From 17887901fd4052103c5b3491dfce1dd04ff6967a Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 14 Apr 1994 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1994-04-14

---
 carrera/screen.c |  60 +++++++------
 carrera/screen.h |  20 +++--
 pc/devvga.c      | 175 ++++++++++++++++++++++++++++++++++++-
 pc/screen.h      |  20 +++++
 port/devmouse.c  | 218 ++---------------------------------------------
 port/portfns.h   |   5 +-
 6 files changed, 252 insertions(+), 246 deletions(-)
 create mode 100644 pc/screen.h

diff --git a/carrera/screen.c b/carrera/screen.c
index 79ef3add43e12b35239230f74d6201b47907b4ec..0bc520d91b70c80bcbe28463aa10dba5833f3323 100644
--- a/carrera/screen.c
+++ b/carrera/screen.c
@@ -93,7 +93,7 @@ Cursor fatarrow = {
 };
 
 static Rectangle window;
-static Point cursor;
+static Point curpos;
 static int h, w;
 extern Cursor arrow;
 
@@ -126,10 +126,9 @@ screenwin(void)
 	p = add(window.min, Pt(10, 2));
 	subfstring(&gscreen, p, &defont0, "Brazil Console ", S);
 	window.min.y += h+6;
-	cursor = window.min;
+	curpos = window.min;
 	window.max.y = window.min.y+((window.max.y-window.min.y)/h)*h;
 
-	hwcurs = 1;
 	d = DAC;
 	/* cursor color 1: white */
 	d->cr1 = 0x01;
@@ -151,7 +150,7 @@ screenwin(void)
 	d->cr2 = 0;
 	/* initialize with all-transparent cursor */
 	memset(zbuf, 0, sizeof zbuf);
-	hwcursset(zbuf, zbuf, 0, 0);
+	setcursor(zbuf, zbuf, 0, 0);
 	/* enable both planes of cursor */
 	d->cr1 = 0x03;
 	d->cr0 = 0x00;
@@ -252,7 +251,7 @@ scroll(void)
 	bitblt(&gscreen, window.min, &gscreen, r, S);
 	r = Rpt(Pt(window.min.x, window.max.y-o), window.max);
 	bitblt(&gscreen, r.min, &gscreen, r, Zero);
-	cursor.y -= o;
+	curpos.y -= o;
 }
 
 static void
@@ -263,33 +262,33 @@ screenputc(char *buf)
 
 	switch(buf[0]) {
 	case '\n':
-		if(cursor.y+h >= window.max.y)
+		if(curpos.y+h >= window.max.y)
 			scroll();
-		cursor.y += h;
+		curpos.y += h;
 		screenputc("\r");
 		break;
 	case '\r':
-		cursor.x = window.min.x;
+		curpos.x = window.min.x;
 		break;
 	case '\t':
-		pos = (cursor.x-window.min.x)/w;
+		pos = (curpos.x-window.min.x)/w;
 		pos = 8-(pos%8);
-		cursor.x += pos*w;
+		curpos.x += pos*w;
 		break;
 	case '\b':
-		if(cursor.x-w >= 0){
-			r.min.x = cursor.x-w;
-			r.max.x = cursor.x;
-			r.min.y = cursor.y;
-			r.max.y = cursor.y+defont0.height;
+		if(curpos.x-w >= 0){
+			r.min.x = curpos.x-w;
+			r.max.x = curpos.x;
+			r.min.y = curpos.y;
+			r.max.y = curpos.y+defont0.height;
 			bitblt(&gscreen, r.min, &gscreen, r, Zero);
-			cursor.x -= w;
+			curpos.x -= w;
 		}
 		break;
 	default:
-		if(cursor.x >= window.max.x-w)
+		if(curpos.x >= window.max.x-w)
 			screenputc("\n");
-		cursor = subfstring(&gscreen, cursor, &defont0, buf, S);
+		curpos = subfstring(&gscreen, curpos, &defont0, buf, S);
 	}
 }
 
