriv->pBanks[i]);
+
+        Xfree(pScreenPriv->pBanks);
+        Xfree(pScreenPriv);
+
+        return FALSE;
+    }
+
+    /* Open for business */
+
+    pScreenPriv->type = type;
+    pScreenPriv->nBanks = nBanks;
+    pScreenPriv->maxRects = maxRects;
+    pScreenPriv->nBankBPP = nBankBPP;
+    pScreenPriv->BankInfo = *pBankInfo;
+    pScreenPriv->nBitsPerBank = nBitsPerBank;
+    pScreenPriv->nBitsPerScanline = nBitsPerScanline;
+    pScreenPriv->nPixelsPerScanlinePadUnit = nPixelsPerScanlinePadUnit;
+
+    SCREEN_WRAP(CreateScreenResources, miBankCreateScreenResources);
+    SCREEN_WRAP(ModifyPixmapHeader,    miBankModifyPixmapHeader);
+    SCREEN_WRAP(CloseScreen,           miBankCloseScreen);
+    SCREEN_WRAP(GetImage,              miBankGetImage);
+    SCREEN_WRAP(GetSpans,              miBankGetSpans);
+    SCREEN_WRAP(CreateGC,              miBankCreateGC);
+    SCREEN_WRAP(PaintWindowBackground, miBankPaintWindow);
+    SCREEN_WRAP(PaintWindowBorder,     miBankPaintWindow);
+    SCREEN_WRAP(CopyWindow,            miBankCopyWindow);
+
+    pScreenPriv->BackingStoreFuncs     = pScreen->BackingStoreFuncs;
+
+    pScreen->BackingStoreFuncs.SaveAreas      = miBankSaveAreas;
+    pScreen->BackingStoreFuncs.RestoreAreas   = miBankRestoreAreas;
+    /* ??????????????????????????????????????????????????????????????
+    pScreen->BackingStoreFuncs.SetClipmaskRgn = miBankSetClipmaskRgn;
+    ?????????????????????????????????????????????????????????????? */
+
+    BANK_SCRPRIVLVAL = (pointer)pScreenPriv;
+
+    return TRUE;
+}
+
+/* This is used to force GC revalidation when the banking type is changed */
+/*ARGSUSED*/
+static int
+miBankNewSerialNumber(
+    WindowPtr pWin,
+    pointer   unused
+)
+{
+    pWin->drawable.serialNumber = NEXT_SERIAL_NUMBER;
+    return WT_WALKCHILDREN;
+}
+
+/* This entry modifies the banking interface */
+Bool
+miModifyBanking(
+    ScreenPtr     pScreen,
+    miBankInfoPtr pBankInfo
+)
+{
+    unsigned int type;
+
+    if (!pScreen)
+        return FALSE;
+
+    if (miBankGeneration == serverGeneration)
+    {
+        SCREEN_INIT;
+
+        if (pScreenPriv)
+        {
+            if (!pBankInfo || !pBankInfo->BankSize ||
+                !pBankInfo->pBankA || !pBankInfo->pBankB ||
+                !pBankInfo->SetSourceBank || !pBankInfo->SetDestinationBank ||
+                !pBankInfo->SetSourceAndDestinationBanks)
+                return FALSE;
+
+            /* BankSize and nBankDepth cannot, as yet, be changed */
+            if ((pScreenPriv->BankInfo.BankSize != pBankInfo->BankSize) ||
+                (pScreenPriv->BankInfo.nBankDepth != pBankInfo->nBankDepth))
+                return FALSE;
+
+            if ((type = miBankDeriveType(pScreen, pBankInfo)) == BANK_NOBANK)
+                return FALSE;
+
+            /* Reset banking info */
+            pScreenPriv->BankInfo = *pBankInfo;
+            if (type != pScreenPriv->type)
+            {
+                /*
+                 * Banking type is changing.  Revalidate all window GC's.
+                 */
+                pScreenPriv->type = type;
+                WalkTree(pScreen, miBankNewSerialNumber, 0);
+            }
+
+            return TRUE;
+        }
+    }
+
+    if (!pBankInfo || !pBankInfo->BankSize)
+        return TRUE;                            /* No change requested */
+
+    return FALSE;
+}
+
+/*
+ * Given various screen attributes, determine the minimum scanline width such
+ * that each scanline is server and DDX padded and any pixels with imbedded
+ * bank boundaries are off-screen.  This function returns -1 if such a width
+ * cannot exist.  This function exists because the DDX needs to be able to
+ * determine this width before initializing a frame buffer.
