This patch is a small change to the saved patch "piemenus-rio".
It changes the behaviour of the piemenus, to be no more drawn
outside of the screen. Besides this is there a style update, to
be more consistent with the "Plan 9 style option int variables"
and the style of whole libdraw.

Reference: /n/sources/patch/sorry/rio-piemenu-update
Date: Tue Aug  9 10:57:30 CES 2005

--- /sys/src/libdraw/piemenuhit.c	Thu Jan  1 00:00:00 1970
+++ /sys/src/libdraw/piemenuhit.c	Tue Aug  9 10:57:05 2005
@@ -0,0 +1,215 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <thread.h>
+#include <mouse.h>
+
+static Image *back, *bord, *high;
+
+double
+rad(double i)
+{
+
+	return (i * PI) / 180;
+}
+
+double
+dist(Point p0, Point p1)
+{
+
+	return sqrt((p0.x - p1.x) * (p0.x - p1.x) + (p0.y - p1.y) * (p0.y - p1.y));
+}
+
+Point
+cente(Point p0, Point p1, Point p2)
+{
+	double l, d;
+	Point r0, r1;
+
+	l = dist(p2, p0);
+	r0.x = p2.x + (((p0.x - p2.x) / l) * l / 2);
+	r0.y = p2.y + (((p0.y - p2.y) / l) * l / 2);
+
+	l = dist(p1, p0);
+	r1.x = p1.x + (((p0.x - p1.x) / l) * l / 2);
+	r1.y = p1.y + (((p0.y - p1.y) / l) * l / 2);
+
+	l = p2.y - r1.y - p1.y + r0.y;
+	d = (double)(r0.y - r1.y) / l;
+
+	r1.x = r0.x + d * (p1.x - r0.x);
+	r1.y = r0.y + d * (p1.y - r0.y);
+
+	return r1;
+}
+
+void
+draw_pie(Point p, int r, Image *b, Image *w, Image *h, Menu *m, int a, int n)
+{
+	Point p0, p1;
+	double d, e, sr;
+	char *item;
+
+	e = 360 / n;
+	d = 0;
+	sr = -1;
+
+	ellipse(screen, p, r, r, 1, h, ZP);
+	fillellipse(screen, p, r - 1, r - 1, w, ZP);
+	if(a > 0)
+		fillarc(screen, p, r, r, b, ZP, (a - 1) * e, e);
+
+	p0 = p;
+	p1 = p;
+
+	p0.x += cos(rad(d)) * r;
+	p0.y += sin(rad(d)) * r;
+	p1.x += cos(rad(d + e)) * r;
+	p1.y += sin(rad(d + e)) * r;
+	
+	sr = dist(cente(p, p0, p1), p);
+
+	d = e / 2;
+
+	while(--n >= 0){
+		p0 = p;
+		item = strdup(m->item[n]);
+		if(strlen(item) > 8){
+			item[8] = '\0';
+			item[7] = '.';
+			item[6] = '.';
+			item[5] = '.';
+		}
+
+		p0.x += cos(rad(d)) * sr;
+		p0.y += sin(rad(d)) * sr;
+	
+		p0.x -= stringwidth(font, item) / 2;
+		p0.y -= font->height / 2;
+
+		string(screen, p0, (n == (a - 1)) ? display->white : display->black, ZP, font, item);
+		free(item);
+		d += e;
+	}
+
+	return;
+}
+
+int
+piemenuhit(int but, Mousectl *mc, Menu *menu, Screen *scr)
+{
+	Rectangle menur;
+	Image *b, *backup, *back, *high, *bord;
+	int maxwid, nitem, i, t, set;
+	double cdeli, cpart, radius;
+	Point p;
+	char *item;
+
+	back = allocimagemix(display, DPalegreen, DWhite);
+	high = allocimage(display, Rect(0,0,1,1), screen->chan, 1, DDarkgreen);
+	bord = allocimage(display, Rect(0,0,1,1), screen->chan, 1, DMedgreen);
+	set = 1;
+
+	if(back == nil || high == nil || bord == nil){
+		set = 0;
+		back = display->white;
+		high = display->black;
+		bord = display->black;
+	}
+
+	replclipr(screen, 0, screen->r);
+	maxwid = 0;
+	nitem = 0;
+	while(item = menu->item ? menu->item[nitem] : (*menu->gen)(nitem)){
+		item = strdup(item);
+		if(strlen(item) > 8)
+			item[8] = '\0';
+
+		i = stringwidth(font, item);
+		if(i > maxwid)
+			maxwid = i;
+		free(item);
+		nitem++;
+	}
+	if(menu->lasthit < 0 || menu->lasthit >= nitem)
+		menu->lasthit = -1;
+
+	p = mc->xy;
+	radius = ((font->height / 2) + maxwid);
