kernel: cleanup the software mouse cursor mess

The swcursor used a 32x32 image for saving/restoring
screen contents for no reason.

Add a doflush argument to swcursorhide(), so that
disabling software cursor with a double buffered
softscreen is properly hidden. The doflush parameter
should be set to 0 in all other cases as swcursordraw()
will flushes both (current and previours) locations.

Make sure swcursorinit() and swcursorhide() clear the
visibility flag, even when gscreen is nil.

Remove the cursor locking and just do everything within
the drawlock. All cursor functions such as curson(),
cursoff() and setcursor() will be called drawlock
locked. This also means &cursor can be read.

Fix devmouse cursor reads and writes. We now have the
global cursor variable that is only modified under
the drawlock. So copy under drawlock.

Move the pc software cursor implementation into vgasoft
driver, so screen.c does not need to handle it as
a special case.

Remove unused functions such as drawhasclients().

2 files changed, 9 insertions, 52 deletions

diff --git a/sys/src/9/omap/screen.c b/sys/src/9/omap/screen.c
index 0a4e005c5..0e9d2f0dc 100644
--- a/sys/src/9/omap/screen.c
+++ b/sys/src/9/omap/screen.c
@@ -189,24 +189,6 @@ static	ulong	rep(ulong, int);
 static	void	screenputc(char *buf);
 static	void	screenwin(void);
 
-/*
- * Software cursor. 
- */
-int	swvisible;	/* is the cursor visible? */
-int	swenabled;	/* is the cursor supposed to be on the screen? */
-Memimage*	swback;	/* screen under cursor */
-Memimage*	swimg;	/* cursor image */
-Memimage*	swmask;	/* cursor mask */
-Memimage*	swimg1;
-Memimage*	swmask1;
-
-Point	swoffset;
-Rectangle	swrect;	/* screen rectangle in swback */
-Point	swpt;	/* desired cursor location */
-Point	swvispt;	/* actual cursor location */
-int	swvers;	/* incremented each time cursor image changes */
-int	swvisvers;	/* the version on the screen */
-
 static void
 lcdoff(void)
 {
@@ -330,28 +312,21 @@ screenpower(int on)
 	blankscreen(on == 0);
 }
 
+/* called from devmouse */
+
 void
 cursoron(void)
 {
-	qlock(&drawlock);
-	lock(&cursor);
-	swcursorhide();
+	swcursorhide(0);
 	swcursordraw(mousexy());
-	unlock(&cursor);
-	qunlock(&drawlock);
 }
 
 void
 cursoroff(void)
 {
-	qlock(&drawlock);
-	lock(&cursor);
-	swcursorhide();
-	unlock(&cursor);
-	qunlock(&drawlock);
+	swcursorhide(0);
 }
 
-/* called from devmouse */
 void
 setcursor(Cursor* curs)
 {
@@ -404,10 +379,7 @@ screeninit(void)
 		iprint("screen: frame buffer at %#p for %dx%d\n",
 			framebuf, oscreen.settings->wid, oscreen.settings->ht);
 
-		swenabled = 1;
 		swcursorinit();		/* needs gscreen set */
-		setcursor(&arrow);
-
 		first = 0;
 	}
 }
diff --git a/sys/src/9/omap/screen.h b/sys/src/9/omap/screen.h
index d06f83863..287e2ff8c 100644
--- a/sys/src/9/omap/screen.h
+++ b/sys/src/9/omap/screen.h
@@ -1,22 +1,13 @@
 typedef struct Cursor Cursor;
-typedef struct Cursorinfo	Cursorinfo;
 typedef struct OScreen OScreen;
 typedef struct Omap3fb Omap3fb;
 typedef struct Settings Settings;
 
-struct Cursorinfo
-{
-	Cursor;
-	Lock;
-};
-
-extern Cursor	arrow;
-extern Cursorinfo cursor;
-
 /* devmouse.c */
-extern void mousetrack(int, int, int, ulong);
-extern void absmousetrack(int, int, int, ulong);
-extern Point mousexy(void);
+extern Cursor	cursor;
+extern void	mousetrack(int, int, int, ulong);
+extern void	absmousetrack(int, int, int, ulong);
+extern Point	mousexy(void);
 
 extern void	mouseaccelerate(int);
 extern void	mouseresize(void);
@@ -33,15 +24,9 @@ extern int	screenaperture(int, int);
 extern Rectangle physgscreenr;	/* actual monitor size */
 extern void	blankscreen(int);
 
-extern void swcursorinit(void);
-extern void swcursorhide(void);
-extern void swcursoravoid(Rectangle);
-extern void swcursorunhide(void);
-
 /* devdraw.c */
 extern void	deletescreenimage(void);
 extern void	resetscreenimage(void);
-extern int		drawhasclients(void);
 extern void	setscreenimageclipr(Rectangle);
 extern void	drawflush(void);
 extern QLock	drawlock;
@@ -49,7 +34,7 @@ extern QLock	drawlock;
 #define ishwimage(i)	0		/* for ../port/devdraw.c */
 
 /* swcursor.c */
-void		swcursorhide(void);
+void		swcursorhide(int);
 void		swcursoravoid(Rectangle);
 void		swcursordraw(Point);
 void		swcursorload(Cursor *);