+ */
+int
+miScanLineWidth(
+    unsigned int     xsize,         /* pixels */
+    unsigned int     ysize,         /* pixels */
+    unsigned int     width,         /* pixels */
+    unsigned long    BankSize,      /* char's */
+    PixmapFormatRec *pBankFormat,
+    unsigned int     nWidthUnit     /* bits */
+)
+{
+    unsigned long nBitsPerBank, nBitsPerScanline, nBitsPerScanlinePadUnit;
+    unsigned long minBitsPerScanline, maxBitsPerScanline;
+
+    /* Sanity checks */
+
+    if (!nWidthUnit || !pBankFormat)
+        return -1;
+
+    nBitsPerBank = BankSize * 8;
+    if (nBitsPerBank % pBankFormat->scanlinePad)
+        return -1;
+
+    if (xsize > width)
+        width = xsize;
+    nBitsPerScanlinePadUnit = miLCM(pBankFormat->scanlinePad, nWidthUnit);
+    nBitsPerScanline =
+        (((width * pBankFormat->bitsPerPixel) + nBitsPerScanlinePadUnit - 1) /
+         nBitsPerScanlinePadUnit) * nBitsPerScanlinePadUnit;
+    width = nBitsPerScanline / pBankFormat->bitsPerPixel;
+
+    if (!xsize || !(nBitsPerBank % pBankFormat->bitsPerPixel))
+        return (int)width;
+
+    /*
+     * Scanlines will be server-pad aligned at this point.  They will also be
+     * a multiple of nWidthUnit bits long.  Ensure that pixels with imbedded
+     * bank boundaries are off-screen.
+     *
+     * It seems reasonable to limit total frame buffer size to 1/16 of the
+     * theoretical maximum address space size.  On a machine with 32-bit
+     * addresses (to 8-bit quantities) this turns out to be 256MB.  Not only
+     * does this provide a simple limiting condition for the loops below, but
+     * it also prevents unsigned long wraparounds.
+     */
+    if (!ysize)
+        return -1;
+
+    minBitsPerScanline = xsize * pBankFormat->bitsPerPixel;
+    if (minBitsPerScanline > nBitsPerBank)
+        return -1;
+
+    if (ysize == 1)
+        return (int)width;
+
+    maxBitsPerScanline =
+        (((unsigned long)(-1) >> 1) - minBitsPerScanline) / (ysize - 1);
+    while (nBitsPerScanline <= maxBitsPerScanline)
+    {
+        unsigned long BankBase, BankUnit;
+
+        BankUnit = ((nBitsPerBank + nBitsPerScanline - 1) / nBitsPerBank) *
+            nBitsPerBank;
+        if (!(BankUnit % nBitsPerScanline))
+            return (int)width;
+
+        for (BankBase = BankUnit;  ;  BankBase += nBitsPerBank)
+        {
+            unsigned long x, y;
+
+            y = BankBase / nBitsPerScanline;
+            if (y >= ysize)
+                return (int)width;
+
+            x = BankBase % nBitsPerScanline;
+            if (!(x % pBankFormat->bitsPerPixel))
+                continue;
+
+            if (x < minBitsPerScanline)
+            {
+                /*
+                 * Skip ahead certain widths by dividing the excess scanline
+                 * amongst the y's.
+                 */
+                y *= nBitsPerScanlinePadUnit;
+                nBitsPerScanline +=
+                    ((x + y - 1) / y) * nBitsPerScanlinePadUnit;
+                width = nBitsPerScanline / pBankFormat->bitsPerPixel;
+                break;
+            }
+
+            if (BankBase != BankUnit)
+                continue;
+
+            if (!(nBitsPerScanline % x))
+                return (int)width;
+
+            BankBase = ((nBitsPerScanline - minBitsPerScanline) /
+                (nBitsPerScanline - x)) * BankUnit;
+        }
+    }
+
+    return -1;
+}