+	radius += radius * nitem / 8;
+	if(p.x + radius > screen->r.max.x)
+		p.x = screen->r.max.x - radius;
+	if(p.x - radius < screen->r.min.x)
+		p.x = screen->r.min.x + radius;
+	if(p.y + radius > screen->r.max.y)
+		p.y = screen->r.max.y - radius;
+	if(p.y - radius < screen->r.min.y)
+		p.y = screen->r.min.y + radius;
+	moveto(mc, p);
+
+	menur.min = Pt(p.x - radius - 1, p.y - radius - 1);
+	menur.max = Pt(p.x + radius + 2, p.y + radius + 2);
+	
+	cpart = 360 / nitem;
+	cdeli = cpart / 2;
+	
+	if(scr){
+		b = allocwindow(scr, menur, Refbackup, DNofill);
+		if(b == nil)
+			b = screen;
+		backup = nil;
+	}else{
+		b = screen;
+		backup = allocimage(display, Rect(0, 0, Dx(menur), Dy(menur)), screen->chan, 0, DNofill);
+		if(backup)
+			draw(backup, backup->r, screen, nil, menur.min);
+	}
+	
+	draw_pie(p, radius, high, back, bord, menu, menu->lasthit, nitem);
+
+	while(mc->buttons & (1<<(but-1))){
+		if(dist(p, mc->xy) < radius && dist(p, mc->xy) != 0){
+			cdeli = acos((p.x - mc->xy.x) / dist(p, mc->xy));
+			if(mc->xy.y >= p.y)
+				cdeli += rad(180);
+			if(mc->xy.y < p.y)
+				cdeli = rad(180) - cdeli;
+
+			i = -1;
+			t = -1;
+			while(++t <= nitem){
+				if(cdeli < rad(t * cpart) && cdeli <= rad((t + 1) * cpart)){
+					i = t;
+					break;
+				}
+			}
+
+			if(i != menu->lasthit || (menu->lasthit == -1 && i != -1)){
+				menu->lasthit = i;
+				draw_pie(p, radius, high, back, bord, menu, menu->lasthit, nitem);
+			}
+		} else {
+			if(menu->lasthit != -1){
+				menu->lasthit = -1;
+				draw_pie(p, radius, high, back, bord, menu, menu->lasthit, nitem);
+			}
+		}
+		readmouse(mc);
+	}
+	if(b != screen)
+		freeimage(b);
+	if(backup){
+		draw(screen, menur, backup, nil, ZP);
+		freeimage(backup);
+	}
+	replclipr(screen, 0, screen->clipr);
+	flushimage(display, 1);
+
+	if(set){
+		freeimage(back);
+		freeimage(bord);
+		freeimage(high);
+	}
+
+	return menu->lasthit - 1;
+}
--- /sys/src/libdraw/epiemenuhit.c	Thu Jan  1 00:00:00 1970
+++ /sys/src/libdraw/epiemenuhit.c	Tue Aug  9 10:57:18 2005
@@ -0,0 +1,206 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <event.h>
+
+static Image *back, *bord, *high;
+
+double
+erad(double i)
+{
+
+	return (i * PI) / 180;
+}
+
+double
+edist(Point p0, Point p1)
+{
+
+	return sqrt((p0.x - p1.x) * (p0.x - p1.x) + (p0.y - p1.y) * (p0.y - p1.y));
+}
+
+Point
+ecente(Point p0, Point p1, Point p2)
+{
+	double l, d;
+	Point r0, r1;
+
+	l = edist(p2, p0);
+	r0.x = p2.x + (((p0.x - p2.x) / l) * l / 2);
+	r0.y = p2.y + (((p0.y - p2.y) / l) * l / 2);
+
+	l = edist(p1, p0);
+	r1.x = p1.x + (((p0.x - p1.x) / l) * l / 2);
+	r1.y = p1.y + (((p0.y - p1.x) / l) * l / 2);
+
+	l = p2.x - r1.x - p1.x + r0.x;
+	d = (double)(r0.x - r1.x) / l;
+
+	r1.x = r0.x + d * (p1.x - r0.x);
+	r1.y = r0.y + d * (p1.y - r0.y);
+
+	return r1;
+}
+
+void
+edraw_pie(Point p, int r, Image *b, Image *w, Image *h, Menu *m, int a, int n)
+{
+	Point p0, p1;
+	double d, e, sr;
+	char *item;
+
+	e = 360 / n;
+	d = 0;
+	sr = -1;
+
+	ellipse(screen, p, r, r, 1, h, ZP);
+	fillellipse(screen, p, r - 1, r - 1, w, ZP);
+	if(a > 0)
+		fillarc(screen, p, r, r, b, ZP, (a - 1) * e, e);
+
+	p0 = p;
+	p1 = p;
+
+	p0.x += cos(erad(d)) * r;
+	p0.y += sin(erad(d)) * r;
+	p1.x += cos(erad(d + e)) * r;
