mifillarc.c

linux下电话本所依赖的一些图形库

	miGetPieEdge(arc, angle1, &slice->edge1,
		     slice->edge1_top, !slice->edge1_top);
	miGetPieEdge(arc, angle2, &slice->edge2,
		     slice->edge2_top, slice->edge2_top);
    }
    else
    {
	double w2, h2, x1, y1, x2, y2, dx, dy, scale;
	int signdx, signdy, y, k;
	gboolean isInt1 = TRUE, isInt2 = TRUE;

	w2 = (double)arc->width / 2.0;
	h2 = (double)arc->height / 2.0;
	if ((angle1 == 0) || (angle1 == HALFCIRCLE))
	{
	    x1 = angle1 ? -w2 : w2;
	    y1 = 0.0;
	}
	else if ((angle1 == QUADRANT) || (angle1 == QUADRANT3))
	{
	    x1 = 0.0;
	    y1 = (angle1 == QUADRANT) ? h2 : -h2;
	}
	else
	{
	    isInt1 = FALSE;
	    x1 = Dcos(angle1) * w2;
	    y1 = Dsin(angle1) * h2;
	}
	if ((angle2 == 0) || (angle2 == HALFCIRCLE))
	{
	    x2 = angle2 ? -w2 : w2;
	    y2 = 0.0;
	}
	else if ((angle2 == QUADRANT) || (angle2 == QUADRANT3))
	{
	    x2 = 0.0;
	    y2 = (angle2 == QUADRANT) ? h2 : -h2;
	}
	else
	{
	    isInt2 = FALSE;
	    x2 = Dcos(angle2) * w2;
	    y2 = Dsin(angle2) * h2;
	}
	dx = x2 - x1;
	dy = y2 - y1;
	if (arc->height & 1)
	{
	    y1 -= 0.5;
	    y2 -= 0.5;
	}
	if (arc->width & 1)
	{
	    x1 += 0.5;
	    x2 += 0.5;
	}
	if (dy < 0.0)
	{
	    dy = -dy;
	    signdy = -1;
	}
	else
	    signdy = 1;
	if (dx < 0.0)
	{
	    dx = -dx;
	    signdx = -1;
	}
	else
	    signdx = 1;
	if (isInt1 && isInt2)
	{
	    slice->edge1.dx = dx * 2;
	    slice->edge1.dy = dy * 2;
	}
	else
	{
	    scale = (dx > dy) ? dx : dy;
	    slice->edge1.dx = floor((dx * 32768) / scale + .5);
	    slice->edge1.dy = floor((dy * 32768) / scale + .5);
	}
	if (!slice->edge1.dy)
	{
	    if (signdx < 0)
	    {
		y = floor(y1 + 1.0);
		if (y >= 0)
		{
		    slice->min_top_y = y;
		    slice->min_bot_y = arc->height;
		}
		else
		{
		    slice->max_bot_y = -y - (arc->height & 1);
		}
	    }
	    else
	    {
		y = floor(y1);
		if (y >= 0)
		    slice->max_top_y = y;
		else
		{
		    slice->min_top_y = arc->height;
		    slice->min_bot_y = -y - (arc->height & 1);
		}
	    }
	    slice->edge1_top = TRUE;
	    slice->edge1.x = 65536;
	    slice->edge1.stepx = 0;
	    slice->edge1.e = 0;
	    slice->edge1.dx = -1;
	    slice->edge2 = slice->edge1;
	    slice->edge2_top = FALSE;
	}
	else if (!slice->edge1.dx)
	{
	    if (signdy < 0)
		x1 -= 1.0;
	    slice->edge1.x = ceil(x1);
	    slice->edge1_top = signdy < 0;
	    slice->edge1.x += arc->x + (arc->width >> 1);
	    slice->edge1.stepx = 0;
	    slice->edge1.e = 0;
	    slice->edge1.dx = -1;
	    slice->edge2_top = !slice->edge1_top;
	    slice->edge2 = slice->edge1;
	}
	else
	{
	    if (signdx < 0)
		slice->edge1.dx = -slice->edge1.dx;
	    if (signdy < 0)
		slice->edge1.dx = -slice->edge1.dx;
	    k = ceil(((x1 + x2) * slice->edge1.dy - (y1 + y2) * slice->edge1.dx) / 2.0);
	    slice->edge2.dx = slice->edge1.dx;
	    slice->edge2.dy = slice->edge1.dy;
	    slice->edge1_top = signdy < 0;
	    slice->edge2_top = !slice->edge1_top;
	    miGetArcEdge(arc, &slice->edge1, k,
			 slice->edge1_top, !slice->edge1_top);
	    miGetArcEdge(arc, &slice->edge2, k,
			 slice->edge2_top, slice->edge2_top);
	}
    }
}

