From a9d6c0d92be5789d996616184af67acc0cb9e901 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Tue, 14 Mar 2000 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2000-03-14

---
 port/devmouse.c | 71 ++++++++++++++++++++++++++++-------
 port/latin1.h   | 99 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 157 insertions(+), 13 deletions(-)
 create mode 100644 port/latin1.h

diff --git a/port/devmouse.c b/port/devmouse.c
index 107203ac3514953986969236f52e3d96f9ab7599..ecba107a9d8a0cef8c857c494ca0dc975fac33d5 100644
--- a/port/devmouse.c
+++ b/port/devmouse.c
@@ -12,16 +12,23 @@
 #include	"screen.h"
 
 typedef struct Mouseinfo	Mouseinfo;
+typedef struct Mousestate	Mousestate;
+
+struct Mousestate
+{
+	Point	xy;			/* mouse.xy */
+	int	buttons;		/* mouse.buttons */
+	ulong	counter;	/* increments every update */
+	ulong	msec;	/* time of last event */
+};
 
 struct Mouseinfo
 {
+	Mousestate;
 	int	dx;
 	int	dy;
 	int	track;		/* dx & dy updated */
-	Point	xy;			/* mouse.xy */
-	int	buttons;		/* mouse.buttons */
 	int	redraw;		/* update cursor on screen */
-	ulong	counter;	/* increments every update */
 	ulong	lastcounter;	/* value when /dev/mouse read */
 	Rendez	r;
 	Ref;
@@ -30,6 +37,10 @@ struct Mouseinfo
 	int	inopen;
 	int	acceleration;
 	int	maxacc;
+	Mousestate 	queue[16];	/* circular buffer of click events */
+	int	ri;	/* read index into queue */
+	int	wi;	/* write index into queue */
+	uchar	qfull;	/* queue is full */
 };
 
 Mouseinfo	mouse;
@@ -186,6 +197,7 @@ mouseread(Chan *c, void *va, long n, vlong off)
 	uchar *p;
 	static int map[8] = {0, 4, 2, 6, 1, 5, 3, 7 };
 	ulong offset = off;
+	Mousestate m;
 
 	p = va;
 	switch(c->qid.path){
@@ -210,15 +222,33 @@ mouseread(Chan *c, void *va, long n, vlong off)
 		while(mousechanged(0) == 0)
 			sleep(&mouse.r, mousechanged, 0);
 
-		while(!canlock(&cursor))
-			tsleep(&up->sleep, return0, 0, TK2MS(1));
+		mouse.qfull = 0;
+
+		/*
+		 * No lock of the indicies is necessary here, because ri is only
+		 * updated by us, and there is only one mouse reader
+		 * at a time.  I suppose that more than one process
+		 * could try to read the fd at one time, but such behavior
+		 * is degenerate and already violates the calling
+		 * conventions for sleep above.
+		 */
+		if(mouse.ri != mouse.wi) {
+			m = mouse.queue[mouse.ri];
+			if(++mouse.ri == nelem(mouse.queue))
+				mouse.ri = 0;
+		} else {
+			while(!canlock(&cursor))
+				tsleep(&up->sleep, return0, 0, TK2MS(1));
+	
+			m = mouse.Mousestate;
+			unlock(&cursor);
+		}
 
 		sprint(buf, "m%11d %11d %11d %11lud",
-			mouse.xy.x, mouse.xy.y,
-			buttonmap[mouse.buttons&7],
-			TK2MS(MACHP(0)->ticks));
-		mouse.lastcounter = mouse.counter;
-		unlock(&cursor);
+			m.xy.x, m.xy.y,
+			buttonmap[m.buttons&7],
+			m.msec);
+		mouse.lastcounter = m.counter;
 		if(n > 1+4*12)
 			n = 1+4*12;
 		memmove(va, buf, n);
@@ -457,7 +487,7 @@ scale(int x)
 void
 mousetrack(int b, int dx, int dy)
 {
-	int x, y;
+	int x, y, lastb;
 
