/*
 *
 * Copyright © 2000 Keith Packard
 *
 * 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 Keith Packard not be used in
 * advertising or publicity pertaining to distribution of the software without
 * specific, written prior permission.  Keith Packard makes no
 * representations about the suitability of this software for any purpose.  It
 * is provided "as is" without express or implied warranty.
 *
 * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL KEITH PACKARD 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.
 */

/*
 * Thanks to Daniel Chemko <dchemko@intrinsyc.com> for making the 90 and 180
 * orientations work.
 */

#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#include <stdlib.h>

#include    <X11/X.h>
#include    "scrnintstr.h"
#include    "windowstr.h"
#include    <X11/fonts/font.h>
#include    "dixfontstr.h"
#include    <X11/fonts/fontstruct.h>
#include    "mi.h"
#include    "regionstr.h"
#include    "globals.h"
#include    "gcstruct.h"
#include    "shadow.h"
#include    "fb.h"

#define DANDEBUG         0

#if ROTATE == 270

#define SCRLEFT(x,y,w,h)    (pScreen->height - ((y) + (h)))
#define SCRY(x,y,w,h)	    (x)
#define SCRWIDTH(x,y,w,h)   (h)
#define FIRSTSHA(x,y,w,h)   (((y) + (h) - 1) * shaStride + (x))
#define STEPDOWN(x,y,w,h)   ((w)--)
#define NEXTY(x,y,w,h)	    ((x)++)
#define SHASTEPX(stride)    -(stride)
#define SHASTEPY(stride)    (1)

#elif ROTATE == 90

#define SCRLEFT(x,y,w,h)    (y)
#define SCRY(x,y,w,h)	    (pScreen->width - ((x) + (w)) - 1)
#define SCRWIDTH(x,y,w,h)   (h)
#define FIRSTSHA(x,y,w,h)   ((y) * shaStride + (x + w - 1))
#define STEPDOWN(x,y,w,h)   ((w)--)
#define NEXTY(x,y,w,h)	    ((void)(x))
#define SHASTEPX(stride)    (stride)
#define SHASTEPY(stride)    (-1)

#elif ROTATE == 180

#define SCRLEFT(x,y,w,h)    (pScreen->width - ((x) + (w)))
#define SCRY(x,y,w,h)	    (pScreen->height - ((y) + (h)) - 1)
#define SCRWIDTH(x,y,w,h)   (w)
#define FIRSTSHA(x,y,w,h)   ((y + h - 1) * shaStride + (x + w - 1))
#define STEPDOWN(x,y,w,h)   ((h)--)
#define NEXTY(x,y,w,h)	    ((void)(y))
#define SHASTEPX(stride)    (-1)
#define SHASTEPY(stride)    -(stride)

#else

#define SCRLEFT(x,y,w,h)    (x)
#define SCRY(x,y,w,h)	    (y)
#define SCRWIDTH(x,y,w,h)   (w)
#define FIRSTSHA(x,y,w,h)   ((y) * shaStride + (x))
#define STEPDOWN(x,y,w,h)   ((h)--)
#define NEXTY(x,y,w,h)	    ((y)++)
#define SHASTEPX(stride)    (1)
#define SHASTEPY(stride)    (stride)

#endif

_X_EXPORT void
FUNC (ScreenPtr	    pScreen,
      shadowBufPtr  pBuf)
{
    RegionPtr	damage = shadowDamage (pBuf);
    PixmapPtr	pShadow = pBuf->pPixmap;
    int		nbox = REGION_NUM_RECTS (damage);
    BoxPtr	pbox = REGION_RECTS (damage);
    FbBits	*shaBits;
    Data	*shaBase, *shaLine, *sha;
    FbStride	shaStride;
    int		scrBase, scrLine, scr;
    int		shaBpp;
    int		shaXoff, shaYoff;   /* XXX assumed to be zero */
    int		x, y, w, h, width;
    int         i;
    Data	*winBase = NULL, *win;
    CARD32	winSize;

    fbGetDrawable (&pShadow->drawable, shaBits, shaStride, shaBpp, shaXoff, shaYoff);
    shaBase = (Data *) shaBits;
    shaStride = shaStride * sizeof (FbBits) / sizeof (Data);
#if (DANDEBUG > 1)
    ErrorF ("-> Entering Shadow Update:\r\n   |- Origins: pShadow=%x, pScreen=%x, damage=%x\r\n   |- Metrics: shaStride=%d, shaBase=%x, shaBpp=%d\r\n   |                                                     \n", pShadow, pScreen, damage, shaStride, shaBase, shaBpp);
#endif
    while (nbox--)
    {
        x = pbox->x1;
        y = pbox->y1;
        w = (pbox->x2 - pbox->x1);
        h = pbox->y2 - pbox->y1;
        
#if (DANDEBUG > 2)
        ErrorF ("   |-> Redrawing box - Metrics: X=%d, Y=%d, Width=%d, Height=%d\n", x, y, w, h);
#endif
        scrLine = SCRLEFT(x,y,w,h);
        shaLine = shaBase + FIRSTSHA(x,y,w,h);
        
        while (STEPDOWN(x,y,w,h))
        {
            winSize = 0;
            scrBase = 0;
            width = SCRWIDTH(x,y,w,h);
            scr = scrLine;
            sha = shaLine;
#if (DANDEBUG > 3)
            ErrorF ("   |   |-> StepDown - Metrics: width=%d, scr=%x, sha=%x\n", width, scr, sha);
#endif
            while (width)
            {
                /*  how much remains in this window */
                i = scrBase + winSize - scr;
                if (i <= 0 || scr < scrBase)
                {
                    winBase = (Data *) (*pBuf->window) (pScreen,
							SCRY(x,y,w,h),
							scr * sizeof (Data),
							SHADOW_WINDOW_WRITE,
							&winSize,
							pBuf->closure);
                    if(!winBase)
                        return;
                    scrBase = scr;
                    winSize /= sizeof (Data);
                    i = winSize;
#if(DANDEBUG > 4)
                    ErrorF ("   |   |   |-> Starting New Line - Metrics: winBase=%x, scrBase=%x, winSize=%d\r\n   |   |   |   Xstride=%d, Ystride=%d, w=%d h=%d\n", winBase, scrBase, winSize, SHASTEPX(shaStride), SHASTEPY(shaStride), w, h);
#endif
                }
                win = winBase + (scr - scrBase);
                if (i > width)
                    i = width;
                width -= i;
                scr += i;
#if(DANDEBUG > 5)
		ErrorF ("   |   |   |-> Writing Line - Metrics: win=%x, sha=%x\n", win, sha);
#endif
                while (i--)
                {
#if(DANDEBUG > 6)
		    ErrorF ("   |   |   |-> Writing Pixel - Metrics: win=%x, sha=%d, remaining=%d\n", win, sha, i);
#endif
                    *win++ = *sha;
                    sha += SHASTEPX(shaStride);
                } /*  i */
            } /*  width */
            shaLine += SHASTEPY(shaStride);
            NEXTY(x,y,w,h);
        } /*  STEPDOWN */
        pbox++;
    } /*  nbox */
}