From 9ed778807ac6f88db5e776e61f62d9f1a5f9921d Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Tue, 26 Oct 1993 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1993-10-26

---
 carrera/screen.c | 49 +++++++++++++++++++++---------------------------
 port/devmouse.c  | 28 +++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 28 deletions(-)

diff --git a/carrera/screen.c b/carrera/screen.c
index 34494df3fb994c5790a1b703d9fc1926ac948b4d..6c05f6ef2e6c716c9d53c1c238f4d81d4ffcf4c6 100644
--- a/carrera/screen.c
+++ b/carrera/screen.c
@@ -534,32 +534,24 @@ mousescreenupdate(void)
 	unlock(&screenlock);
 }
 
+extern	cursorlock(Rectangle);
+extern	cursorunlock(void);
 /*
- * graphics
+ * paste tile into screen.
+ * tile is at location r, first pixel in *data.  tl is length of scan line to insert,
+ * l is amount to advance data after each scan line.
  */
 void
-screenload(Rectangle r, uchar *data, long n)
+screenload(Rectangle r, uchar *data, int tl, int l)
 {
-	int y, ws, l, t, lpart, rpart, mx, m, mr;
+	int y, lpart, rpart, mx, m, mr;
 	uchar *q;
 
-	if(!rectclip(&r, gscreen.r))
+	if(!rectclip(&r, gscreen.r) || tl<=0)
 		return;
 	lock(&screenlock);
-	ws = 8>>gscreen.ldepth;	/* pixels per byte */
-	/* set l to number of bytes of data per scan line */
-	if(r.min.x >= 0)
-		l = (r.max.x+ws-1)/ws - r.min.x/ws;
-	else{		/* make positive before divide */
-		t = (-r.min.x)+ws-1;
-		t = (t/ws)*ws;
-		l = (t+r.max.x+ws-1)/ws;
-	}
-	if(n != l*Dy(r)){
-		unlock(&screenlock);
-		error("bad tile size");
-	}
-	cursoroff(1);
+	cursorlock(r);
+	screenupdate();
 	q = gbaddr(&gscreen, r.min);
 	mx = 7>>gscreen.ldepth;
 	lpart = (r.min.x & mx) << gscreen.ldepth;
@@ -573,40 +565,41 @@ screenload(Rectangle r, uchar *data, long n)
 		for(y=r.min.y; y<r.max.y; y++){
 			*q ^= (*data^*q) & m;
 			q += gscreen.width*sizeof(ulong);
-			data++;
+			data += l;
 		}
 	}else if(lpart==0 && rpart==0){	/* easy case */
 		for(y=r.min.y; y<r.max.y; y++){
-			memmove(q, data, l);
+			memmove(q, data, tl);
 			q += gscreen.width*sizeof(ulong);
 			data += l;
 		}
 	}else if(rpart==0){
 		for(y=r.min.y; y<r.max.y; y++){
 			*q ^= (*data^*q) & m;
-			if(l > 1)
-				memmove(q+1, data+1, l-1);
+			if(tl > 1)
+				memmove(q+1, data+1, tl-1);
 			q += gscreen.width*sizeof(ulong);
 			data += l;
 		}
 	}else if(lpart == 0){
 		for(y=r.min.y; y<r.max.y; y++){
-			if(l > 1)
-				memmove(q, data, l-1);
-			q[l-1] ^= (data[l-1]^q[l-1]) & mr;
+			if(tl > 1)
+				memmove(q, data, tl-1);
+			q[tl-1] ^= (data[tl-1]^q[tl-1]) & mr;
 			q += gscreen.width*sizeof(ulong);
 			data += l;
 		}
 	}else for(y=r.min.y; y<r.max.y; y++){
 			*q ^= (*data^*q) & m;
 			if(l > 2)
-				memmove(q+1, data+1, l-2);
-			q[l-1] ^= (data[l-1]^q[l-1]) & mr;
+				memmove(q+1, data+1, tl-2);
+			q[tl-1] ^= (data[tl-1]^q[l-1]) & mr;
 			q += gscreen.width*sizeof(ulong);
 			data += l;
 		}
 	mbbrect(r);
-	cursoron(1);
+	screenupdate();
+	cursorunlock();
 	screenupdate();
 	unlock(&screenlock);
 }
diff --git a/port/devmouse.c b/port/devmouse.c
index f92a7d35c5d23c42fc9070b63f9a5671d5f7b5fa..9fc9ed2902d072fece7395667649cfbcb66c4dad 100644
--- a/port/devmouse.c
+++ b/port/devmouse.c
@@ -54,6 +54,7 @@ struct Cursorinfo
 	Lock;
 	int	visible;	/* on screen */
 	int	disable;	/* from being used */
+	int	frozen;	/* from being used */
 	Rectangle r;		/* location */
 };
 
@@ -382,6 +383,33 @@ Cursortocursor(Cursor *c)
 	unlock(&cursor);
 }
 
+void
+cursorlock(Rectangle r)
+{
+	if(hwcurs)
+		return;
+	lock(&cursor);
+	if(rectXrect(cursor.r, r)){
+		cursoroff(0);
+		cursor.frozen = 1;
+	}
+	cursor.disable++;
+	unlock(&cursor);
+}
+
+void
+cursorunlock(void)
+{
+	if(hwcurs)
+		return;
+	lock(&cursor);
+	cursor.disable--;
+	if(cursor.frozen)
+		cursoron(0);
+	cursor.frozen = 0;
+	unlock(&cursor);
+}
+
 void
 cursoron(int dolock)
 {