Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!pacbell!att-ih!alberta!calgary!allan
From: allan@calgary.UUCP (Jeff Allan)
Newsgroups: comp.graphics
Subject: Re: Fast Zoom for Suns
Message-ID: <1505@vaxb.calgary.UUCP>
Date: 31 Mar 88 15:52:27 GMT
References: <1054@radio.toronto.edu>
Organization: U. of Calgary, Calgary, Ab.
Lines: 29
Summary: A proposed solution

In article <1054@radio.toronto.edu>, brian@radio.toronto.edu 
(Brian Glendenning) writes:
> Does anyone have a piece of code to do a fast zoom to a window under suntools?
> I have a program that acts as a graphics server to a large astronomy package,
> and every last little bit of speed will be felt.
>                                        111000111000111000111000111000
> 1010101010101010  Zoom by 3 (say) ---> 111000111000111000111000111000 -> pw_rop
>                                        111000111000111000111000111000
> 
> (original image line)                        (zoomed temp array)

I'm not really familiar with the Sun but is occurs to me that there is a 
fast raster copy primitive that operates in the screen buffer.
If this is the case then I suggest you use it to "fatbits" your image
in two passes: one for vertical and one for horizontal.

To double the upper-left corner of a 100 by 100 image (origin in upper-left):

for (r=49; r>=0; r--) {
    pw_copy row(r) into row(2*r) and row(2*r+1)
}
for (c=49; c>=0; c--) {
    pw_copy col(c) into col(2*c) and col(2*c+1)
}

Hope this helps.

-- 
        Jeff Allan,  University of Calgary
	..!{ubc-vision,ihnp4}!alberta!calgary!allan