Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!mark
From: mark@tut.cis.ohio-state.edu (Mark Jansen)
Newsgroups: comp.sys.next
Subject: animation on the next machine
Message-ID: <54308@tut.cis.ohio-state.edu>
Date: 10 Jul 89 04:34:32 GMT
Reply-To: Mark Jansen <mark@cis.ohio-state.edu>
Organization: Ohio State University Computer and Information Science
Lines: 54

I am trying to do a simple animation on the NeXT machine, bitmaps seem to be
the logical object to use but I'm having trouble, the 0.9 documentation is
not complete.  What would be the correct ways to do the following four
simple operations.  Here are my guesses.

1) read a tiff file into a bitmap

	char *flnm;
	Bitmap aBitmap;

	aBitmap = [ Bitmap newFromTIFF:flnm ];

2) write a bitmap into a tiff file

	int      fd;
	NXStream *img_stream;
	Bitmap aBitmap;

	img_stream NXOpenFile( fd, "w" );
	[ aBitmap writeTIFF: img_stream ]

	the documentation says that what a stream is but how do I get one
	from a filename?  Some C functions use something called a file 
	descriptor of type int.(fd above)How do I get one of those?
        There is a c function to get a "typed stream" how is that different 
	from an untyped stream?

3) write a bitmap to a view on the megapixel display
	
	NXPOINT scr_point;

	[ aBitmap composite:NX_COPY
	          toPoint: scr_point ];

	is that point the bitmap is sent to in world coordinates or in
	whatever is the focused view or window of the application this is
	running to?

4) read a bitmap from a view on the display

	this one I am really unsure of. Perhaps something like.
	
	PSsizeimage()?
	img_data = malloc()
	NXReadBitmap(x,y,dx,dy,
			 dx,dy, 2, img_data)
	[ aBitmap readImage:img ];
	
	What are the coordinates for these NX and PS functions, do they 
	also use the focused view context or not?  n

are there better ways?  should I skip the bitmap part and just use images
and the C functions that manipulate images?  Would that be significantly 
faster?  I could use some help.  I'm pretty stuck.