+	p1.y += sin(erad(d + e)) * r;
+	
+	sr = edist(ecente(p, p0, p1), p);
+
+	d = e / 2;
+
+	while(--n >= 0){
+		p0 = p;
+		item = strdup(m->item[n]);
+		if(strlen(item) > 8){
+			item[8] = '\0';
+			item[7] = '.';
+			item[6] = '.';
+			item[5] = '.';
+		}
+
+		p0.x += cos(erad(d)) * sr;
+		p0.y += sin(erad(d)) * sr;
+	
+		p0.x -= stringwidth(font, item) / 2;
+		p0.y -= font->height / 2;
+
+		string(screen, p0, (n == (a - 1)) ? display->white : display->black, ZP, font, item);
+		free(item);
+		d += e;
+	}
+
+	return;
+}
+
+int
+epiemenuhit(int but, Mouse *m, Menu *menu)
+{
+	Rectangle menur;
+	Image *b, *back, *high, *bord;
+	int maxwid, nitem, i, t;
+	double cdeli, cpart, radius;
+	Point p;
+	char *item, set;
+
+	back = allocimagemix(display, DPalegreen, DWhite);
+	high = allocimage(display, Rect(0,0,1,1), screen->chan, 1, DDarkgreen);
+	bord = allocimage(display, Rect(0,0,1,1), screen->chan, 1, DMedgreen);
+	set = 1;
+
+	if(back == nil || high == nil || bord == nil){
+		set = 0;
+		back = display->white;
+		high = display->black;
+		bord = display->black;
+	}
+
+	replclipr(screen, 0, screen->r);
+	maxwid = 0;
+	nitem = 0;
+	while(item = menu->item ? menu->item[nitem] : (*menu->gen)(nitem)){
+		item = strdup(item);
+		if(strlen(item) > 8)
+			item[8] = '\0';
+
+		i = stringwidth(font, item);
+		if(i > maxwid)
+			maxwid = i;
+		free(item);
+		nitem++;
+	}
+	if(menu->lasthit < 0 || menu->lasthit >= nitem)
+		menu->lasthit = -1;
+
+	p = m->xy;
+	radius = ((font->height / 2) + maxwid);
+	radius += radius * nitem / 8;
+	if(p.x + radius > screen->r.max.x)
+		p.x = screen->r.max.x - radius;
+	if(p.x - radius < screen->r.min.x)
+		p.x = screen->r.min.x + radius;
+	if(p.y + radius > screen->r.max.y)
+		p.y = screen->r.max.y - radius;
+	if(p.y - radius < screen->r.min.y)
+		p.y = screen->r.min.y + radius;
+	emoveto(p);
+
+	menur.min = Pt(p.x - radius - 1, p.y - radius - 1);
+	menur.max = Pt(p.x + radius + 2, p.y + radius + 2);
+	
+	cpart = 360 / nitem;
+	cdeli = cpart / 2;
+	
+	b = allocimage(display, Rect(0, 0, Dx(menur), Dy(menur)), screen->chan, 0, DNofill);
+	if(b == 0)
+		b = screen;
+	draw(b, b->r, screen, nil, menur.min);
+	
+	edraw_pie(p, radius, high, back, bord, menu, menu->lasthit, nitem);
+
+	while(m->buttons & (1<<(but-1))){
+		if(edist(p, m->xy) < radius && edist(p, m->xy) != 0){
+			cdeli = acos((p.x - m->xy.x) / edist(p, m->xy));
+			if(m->xy.y >= p.y)
+				cdeli += erad(180);
+			if(m->xy.y < p.y)
+				cdeli = erad(180) - cdeli;
+
+			i = -1;
+			t = -1;
+			while(++t <= nitem){
+				if(cdeli < erad(t * cpart) && cdeli <= erad((t + 1) * cpart)){
+					i = t;
+					break;
+				}
+			}
+
+			if(i != menu->lasthit || (menu->lasthit == -1 && i != -1)){
+				menu->lasthit = i;
+				edraw_pie(p, radius, high, back, bord, menu, menu->lasthit, nitem);
+			}
+		} else {
+			if(menu->lasthit != -1){
+				menu->lasthit = -1;
+				edraw_pie(p, radius, high, back, bord, menu, menu->lasthit, nitem);
+			}
+		}
+		flushimage(display, 1);
+		*m = emouse();
+	}
+
+	draw(screen, menur, b, nil, ZP);
+	if(b != screen)
+		freeimage(b);
+
+	replclipr(screen, 0, screen->clipr);
+
+	if(set){
+		freeimage(back);
+		freeimage(bord);
+		freeimage(high);
+	}
+
+	return menu->lasthit - 1;
+}