From 2a08c37c3db23b27b963442fe273097915bc30ea Mon Sep 17 00:00:00 2001
From: glenda <glenda@r51>
Date: Fri, 1 Jan 1988 08:56:45 +0000
Subject: [PATCH] spirals!

---
 .plan    |  4 ++++
 spiral.c | 23 +++++++++++++++++++----
 2 files changed, 23 insertions(+), 4 deletions(-)
 create mode 100644 .plan

diff --git a/.plan b/.plan
new file mode 100644
index 0000000000000000000000000000000000000000..b12434bc5384003be282ca99880c11c99c2675f7
--- /dev/null
+++ b/.plan
@@ -0,0 +1,4 @@
+TODO for spirals.c:
+ * maybe fix screen tearing
+ * generate a proper spiral
+ * make the center a little less ugly
diff --git a/spiral.c b/spiral.c
index 5edb443aa252dddc9ac9c80d7e1515b856377548..53a211a283fe540fc21208abebd89d8435a12720 100644
--- a/spiral.c
+++ b/spiral.c
@@ -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