/*
 * Common rootless definitions and code
 */
/*
 * Copyright (c) 2001 Greg Parker. All Rights Reserved.
 * Copyright (c) 2002-2003 Torrey T. Lyons. All Rights Reserved.
 * Copyright (c) 2002 Apple Computer, Inc. All rights reserved.
 *
 * 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
 * THE ABOVE LISTED COPYRIGHT HOLDER(S) 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(s) of the above copyright
 * holders shall not be used in advertising or otherwise to promote the sale,
 * use or other dealings in this Software without prior written authorization.
 */

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

#include <stddef.h> /* For NULL */
#include <limits.h> /* For CHAR_BIT */

#include "rootlessCommon.h"

unsigned int rootless_CopyBytes_threshold = 0;
unsigned int rootless_FillBytes_threshold = 0;
unsigned int rootless_CompositePixels_threshold = 0;
unsigned int rootless_CopyWindow_threshold = 0;
#ifdef ROOTLESS_GLOBAL_COORDS
int rootlessGlobalOffsetX = 0;
int rootlessGlobalOffsetY = 0;
#endif

RegionRec rootlessHugeRoot = {{-32767, -32767, 32767, 32767}, NULL};

/* Following macro from miregion.c */

/*  true iff two Boxes overlap */
#define EXTENTCHECK(r1,r2) \
      (!( ((r1)->x2 <= (r2)->x1)  || \
          ((r1)->x1 >= (r2)->x2)  || \
          ((r1)->y2 <= (r2)->y1)  || \
          ((r1)->y1 >= (r2)->y2) ) )


/*
 * TopLevelParent
 *  Returns the top-level parent of pWindow.
 *  The root is the top-level parent of itself, even though the root is
 *  not otherwise considered to be a top-level window.
 */
WindowPtr
TopLevelParent(WindowPtr pWindow)
{
    WindowPtr top;

    if (IsRoot(pWindow))
        return pWindow;

    top = pWindow;
    while (top && ! IsTopLevel(top))
        top = top->parent;

    return top;
}


/*
 * IsFramedWindow
 *  Returns TRUE if this window is visible inside a frame
 *  (e.g. it is visible and has a top-level or root parent)
 */
Bool
IsFramedWindow(WindowPtr pWin)
{
    WindowPtr top;

    if (!pWin->realized)
        return FALSE;
    top = TopLevelParent(pWin);

    return (top && WINREC(top));
}


/*
 * RootlessStartDrawing
 *  Prepare a window for direct access to its backing buffer.
 *  Each top-level parent has a Pixmap representing its backing buffer,
 *  which all of its children inherit.
 */
void RootlessStartDrawing(WindowPtr pWindow)
{
    ScreenPtr pScreen = pWindow->drawable.pScreen;
    WindowPtr top = TopLevelParent(pWindow);
    RootlessWindowRec *winRec;

    if (top == NULL)
        return;
    winRec = WINREC(top);
    if (winRec == NULL)
        return;

    // Make sure the window's top-level parent is prepared for drawing.
    if (!winRec->is_drawing) {
        int bw = wBorderWidth(top);

        SCREENREC(pScreen)->imp->StartDrawing(winRec->wid, &winRec->pixelData,
                                              &winRec->bytesPerRow);

        winRec->pixmap =
            GetScratchPixmapHeader(pScreen, winRec->width, winRec->height,
                                   top->drawable.depth,
                                   top->drawable.bitsPerPixel,
                                   winRec->bytesPerRow,
                                   winRec->pixelData);
        SetPixmapBaseToScreen(winRec->pixmap,
                              top->drawable.x - bw, top->drawable.y - bw);

        winRec->is_drawing = TRUE;
    }

    winRec->oldPixmap = pScreen->GetWindowPixmap(pWindow);
    pScreen->SetWindowPixmap(pWindow, winRec->pixmap);
}