@@ -408,7 +407,7 @@ rep(ulong v, int n)
 }
 
 void
-hwcursset(ulong *s, ulong *c, int offx, int offy)
+setcursor(ulong *s, ulong *c, int offx, int offy)
 {
 	Dac *d;
 	int x, y;
@@ -453,20 +452,29 @@ hwcursset(ulong *s, ulong *c, int offx, int offy)
 }
 
 void
-hwcursmove(int x, int y)
+cursoron(int dolock)
 {
 	Dac *d;
+	Point p;
+
+	p = mousexy();
 
 	d = DAC;
 
-	x += 380;		/* adjusted by experiment */
-	y += 11;		/* adjusted by experiment */
+	if(dolock)
+		lock(&cursor);
+
+	p.x += 380;		/* adjusted by experiment */
+	p.y += 11;		/* adjusted by experiment */
 	d->cr1 = 03;
 	d->cr0 = 01;
-	d->cr2 = x&0xFF;
-	d->cr2 = (x>>8)&0xF;
-	d->cr2 = y&0xFF;
-	d->cr2 = (y>>8)&0xF;
+	d->cr2 = p.x&0xFF;
+	d->cr2 = (p.x>>8)&0xF;
+	d->cr2 = p.y&0xFF;
+	d->cr2 = (p.y>>8)&0xF;
+
+	if(dolock)
+		unlock(&cursor);
 }
 
 int
diff --git a/carrera/screen.h b/carrera/screen.h
index cc88c2916a18de3811f1d1de960852df7f781251..5f189e08c7930ecb0ac6744a33fe27e7dc6df71b 100644
--- a/carrera/screen.h
+++ b/carrera/screen.h
@@ -1,8 +1,16 @@
-extern void		mouseupdate(int);
+typedef struct Cursorinfo	Cursorinfo;
 
-#define	hwscreenwrite(a, b)
+struct Cursorinfo
+{
+	Cursor;
+	Lock;
+};
 
-#define mbbpt(x)
-#define mbbrect(x)
-#define mousescreenupdate()
-#define mousectl(s)
+extern Cursorinfo	cursor;
+
+extern void	mouseupdate(int);
+extern void	cursoron(int);
+#define		cursoroff(x)
+#define		mousectl(s)
+extern Point	mousexy(void);
+#define		hwscreenwrite(a, b)
diff --git a/pc/devvga.c b/pc/devvga.c
index 98fb23f7b6ec194bc84eff5a9133eb9477d68b02..ce22cbaec74607c68f8ddd9baec55d8e5058a757 100644
--- a/pc/devvga.c
+++ b/pc/devvga.c
@@ -7,6 +7,7 @@
 #include	"../port/error.h"
 
 #include	<libg.h>
+#include	"screen.h"
 
 enum
 {
@@ -209,6 +210,7 @@ void
 vgareset(void)
 {
 	vgacard = &vgachips[Generic];
+	cursor.disable++;
 }
 
 void
@@ -219,6 +221,7 @@ vgainit(void)
 Chan*
 vgaattach(char *upec)
 {
+	print("visible %d disable %d frozen %d\n", cursor.visible, cursor.disable, cursor.frozen);
 	return devattach('v', upec);
 }
 
@@ -456,6 +459,8 @@ setscreen(int maxx, int maxy, int ldepth)
 		error(Ebadarg);
 	}
 
+	lock(&screenlock);
+
 	/*
 	 *  setup a bitmap for the new size
 	 */
@@ -497,13 +502,18 @@ setscreen(int maxx, int maxy, int ldepth)
 
 	window.min = Pt(50, 50);
 	window.max = add(window.min, Pt(10+w*64, Footprint/(BY2WD*gscreen.width)));
+	if(window.max.y >= gscreen.r.max.y)
+		window.max.y = gscreen.r.max.y;
+	if(window.max.x >= gscreen.r.max.x)
+		window.max.x = gscreen.r.max.x;
 
 	vgacard->setpage(0);
 	bitblt(&gscreen, window.min, &gscreen, window, Zero);
 	window = inset(window, 5);
 	curpos = window.min;
 	window.max.y = window.min.y+((window.max.y-window.min.y)/h)*h;
-	hwcurs = 0;
+
+	cursorinit();
 }
 