 	if(gscreen==nil)
 		return;
@@ -476,10 +506,25 @@ mousetrack(int b, int dx, int dy)
 		y = gscreen->r.min.y;
 	if(y >= gscreen->r.max.y)
 		y = gscreen->r.max.y;
-	mouse.counter++;
+
+	lastb = mouse.buttons;
 	mouse.xy = Pt(x, y);
 	mouse.buttons = b;
 	mouse.redraw = 1;
+	mouse.counter++;
+	mouse.msec = TK2MS(MACHP(0)->ticks);
+
+	/*
+	 * if the queue fills, we discard the entire queue and don't
+	 * queue any more events until a reader polls the mouse.
+	 */
+	if(!mouse.qfull && lastb != b) {	/* add to ring */
+		mouse.queue[mouse.wi] = mouse.Mousestate;
+		if(++mouse.wi == nelem(mouse.queue))
+			mouse.wi = 0;
+		if(mouse.wi == mouse.ri)
+			mouse.qfull = 1;
+	}
 	wakeup(&mouse.r);
 	drawactive(1);
 }
@@ -561,7 +606,7 @@ mouseputc(Queue*, int c)
 int
 mousechanged(void*)
 {
-	return mouse.lastcounter - mouse.counter;
+	return mouse.lastcounter != mouse.counter;
 }
 
