Subject: Re: R: [stella] PCMSG 2.4 (ok, I've had enough...) From: Eckhard_Stolberg@xxxxxxxxxxxxxxxxxxxxx (Eckhard Stolberg) Date: Thu, 21 Aug 1997 16:50:54 +0200 |
>Hmmm, this happens here too, but I don't think that it's like you're >saying. >Should the programs draw too much lines sometimes, then the color loss >would happen also in the PAL version, because the only differences are >228-192 additional scanlines in the kernel, and different time values for >Vblank and Overscan. What I meant was this: If you are setting up the Overscan timer for 30 lines in NTSC mode, but the routines, that you are executing during Overscan, take let's say cycles for 31 lines, then the timer would have been run out by the time your game enters the INTIM loop. Therefore the INTIM loop would have to wait until the timer reaches zero again and produce too many lines while doing so. If you set up the Overscan timer for 36 lines in PAL mode and the routine still takes 31 lines to execute, there would be no problem with the timer loop. >Moreover, the positionig routine is based on a table and is very simple, I >don't think there can be problems with it. Anyway I'll give a look... this >is a very good reason to use the new debugging features of PCAE 2.0! :) I was just guessing, that it is a problem with the sprites, because your game produces too many lines depending on how many sprites are on the screen. It can be any routine actually. You should also note, that this problem didn't happen with any of the older versions, so it has most likely something to do with the new additions to this one. Also make sure you get the new 2.0a version of PCAE. That one comes with an improved PAL palette by me. :-) >> Therefore shifting >> some of the unused onscreen lines to the timer should fix the problem and >> make a TV standard switch obsolete. > >Now that I'm thinking... how could the two versions be really the same? >If 228 lines MUST be drawn in PAL, then the PAL image will be someway >shrunk ... >There's something not really clear here. You don't have to draw any lines at all. You just have to make sure that the time between two vsync phases isn't too short for your TV to sync to, if you want to get a stable picture. However the screen ratio is different on PAL and NTSC. You can fit 228 lines on PAL in the same space that NTSC needs to display 192 lines. Therefore NTSC graphics will always look a bit condensed on a PAL TV. Did you find a name for the game yet? While playing it yesterday I made up a story about it. It is a bit far fetched and you might need to change some of your graphics a bit to meet the theme fully, but it's the best I could come up with. You could call the game Space Oysters, Oysteroids, EnergOysters or something like that. The backgroud story would go like this: In the Irata solar system lies the planet Stella. It is surrounded by an energy belt. In this belt there live space oysters. They make good food, so there are other outer space creatures living among them, that eat the oysters. When big human colony ships where approaching planet Stella they couldn'd fly through the oyster belt, so they just dumped their trash there, only to encounter a scientific phenomenon. When the trash got into the oyster shell, the oytsers surrounded it with some supra leading material, producing an energy pearl and exploded. When some of these pearls accidentely chained up, they produced a short circuit between two of the energy streams, that run around the planet. The pearls melted together producing a power chystal, that absorbed all the energy, that was floating through it. These power chrystals make good portable power supplies. Therefore the humans build small ships and equipped them with trash guns, in order to produce the crystals purposefully. The player now has to fly one of those ships and produce as many power chrystals as possible. The oysters have to be hit when their shell is open. Therefore it sometimes takes more than one shot to turn them into pearls. If the spaceship's fuel runs out, it has to land on planet Stella and deliver the chrystals. Since they are worth a lot of money, competition is hard and unfair. Competing captains have installed killer satellites in the small landing corridor between the energy belt and the surface, that would go after every unidentifiable spaceship and destroy it. They are heavily armoured, so that you can't do anything against them with your small trash gun. Luckily the power chrystals contain enough energy to fry those satellites. Unfortunately they are so heavy, that you can't shoot them. Therefore you must drop them off and try to manouver the satellite into one, if you want to be able to land safely. As I said, very far fetched, but at least it explains all game elements. :-) I hope you like it anyway. You could award bonus points for every chrystal, that has not been used to destroy the satellite. Also you could award extra ships, if enough points have been scored. Ciao, Eckhard Stolberg -- Archives updated once/day at http://www.biglist.com/lists/stella/archives/ Unsubscribing and other info at http://www.biglist.com/lists/stella/stella.html
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