xserver/hw/xfree86/xaa/xaaFillArc.c

/*
 * Copyright 1996  The XFree86 Project
 *
 * 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 
 * HARM HANEMAAYER 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.
 * 
 * Written by Harm Hanemaayer (H.Hanemaayer@inter.nl.net).
 */
 
/*
 * Filled solid arcs, based on cfbfillarc.c.
 *
 * Fill arc using calls to low-level span fill. Because the math for
 * each span can be done concurrently with the drawing of the span
 * with a graphics coprocessor operation, this is faster than just
 * using miPolyFillArc, which first calculates all the spans and then
 * calls FillSpans.
 *
 * Clipped arcs are dispatched to FillSpans.
 */
#ifdef HAVE_XORG_CONFIG_H
#include <xorg-config.h>
#endif

#include <limits.h>

#include "misc.h"
#include "xf86.h"
#include "xf86_OSproc.h"

#include <X11/X.h>
#include "scrnintstr.h"
#include "pixmapstr.h"
#include "xf86str.h"
#include "xaa.h"
#include "xaalocal.h"
#include "mifillarc.h"
#include "mi.h"

/*
 * This is based on the integer-math versions from mi. Perhaps on a
 * Pentium, the floating-point (double)-math version is faster.
 */

static void
XAAFillEllipseSolid(DrawablePtr pDraw, GCPtr pGC, xArc *arc)
{
    XAAInfoRecPtr infoRec = GET_XAAINFORECPTR_FROM_GC(pGC);
    register int x, y, e;
    int yk, xk, ym, xm, dx, dy, xorg, yorg;
    int slw;
    miFillArcRec info;

    (*infoRec->SetupForSolidFill)(infoRec->pScrn, pGC->fgPixel, pGC->alu,
		pGC->planemask);

    miFillArcSetup(arc, &info);
    MIFILLARCSETUP();
    if (pGC->miTranslate)
    {
	xorg += pDraw->x;
	yorg += pDraw->y;
    }
    while (y > 0)
    {
	MIFILLARCSTEP(slw);
	if (slw > 0) {
	    (*infoRec->SubsequentSolidFillRect)(infoRec->pScrn, xorg - x,
		    yorg - y, slw, 1);
            if (miFillArcLower(slw))
		(*infoRec->SubsequentSolidFillRect)(infoRec->pScrn,
			xorg - x, yorg + y + dy, slw, 1);
	}
    }

    SET_SYNC_FLAG(infoRec);
}


#define ADDSPAN(l,r) \
    if (r >= l) \
	(*infoRec->SubsequentSolidFillRect)( \
	    infoRec->pScrn, l, ya, r - l + 1, 1);

#define ADDSLICESPANS(flip) \
    if (!flip) \
    { \
	ADDSPAN(xl, xr); \
    } \
    else \
    { \
	xc = xorg - x; \
	ADDSPAN(xc, xr); \
	xc += slw - 1; \
	ADDSPAN(xl, xc); \
    }

static void
XAAFillArcSliceSolid(DrawablePtr pDraw, GCPtr pGC, xArc *arc)
{ 
    XAAInfoRecPtr infoRec = GET_XAAINFORECPTR_FROM_GC(pGC);
    int yk, xk, ym, xm, dx, dy, xorg, yorg, slw;
    register int x, y, e;
    miFillArcRec info;
    miArcSliceRec slice;
    int ya, xl, xr, xc;

    (*infoRec->SetupForSolidFill)(infoRec->pScrn, pGC->fgPixel, pGC->alu,
        pGC->planemask);

    miFillArcSetup(arc, &info);
    miFillArcSliceSetup(arc, &slice, pGC);
    MIFILLARCSETUP();
    slw = arc->height;
    if (slice.flip_top || slice.flip_bot)
	slw += (arc->height >> 1) + 1;
    if (pGC->miTranslate)
    {
	xorg += pDraw->x;
	yorg += pDraw->y;
	slice.edge1.x += pDraw->x;
	slice.edge2.x += pDraw->x;
    }
    while (y > 0)
    {
	MIFILLARCSTEP(slw);
	MIARCSLICESTEP(slice.edge1);
	MIARCSLICESTEP(slice.edge2);
	if (miFillSliceUpper(slice))
	{
	    ya = yorg - y;
	    MIARCSLICEUPPER(xl, xr, slice, slw);
	    
	    ADDSLICESPANS(slice.flip_top);
	}
	if (miFillSliceLower(slice))
	{
	    ya = yorg + y + dy;
	    MIARCSLICELOWER(xl, xr, slice, slw);
	    ADDSLICESPANS(slice.flip_bot);
	}
    }

    SET_SYNC_FLAG(infoRec);
}


void
XAAPolyFillArcSolid(DrawablePtr pDraw, GCPtr pGC, int narcs, xArc *parcs)
{
    register xArc *arc;
    register int i;
    int x2, y2;
    BoxRec box;
    RegionPtr cclip;

    cclip = pGC->pCompositeClip;

    if(!REGION_NUM_RECTS(cclip))
	return;

    for (arc = parcs, i = narcs; --i >= 0; arc++)
    {
	if (miFillArcEmpty(arc))
	    continue;
	if (miCanFillArc(arc))
	{
	    box.x1 = arc->x + pDraw->x;
	    box.y1 = arc->y + pDraw->y;
 	    /*
 	     * Because box.x2 and box.y2 get truncated to 16 bits, and the
 	     * RECT_IN_REGION test treats the resulting number as a signed
 	     * integer, the RECT_IN_REGION test alone can go the wrong way.
 	     * This can result in a server crash because the rendering
 	     * routines in this file deal directly with cpu addresses
 	     * of pixels to be stored, and do not clip or otherwise check
 	     * that all such addresses are within their respective pixmaps.
 	     * So we only allow the RECT_IN_REGION test to be used for
 	     * values that can be expressed correctly in a signed short.
 	     */
 	    x2 = box.x1 + (int)arc->width + 1;
 	    box.x2 = x2;
 	    y2 = box.y1 + (int)arc->height + 1;
 	    box.y2 = y2;
 	    if ( (x2 <= SHRT_MAX) && (y2 <= SHRT_MAX) &&
 		    (RECT_IN_REGION(pDraw->pScreen, cclip, &box) == rgnIN) )
	    {
		if ((arc->angle2 >= FULLCIRCLE) ||
		    (arc->angle2 <= -FULLCIRCLE))
		    XAAFillEllipseSolid(pDraw, pGC, arc);
		else
		    XAAFillArcSliceSolid(pDraw, pGC, arc);
		continue;
	    }
	}
	miPolyFillArc(pDraw, pGC, 1, arc);
    }
}