TinyX/render/mitrap.c

/*
 *
 * Copyright © 2002 Keith Packard, member of The XFree86 Project, Inc.
 *
 * 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.
 */

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

#include "scrnintstr.h"
#include "gcstruct.h"
#include "pixmapstr.h"
#include "windowstr.h"
#include "servermd.h"
#include "mi.h"
#include "picturestr.h"
#include "mipict.h"

PicturePtr
miCreateAlphaPicture(ScreenPtr pScreen,
                     PicturePtr pDst,
                     PictFormatPtr pPictFormat, CARD16 width, CARD16 height)
{
    PixmapPtr pPixmap;

    PicturePtr pPicture;

    GCPtr pGC;

    int error;

    xRectangle rect;

    if (width > 32767 || height > 32767)
        return 0;

    if (!pPictFormat) {
        if (pDst->polyEdge == PolyEdgeSharp)
            pPictFormat = PictureMatchFormat(pScreen, 1, PICT_a1);
        else
            pPictFormat = PictureMatchFormat(pScreen, 8, PICT_a8);
        if (!pPictFormat)
            return 0;
    }

    pPixmap = (*pScreen->CreatePixmap) (pScreen, width, height,
                                        pPictFormat->depth);
    if (!pPixmap)
        return 0;
    pGC = GetScratchGC(pPixmap->drawable.depth, pScreen);
    if (!pGC) {
        (*pScreen->DestroyPixmap) (pPixmap);
        return 0;
    }
    ValidateGC(&pPixmap->drawable, pGC);
    rect.x = 0;
    rect.y = 0;
    rect.width = width;
    rect.height = height;
    (*pGC->ops->PolyFillRect) (&pPixmap->drawable, pGC, 1, &rect);
    FreeScratchGC(pGC);
    pPicture = CreatePicture(0, &pPixmap->drawable, pPictFormat,
                             0, 0, serverClient, &error);
    (*pScreen->DestroyPixmap) (pPixmap);
    return pPicture;
}

static xFixed
miLineFixedX(xLineFixed * l, xFixed y, Bool ceil)
{
    xFixed dx = l->p2.x - l->p1.x;

    xFixed_32_32 ex = (xFixed_32_32) (y - l->p1.y) * dx;

    xFixed dy = l->p2.y - l->p1.y;

    if (ceil)
        ex += (dy - 1);
    return l->p1.x + (xFixed) (ex / dy);
}

void
miTrapezoidBounds(int ntrap, xTrapezoid * traps, BoxPtr box)
{
    box->y1 = MAXSHORT;
    box->y2 = MINSHORT;
    box->x1 = MAXSHORT;
    box->x2 = MINSHORT;
    for (; ntrap; ntrap--, traps++) {
        INT16 x1, y1, x2, y2;

        if (!xTrapezoidValid(traps))
            continue;
        y1 = xFixedToInt(traps->top);
        if (y1 < box->y1)
            box->y1 = y1;

        y2 = xFixedToInt(xFixedCeil(traps->bottom));
        if (y2 > box->y2)
            box->y2 = y2;

        x1 = xFixedToInt(min(miLineFixedX(&traps->left, traps->top, FALSE),
                             miLineFixedX(&traps->left, traps->bottom, FALSE)));
        if (x1 < box->x1)
            box->x1 = x1;

        x2 = xFixedToInt(xFixedCeil
                         (max
                          (miLineFixedX(&traps->right, traps->top, TRUE),
                           miLineFixedX(&traps->right, traps->bottom, TRUE))));
        if (x2 > box->x2)
            box->x2 = x2;
    }
}

void
miTrapezoids(CARD8 op,
             PicturePtr pSrc,
             PicturePtr pDst,
             PictFormatPtr maskFormat,
             INT16 xSrc, INT16 ySrc, int ntrap, xTrapezoid * traps)
{
    ScreenPtr pScreen = pDst->pDrawable->pScreen;

    PictureScreenPtr ps = GetPictureScreen(pScreen);

    /*
     * Check for solid alpha add
     */
    if (op == PictOpAdd && miIsSolidAlpha(pSrc)) {
        for (; ntrap; ntrap--, traps++)
            (*ps->RasterizeTrapezoid) (pDst, traps, 0, 0);
    }
    else if (maskFormat) {
        PicturePtr pPicture;

        BoxRec bounds;

        INT16 xDst, yDst;

        INT16 xRel, yRel;

        xDst = traps[0].left.p1.x >> 16;
        yDst = traps[0].left.p1.y >> 16;

        miTrapezoidBounds(ntrap, traps, &bounds);
        if (bounds.y1 >= bounds.y2 || bounds.x1 >= bounds.x2)
            return;
        pPicture = miCreateAlphaPicture(pScreen, pDst, maskFormat,
                                        bounds.x2 - bounds.x1,
                                        bounds.y2 - bounds.y1);
        if (!pPicture)
            return;
        for (; ntrap; ntrap--, traps++)
            (*ps->RasterizeTrapezoid) (pPicture, traps, -bounds.x1, -bounds.y1);
        xRel = bounds.x1 + xSrc - xDst;
        yRel = bounds.y1 + ySrc - yDst;
        CompositePicture(op, pSrc, pPicture, pDst,
                         xRel, yRel, 0, 0, bounds.x1, bounds.y1,
                         bounds.x2 - bounds.x1, bounds.y2 - bounds.y1);
        FreePicture(pPicture, 0);
    }
    else {
        if (pDst->polyEdge == PolyEdgeSharp)
            maskFormat = PictureMatchFormat(pScreen, 1, PICT_a1);
        else
            maskFormat = PictureMatchFormat(pScreen, 8, PICT_a8);
        for (; ntrap; ntrap--, traps++)
            miTrapezoids(op, pSrc, pDst, maskFormat, xSrc, ySrc, 1, traps);
    }
}