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/* Copyright INRIA */
#include <X11/Intrinsic.h>
#include "bezier.h"
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#define MIN(a,b) ((a) < (b) ? (a) : (b))
#define FIXED(a) (((int) (a)) << 16)
#define INT(a) (((a) + (1 << 15)) >> 16 )
static short *pointptr;
static int npoint;
/*
* bez: Subdivide a Bezier spline, until it is thin enough to be
* considered a line. Store line point in static array points.
*/
int bez(x0, y0, x1, y1, x2, y2, x3, y3)
int x0, y0, x1, y1, x2, y2, x3, y3;
{
int maxx,minx,maxy,miny;
/* find bounding box of 4 control points */
maxx = x0;
maxx = MAX(maxx, x1);
maxx = MAX(maxx, x2);
maxx = MAX(maxx, x3);
maxy = y0;
maxy = MAX(maxy, y1);
maxy = MAX(maxy, y2);
maxy = MAX(maxy, y3);
minx = x0;
minx = MIN(minx, x1);
minx = MIN(minx, x2);
minx = MIN(minx, x3);
miny = y0;
miny = MIN(miny, y1);
miny = MIN(miny, y2);
miny = MIN(miny, y3);
if (((maxx - minx) < FIXED(2)) || ((maxy - miny) < FIXED(2))) {
/* Consider it a line segment */
npoint++;
*pointptr++ = INT(x3);
*pointptr++ = INT(y3);
}
else {
register int tempx, tempy;
/* Subdivide into 2 new beziers */
tempx = (x0 >> 3) + 3 * (x1 >> 3) + 3 * (x2 >> 3) + (x3 >> 3);
tempy = (y0 >> 3) + 3 * (y1 >> 3) + 3 * (y2 >> 3) + (y3 >> 3);
bez(x0, y0,
(x0 >> 1) + (x1 >> 1), (y0 >> 1) + (y1 >> 1),
(x0 >> 2) + (x1 >> 1) + (x2 >> 2),
(y0 >> 2) + (y1 >> 1) + (y2 >> 2),
tempx, tempy);
bez(tempx, tempy,
(x3 >> 2) + (x2 >> 1) + (x1 >> 2),
(y3 >> 2) + (y2 >> 1) + (y1 >> 2),
(x3 >> 1) + (x2 >> 1), (y3 >> 1) + (y2 >> 1),
x3, y3);
}
}
void DrawBezier(dpy, d, gc, bpoints)
Display *dpy;
Drawable d;
GC gc;
xBezier *bpoints;
{
short points[2000];
npoint = 1;
pointptr = points;
*pointptr++ = bpoints->x0;
*pointptr++ = bpoints->y0;
bez(FIXED(bpoints->x0),FIXED(bpoints->y0),FIXED(bpoints->x1),
FIXED(bpoints->y1),FIXED(bpoints->x2),FIXED(bpoints->y2),
FIXED(bpoints->x3),FIXED(bpoints->y3));
XDrawLines(dpy,d,gc,(XPoint*)points,npoint,CoordModeOrigin);
}
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