afbzerarc.c   [plain text]

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

Copyright (c) 1989  X Consortium

Permission is hereby granted, free of charge, to any person obtaining a copy
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AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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Except as contained in this notice, the name of the X Consortium shall not be
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in this Software without prior written authorization from the X Consortium.

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


/* 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
 */

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

#include <X11/X.h>
#include <X11/Xprotostr.h>
#include "regionstr.h"
#include "gcstruct.h"
#include "pixmapstr.h"
#include "scrnintstr.h"
#include "afb.h"
#include "maskbits.h"
#include "mizerarc.h"
#include "mi.h"

/*
 * Note: LEFTMOST must be the bit leftmost in the actual screen
 * representation.  This depends also on the IMAGE_BYTE_ORDER.
 * LONG2CHARS() takes care of the re-ordering as required. (DHD)
 */
#if (BITMAP_BIT_ORDER == MSBFirst)
#define LEFTMOST		((PixelType) LONG2CHARS((1 << PLST)))
#else
#define LEFTMOST		((PixelType) LONG2CHARS(1))
#endif

#define Pixelate(base,yoff,xoff) \
{ \
	paddr = afbScanlineOffset(base, (yoff) + ((xoff)>>PWSH)); \
	pmask = SCRRIGHT(LEFTMOST, (xoff) & PIM); \
	for (de = 0; de < depthDst; de++, paddr += sizeDst) /* @@@ NEXT PLANE @@@ */ \
		switch (rrops[de]) { \
			case RROP_BLACK: \
				*paddr &= ~pmask; \
				break; \
			case RROP_WHITE: \
				*paddr |= pmask; \
				break; \
			case RROP_INVERT: \
				*paddr ^= pmask; \
				break; \
			case RROP_NOP: \
				break; \
		} \
}

#define DoPix(bit,base,yoff,xoff) if (mask & bit) Pixelate(base,yoff,xoff);

static void
afbZeroArcSS(DrawablePtr pDraw, GCPtr pGC, xArc *arc)
{
	miZeroArcRec info;
	Bool do360;
	register int de;
	register int x, y, a, b, d, mask;
	register int k1, k3, dx, dy;
	PixelType *addrl;
	PixelType *yorgl, *yorgol;
	int nlwidth, yoffset, dyoffset;
	int sizeDst, depthDst;
	PixelType pmask;
	register PixelType *paddr;
	register unsigned char *rrops;

	rrops = ((afbPrivGC *)(pGC->devPrivates[afbGCPrivateIndex].ptr))->rrops;

	afbGetPixelWidthSizeDepthAndPointer(pDraw, nlwidth, sizeDst, depthDst,
													 addrl);
	do360 = miZeroArcSetup(arc, &info, TRUE);
	yorgl = addrl + ((info.yorg + pDraw->y) * nlwidth);
	yorgol = addrl + ((info.yorgo + pDraw->y) * nlwidth);
	info.xorg += pDraw->x;
	info.xorgo += pDraw->x;
	MIARCSETUP();
	yoffset = y ? nlwidth : 0;
	dyoffset = 0;
	mask = info.initialMask;
	if (!(arc->width & 1)) {
		DoPix(2, yorgl, 0, info.xorgo);
		DoPix(8, yorgol, 0, info.xorgo);
	}
	if (!info.end.x || !info.end.y) {
		mask = info.end.mask;
		info.end = info.altend;
	}
	if (do360 && (arc->width == arc->height) && !(arc->width & 1)) {
		int xoffset = nlwidth;
		PixelType *yorghl = afbScanlineDeltaNoBankSwitch(yorgl, info.h, nlwidth);
		int xorghp = info.xorg + info.h;
		int xorghn = info.xorg - info.h;

		while (1) {
			Pixelate(yorgl, yoffset, info.xorg + x);
			Pixelate(yorgl, yoffset, info.xorg - x);
			Pixelate(yorgol, -yoffset, info.xorg - x);
			Pixelate(yorgol, -yoffset, info.xorg + x);
			if (a < 0)
				break;
			Pixelate(yorghl, -xoffset, xorghp - y);
			Pixelate(yorghl, -xoffset, xorghn + y);
			Pixelate(yorghl, xoffset, xorghn + y);
			Pixelate(yorghl, xoffset, xorghp - y);
			xoffset += nlwidth;
			MIARCCIRCLESTEP(yoffset += nlwidth;);
		}
		x = info.w;
		yoffset = info.h * nlwidth;
	} else if (do360) {
		while (y < info.h || x < info.w) {
			MIARCOCTANTSHIFT(dyoffset = nlwidth;);
			Pixelate(yorgl, yoffset, info.xorg + x);
			Pixelate(yorgl, yoffset, info.xorgo - x);
			Pixelate(yorgol, -yoffset, info.xorgo - x);
			Pixelate(yorgol, -yoffset, info.xorg + x);
			MIARCSTEP(yoffset += dyoffset;, yoffset += nlwidth;);
		}
	} else {
		while (y < info.h || x < info.w) {
			MIARCOCTANTSHIFT(dyoffset = nlwidth;);
			if ((x == info.start.x) || (y == info.start.y)) {
				mask = info.start.mask;
				info.start = info.altstart;
			}
			DoPix(1, yorgl, yoffset, info.xorg + x);
			DoPix(2, yorgl, yoffset, info.xorgo - x);
			DoPix(4, yorgol, -yoffset, info.xorgo - x);
			DoPix(8, yorgol, -yoffset, info.xorg + x);
			if ((x == info.end.x) || (y == info.end.y)) {
				mask = info.end.mask;
				info.end = info.altend;
			}
			MIARCSTEP(yoffset += dyoffset;, yoffset += nlwidth;);
		}
	}
	if ((x == info.start.x) || (y == info.start.y))
		mask = info.start.mask;
	DoPix(1, yorgl, yoffset, info.xorg + x);
	DoPix(4, yorgol, -yoffset, info.xorgo - x);
	if (arc->height & 1) {
		DoPix(2, yorgl, yoffset, info.xorgo - x);
		DoPix(8, yorgol, -yoffset, info.xorg + x);
	}
}

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

	cclip = pGC->pCompositeClip;
	for (arc = parcs, i = narcs; --i >= 0; arc++) {
		if (miCanZeroArc(arc)) {
			box.x1 = arc->x + pDraw->x;
			box.y1 = arc->y + pDraw->y;
			box.x2 = box.x1 + (int)arc->width + 1;
			box.y2 = box.y1 + (int)arc->height + 1;
			if (RECT_IN_REGION(pDraw->pScreen, cclip, &box) == rgnIN)
				afbZeroArcSS(pDraw, pGC, arc);
			else
				miZeroPolyArc(pDraw, pGC, 1, arc);
		} else
			miPolyArc(pDraw, pGC, 1, arc);
	}
}