ref: c207b78d079803605d8aec2fe63a059fc4bdb2c6
parent: dda99bbfe55bcf25ec33934c40efc4f9fdca685a
author: Ori Bernstein <ori@eigenstate.org>
date: Sat Jan 9 07:20:49 EST 2021
libdraw: add bezierpts This patch exposes the bezierpts function, providing a way to get the points on a path, similar how bezsplinepts gives them for b splines.
--- a/sys/include/draw.h
+++ b/sys/include/draw.h
@@ -436,6 +436,7 @@
extern Point stringsubfont(Image*, Point, Image*, Subfont*, char*);
extern int bezier(Image*, Point, Point, Point, Point, int, int, int, Image*, Point);
extern int bezierop(Image*, Point, Point, Point, Point, int, int, int, Image*, Point, Drawop);
+extern int bezierpts(Point, Point, Point, Point, Point**);
extern int bezspline(Image*, Point*, int, int, int, int, Image*, Point);
extern int bezsplineop(Image*, Point*, int, int, int, int, Image*, Point, Drawop);
extern int bezsplinepts(Point*, int, Point**);
--- a/sys/man/2/draw
+++ b/sys/man/2/draw
@@ -103,6 +103,8 @@
int end0, int end1, int radius, Image *src, Point sp,
Drawop op)
.PB
+int bezierpts(Point p0, Point p1, Point p2, Point p3, Point **pp)
+.PB
int bezspline(Image *dst, Point *pt, int npt, int end0, int end1,
int radius, Image *src, Point sp)
.PB
@@ -602,6 +604,16 @@
.I a
in
.IR dst .
+.TP
+\f5bezierpts(\f2a\fP, \f2b\fP, \f2c\fP, \f2d\fP, \f2pp\fP)
+.I Bezierpts
+returns in
+.I pp
+a list of points making up the open polygon that
+.I bezier
+would draw.
+The caller is responsible for freeing
+.IR *pp .
.TP
\f5bezspline(\f2dst\fP, \f2p\fP, \f2np\fP, \f2end0\fP, \f2end1\fP, \f2thick\fP, \f2src\fP, \f2sp\fP)
.I Bezspline
--- a/sys/src/libdraw/bezier.c
+++ b/sys/src/libdraw/bezier.c
@@ -98,12 +98,23 @@
}
static void
-bezierpts(Plist *l, Point p0, Point p1, Point p2, Point p3)
+_bezierpts(Plist *l, Point p0, Point p1, Point p2, Point p3)
{bpts(l, p0, p1, p2, p3);
appendpt(l, p3);
}
+int
+bezierpts(Point p0, Point p1, Point p2, Point p3, Point **pp)
+{+ Plist l;
+ l.p = nil;
+ l.np = 0;
+ _bezierpts(&l, p0, p1, p2, p3);
+ *pp = l.p;
+ return l.np;
+}
+
static void
_bezsplinepts(Plist *l, Point *pt, int npt)
{@@ -167,7 +178,7 @@
Plist l;
l.np = 0;
- bezierpts(&l, p0, p1, p2, p3);
+ _bezierpts(&l, p0, p1, p2, p3);
if(l.np == -1)
return 0;
if(l.np != 0){@@ -211,7 +222,7 @@
Plist l;
l.np = 0;
- bezierpts(&l, p0, p1, p2, p3);
+ _bezierpts(&l, p0, p1, p2, p3);
if(l.np == -1)
return 0;
if(l.np != 0){