Re: A83: ASM Help

To: <assembly-83@lists.ticalc.org>
Subject: Re: A83: ASM Help
From: "David Phillips" <electrum@tfs.net>
Date: Wed, 28 Oct 1998 20:56:23 -0600
Delivered-To: assembly-83-outgoing@towerguard.unix.edu.sollentuna.se
Reply-To: assembly-83@lists.ticalc.org

Flicker is caused by two things:  slow erase/move/draw cycle and the slow
lcd refresh rate.  There is nothing you can do about the lcd being slow,
besides not trying to move graphics too fast.  The other thing that causes
flicker is waiting too long after you erase the sprite to redraw it.  The
basic setup for sprites is to erase them, compute their new positions, then
redraw all of them.  If too much time passes after they are erased before
they are redrawn, the user will perceive that as flicker.

However, because the 83 uses a display controller and not a memory mapped
display, there should not be any flicker caused by this, because it should
only be dumped to the display controller after the sprites have been
completely erased and redrawn.  You are probably just moving a sprite too
fast, as usually happens on your first sprite program where all you do is
move a sprite around the screen.  Waiting longer in between frames should
solve your problem.

-----Original Message-----
From: Gary Hanson <ghanson@bellsouth.net>
To: assembly-83@lists.ticalc.org <assembly-83@lists.ticalc.org>
Date: Wednesday, October 28, 1998 8:45 PM
Subject: Re: A83: ASM Help

>
>no im talkin about when its moving across the screen and it still blinks
even when i
>make it move 2 pixels at a time
>Olle Hedman wrote:
>
>> The reson why it blinks when you hold down a key is not the
spriteroutine.. its
>> in your codeing..  I assume now that you mean it is blinking when you
hold down
>> a key, and the sprite isnt moving.. (like its at the edge of the screen
>> or such..) the way to solve this is to never erase a sprite unless you
are going
>> to move it.. i you do..  it will flicker.. I mean..  when its at the
edge, not
>> only skip the changeing of spriteposition.. also skip the updating of the
>> sprite..
>>
>> /Olle Hedman - alh
>>
>> Gary Hanson wrote:
>> >
>> > i already know some basic Assembly for the ti-83 from a help file i
>> > downloaded but i wanna find out about better stuff like stuff used to
>> > program pacman for sos and how to set it up to make levels with numbers
>> > and stuff where can i find out about this plz help i am stuck on a game
>> >
>> > also does anyone have a sprite routine that doesn't blink when u hold
>> > down a key (movax's)
>> > help!
>> > felix
>
>

Follow-Ups:

Re: A83: ASM Help

From: Gary Hanson <ghanson@bellsouth.net>