Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!ucsd!ucbvax!hoptoad!tim
From: tim@hoptoad.uucp (Tim Maroney)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Marquee Help?
Message-ID: <9518@hoptoad.uucp>
Date: 6 Jan 90 08:10:10 GMT
References: <18304@dartvax.Dartmouth.EDU>
Reply-To: tim@hoptoad.UUCP (Tim Maroney)
Organization: Eclectic Software, San Francisco
Lines: 224

In article <18304@dartvax.Dartmouth.EDU> sean@eleazar.dartmouth.edu
(Sean P. Nolan) writes:
>I saw on here recently a passing mention that someone was using code that
>produced the MacPaint-like Marquee around a selection. The Johnny Carson theme
>comes to mind. But I have been trying, off-and-on, to figure out how to do
>just that, given a selection rectangle and a nifty slot to do its thing in
>my Event loop.
>
>If anybody has the ah-ha insight on how to do this, I'd really appreciate a
>note. Currently I shoved the problem aside and just InvertRect the selection,
>which is uuuuuuuugly.

Might as well just post dwb's code that I got from a local BBS:

;
; (c) Copyright 1987, David W. Berry
;
				case		object
				string		pascal
				
				load	'MacStuff'
			
				export		MarqueeRect, MoveMarqueeRect

patterns		record		entry,decr
marqueePat		dc.l		$0f87c3e1, $f0783c1e
shiftPat		dc.l		$88442211, $88442211
				endr
			
;
;	Frame rectangle, using marquee pattern.  The rect is drawn in xor mode.
;	This procedure should be called to draw the marquee initially, then
;	MoveMarqueeRect should be called repeatedly to move the pattern.
;	Finally, call MarqueeRect again to erase the marquee.  The display
;	will end up the same as it was before.
;

MarqueeRect		proc		export

Frame			record		{a6link},decr
rect			ds.l		1
return			ds.l		1
a6link			ds.l		1
state			ds.b		psRec
locals			equ			*
				endr
			
				with		Frame
			
				link		a6,#locals
				pea			state(a6)
				_GetPenState
			
				_PenNormal
				
				pea			patterns.marqueePat
				_PenPat
			
				move.w		#patXor,-(a7)
				_PenMode
			
				move.l		rect(a6),-(a7)
				_FrameRect
			
				pea			state(a6)
				_SetPenState
				
				unlk		a6
				rts
			
				endproc
				
;
;	Frame rectangle, using pattern that moves the marquee.  Then shift
;	the pattern and the marquee pattern, to keep the two in sync.
;	This procedure must be called repeatedly to achieve the effect of
;	motion.
;

MoveMarqueeRect	proc	export

Frame			record	{a6link},decr
rect			ds.l	1
return			ds.l	1
a6link			ds.l	1
state			ds.b	psRec
locals			equ		*
				endr
				
				with	Frame
				
				link	a6,#locals
				
				pea		state(a6)
				_GetPenState
				
				_PenNormal
				
				pea		patterns.shiftPat
				_PenPat
				
				move	#patXor,-(a7)
				_PenMode
				
				move.l	rect(a6),-(a7)
				_FrameRect
				
				pea		state(a6)
				_SetPenState
				
	; shift the marquee pattern 1 slot to the left
				lea		patterns.marqueePat,a0
				bsr.s	rotate
	
	; likewise the shift pattern
				lea		patterns.shiftPat,a0
				bsr.s	rotate
				
				unlk	a6
				rts

rotate:			move.l		(a0),d1
				move.l		4(a0),d0
				rol.l		#8,d0
				rol.l		#8,d1
				move.b		d0,d2
				move.b		d1,d0
				move.b		d2,d1
				move.l		d1,(a0)
				move.l		d0,4(a0)
				rts

				endproc
				
				end
				

End of quoted code marquee.a.

Here's MPW C code I use for the same effect.  I'm afraid it's rather
environment-dependent, but you should still be able to break it to
your will.

static void RotatePatterns(Pattern marquee, Pattern shift)
{	unsigned char c;
	c = marquee[0];
	BlockMove(marquee + 1, marquee, 7);
	marquee[7] = c;
	c = shift[0];
	BlockMove(shift + 1, shift, 7);
	shift[7] = c;
}

static void
click(WindowPtr window, DocStorage **storage, EventRecord *event,
      Boolean *changed, Boolean *selected)
{	Point start, now; Rect r, r2; short tmp;
	DocInfo doc; Pattern marquee, shift; PenState pen;
#pragma unused (changed)
	unselect(window, storage);
	GetDocInfo(window, &doc);
	start = now = event->where;
	GetPenState(&pen);
	PenNormal();
	BlockMove((Ptr)(*storage)->marquee, (Ptr)marquee, 8);
	BlockMove((Ptr)(*storage)->shift, (Ptr)shift, 8);
	PenPat(marquee);
	PenMode(patXor);
	SetRect(&r, start.h, start.v, now.h, now.v);
	FrameRect(&r);
	while (WaitMouseUp()) {
		PenPat(shift);
		FrameRect(&r);
		RotatePatterns(marquee, shift);
		GetMouse(&now);
		SetRect(&r2, start.h, start.v, now.h, now.v);
		if (r2.left > r2.right)
			{ tmp = r2.left; r2.left = r2.right; r2.right = tmp; }
		if (r2.top > r2.bottom)
			{ tmp = r2.top; r2.top = r2.bottom; r2.bottom = tmp; }
		if (EqualRect(&r, &r2)) continue;
		PenPat(marquee);
		FrameRect(&r);
		FrameRect(&r2);
		r = r2;
	}
	if (*selected = !EmptyRect(&r))
		OffsetRect(&r, GetCtlValue(doc.hScroll), GetCtlValue(doc.vScroll));
	else {	PenPat(marquee); FrameRect(&r); SetRect(&r, 0, 0, 0, 0); }
	BlockMove((Ptr)marquee, (Ptr)(*storage)->marquee, 8);
	BlockMove((Ptr)shift, (Ptr)(*storage)->shift, 8);
	(*storage)->selRect = r;
	SetPenState(&pen);
}

static void idle(WindowPtr window, DocStorage **storage)
{	Pattern marquee, shift; Rect r; PenState pen; DocInfo doc;
	r = (*storage)->selRect;
	if (EmptyRect(&r)) return;
	GetDocInfo(window, &doc);
	GetPenState(&pen);
	PenNormal();
	BlockMove((Ptr)(*storage)->marquee, (Ptr)marquee, 8);
	BlockMove((Ptr)(*storage)->shift, (Ptr)shift, 8);
	PenPat(shift);
	PenMode(patXor);
	OffsetRect(&r, -GetCtlValue(doc.hScroll), -GetCtlValue(doc.vScroll));
	FrameRect(&r);
	RotatePatterns(marquee, shift);
	BlockMove((Ptr)marquee, (Ptr)(*storage)->marquee, 8);
	BlockMove((Ptr)shift, (Ptr)(*storage)->shift, 8);
	SetPenState(&pen);
}

And in Rez, the patterns are:

resource 'PAT#' (33) { {
	$"0f 87 c3 e1 f0 78 3c 1e" ,
	$"88 44 22 11 88 44 22 11"
} };
-- 
Tim Maroney, Mac Software Consultant, sun!hoptoad!tim, tim@toad.com

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