Make rio and libframe play nicer with fonts with fractional
alpha channels, by always using stringbg and not string.
Using plain string will redraw the text on top of what is already
there.  If the text is partially transparent, the underlying text
bleeds through.  Since rio grays out text in non-foreground 
windows, using plain string results in text getting darker and
darker as you switch between text windows.

This attempt certainly fixes bugs present in previous attempts
involving selected text and losing the tick.

I have tested it quite a bit and believe it has a good chance of being correct.


Reference: /n/sources/patch/applied/alphafont
Date: Wed Nov 28 00:51:14 CET 2007
Signed-off-by: rsc@swtch.com

--- /sys/include/frame.h	Wed Nov 28 00:48:13 2007
+++ /sys/include/frame.h	Wed Nov 28 00:48:13 2007
@@ -58,7 +58,7 @@
 void	frselect(Frame*, Mousectl*);
 void	frselectpaint(Frame*, Point, Point, Image*);
 void	frdrawsel(Frame*, Point, ulong, ulong, int);
-void	frdrawsel0(Frame*, Point, ulong, ulong, Image*, Image*);
+Point frdrawsel0(Frame*, Point, ulong, ulong, Image*, Image*);
 void	frinit(Frame*, Rectangle, Font*, Image*, Image**);
 void	frsetrects(Frame*, Rectangle, Image*);
 void	frclear(Frame*, int);
@@ -80,13 +80,14 @@
 int	_frnewwid(Frame*, Point, Frbox*);
 int	_frnewwid0(Frame*, Point, Frbox*);
 void	_frclean(Frame*, Point, int, int);
-void	_frredraw(Frame*, Point, Image*, Image*);
+void	_frdrawtext(Frame*, Point, Image*, Image*);
 void	_fraddbox(Frame*, int, int);
 Point	_frptofcharptb(Frame*, ulong, Point, int);
 Point	_frptofcharnb(Frame*, ulong, int);
 int	_frstrlen(Frame*, int);
 void	frtick(Frame*, Point, int);
 void	frinittick(Frame*);
+void	frredraw(Frame*);
 
 #define	NRUNE(b)	((b)->nrune<0? 1 : (b)->nrune)
 #define	NBYTE(b)	strlen((char*)(b)->ptr)
--- /sys/src/libframe/frinsert.c	Wed Nov 28 00:48:14 2007
+++ /sys/src/libframe/frinsert.c	Wed Nov 28 00:48:14 2007
@@ -262,7 +262,7 @@
 	else
 		col = f->cols[BACK];
 	frselectpaint(f, ppt0, ppt1, col);
-	_frredraw(&frame, ppt0, f->cols[TEXT], col);
+	_frdrawtext(&frame, ppt0, f->cols[TEXT], col);
 	_fraddbox(f, nn0, frame.nbox);
 	for(n=0; n<frame.nbox; n++)
 		f->box[nn0+n] = frame.box[n];
--- /sys/src/libframe/frdraw.c	Wed Nov 28 00:48:14 2007
+++ /sys/src/libframe/frdraw.c	Wed Nov 28 00:48:14 2007
@@ -6,7 +6,7 @@
 #include <frame.h>
 
 void
-_frredraw(Frame *f, Point pt, Image *text, Image *back)
+_frdrawtext(Frame *f, Point pt, Image *text, Image *back)
 {
 	Frbox *b;
 	int nb;
@@ -15,7 +15,7 @@
 	for(nb=0,b=f->box; nb<f->nbox; nb++, b++){
 		_frcklinewrap(f, &pt, b);
 		if(b->nrune >= 0){
-			stringbg(f->b, pt, text, ZP, f->font, (char *)b->ptr, back, ZP);
+			stringbg(f->b, pt, text, ZP, f->font, (char*)b->ptr, back, ZP);
 		}
 		pt.x += b->wid;
 	}
@@ -57,7 +57,7 @@
 	frdrawsel0(f, pt, p0, p1, back, text);
 }
 
-void
+Point
 frdrawsel0(Frame *f, Point pt, ulong p0, ulong p1, Image *back, Image *text)
 {
 	Frbox *b;
@@ -78,7 +78,7 @@
 		if(p >= p0){
 			qt = pt;
 			_frcklinewrap(f, &pt, b);
-			// fill in the end of a wrapped line
+			/* fill in the end of a wrapped line */
 			if(pt.y > qt.y)
 				draw(f->b, Rect(qt.x, qt.y, f->r.max.x, pt.y), back, nil, qt);
 		}
@@ -115,6 +115,29 @@
 		if(pt.y > qt.y)
 			draw(f->b, Rect(qt.x, qt.y, f->r.max.x, pt.y), back, nil, qt);
 	}
+	return pt;
+}
+
+void
+frredraw(Frame *f)
+{
+	int ticked;
+	Point pt;
+
+	if(f->p0 == f->p1){
+		ticked = f->ticked;
+		if(ticked)
+			frtick(f, frptofchar(f, f->p0), 0);
+		frdrawsel0(f, frptofchar(f, 0), 0, f->nchars, f->cols[BACK], f->cols[TEXT]);
+		if(ticked)
+			frtick(f, frptofchar(f, f->p0), 1);
+		return;
+	}
+
+	pt = frptofchar(f, 0);
+	pt = frdrawsel0(f, pt, 0, f->p0, f->cols[BACK], f->cols[TEXT]);
+	pt = frdrawsel0(f, pt, f->p0, f->p1, f->cols[HIGH], f->cols[HTEXT]);
+	pt = frdrawsel0(f, pt, f->p1, f->nchars, f->cols[BACK], f->cols[TEXT]);
 }
 
 void
--- /sys/src/cmd/rio/wind.c	Wed Nov 28 00:48:15 2007
+++ /sys/src/cmd/rio/wind.c	Wed Nov 28 00:48:15 2007
@@ -710,7 +710,7 @@
 {
 	wsetcols(w);
 	if(!w->mouseopen)
-		_frredraw(w, w->Frame.r.min, w->cols[TEXT], nil);
+		frredraw(w);
 	if(w == input){
 		wborder(w, Selborder);
 		wsetcursor(w, 0);