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/* This file is part of the GNU libxmi package.
Copyright (C) 1985, 1986, 1987, 1988, 1989, X Consortium. For an
associated permission notice, see the accompanying file README-X.
GNU enhancements Copyright (C) 1998, 1999, 2000, 2005, Free Software
Foundation, Inc.
The GNU libxmi package is free software. You may redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software foundation; either version 2, or (at your
option) any later version.
The GNU libxmi package is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License along
with the GNU plotutils package; see the file COPYING. If not, write to
the Free Software Foundation, Inc., 51 Franklin St., Fifth Floor,
Boston, MA 02110-1301, USA. */
/* This header file is included by mi_zerarc.c, which draws a single-pixel
(i.e. Bresenham) poly-arc using a fast integer algorithm. It defines
structures and macros used in the algorithm. */
typedef struct
{
int x;
int y;
unsigned int mask;
} miZeroArcPt;
typedef struct
{
int x, y, k1, k3, a, b, d, dx, dy;
int alpha, beta;
int xorg, yorg; /* upper left corner */
int xorgo, yorgo;
unsigned int w, h;
unsigned int initialMask;
miZeroArcPt start, altstart, end, altend;
int firstx, firsty;
int startAngle, endAngle; /* in 1/64 degrees */
} miZeroArc;
/* miZeroPolyArc() draws an arc only if it satisfies the following size
constraint. If it doesn't, miZeroPolyArc() hands it off to miPolyArc(),
which uses a floating point algorithm. */
#define MI_CAN_ZERO_ARC(arc) (((arc)->width == (arc)->height) || \
(((arc)->width <= 800) && ((arc)->height <= 800)))
/* used for setup only */
#define MIARCSETUP(info, x, y, k1, k3, a, b, d, dx, dy) \
x = info.x; \
y = info.y; \
k1 = info.k1; \
k3 = info.k3; \
a = info.a; \
b = info.b; \
d = info.d; \
dx = info.dx; \
dy = info.dy
#define MIARCOCTANTSHIFT(info, x, y, dx, dy, a, b, d, k1, k3, clause) \
if (a < 0) \
{ \
if (y == (int)info.h) \
{ \
d = -1; \
a = b = k1 = 0; \
} \
else \
{ \
dx = (k1 << 1) - k3; \
k1 = dx - k1; \
k3 = -k3; \
b = b + a - (k1 >> 1); \
d = b + ((-a) >> 1) - d + (k3 >> 3); \
if (dx < 0) \
a = -((-dx) >> 1) - a; \
else \
a = (dx >> 1) - a; \
dx = 0; \
dy = 1; \
clause \
} \
}
#define MIARCSTEP(x, y, dx, dy, a, b, d, k1, k3, move1, move2) \
b -= k1; \
if (d < 0) \
{ \
x += dx; \
y += dy; \
a += k1; \
d += b; \
move1 \
} \
else \
{ \
x++; \
y++; \
a += k3; \
d -= a; \
move2 \
}
#define MIARCCIRCLESTEP(x, y, a, b, d, k1, k3, clause) \
b -= k1; \
x++; \
if (d < 0) \
{ \
a += k1; \
d += b; \
} \
else \
{ \
y++; \
a += k3; \
d -= a; \
clause \
}
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