From 287aedc57a75e36864206a80c0bf4e7bc31790ff Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sat, 16 Dec 1995 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1995-12-16

---
 carrera/kbd.c   |  5 +++++
 pc/kbd.c        |  6 ++++++
 port/devmouse.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++-
 port/portfns.h  |  1 +
 4 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/carrera/kbd.c b/carrera/kbd.c
index 6020b22c9882976ad5dfd961062630c7116851e6..daabfe594995067ebb818deb89f9b6a36daff4b4 100644
--- a/carrera/kbd.c
+++ b/carrera/kbd.c
@@ -406,6 +406,11 @@ mousectl(char *cmd)
 		mousecmd(0xF4);	/* enabled */
 		splx(s);
 	}
+	else if(strcmp(cmd, "accelerated") == 0){
+		s = splhi();
+		mousecmd(0xE7);
+		splx(s);
+	}
 	else
 		error(Ebadctl);
 }
diff --git a/pc/kbd.c b/pc/kbd.c
index 55f046fb04dcb2e5575cc29616fdbc5e408d2c10..405b6b706d8cba7412370e54d7b9a89807ed229c 100644
--- a/pc/kbd.c
+++ b/pc/kbd.c
@@ -574,6 +574,9 @@ mousectl(char *arg)
 			mousecmd(0xE7);
 			splx(x);
 			break;
+		default:
+			mouseaccelerate(field[1]);
+			break;
 		}
 	} else if(strcmp(field[0], "linear") == 0){
 		switch(mousetype){
@@ -582,6 +585,9 @@ mousectl(char *arg)
 			mousecmd(0xE6);
 			splx(x);
 			break;
+		default:
+			mouseaccelerate("0");
+			break;
 		}
 	} else if(strcmp(field[0], "res") == 0){
 		if(n < 2)
diff --git a/port/devmouse.c b/port/devmouse.c
index ddda7bcec6c5be48d37a65ac60c972a9000a3da6..8ab06424fd32aa327bc2ebac5bfc43bb61a1bbb6 100644
--- a/port/devmouse.c
+++ b/port/devmouse.c
@@ -27,6 +27,8 @@ struct Mouseinfo
 	Ref;
 	QLock;
 	int	open;
+	int	acceleration;
+	int	maxacc;
 };
 
 Mouseinfo	mouse;
@@ -272,7 +274,10 @@ mousewrite(Chan *c, void *va, long n, ulong)
 		if(n >= sizeof(buf))
 			n = sizeof(buf)-1;
 		strncpy(buf, va, n);
-		buf[n] = 0;
+		if(buf[n - 1] == '\n')
+			buf[n-1] = 0;
+		else
+			buf[n] = 0;
 		mousectl(buf);
 		return n;
 
@@ -338,6 +343,34 @@ mouseclock(void)
 	graphicsactive(0);
 }
 
+static int
+scale(int x)
+{
+	int sign = 1;
+
+	if(x < 0){
+		sign = -1;
+		x = -x;
+	}
+	switch(x){
+	case 0:
+	case 1:
+	case 2:
+	case 3:
+		break;
+	case 4:
+		x = 6 + (mouse.acceleration>>2);
+		break;
+	case 5:
+		x = 9 + (mouse.acceleration>>1);
+		break;
+	default:
+		x *= mouse.maxacc;
+		break;
+	}
+	return sign*x;
+}
+
 /*
  *  called at interrupt level to update the structure and
  *  awaken any waiting procs.
@@ -347,6 +380,10 @@ mousetrack(int b, int dx, int dy)
 {
 	int x, y;
 
+	if(mouse.acceleration){
+		dx = scale(dx);
+		dy = scale(dy);
+	}
 	x = mouse.xy.x + dx;
 	if(x < gscreen.r.min.x)
 		x = gscreen.r.min.x;
@@ -449,3 +486,15 @@ mousexy(void)
 {
 	return mouse.xy;
 }
+
+void
+mouseaccelerate(char *x)
+{
+	if(x == 0)
+		x = "1";
+	mouse.acceleration = atoi(x);
+	if(mouse.acceleration < 3)
+		mouse.maxacc = 2;
+	else
+		mouse.maxacc = mouse.acceleration;
+}
diff --git a/port/portfns.h b/port/portfns.h
index 0170884534e66388c2f179fe4fcf5a21c61270d4..5ab08f43963fb066b5388538a90fe3bc5f52603c 100644
--- a/port/portfns.h
+++ b/port/portfns.h
@@ -142,6 +142,7 @@ void		mntrepl(char*);
 long		mntwrite9p(Chan*, void*, long, ulong);
 int		mount(Chan*, Chan*, int, char*);
 void		mountfree(Mount*);
+void		mouseaccelerate(char*);
 void		mousebuttons(int);
 void		mouseclock(void);
 void		mousectl(char*);