#define ADDSPANS() \
    pts->x = xorg - x; \
    pts->y = yorg - y; \
    pts->width = slw; \
    pts++; \
    if (miFillArcLower(slw)) \
    { \
	pts->x = xorg - x; \
	pts->y = yorg + y + dy; \
        pts->width = slw; \
	pts++; \
    }

static void
miFillEllipseI(GdkDrawable *pDraw, GdkGC *pGC, miArc *arc)
{
    register int x, y, e;
    int yk, xk, ym, xm, dx, dy, xorg, yorg;
    int slw;
    miFillArcRec info;
    GdkSpan* points;
    register GdkSpan* pts;

    points = (GdkSpan*)ALLOCATE_LOCAL(sizeof(GdkSpan) * arc->height);
    if (!points)
	return;
    miFillArcSetup(arc, &info);
    MIFILLARCSETUP();
    pts = points;
    while (y > 0)
    {
	MIFILLARCSTEP(slw);
	ADDSPANS();
    }
    gdk_fb_fill_spans(pDraw, pGC, points, pts - points, FALSE);

    DEALLOCATE_LOCAL(points);
}

static void
miFillEllipseD(GdkDrawable *pDraw, GdkGC *pGC, miArc *arc)
{
    register int x, y;
    int xorg, yorg, dx, dy, slw;
    double e, yk, xk, ym, xm;
    miFillArcDRec info;
    GdkSpan* points;
    register GdkSpan* pts;

    points = (GdkSpan*)ALLOCATE_LOCAL(sizeof(GdkSpan) * arc->height);
    if (!points)
	return;
    miFillArcDSetup(arc, &info);
    MIFILLARCSETUP();
    pts = points;
    while (y > 0)
    {
	MIFILLARCSTEP(slw);
	ADDSPANS();
    }
    gdk_fb_fill_spans(pDraw, pGC, points, pts - points, FALSE);
    DEALLOCATE_LOCAL(points);
}

#define ADDSPAN(l,r) \
    if (r >= l) \
    { \
	pts->x = l; \
	pts->y = ya; \
        pts->width = r - l + 1; \
	pts++; \
    }

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

static void
miFillArcSliceI(GdkDrawable *pDraw, GdkGC *pGC, miArc *arc)
{
    int yk, xk, ym, xm, dx, dy, xorg, yorg, slw;
    register int x, y, e;
    miFillArcRec info;
    miArcSliceRec slice;
    int ya, xl, xr, xc;
    GdkSpan* points;
    register GdkSpan* pts;

    miFillArcSetup(arc, &info);
    miFillArcSliceSetup(arc, &slice, pGC);
    MIFILLARCSETUP();
    slw = arc->height;
    if (slice.flip_top || slice.flip_bot)
	slw += (arc->height >> 1) + 1;
    points = (GdkSpan*)ALLOCATE_LOCAL(sizeof(GdkSpan) * slw);
    if (!points)
	return;
    pts = points;
    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);
	}
    }
    
    gdk_fb_fill_spans(pDraw, pGC, points, pts - points, FALSE);
    DEALLOCATE_LOCAL(points);
}

static void
miFillArcSliceD(GdkDrawable *pDraw, GdkGC *pGC, miArc *arc)
{
    register int x, y;
    int dx, dy, xorg, yorg, slw;
    double e, yk, xk, ym, xm;
    miFillArcDRec info;
    miArcSliceRec slice;
    int ya, xl, xr, xc;
    GdkSpan* points;
    register GdkSpan* pts;

    miFillArcDSetup(arc, &info);
    miFillArcSliceSetup(arc, &slice, pGC);
    MIFILLARCSETUP();
    slw = arc->height;
    if (slice.flip_top || slice.flip_bot)
	slw += (arc->height >> 1) + 1;
    points = (GdkSpan*)ALLOCATE_LOCAL(sizeof(GdkSpan) * slw);
    if (!points)
	return;
    pts = points;
    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);
	}
    }
    gdk_fb_fill_spans(pDraw, pGC, points, pts - points, FALSE);

    DEALLOCATE_LOCAL(points);
}

/* MIPOLYFILLARC -- The public entry for the PolyFillArc request.
 * Since we don't have to worry about overlapping segments, we can just
 * fill each arc as it comes.
 */
void
miPolyFillArc(GdkDrawable *pDraw, GdkGC *pGC, int narcs, miArc *parcs)
{
    register int i;
    register miArc *arc;

    for(i = narcs, arc = parcs; --i >= 0; arc++)
    {
	if (miFillArcEmpty(arc))
	    continue;;
	if ((arc->angle2 >= FULLCIRCLE) || (arc->angle2 <= -FULLCIRCLE))
	{
	    if (miCanFillArc(arc))
		miFillEllipseI(pDraw, pGC, arc);
	    else
		miFillEllipseD(pDraw, pGC, arc);
	}
	else
	{
	    if (miCanFillArc(arc))
		miFillArcSliceI(pDraw, pGC, arc);
	    else
		miFillArcSliceD(pDraw, pGC, arc);
	}
    }
}