ref: b3822385045bb11446f479afb67733ff21c77823
parent: e40277aa9e1d188a779ca42058e7932fb445f420
author: rodri <[email protected]>
date: Tue May 12 06:48:16 EDT 2020
new toy: bsplines
--- /dev/null
+++ b/bsplines.c
@@ -1,0 +1,138 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <event.h>
+#include <keyboard.h>
+
+typedef struct Point2 Point2;
+typedef struct Bspline Bspline;
+
+struct Point2
+{+ double x, y, w;
+};
+
+struct Bspline
+{+ Point2 *pts;
+ ulong npt;
+};
+
+enum {+ Cbg,
+ Cctl,
+ Cbez,
+ NCOLOR
+};
+
+Image *pal[NCOLOR];
+Bspline *bsplines;
+Point2 *pts;
+ulong nbspline, npt;
+
+Point2
+Pt2(double x, double y, double w)
+{+ return (Point2){x,y,w};+}
+
+Point
+toscreen(Point2 p)
+{+ return addpt(screen->r.min, Pt(p.x,p.y));
+}
+
+Point2
+fromscreen(Point p)
+{+ p = subpt(p, screen->r.min);
+ return Pt2(p.x,p.y,1);
+}
+
+void
+initpalette(void)
+{+ pal[Cbg] = allocimage(display, Rect(0,0,1,1), screen->chan, 1, 0x000000ff);
+ pal[Cctl] = allocimage(display, Rect(0,0,1,1), screen->chan, 1, 0x00ff00ff);
+ pal[Cbez] = allocimage(display, Rect(0,0,1,1), screen->chan, 1, 0xff0000ff);
+}
+
+void
+redraw(void)
+{+ Point *bpts;
+ int i, j;
+
+ draw(screen, screen->r, pal[Cbg], nil, ZP);
+ for(i = 0; i < nbspline; i++){+ bpts = malloc(bsplines[i].npt*sizeof(Point));
+ for(j = 0; j < bsplines[i].npt; j++)
+ bpts[j] = toscreen(bsplines[i].pts[j]);
+ bezspline(screen, bpts, bsplines[i].npt, Endsquare, Endsquare, 0, pal[Cbez], ZP);
+ free(bpts);
+ }
+ for(i = 0; i < npt; i++)
+ fillellipse(screen, toscreen(pts[i]), 2, 2, pal[Cctl], ZP);
+ flushimage(display, 1);
+}
+
+void
+usage(void)
+{+ fprint(2, "usage: %s\n", argv0);
+ exits("usage");+}
+
+void
+main(int argc, char *argv[])
+{+ Event e;
+ Bspline b;
+
+ ARGBEGIN{+ default: usage();
+ }ARGEND;
+ if(argc > 0)
+ usage();
+ if(initdraw(nil, nil, nil) < 0)
+ sysfatal("initdraw: %r");+ initpalette();
+ einit(Emouse|Ekeyboard);
+ redraw();
+ for(;;)
+ switch(event(&e)){+ case Emouse:
+ if((e.mouse.buttons&1) != 0){+ pts = realloc(pts, ++npt*sizeof(Point2));
+ pts[npt-1] = fromscreen(e.mouse.xy);
+ redraw();
+ }
+ if((e.mouse.buttons&4) != 0){+ if(npt > 1){+ b.pts = pts;
+ b.npt = npt;
+ bsplines = realloc(bsplines, ++nbspline*sizeof(Bspline));
+ bsplines[nbspline-1] = b;
+ pts = nil;
+ npt = 0;
+ }
+ redraw();
+ }
+ break;
+ case Ekeyboard:
+ switch(e.kbdc){+ case 'q':
+ case Kdel:
+ exits(0);
+ }
+ break;
+ }
+}
+
+void
+eresized(int)
+{+ if(getwindow(display, Refnone) < 0)
+ sysfatal("resize failed");+ redraw();
+}
--- a/mkfile
+++ b/mkfile
@@ -4,5 +4,6 @@
TARG=\
triangles\
beziers\
+ bsplines\
</sys/src/cmd/mkmany