games/galaxy: new mouse behavior

MB1 moves the galaxy. MB2 zooms the galaxy. New body creation
moved to the menu

sys/man/1/galaxy

@@ -38,23 +38,20 @@ option. If no file is read then the simulator starts with an empty
 universe.
 .SS Mouse commands
 .PP
-New planetary bodies can be created with mouse button 1.
+Holding mouse button 1 while dragging repositions the visible region of
-Holding button 1 will reposition the body.
+the galaxy. Holding mouse button 2 while dragging up or down zooms the
+visible region of the galaxy in or out, respectively.
+Mouse button 3 opens a menu with the following options:
+.TP
+.B "new body"
+Creates a new galactic body.
+Holding button 1 positions the body.
 Holding a button 1-2 chord changes the mass/size
 of the body. Holding a button 1-3 chord
 changes the initial velocity of the body. Releasing button 1
 restarts the simulator with the new body in motion. When new
 bodies are created, the simulator maintains the Galilean (inertial)
 reference frame where the center of mass of the galaxy is at rest.
-.PP
-Mouse button 2 repositions the visible region of the galaxy by dragging.
-.PP
-Mouse button 3 opens a menu with the following options:
-.TP
-.B zoom
-Prompts for a floating point value to change the scale of the
-simulation. E.g. a value of 2 will halve the scale (zoom in)
-and a value of 0.5 will double the scale (zoom out).
 .TP
 .B speed
 Prompts for a floating point value to change the speed of

sys/src/games/galaxy/galaxy.c

@@ -20,6 +20,18 @@ Cursor crosscursor = {
 	 0x01, 0x80, 0x01, 0x80, 0x01, 0x80, 0x00, 0x00, }
 };
 
+Cursor zoomcursor = {
+	{-7, -7},
+	{0x1F, 0xF8, 0x3F, 0xFC, 0x7F, 0xFE, 0xFB, 0xDF,
+	 0xF3, 0xCF, 0xE3, 0xC7, 0xFF, 0xFF, 0xFF, 0xFF,
+	 0xFF, 0xFF, 0xFF, 0xFF, 0xE3, 0xC7, 0xF3, 0xCF,
+	 0x7B, 0xDF, 0x7F, 0xFE, 0x3F, 0xFC, 0x1F, 0xF8, },
+	{0x00, 0x00, 0x0F, 0xF0, 0x31, 0x8C, 0x21, 0x84,
+	 0x41, 0x82, 0x41, 0x82, 0x41, 0x82, 0x7F, 0xFE,
+	 0x7F, 0xFE, 0x41, 0x82, 0x41, 0x82, 0x41, 0x82,
+	 0x21, 0x84, 0x31, 0x8C, 0x0F, 0xF0, 0x00, 0x00, }
+};
+
 Cursor pausecursor={
 	0, 0,
 	0x01, 0x80, 0x03, 0xC0, 0x07, 0xE0, 0x07, 0xe0,
@@ -35,7 +47,7 @@ Cursor pausecursor={
 
 enum {
 	STK = 8192,
-	ZOOM = 0,
+	DOBODY = 0,
 	SPEED,
 	GRAV,
 	SAVE,
@@ -56,12 +68,12 @@ double
 	LIM = 10,
 	dt²;
 char *file;
-int showv, showa, throttle;
+int showv, showa, throttle, paused;
 
 char *menustr[] = {
+	[DOBODY]	"new body",
 	[SAVE]	"save",
 	[LOAD]	"load",
-	[ZOOM]	"zoom",
 	[SPEED]	"speed",
 	[GRAV]	"gravity",
 	[EXIT]	"exit",
@@ -106,7 +118,7 @@ randcol(void)
 void
 pause(int p, int id)
 {
-	static int paused, pid = -1;
+	static int pid = -1;
 
 	switch(p) {
 	default:
@@ -253,7 +265,15 @@ dobody(void)
 	double f;
 	Body *b;
 