 /*
@@ -1164,3 +1174,166 @@ setcolor(ulong p, ulong r, ulong g, ulong b)
 	unlock(&screenlock);
 	return ~0;
 }
+
+
+/*
+ *  software cursor
+ */
+
+ulong backbits[16*5];
+ulong workbits[16*5];
+Bitmap cursorwork =
+{
+	{0, 0, 16+8, 16},
+	{0, 0, 16+8, 16},
+	0,
+	workbits,
+	0,
+	1,
+};
+
+Bitmap	clr =
+{
+	{0, 0, 16, 16},
+	{0, 0, 16, 16},
+	0,
+	0,
+	0,
+	1,
+};
+
+Bitmap	set =
+{
+	{0, 0, 16, 16},
+	{0, 0, 16, 16},
+	0,
+	0,
+	0,
+	1,
+};
+
+void
+cursorinit(void)
+{
+	static int already;
+
+	lock(&cursor);
+
+	cursorwork.ldepth = gscreen.ldepth;
+	cursorwork.width = ((cursorwork.r.max.x << gscreen.ldepth) + 31) >> 5;
+	cursor.l = cursorwork.width*BY2WD;
+
+	if(!already){
+		cursor.disable--;
+		already = 1;
+	}
+
+	unlock(&cursor);
+}
+
+void
+setcursor(ulong *setbits, ulong *clrbits, int offx, int offy)
+{
+	USED(offx, offy);
+	set.base = setbits;
+	clr.base = clrbits;
+}
+
+void
+cursoron(int dolock)
+{
+	int off;
+	Rectangle r;
+	uchar *a;
+	struct {
+		Bitmap *dm;
+		Point p;
+		Bitmap *sm;
+		Rectangle r;
+		Fcode f;
+	} xx;
+	extern int graphicssubtile(uchar*, int, int, Rectangle, Rectangle, uchar**);
+
+	if(cursor.disable)
+		return;
+	if(dolock)
+		lock(&cursor);
+
+	if(cursor.visible++ == 0){
+		cursor.r.min = mousexy();
+		cursor.r.max = add(cursor.r.min, Pt(16, 16));
+		cursor.r = raddp(cursor.r, cursor.offset);
+	
+		/* bit offset into backup area */
+		if(cursor.r.min.x < 0)
+			off = cursor.r.min.x;
+		else
+			off = ((1<<gscreen.ldepth)*cursor.r.min.x) & 7;
+	
+		/* clip the cursor rectangle */
+		xx.dm = &cursorwork;
+		xx.p = Pt(off, 0);
+		xx.sm = &gscreen;
+		xx.r = cursor.r;
+		bitbltclip(&xx);
+	
+		/* tile width */
+		cursor.tl = graphicssubtile(0, cursor.l, gscreen.ldepth,
+				gscreen.r, xx.r, &a);
+		if(cursor.tl > 0){
+			/* get tile */
+			screenunload(xx.r, (uchar*)workbits, cursor.tl, cursor.l, 0);
+	
+			/* save for cursoroff */
+			memmove(backbits, workbits, cursor.l*16);
+	
+			/* add mouse into work area */
+			r = Rect(0, 0, Dx(xx.r), Dy(xx.r));
+			bitblt(&cursorwork, xx.p, &clr, r, S|D);
+			bitblt(&cursorwork, xx.p, &set, r, D&~S);
+	
+			/* put back tile */
+			cursor.clipr = xx.r;
+			screenload(xx.r, (uchar*)workbits, cursor.tl, cursor.l, 0);
+		}
+	}
+
+	if(dolock)
+		unlock(&cursor);
+}
+
+void
+cursoroff(int dolock)
+{
+	if(cursor.disable)
+		return;
+	if(dolock)
+		lock(&cursor);
+	if(--cursor.visible == 0 && cursor.tl > 0)
+		screenload(cursor.clipr, (uchar*)backbits, cursor.tl, cursor.l, 0);
+	if(dolock)
+		unlock(&cursor);
+}
+
+void
+cursorlock(Rectangle r)
+{
+	lock(&cursor);
+	if(rectXrect(cursor.r, r)){
+		cursoroff(0);
+		cursor.frozen = 1;
+	}
+	cursor.disable++;
+	unlock(&cursor);
+}
+
+void
+cursorunlock(void)
+{
+	lock(&cursor);
+	cursor.disable--;
+	if(cursor.frozen)
+		cursoron(0);
+	cursor.frozen = 0;
+	unlock(&cursor);
+}
diff --git a/pc/screen.h b/pc/screen.h
new file mode 100644
index 0000000000000000000000000000000000000000..be8f0980350bddec67df1796f54c62eabc984549
--- /dev/null
+++ b/pc/screen.h
@@ -0,0 +1,20 @@
+typedef struct Cursorinfo	Cursorinfo;
+
+struct Cursorinfo
+{
+	Cursor;
+	Lock;
+	int	visible;	/* on screen */
+	int	disable;	/* from being used */
+	int	frozen;		/* from being used */
+	Rectangle r;		/* location */
+	Rectangle clipr;	/* r clipped into screen */
+	int	l;		/* width of cursorwork (in bytes) */
+	int	tl;		/* scan line byte width of mouse at r */
+};
+
+Cursorinfo	cursor;
+extern void	cursoron(int);
+extern void	cursoroff(int);
+extern Point	mousexy(void);
+extern void	cursorinit(void);
diff --git a/port/devmouse.c b/port/devmouse.c
index 4e0b2bcb0f81aa27483f86b754ae4b6c8dd768b2..e2a272f57f5f6dbed7b289304c713e0dfb1bb889 100644
--- a/port/devmouse.c
+++ b/port/devmouse.c
@@ -9,26 +9,7 @@
 #include	"devtab.h"
 #include	"screen.h"
 
