2 files changed, 23 insertions(+), 4 deletions(-)

A .plan
M spiral.c

@@ 0,0 1,4 @@
+TODO for spirals.c:
+ * maybe fix screen tearing
+ * generate a proper spiral
+ * make the center a little less ugly

@@ 4,6 4,7 @@
 #include <event.h>
 
 #define RAD (PI * 2)
+#define DEG (PI / 180.0)
 
 Image *bg,*fg;
 


@@ 11,13 12,14 @@ int frametime;
 double spr;
 int wings;
 double wingrads;
+double eccen;
 
 vlong starttime;
 
 void
 usage(void)
 {
-	fprint(2,"usage: %s [-f framerate] [-r rpm] [-w wings]\n", argv0);
+	fprint(2,"usage: %s [-f framerate] [-r rpm] [-w wings] [-e deg]\n", argv0);
 	exits("usage");
 }
 


@@ 62,17 64,26 @@ drawframe(double ts)
 {
 	double radians, radius;
 	Point center;
+	Point wingpoints[6];
 
 	radians = fmod(ts / spr, spr) * RAD;
-	radius = imageradius(screen);
+	radius = imageradius(screen) * 1.4;
 	center = imagecenter(screen);
+	wingpoints[0] = center;
+	wingpoints[5] = addpt(center, Pt(1, 1));
 
 	draw(screen, screen->r, bg, nil, SPt(0, 0));
 
 	for(int i = 0; i < wings; i++)
 	{
-		line(screen, center, addpt(vecpt(radians, radius), center), Enddisc, Enddisc, 2, fg, Pt(0,0));
-		radians += wingrads * 2;
+		wingpoints[1] = addpt(center, vecpt(radians + eccen, radius / 3));
+		wingpoints[2] = addpt(center, vecpt(radians, radius));
+		radians += wingrads;
+		wingpoints[3] = addpt(center, vecpt(radians, radius));
+		wingpoints[4] = addpt(center, vecpt(radians + eccen, radius / 3));
+		radians += wingrads;
+
+		fillbezspline(screen, wingpoints, 6, ~0, fg, Pt(0, 0));
 	}
 }
 


@@ 99,6 110,7 @@ main(int argc, char* argv[])
 	frametime = 1.0 / 30.0 * 1000;
 	wings = 3;
 	spr = 2;
+	eccen = RAD / 6;
 
 	ARGBEGIN{
 	case 'f':


@@ 110,6 122,9 @@ main(int argc, char* argv[])
 	case 'w':
 		wings = atoi(EARGF(usage()));
 		break;
+	case 'e':
+		eccen = DEG * atof(EARGF(usage()));
+		break;
 	default:
 		usage();
 	} ARGEND