/* $XFree86: xc/programs/Xserver/cfb/cfbzerarc.c,v 3.3 2001/12/14 19:59:25 dawes Exp $ */
/************************************************************

Copyright 1989, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
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The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

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Except as contained in this notice, the name of The Open Group shall not be
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in this Software without prior written authorization from The Open Group.

********************************************************/

/* $Xorg: cfbzerarc.c,v 1.4 2001/02/09 02:04:39 xorgcvs Exp $ */

/* Derived from:
 * "Algorithm for drawing ellipses or hyperbolae with a digital plotter"
 * by M. L. V. Pitteway
 * The Computer Journal, November 1967, Volume 10, Number 3, pp. 282-289
 */

#include "X.h"
#include "Xprotostr.h"
#include "miscstruct.h"
#include "gcstruct.h"
#include "pixmapstr.h"
#include "scrnintstr.h"
#include "cfb.h"
#include "cfbmskbits.h"
#include "mizerarc.h"
#include "cfbrrop.h"
#include "mi.h"

#ifdef PIXEL_ADDR

static void
RROP_NAME(cfbZeroArcSS8) (pDraw, pGC, arc)
    DrawablePtr pDraw;
    GCPtr pGC;
    xArc *arc;
{
    miZeroArcRec info;
    Bool do360;
    register int x;
    PixelType *addrp;
    register PixelType *yorgp, *yorgop;
#if PSZ == 24
    int xorg, xorg3, xorgo, xorgo3;
    register int xtmp;
#endif
    RROP_DECLARE
    register int yoffset;
    int npwidth, dyoffset;
    register int y, a, b, d, mask;
    register int k1, k3, dx, dy;

    cfbGetPixelWidthAndPointer(pDraw,npwidth, addrp)

    RROP_FETCH_GC (pGC);
    do360 = miZeroArcSetup(arc, &info, TRUE);
    yorgp = addrp + ((info.yorg + pDraw->y) * npwidth);
    yorgop = addrp + ((info.yorgo + pDraw->y) * npwidth);
    info.xorg += pDraw->x;
    info.xorgo += pDraw->x;
#if PSZ == 24
    xorg = info.xorg;
    xorg3 = xorg * 3;
    info.xorg = (info.xorg * 3) >> 2;
    xorgo = info.xorgo;
    xorgo3 = xorgo * 3; 
    info.xorgo = (info.xorgo * 3) >> 2;
#endif
    MIARCSETUP();
    yoffset = y ? npwidth : 0;
    dyoffset = 0;
    mask = info.initialMask;
    if (!(arc->width & 1))
    {
#if PSZ == 24
	if (mask & 2)
	    RROP_SOLID24((yorgp + info.xorgo), xorgo);
	if (mask & 8)
	    RROP_SOLID24((yorgop + info.xorgo), xorgo);
#else
	if (mask & 2)
	    RROP_SOLID((yorgp + info.xorgo));
	if (mask & 8)
	    RROP_SOLID((yorgop + info.xorgo));
#endif /* PSZ == 24 */
    }
    if (!info.end.x || !info.end.y)
    {
	mask = info.end.mask;
	info.end = info.altend;
    }
    if (do360 && (arc->width == arc->height) && !(arc->width & 1))
    {
	register int xoffset = npwidth;
#if PSZ == 24
	PixelType *yorghb = yorgp + (info.h * npwidth);
	register int tmp1, tmp2, tmp1_3, tmp2_3;

	tmp1 = xorg + info.h;
	tmp1_3 = tmp1 * 3;
	tmp2 = xorg - info.h;
	tmp2_3 = tmp2 * 3;
	while (1)
	{
	    xtmp = (xorg3 + x * 3) >> 2;
	    RROP_SOLID24(yorgp + yoffset + xtmp, xorg + x);
	    RROP_SOLID24(yorgop - yoffset + xtmp, xorg + x);
	    xtmp = (xorg3 - x * 3) >> 2;
	    RROP_SOLID24(yorgp + yoffset + xtmp, xorg - x);
	    RROP_SOLID24(yorgop - yoffset + xtmp, xorg - x);
	    if (a < 0)
		break;
	    xtmp = (tmp1_3 - y * 3) >> 2;
	    RROP_SOLID24(yorghb - xoffset + xtmp, tmp1 - y);
	    RROP_SOLID24(yorghb + xoffset + xtmp, tmp1 - y);
	    xtmp = (tmp2_3 + y * 3) >> 2;
	    RROP_SOLID24(yorghb - xoffset + xtmp, tmp2 + y);
	    RROP_SOLID24(yorghb + xoffset + xtmp, tmp2 + y);
	    xoffset += npwidth;
	    MIARCCIRCLESTEP(yoffset += npwidth;);
	}
#else
	PixelType *yorghb = yorgp + (info.h * npwidth) + info.xorg;
	PixelType *yorgohb = yorghb - info.h;