-/*
- * Some monochrome screens are reversed from what we like:
- * We want 0's bright and 1's dark.
- * Indexed by an Fcode, these compensate for the source bitmap being wrong
- * (exchange S rows) and destination (exchange D columns and invert result)
- */
-int flipS[] = {
-	0x0, 0x4, 0x8, 0xC, 0x1, 0x5, 0x9, 0xD,
-	0x2, 0x6, 0xA, 0xE, 0x3, 0x7, 0xB, 0xF
-};
-
-int flipD[] = {
-	0xF, 0xD, 0xE, 0xC, 0x7, 0x5, 0x6, 0x4,
-	0xB, 0x9, 0xA, 0x8, 0x3, 0x1, 0x2, 0x0, 
-};
-
-int flipping;	/* are flip tables being used to transform Fcodes? */
-
 typedef struct Mouseinfo	Mouseinfo;
-typedef struct Cursorinfo	Cursorinfo;
 
 struct Mouseinfo
 {
@@ -48,29 +29,12 @@ struct Mouseinfo
 	int	open;
 };
 
-struct Cursorinfo
-{
-	Cursor;
-	Lock;
-	int	visible;	/* on screen */
-	int	disable;	/* from being used */
-	int	frozen;	/* from being used */
-	Rectangle r;		/* location */
-
-	int	l;
-	int	tl;
-	int	setop;
-	int	clrop;
-	Rectangle clipr;
-};
-
 Mouseinfo	mouse;
 Cursorinfo	cursor;
 int		mouseshifted;
 int		mousetype;
 int		mouseswap;
-int		hwcurs;
-Cursor	curs;
+Cursor		curs;
 
