RE: skipdraw from Eric Ball WAS: [stella] Finally underway: 2600 Cookbook

Subject: RE: skipdraw from Eric Ball WAS: [stella] Finally underway: 2600 Cookbook
From: Thomas Jentzsch <tjentzsch@xxxxxx>
Date: Tue, 13 Apr 2004 17:14:58 +0200
Dennis wrote:
>y is set to the height of the kernel at the beginning of your
>kernel. Then it's decremented with each scan line (1LK) or ever
>other scan line (2LK).
>This saves you from loading y to load your graphics.

Yup, the trick is to setup P0_ptr outside the kernel, so that it 
points to your graphics exactly when the right scanlines (= y-
values) are reached. 

To avoid page penalties, this also requires the graphics to start 
at (align 256 + kernel-height).

Have fun!	
Thomas


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