[stella] single line kernels and horizontal position calculation
Subject: [stella] single line kernels and horizontal position calculation|
From: Glenn Saunders <cybpunks@xxxxxxxxxxxx>
Date: Mon, 12 Feb 2001 00:34:41 -0800
I was wondering, in single-line kernels and sprites which have different
horizontal positions on the same screen, how is horizontal motion typically
It looks like no matter how fast the horizontal calculation routine that it
winds up consuming too much time on the scanline to scan out the results on
the same line, hence the traditional 2-line kernel utilizing VDEL.
Take a game like Atlantis, for instance. It only draws one sprite going
across the screen on any given scanline, right? And it enforces vertical
separation so that there is time to calculate new horizontal positions
between ships. But other games have more free-form displays which would
have objects moving vertically through the "compute scanlines".
I am thinking that the only way to solve this is to use tables to
Does anyone have any tables handy for this purpose?
I may need to do something because I am going to have to adjust the missile
positions on every line AND rewrite the playfield. I could precalculate
the missile offsets during VBLANK but I may be short on the RAM needed to
store these values.
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