From 16b2039dcba74f8a3b3a906600a5da0fa10ac87d Mon Sep 17 00:00:00 2001
From: glenda <glenda@r51>
Date: Fri, 1 Jan 1988 08:25:12 +0000
Subject: [PATCH] wings!

---
 spiral.c | 119 ++++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 108 insertions(+), 11 deletions(-)

diff --git a/spiral.c b/spiral.c
index fe6f494e65a7795f0558dbccf25ae567dd6fd6c2..5edb443aa252dddc9ac9c80d7e1515b856377548 100644
--- a/spiral.c
+++ b/spiral.c
@@ -2,45 +2,142 @@
 #include <libc.h>
 #include <draw.h>
 #include <event.h>
-#include <cursor.h>
+
+#define RAD (PI * 2)
+
+Image *bg,*fg;
+
+int frametime;
+double spr;
+int wings;
+double wingrads;
+
+vlong starttime;
 
 void
 usage(void)
 {
-	fprint(2,"usage: %s\n", argv0);
+	fprint(2,"usage: %s [-f framerate] [-r rpm] [-w wings]\n", argv0);
 	exits("usage");
 }
 
 Point
-Spt(int x, int y)
+SPt(int x, int y)
 {
 	return addpt(Pt(x, y), screen->r.min);
 }
 
 Rectangle
-Srect(int x0, int y0, int x1, int y1)
+SRect(int x0, int y0, int x1, int y1)
 {
 	return rectaddpt(Rect(x0, y0, x1, y1), screen->r.min);
 }
 
+Point
+imagecenter(Image* img)
+{
+	return divpt(addpt(img->r.min, img->r.max), 2);
+}
+
+double
+imageradius(Image* img)
+{
+	Point dims;
+	dims = divpt(subpt(img->r.max, img->r.min), 2);
+	return 1.4 + sqrt(dims.x*dims.x + dims.y*dims.y);
+}
+
+Point
+vecpt(double radians, double radius)
+{
+	double x,y;
+	x = sin(radians) * radius;
+	y = cos(radians) * radius;
+
+	return Pt(x + 1, y + 1);
+}
+
+void
+drawframe(double ts)
+{
+	double radians, radius;
+	Point center;
+
+	radians = fmod(ts / spr, spr) * RAD;
+	radius = imageradius(screen);
+	center = imagecenter(screen);
+
+	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;
+	}
+}
+
+double
+ftime(void)
+{
+	return ((double)(nsec() - starttime)) / 1000000000.0;
+}
+
+void
+eresized(int new)
+{
+	if(new && getwindow(display, Refnone) < 0)
+		fprint(2,"can't reattach to window\n");
+	drawframe(ftime());
+}
+
 void
 main(int argc, char* argv[])
 {
-	Image* drawsrc;
+	int timer,etype;
+	Event e;
+
+	frametime = 1.0 / 30.0 * 1000;
+	wings = 3;
+	spr = 2;
 
 	ARGBEGIN{
+	case 'f':
+		frametime = 1.0 / atof(EARGF(usage())) * 1000;
+		break;
+	case 'r':
+		spr = 1.0 / (atof(EARGF(usage())) / 60.0);
+		break;
+	case 'w':
+		wings = atoi(EARGF(usage()));
+		break;
 	default:
 		usage();
 	} ARGEND
 
-	if (initdraw(nil, nil, "spiral") == -1)
+	if(wings < 1) wings = 1;
+	wingrads = PI / (double) wings;
+
+	if(initdraw(nil, nil, "spiral") < 0)
 		sysfatal("initdraw: %r");
 
-	drawsrc = allocimagemix(display, DPurpleblue, DPurpleblue);
-	if (!drawsrc)
+	fg = allocimage(display, Rect(0,0, 1,1), GREY1, 1, DBlack);
+	if(!fg)
 		sysfatal("couldn't allocimage!");
 
-	line(screen, Spt(10,10), Spt(50,50), Enddisc, Endsquare, 5, drawsrc, Spt(0,0));
-	flushimage(display, 1);
-	sleep(10*1000);
+	bg = allocimage(display, Rect(0,0, 1,1), GREY1, 1, DWhite);
+	if(!bg)
+		sysfatal("couldn't allocimage!");
+
+	starttime = nsec();
+
+	einit(Emouse);
+	timer = etimer(0, frametime);
+
+	for(;;)
+	{
+		etype = event(&e);
+
+		if (etype == timer)
+			drawframe(ftime());
+	}
 }