 Cursor	arrow =
 {
@@ -88,45 +52,11 @@ Cursor	arrow =
 };
 
 ulong setbits[16];
-Bitmap	set =
-{
-	{0, 0, 16, 16},
-	{0, 0, 16, 16},
-	0,
-	setbits,
-	1,
-	0,
-};
-
 ulong clrbits[16];
-Bitmap	clr =
-{
-	{0, 0, 16, 16},
-	{0, 0, 16, 16},
-	0,
-	clrbits,
-	1,
-	0,
-};
-
-ulong backbits[16*5];
-ulong workbits[16*5];
-Bitmap cursorwork =
-{
-	{0, 0, 16+8, 16},
-	{0, 0, 16+8, 16},
-	0,
-	workbits,
-	1,
-	0,
-};
 
 void	Cursortocursor(Cursor*);
 int	mousechanged(void*);
 
-extern	void	screenload(Rectangle, uchar*, int, int, int);
-extern	void	screenunload(Rectangle, uchar*, int, int, int);
-
 enum{
 	Qdir,
 	Qcursor,
@@ -147,49 +77,19 @@ extern	Bitmap	gscreen;
 void
 mousereset(void)
 {
-	ulong r;
-
 	if(!conf.monitor)
 		return;
 
-	getcolor(0, &r, &r, &r);
-	if(r == 0)
-		flipping = 1;
-	flipping = 0;	/* howard, why is this necessary to get a black arrow on carrera? */
 	curs = arrow;
 	Cursortocursor(&arrow);
 }
 
-void
-cursorinit(void)
-{
-	cursorwork.ldepth = gscreen.ldepth;
-	cursorwork.width = ((cursorwork.r.max.x << gscreen.ldepth) + 31) >> 5;
-
-	cursor.l = cursorwork.width*BY2WD;
-
-	if(flipping){
-		cursor.setop = flipD[S|D];
-		cursor.clrop = flipD[D&~S];
-	} else {
-		cursor.setop = S|D;
-		cursor.clrop = D&~S;
-	}
-}
-
 void
 mouseinit(void)
 {
 	if(!conf.monitor)
 		return;
 
-	if(gscreen.ldepth > 3){
-		print("mouse can't work ldepth > 3");
-		cursor.disable = 1;
-	}
-
-	cursorinit();
-
 	cursoron(1);
 }
 
@@ -198,7 +98,6 @@ mouseattach(char *spec)
 {
 	if(!conf.monitor)
 		error(Egreg);
-	cursorinit();
 	return devattach('m', spec);
 }
 
@@ -408,7 +307,7 @@ Cursortocursor(Cursor *c)
 	uchar *p;
 
 	lock(&cursor);
-	memmove(&cursor, c, sizeof(Cursor));
+	memmove(&cursor.Cursor, c, sizeof(Cursor));
 	for(i=0; i<16; i++){
 		p = (uchar*)&setbits[i];
 		*p = c->set[2*i];
@@ -417,115 +316,10 @@ Cursortocursor(Cursor *c)
 		*p = c->clr[2*i];
 		*(p+1) = c->clr[2*i+1];
 	}
-	if(hwcurs)
-		hwcursset(set.base, clr.base, cursor.offset.x, cursor.offset.y);
-	unlock(&cursor);
-}
-
-void
-cursorlock(Rectangle r)
-{
-	if(hwcurs)
-		return;
-	lock(&cursor);
-	if(rectXrect(cursor.r, r)){
-		cursoroff(0);
-		cursor.frozen = 1;
-	}
-	cursor.disable++;
+	setcursor(setbits, clrbits, cursor.offset.x, cursor.offset.y);
 	unlock(&cursor);
 }
 
