Storing images

[J. Landman Gay]

Judy Perry <jperryl at ecs.fullerton.edu> wrote:

> Maybe it's the non-assembly code programmer in me, but it's just not clear
> why, once you've embedded something, you have to re-embed it with each
> usage.  This is just nuts.  This results in bloatware.

I think there's some confusion -- you don't have to embed an image 
multiple times. Only one copy is needed. Actually, the Revolution way 
acts almost identically to HyperCard's resource-fork method, the only 
difference is that instead of placing the image in the Mac-only resource 
fork, you place it somewhere in the stack itself (or in any stack that 
is in the message hierarchy, such as a substack.) Once you get the image 
imported, it can be used over and over again without any duplication, 
just as addcolor does in HC.

For example, in my Klondike game I have a card that the user never sees 
which stores all the images the stack needs. The game uses 
playing-card-sized buttons which constantly update their image to 
simulate whatever playing card is currently "face up". Scripts change 
the "playing card" button icon IDs as needed. It is a one-liner to place 
a RAM-based copy of the image if you use a button as the image container.

In HyperCard, we would issue "addcolor colorBtn" along with a long 
string of parameters. This grabs a temporary copy of the image from the 
resource fork and places it over a button. In Revolution, we issue "set 
the icon of btn x to <myImgID>". This grabs a temporary copy of the 
image from the data fork and places it into a button as the icon. An 
extra advantage of this method is that, unlike addcolor images, you can 
move the button around without worrying about leaving the image display 
behind on screen.

There is no duplication of the image graphic when you do this; Rev just 
inserts a temporary copy of the image into RAM just as addcolor does 
when it draws the image to screen. The only difference is the location 
of the original source image and, of course, the syntax used to set the 
button image.

-- 
Jacqueline Landman Gay         |     jacque at hyperactivesw.com
HyperActive Software           |     http://www.hyperactivesw.com