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Atari demoscene BBS
| Re: Beast for STe - SCAM |
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Posted by: Splash/S1
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Apr,02.2015-14:10
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I am not quite sure too. Maybe it could be possible to get a real SodB display on a STe although probably without sprites but the main character. And that would obviously be a nightmare to code without guarantee of success ;) The Phaleon did the job for the main display area of the game and the bottom of the screen on ST. What is missing is the upper background with sky and mountains that they replaced by what looks like a 1 bitplan background keeping 8 colors for the main graphics with maybe some palette tricks here and there. Hardscroll and overscan tricks were probably eating a significant amount of cpu time ?
If i remember correctly, the STe has the native pixel-based hardscroll which will probably save some RAM precalcs compared to ST. I am unsure how many Kb the blitter can process in one VBL thouh but this is the sensitive part. For that reason a way to succeed could be to calculate permanently the surface taken by the main dispay plane (with huge trees etc.) versus the surface taken by the areas where transparency has to be done using the blitter to display the background planes. This calculation has to be done for every 16 pixels horizontal position in the main plane. If this plane is say 4 times 320x200 pixels screens wide, it needs 128Kb RAM for the pics. Then you will need to calculate for every X coordinate multiple of 16 pixels (i.e. one blitter and hardscroll unit) the surface of main plane vs background and create a list of blitter parameters for every area of screen that needs to be blitter processed for transparency with background (src,dst,masks,shifting etc.). You will need in fact 16 entries for every area (one for each possible hardscroll value). This creates (320*4)/16=80 tables of maybe no more than 512 bytes (my 1 pound guess) so a reasonable size. The idea is to let the hardscroll move the largest surface horizontally at anytime and to let the blitter doing the insertion of smaller surfaces. If you are in the forest with huge trees then better to let the hardscroll move all this stuff for free and have blitter doing the small areas interacting with background (actually these areas will have to be splitted again vertically in more sub blitter areas because of the differential background scroll but won't explain here). If you are in an area with just one tree on the side and the background on most of the screen then better having the hardscroll doing all the differential scrolls on the background by using a line interrupt and the blitter copying the tree or the well but all blitter params will have to be splitted by horizontal slices depending on the value of the hardscroll register for the background. Told you: a nightmare. Then you might consider adding some progressive palette change vertically to get more colors. Unsure the sky could be easily done by changing the background color with a line interrupt because of the blitter bus arbitration though. The problem can be simplified if you don't do the differential scroll for background planes.
I started a 320x200 overscan game on falcon a long time ago with 7 bitplanes multidirectional main scroll and 1 bit background and sprites copy by the blitter. It took me ages to remove all the glitches and I had instability of rasters on the sky to solve because of blitter arbitration. Never finished it but the only thing I remember is: hardscroll and blitter are cool but what a pain in the *ss to combine them! ;)
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[All messages in this thread] [Start new thread]
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Topic
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Posted by
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Date
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Beast for STe
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evil
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Apr,01.2015-17:09
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Re: Beast for STe
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dml
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Apr,01.2015-17:30
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Re: Beast for STe
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defjam
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Apr,01.2015-18:31
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Re: Beast for STe
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zwf/pdx
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Apr,01.2015-18:39
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Re: Beast for STe
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Alien / ST-CNX
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Apr,01.2015-19:08
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Re: Beast for STe
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Bart
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Apr,01.2015-19:46
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Re: Beast for STe
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Templeton
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Apr,01.2015-20:58
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Re: Beast for STe
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Splash/S1
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Apr,01.2015-21:23
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Re: Beast for STe
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CiH
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Apr,01.2015-21:30
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Beast for STe - Broken archive
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CiH
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Apr,01.2015-21:35
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Beast for STe - Broken archive
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CiH
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Apr,01.2015-21:36
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Re: Beast for STe - Broken archive
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Grazey/PHF
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Apr,01.2015-21:38
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Re: Beast for STe
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Splash/S1
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Apr,01.2015-21:42
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Beast for STe - SCAM
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evil
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Apr,01.2015-22:38
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Re: Beast for STe - SCAM
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Splash/S1
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Apr,01.2015-23:04
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Re: Beast for STe - SCAM
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CiH
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Apr,01.2015-23:11
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Re: Beast for STe - SCAM
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ggn
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Apr,02.2015-09:29
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Re: Beast for STe - SCAM
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gwEm
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Apr,02.2015-09:30
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Re: Beast for STe - SCAM
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dml
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Apr,02.2015-11:30
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Re: Beast for STe - SCAM
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evil
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Apr,02.2015-13:38
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Re: Beast for STe - SCAM
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Splash/S1
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Apr,02.2015-14:10
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Re: Beast for STe - SCAM
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Alien / ST-CNX
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Apr,02.2015-17:28
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Re: Beast for STe - SCAM
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Bod/Effect
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Apr,02.2015-18:16
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Re: Beast for STe - SCAM
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nativ
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Apr,03.2015-19:56
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Re: Beast for STe - SCAM
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evil
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Apr,04.2015-11:26
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Re: Beast for STe - SCAM
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s_t_s
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Apr,04.2015-14:03
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Re: Beast for STe - SCAM
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ggn
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Apr,04.2015-13:30
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Re: Beast for STe - SCAM
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PeyloW
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Apr,06.2015-23:40
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What's the anti-troll code?
That's your personal code to be able to add comments and messages on the dhs.nu site.
Don't have a code or forgot it? Fix it here.
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