Re: A89: GrayScale and Program Ideas
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Re: A89: GrayScale and Program Ideas
what size do you need and what do you want it to do?
>
>thanks.. is there a working grayscale sprite routine somewhere? Dux's
>doesn't quite work...
>
>Ahmed El-Helw <ahmed@ticalc.org>
> Program Ideas and Upcoming Programs
> the ticalc.org project - http://www.ticalc.org/
>_______________________________________
>http://hail.icestorm.com/asm/
>ICQ: 3350394
>----- Original Message -----
>From: Matt Johnson <matt2000@dogtech.com>
>To: <assembly-89@lists.ticalc.org>
>Sent: Thursday, December 31, 1998 6:53 PM
>Subject: Re: A89: GrayScale and Program Ideas
>
>
>>
>>That is the theory, but not the practice. In reality, you have two
seperate
>>sprites, each which are blitted to two different sections of video memory.
>>The interrupt routine will change the pointer to the screen displayed
>>
>>.. At least this was how it was done on the TI-86. I'm sure it is done the
>>same way for the TI-89, for the simple fact that decoding a 2-bit/pixel
>>sprite would be a lot slower then having two seperate sprites which, when
>>two sepearate video memories are rapidly cycled at the speed from which
the
>>ISR is called, it will look like a 4 color screen.
>>
>>Ugh! I know that is a bad explanation, I have a much more detailed
>>explanation for grayscale in 86 central (http://www.acz.org). The same
>>concepts, I'm pretty sure, are for the TI-89 also.
>>
>>>>Grayscales sprites simply have more bits defining the shade of each
>>>pixel. In the 1-bit system commonly employed, a 0 is completely white
>>>and a 1 is completely black. In a system using multiple-bits per pixel,
>>>00... is still white and a 11... is still black, but other values offer
>>>differing shades of gray. If you wish to use two bits per pixel, 00
>>>would be white, 01 would be light gray, 10 would be dark gray, and 11
>>>would be black. This concept continues through an infinite rang of
>>>possible bits-per-pixel.
>>>
>>>On Thu, 31 Dec 1998 12:20:10 -0500 "Ahmed El-Helw" <ahmed@ticalc.org>
>>>writes:
>>>>
>>>>Hello,
>>>> I had a question - how exactly do grayscale sprites work [how are
>>>>they
>>>>made data wise].. like a normal sprite is simply .db %00010101 on the
>>>>z80..
>>>>how do you do a normal and grayscale sprite on 68k?
>>>>
>>>> As for the program ideas -- i know I should put this on
>>>>ticalc.org, but
>>>>I have to finish alphabetisizing them first :P Yet someone should
>>>>port
>>>>Plane Jump and Diamonds to the 89 :) And we need high score added to
>>>>BoulderDash :) As for SameGame, I still like Jimmy's better :) Maybe
>>>>because it's full screen and bigger blocks? Any thoughts? With all
>>>>due
>>>>respect to the author - you make awesome games.. just my 2 cents worth
>>>>about
>>>>SameGame.
>>>>
>>>>Ahmed El-Helw <ahmed@ticalc.org>
>>>> Program Ideas and Upcoming Programs
>>>> the ticalc.org project - http://www.ticalc.org/
>>>>_______________________________________
>>>>http://hail.icestorm.com/asm/
>>>>ICQ: 3350394
>>>>
>>>>
>>>
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>>
>
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