/*
 * RootlessStopDrawing
 *  Stop drawing to a window's backing buffer. If flush is true,
 *  damaged regions are flushed to the screen.
 */
void RootlessStopDrawing(WindowPtr pWindow, Bool flush)
{
    ScreenPtr pScreen = pWindow->drawable.pScreen;
    WindowPtr top = TopLevelParent(pWindow);
    RootlessWindowRec *winRec;

    if (top == NULL)
        return;
    winRec = WINREC(top);
    if (winRec == NULL)
        return;

    if (winRec->is_drawing) {
        SCREENREC(pScreen)->imp->StopDrawing(winRec->wid, flush);

        FreeScratchPixmapHeader(winRec->pixmap);
        pScreen->SetWindowPixmap(pWindow, winRec->oldPixmap);
        winRec->pixmap = NULL;

        winRec->is_drawing = FALSE;
    }
    else if (flush) {
        SCREENREC(pScreen)->imp->UpdateRegion(winRec->wid, NULL);
    }

    if (flush && winRec->is_reorder_pending) {
        winRec->is_reorder_pending = FALSE;
        RootlessReorderWindow(pWindow);
    }
}


/*
 * RootlessDamageRegion
 *  Mark a damaged region as requiring redisplay to screen.
 *  pRegion is in GLOBAL coordinates.
 */
void
RootlessDamageRegion(WindowPtr pWindow, RegionPtr pRegion)
{
    ScreenPtr pScreen = pWindow->drawable.pScreen;
    RootlessWindowRec *winRec;
    RegionRec clipped;
    WindowPtr pTop;
    BoxPtr b1, b2;

    RL_DEBUG_MSG("Damaged win 0x%x ", pWindow);

    pTop = TopLevelParent(pWindow);
    if (pTop == NULL)
        return;

    winRec = WINREC(pTop);
    if (winRec == NULL)
        return;

    /* We need to intersect the drawn region with the clip of the window
       to avoid marking places we didn't actually draw (which can cause
       problems when the window has an extra client-side backing store)

       But this is a costly operation and since we'll normally just be
       drawing inside the clip, go to some lengths to avoid the general
       case intersection. */

    b1 = REGION_EXTENTS(pScreen, &pWindow->borderClip);
    b2 = REGION_EXTENTS(pScreen, pRegion);

    if (EXTENTCHECK(b1, b2)) {
        /* Regions may overlap. */

        if (REGION_NUM_RECTS(pRegion) == 1) {
            int in;

            /* Damaged region only has a single rect, so we can
               just compare that against the region */

            in = RECT_IN_REGION(pScreen, &pWindow->borderClip,
                                REGION_RECTS (pRegion));
            if (in == rgnIN) {
            /* clip totally contains pRegion */

#ifdef ROOTLESS_TRACK_DAMAGE
                REGION_UNION(pScreen, &winRec->damage,
                                 &winRec->damage, (pRegion));
#else
                SCREENREC(pScreen)->imp->DamageRects(winRec->wid,
                                REGION_NUM_RECTS(pRegion),
                                REGION_RECTS(pRegion),
                                -winRec->x, -winRec->y);
#endif

                RootlessQueueRedisplay(pTop->drawable.pScreen);
                goto out;
            }
            else if (in == rgnOUT) {
                /* clip doesn't contain pRegion */

                goto out;
            }
        }

        /* clip overlaps pRegion, need to intersect */

        REGION_NULL(pScreen, &clipped);
        REGION_INTERSECT(pScreen, &clipped, &pWindow->borderClip, pRegion);

#ifdef ROOTLESS_TRACK_DAMAGE
        REGION_UNION(pScreen, &winRec->damage,
                     &winRec->damage, (pRegion));
#else
        SCREENREC(pScreen)->imp->DamageRects(winRec->wid,
                        REGION_NUM_RECTS(&clipped),
                        REGION_RECTS(&clipped),
                        -winRec->x, -winRec->y);
#endif

        REGION_UNINIT(pScreen, &clipped);