	yorgp += info.xorg;
	yorgop += info.xorg;
	yorghb += info.h;
	while (1)
	{
	    RROP_SOLID(yorgp + yoffset + x);
	    RROP_SOLID(yorgp + yoffset - x);
	    RROP_SOLID(yorgop - yoffset - x);
	    RROP_SOLID(yorgop - yoffset + x);
	    if (a < 0)
		break;
	    RROP_SOLID(yorghb - xoffset - y);
	    RROP_SOLID(yorgohb - xoffset + y);
	    RROP_SOLID(yorgohb + xoffset + y);
	    RROP_SOLID(yorghb + xoffset - y);
	    xoffset += npwidth;
	    MIARCCIRCLESTEP(yoffset += npwidth;);
	}
	yorgp -= info.xorg;
	yorgop -= info.xorg;
#endif /* PSZ == 24 */
	x = info.w;
	yoffset = info.h * npwidth;
    }
    else if (do360)
    {
	while (y < info.h || x < info.w)
	{
	    MIARCOCTANTSHIFT(dyoffset = npwidth;);
#if PSZ == 24
	    xtmp = (xorg3 + x * 3) >> 2;
	    RROP_SOLID24(yorgp + yoffset + xtmp, xorg + x);
	    RROP_SOLID24(yorgop - yoffset + xtmp, xorg + x);
	    xtmp = (xorgo3 - x * 3) >> 2;
	    RROP_SOLID24(yorgp + yoffset + xtmp, xorgo - x);
	    RROP_SOLID24(yorgop - yoffset + xtmp, xorgo - x);
#else
	    RROP_SOLID(yorgp + yoffset + info.xorg + x);
	    RROP_SOLID(yorgp + yoffset + info.xorgo - x);
	    RROP_SOLID(yorgop - yoffset + info.xorgo - x);
	    RROP_SOLID(yorgop - yoffset + info.xorg + x);
#endif
	    MIARCSTEP(yoffset += dyoffset;, yoffset += npwidth;);
	}
    }
    else
    {
	while (y < info.h || x < info.w)
	{
	    MIARCOCTANTSHIFT(dyoffset = npwidth;);
	    if ((x == info.start.x) || (y == info.start.y))
	    {
		mask = info.start.mask;
		info.start = info.altstart;
	    }
#if PSZ == 24
	    if (mask & 1){
	      xtmp = (xorg3 + x * 3) >> 2;
	      RROP_SOLID24(yorgp + yoffset + xtmp, xorg + x);
	    }
	    if (mask & 2){
	      xtmp = (xorgo3 - x * 3) >> 2;
	      RROP_SOLID24(yorgp + yoffset + xtmp, xorgo - x);
	    }
	    if (mask & 4){
	      xtmp = (xorgo3 - x * 3) >> 2;
	      RROP_SOLID24(yorgop - yoffset + xtmp, xorgo - x);
	    }
	    if (mask & 8){
	      xtmp = (xorg3 + x * 3) >> 2;
	      RROP_SOLID24(yorgop - yoffset + xtmp, xorg + x);
	    }
#else
	    if (mask & 1)
		RROP_SOLID(yorgp + yoffset + info.xorg + x);
	    if (mask & 2)
		RROP_SOLID(yorgp + yoffset + info.xorgo - x);
	    if (mask & 4)
		RROP_SOLID(yorgop - yoffset + info.xorgo - x);
	    if (mask & 8)
		RROP_SOLID(yorgop - yoffset + info.xorg + x);
#endif /* PSZ == 24 */
	    if ((x == info.end.x) || (y == info.end.y))
	    {
		mask = info.end.mask;
		info.end = info.altend;
	    }
	    MIARCSTEP(yoffset += dyoffset;, yoffset += npwidth;);
	}
    }
    if ((x == info.start.x) || (y == info.start.y))
	mask = info.start.mask;
#if PSZ == 24
    if (mask & 1){
      xtmp = (xorg3 + x * 3) >> 2;
      RROP_SOLID24(yorgp + yoffset + xtmp, xorg + x);
    }
    if (mask & 4){
      xtmp = (xorgo3 - x * 3) >> 2;
      RROP_SOLID24(yorgop - yoffset + xtmp, xorgo - x);
    }
#else
    if (mask & 1)
	RROP_SOLID(yorgp + yoffset + info.xorg + x);
    if (mask & 4)
	RROP_SOLID(yorgop - yoffset + info.xorgo - x);
#endif /* PSZ == 24 */
    if (arc->height & 1)
    {
#if PSZ == 24
	if (mask & 2){
	  xtmp = (xorgo3 - x * 3) >> 2;
	  RROP_SOLID24(yorgp + yoffset + xtmp, xorgo - x);
	}
	if (mask & 8){
	  xtmp = (xorg3 + x * 3) >> 2;
	  RROP_SOLID24(yorgop - yoffset + xtmp, xorg + x);
	}
#else
	if (mask & 2)
	    RROP_SOLID(yorgp + yoffset + info.xorgo - x);
	if (mask & 8)
	    RROP_SOLID(yorgop - yoffset + info.xorg + x);
#endif /* PSZ == 24 */
    }
}

void
RROP_NAME (cfbZeroPolyArcSS8) (pDraw, pGC, narcs, parcs)
    register DrawablePtr	pDraw;
    GCPtr	pGC;
    int		narcs;
    xArc	*parcs;
{
    register xArc *arc;
    register int i;
    BoxRec box;
    int x2, y2;
    RegionPtr cclip;

    cclip = cfbGetCompositeClip(pGC);
    for (arc = parcs, i = narcs; --i >= 0; arc++)
    {
	if (miCanZeroArc(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 <= MAXSHORT) && (y2 <= MAXSHORT) &&
 		    (RECT_IN_REGION(pDraw->pScreen, cclip, &box) == rgnIN) )
		RROP_NAME (cfbZeroArcSS8) (pDraw, pGC, arc);
	    else
		miZeroPolyArc(pDraw, pGC, 1, arc);
	}
	else
	    miPolyArc(pDraw, pGC, 1, arc);
    }
}

#endif