-	pause(0, 0);
+	for(;;) {
+		readmouse(mc);
+		if(mc->buttons == 0)
+			continue;
+		if(mc->buttons == 1)
+			break;
+		return;
+	}
+
 	b = body();
 	setpos(b);
 	setvel(b);
@@ -278,8 +298,6 @@ dobody(void)
 	gc = center();
 	orig.x += gc.x / scale;
 	orig.y += gc.y / scale;
-
-	pause(1, 0);
 }
 
 char*
@@ -316,19 +334,55 @@ domove(void)
 	Point oldp, off;
 
 	setcursor(mc, &crosscursor);
-	pause(0, 0);
 	oldp = mc->xy;
+	for(;;) {
+		readmouse(mc);
+		if(mc->buttons != 1)
+			break;
+		off = subpt(mc->xy, oldp);
+		oldp = mc->xy;
+		pause(0, 0);
+		orig = addpt(orig, off);
+		drawglxy();
+		pause(1, 0);
+	}
+	setcursor(mc, cursor);
+}
+
+void
+dozoom(void)
+{
+	Point z, d;
+	double f, olds;
+
+	setcursor(mc, &zoomcursor);
+	for(;;) {
+		for(;;) {
+			readmouse(mc);
+			if(mc->buttons == 0)
+				continue;
+			if(mc->buttons != 2)
+				goto End;
+			break;
+		}
+		z = mc->xy;
+		olds = scale;
+		pause(0, 0);
 		for(;;) {
 			readmouse(mc);
 			if(mc->buttons != 2)
 				break;
-		off = subpt(mc->xy, oldp);
-		oldp = mc->xy;
-		orig = addpt(orig, off);
 			drawglxy();
+			line(screen, z, (Point){z.x, mc->xy.y}, Enddisc, Enddisc, 0, display->white, ZP);
+			d = subpt(mc->xy, z);
+			f = tanh((double)d.y/200) + 1;
+			scale = f*olds;
 		}
-	setcursor(mc, cursor);
 		pause(1, 0);
+	}
+
+End:
+	setcursor(mc, cursor);
 }
 
 void
@@ -349,6 +403,9 @@ domenu(void)
 
 	pause(0, 0);
 	switch(menuhit(3, mc, &menu, nil)) {
+	case DOBODY:
+		dobody();
+		break;
 	case SAVE:
 		s = getinput("Enter file:", file);
 		if(s == nil || *s == '\0')
@@ -373,16 +430,6 @@ domenu(void)
 		load(fd);
 		close(fd);
 		break;
-	case ZOOM:
-		s = getinput("Zoom multiplier:", nil);
-		if(s == nil || *s == '\0')
-			break;
-		z = strtod(s, nil);
-		free(s);
-		if(z <= 0)
-			break;
-		scale /= z;
-		break;
 	case SPEED:
 		s = getinput("Speed multiplier:", nil);
 		if(s == nil || *s == '\0')
@@ -420,10 +467,10 @@ mousethread(void*)
 		readmouse(mc);
 		switch(mc->buttons) {
 		case 1:
-			dobody();
+			domove();
 			break;
 		case 2:
-			domove();
+			dozoom();
 			break;
 		case 4:
 			domenu();
@@ -451,7 +498,6 @@ kbdthread(void*)
 {
 	Keyboardctl *realkc;
 	Rune r;
-	static int paused;
 
 	threadsetname("keyboard");
 	realkc = initkeyboard(nil);
@@ -479,16 +525,16 @@ kbdthread(void*)
 			showa ^= 1;
 			break;
 		case ' ':
-			paused ^= 1;
 			if(paused) {
-				cursor = &pausecursor;
-				pause(0, 1);
-			} else {
 				cursor = nil;
 				pause(1, 1);
+			} else {
+				cursor = &pausecursor;
+				pause(0, 1);
 			}
 			setcursor(mc, cursor);
 		}
+		drawglxy();
 	}
 }