        RootlessQueueRedisplay(pTop->drawable.pScreen);
    }

out:
#ifdef ROOTLESSDEBUG
    {
        BoxRec *box = REGION_RECTS(pRegion), *end;
        int numBox = REGION_NUM_RECTS(pRegion);

        for (end = box+numBox; box < end; box++) {
            RL_DEBUG_MSG("Damage rect: %i, %i, %i, %i\n",
                         box->x1, box->x2, box->y1, box->y2);
        }
    }
#endif
    return;
}


/*
 * RootlessDamageBox
 *  Mark a damaged box as requiring redisplay to screen.
 *  pRegion is in GLOBAL coordinates.
 */
void
RootlessDamageBox(WindowPtr pWindow, BoxPtr pBox)
{
    RegionRec region;

    REGION_INIT(pWindow->drawable.pScreen, &region, pBox, 1);

    RootlessDamageRegion(pWindow, &region);

    REGION_UNINIT(pWindow->drawable.pScreen, &region);  /* no-op */
}


/*
 * RootlessDamageRect
 *  Mark a damaged rectangle as requiring redisplay to screen.
 *  (x, y, w, h) is in window-local coordinates.
 */
void
RootlessDamageRect(WindowPtr pWindow, int x, int y, int w, int h)
{
    BoxRec box;
    RegionRec region;

    x += pWindow->drawable.x;
    y += pWindow->drawable.y;

    box.x1 = x;
    box.x2 = x + w;
    box.y1 = y;
    box.y2 = y + h;

    REGION_INIT(pWindow->drawable.pScreen, &region, &box, 1);

    RootlessDamageRegion(pWindow, &region);

    REGION_UNINIT(pWindow->drawable.pScreen, &region);  /* no-op */
}


/*
 * RootlessRedisplay
 *  Stop drawing and redisplay the damaged region of a window.
 */
void
RootlessRedisplay(WindowPtr pWindow)
{
#ifdef ROOTLESS_TRACK_DAMAGE

    RootlessWindowRec *winRec = WINREC(pWindow);
    ScreenPtr pScreen = pWindow->drawable.pScreen;

    RootlessStopDrawing(pWindow, FALSE);

    if (REGION_NOTEMPTY(pScreen, &winRec->damage)) {
        RL_DEBUG_MSG("Redisplay Win 0x%x, %i x %i @ (%i, %i)\n",
                     pWindow, winRec->width, winRec->height,
                     winRec->x, winRec->y);

        // move region to window local coords
        REGION_TRANSLATE(pScreen, &winRec->damage,
                         -winRec->x, -winRec->y);

        SCREENREC(pScreen)->imp->UpdateRegion(winRec->wid, &winRec->damage);

        REGION_EMPTY(pScreen, &winRec->damage);
    }

#else   /* !ROOTLESS_TRACK_DAMAGE */

    RootlessStopDrawing(pWindow, TRUE);

#endif
}


/*
 * RootlessRepositionWindows
 *  Reposition all windows on a screen to their correct positions.
 */
void
RootlessRepositionWindows(ScreenPtr pScreen)
{
    WindowPtr root = WindowTable[pScreen->myNum];
    WindowPtr win;

    if (root != NULL) {
        RootlessRepositionWindow(root);

        for (win = root->firstChild; win; win = win->nextSib) {
            if (WINREC(win) != NULL)
                RootlessRepositionWindow(win);
        }
    }
}


/*
 * RootlessRedisplayScreen
 *  Walk every window on a screen and redisplay the damaged regions.
 */
void
RootlessRedisplayScreen(ScreenPtr pScreen)
{
    WindowPtr root = WindowTable[pScreen->myNum];

    if (root != NULL) {
        WindowPtr win;

        RootlessRedisplay(root);
        for (win = root->firstChild; win; win = win->nextSib) {
            if (WINREC(win) != NULL) {
                RootlessRedisplay(win);
            }
        }
    }
}