 Point
diff --git a/port/latin1.h b/port/latin1.h
new file mode 100644
index 0000000000000000000000000000000000000000..04e535b01f671a1ddbeb727f7e9e095f3af03aba
--- /dev/null
+++ b/port/latin1.h
@@ -0,0 +1,99 @@
+	" ", " i",	L"␣ı",
+	"!~", "-=~",	L"≄≇≉",
+	"!", "!<=>?bmp",	L"¡≮≠≯‽⊄∉⊅",
+	"\"*", "IUiu",	L"ΪΫϊϋ",
+	"\"", "\"AEIOUYaeiouy",	L"¨ÄËÏÖÜŸäëïöüÿ",
+	"$*", "fhk",	L"ϕϑϰ",
+	"$", "BEFHILMRVaefglopv",	L"ℬℰℱℋℐℒℳℛƲɑℯƒℊℓℴ℘ʋ",
+	"\'\"", "Uu",	L"Ǘǘ",
+	"\'", "\'ACEILNORSUYZacegilnorsuyz",	L"´ÁĆÉÍĹŃÓŔŚÚÝŹáćéģíĺńóŕśúýź",
+	"*", "*ABCDEFGHIKLMNOPQRSTUWXYZabcdefghiklmnopqrstuwxyz",	L"∗ΑΒΞΔΕΦΓΘΙΚΛΜΝΟΠΨΡΣΤΥΩΧΗΖαβξδεφγθικλμνοπψρστυωχηζ",
+	"+", "-O",	L"±⊕",
+	",", ",ACEGIKLNORSTUacegiklnorstu",	L"¸ĄÇĘĢĮĶĻŅǪŖŞŢŲąçęģįķļņǫŗşţų",
+	"-*", "l",	L"ƛ",
+	"-", "+-2:>DGHILOTZbdghiltuz~",	L"∓­ƻ÷→ÐǤĦƗŁ⊖ŦƵƀðǥℏɨłŧʉƶ≂",
+	".", ".CEGILOZceglz",	L"·ĊĖĠİĿ⊙Żċėġŀż",
+	"/", "Oo",	L"Øø",
+	"1", "234568",	L"½⅓¼⅕⅙⅛",
+	"2", "-35",	L"ƻ⅔⅖",
+	"3", "458",	L"¾⅗⅜",
+	"4", "5",	L"⅘",
+	"5", "68",	L"⅚⅝",
+	"7", "8",	L"⅞",
+	":", ")-=",	L"☺÷≔",
+	"<!", "=~",	L"≨⋦",
+	"<", "-<=>~",	L"←«≤≶≲",
+	"=", ":<=>OV",	L"≕⋜≡⋝⊜⇒",
+	">!", "=~",	L"≩⋧",
+	">", "<=>~",	L"≷≥»≳",
+	"?", "!?",	L"‽¿",
+	"@\'", "\'",	L"ъ",
+	"@@", "\'EKSTYZekstyz",	L"ьЕКСТЫЗекстыз",
+	"@C", "Hh",	L"ЧЧ",
+	"@E", "Hh",	L"ЭЭ",
+	"@K", "Hh",	L"ХХ",
+	"@S", "CHch",	L"ЩШЩШ",
+	"@T", "Ss",	L"ЦЦ",
+	"@Y", "AEOUaeou",	L"ЯЕЁЮЯЕЁЮ",
+	"@Z", "Hh",	L"ЖЖ",
+	"@c", "h",	L"ч",
+	"@e", "h",	L"э",
+	"@k", "h",	L"х",
+	"@s", "ch",	L"щш",
+	"@t", "s",	L"ц",
+	"@y", "aeou",	L"яеёю",
+	"@z", "h",	L"ж",
+	"@", "ABDFGIJLMNOPRUVXabdfgijlmnopruvx",	L"АБДФГИЙЛМНОПРУВХабдфгийлмнопрувх",
+	"A", "E",	L"Æ",
+	"C", "ACU",	L"⋂ℂ⋃",
+	"Dv", "Zz",	L"DŽDž",
+	"D", "-e",	L"Ð∆",
+	"G", "-",	L"Ǥ",
+	"H", "-H",	L"Ħℍ",
+	"I", "-J",	L"ƗIJ",
+	"L", "&-Jj|",	L"⋀ŁLJLj⋁",
+	"N", "JNj",	L"NJℕNj",
+	"O", "*+-./=EIcoprx",	L"⊛⊕⊖⊙⊘⊜ŒƢ©⊚℗®⊗",
+	"P", "P",	L"ℙ",
+	"Q", "Q",	L"ℚ",
+	"R", "R",	L"ℝ",
+	"S", "S",	L"§",
+	"T", "-u",	L"Ŧ⊨",
+	"V", "=",	L"⇐",
+	"Y", "R",	L"Ʀ",
+	"Z", "-Z",	L"Ƶℤ",
+	"^", "ACEGHIJOSUWYaceghijosuwy",	L"ÂĈÊĜĤÎĴÔŜÛŴŶâĉêĝĥîĵôŝûŵŷ",
+	"_\"", "AUau",	L"ǞǕǟǖ",
+	"_,", "Oo",	L"Ǭǭ",
+	"_.", "Aa",	L"Ǡǡ",
+	"_", "AEIOU_aeiou",	L"ĀĒĪŌŪ¯āēīōū",
+	"`\"", "Uu",	L"Ǜǜ",
+	"`", "AEIOUaeiou",	L"ÀÈÌÒÙàèìòù",
+	"a", "ben",	L"↔æ∠",
+	"b", "()+-0123456789=bknpqru",	L"₍₎₊₋₀₁₂₃₄₅₆₇₈₉₌♝♚♞♟♛♜•",
+	"c", "$Oagu",	L"¢©∩≅∪",
+	"dv", "z",	L"dž",
+	"d", "-adegz",	L"ð↓‡°†ʣ",
+	"e", "lmns",	L"⋯—–∅",
+	"f", "a",	L"∀",
+	"g", "$-r",	L"¤ǥ∇",
+	"h", "-v",	L"ℏƕ",
+	"i", "-bfjps",	L"ɨ⊆∞ij⊇∫",
+	"l", "\"$&\'-jz|",	L"“£∧‘łlj⋄∨",
+	"m", "iou",	L"µ∈×",
+	"n", "jo",	L"nj¬",
+	"o", "AOUaeiu",	L"Å⊚Ůåœƣů",
+	"p", "Odgrt",	L"℗∂¶∏∝",
+	"r", "\"\'O",	L"”’®",
+	"s", "()+-0123456789=abnoprstu",	L"⁽⁾⁺⁻⁰¹²³⁴⁵⁶⁷⁸⁹⁼ª⊂ⁿº⊃√ß∍∑",
+	"t", "-efmsu",	L"ŧ∃∴™ς⊢",
+	"u", "-AEGIOUaegiou",	L"ʉĂĔĞĬŎŬ↑ĕğĭŏŭ",
+	"v\"", "Uu",	L"Ǚǚ",
+	"v", "ACDEGIKLNORSTUZacdegijklnorstuz",	L"ǍČĎĚǦǏǨĽŇǑŘŠŤǓŽǎčďěǧǐǰǩľňǒřšťǔž",
+	"w", "bknpqr",	L"♗♔♘♙♕♖",
+	"x", "O",	L"⊗",
+	"y", "$",	L"¥",
+	"z", "-",	L"ƶ",
+	"|", "Pp|",	L"Þþ¦",
+	"~!", "=",	L"≆",
+	"~", "-=AINOUainou~",	L"≃≅ÃĨÑÕŨãĩñõũ≈",