-void
-cursorunlock(void)
-{
-	if(hwcurs)
-		return;
-	lock(&cursor);
-	cursor.disable--;
-	if(cursor.frozen)
-		cursoron(0);
-	cursor.frozen = 0;
-	unlock(&cursor);
-}
-
-typedef struct
-{
-	Bitmap *dm;
-	Point p;
-	Bitmap *sm;
-	Rectangle r;
-	Fcode f;
-} XXX;
-
-void
-cursoron(int dolock)
-{
-	int off;
-	Rectangle r;
-	uchar *a;
-	XXX x;
-	extern int graphicssubtile(uchar*, int, int, Rectangle, Rectangle, uchar**);
-
-	if(cursor.disable)
-		return;
-	if(dolock)
-		lock(&cursor);
-	if(cursor.visible++ == 0){
-		if(hwcurs)
-			hwcursmove(mouse.xy.x, mouse.xy.y);
-		else {
-			cursor.r.min = mouse.xy;
-			cursor.r.max = add(mouse.xy, Pt(16, 16));
-			cursor.r = raddp(cursor.r, cursor.offset);
-
-			/* bit offset into backup area */
-			off = ((1<<gscreen.ldepth)*cursor.r.min.x) & 7;
-
-			/* clip the cursor rectangle */
-			x.dm = &cursorwork;
-			x.p = Pt(off, 0);
-			x.sm = &gscreen;
-			x.r = cursor.r;
-			bitbltclip(&x);
-
-			/* tile width */
-			cursor.tl = graphicssubtile(0, cursor.l, gscreen.ldepth,
-					gscreen.r, x.r, &a);
-			if(cursor.tl > 0){
-				/* get tile */
-				screenunload(x.r, (uchar*)workbits, cursor.tl, cursor.l, 0);
-
-				/* save for cursoroff */
-				memmove(backbits, workbits, cursor.l*16);
-
-				/* add mouse into work area */
-				r = Rect(0, 0, Dx(x.r), Dy(x.r));
-				bitblt(&cursorwork, x.p, &clr, r, cursor.clrop);
-				bitblt(&cursorwork, x.p, &set, r, cursor.setop);
-
-				/* put back tile */
-				cursor.clipr = x.r;
-				screenload(x.r, (uchar*)workbits, cursor.tl, cursor.l, 0);
-			}
-		}
-	}
-	if(dolock)
-		unlock(&cursor);
-}
-
-void
-cursoroff(int dolock)
-{
-	if(cursor.disable)
-		return;
-	if(dolock)
-		lock(&cursor);
-	if(--cursor.visible == 0 && !hwcurs && cursor.tl > 0)
-		screenload(cursor.clipr, (uchar*)backbits, cursor.tl, cursor.l, 0);
-	if(dolock)
-		unlock(&cursor);
-}
 
 /*
  *  called by the clock routine to redraw the cursor
@@ -652,3 +446,9 @@ mousechanged(void *m)
 	USED(m);
 	return mouse.lastcounter - mouse.counter;
 }
+
+Point
+mousexy(void)
+{
+	return mouse.xy;
+}
diff --git a/port/portfns.h b/port/portfns.h
index 3827d8b39c446fd8243ac78d91d7a12ef0b33739..54ceea9400782baee50ce2c179bdd37c84778279 100644
--- a/port/portfns.h
+++ b/port/portfns.h
@@ -43,8 +43,6 @@ void		copen(Chan*);
 void		copypage(Page*, Page*);
 int		cread(Chan*, uchar*, int, ulong);
 void		cupdate(Chan*, uchar*, int, ulong);
-void		cursoroff(int);
-void		cursoron(int);
 void		cwrite(Chan*, uchar*, int, ulong);
 int		decref(Ref*);
 int		decrypt(void*, void*, int);
@@ -93,8 +91,6 @@ void		gotolabel(Label*);
 int		haswaitq(void*);
 long		hostdomainwrite(char*, int);
 long		hostownerwrite(char*, int);
-void		hwcursmove(int, int);
-void		hwcursset(ulong*, ulong*, int, int);
 void		iallocinit(void);
 long		ibrk(ulong, int);
 void		ilock(Lock*);
@@ -232,6 +228,7 @@ long		seconds(void);
 ulong		segattach(Proc*, ulong, char *, ulong, ulong);
 void		segpage(Segment*, Page*);
 int		setcolor(ulong, ulong, ulong, ulong);
+void		setcursor(ulong*, ulong*, int, int);
 void		setkernur(Ureg*, Proc*);
 int		setlabel(Label*);
 void		setregisters(Ureg*, char*, char*, int);