Acorn Arcade forums: Games: BHP
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BHP |
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johnstlr (08:49 18/7/2001)
davidm (12:56 18/7/2001)
johnstlr (16:27 18/7/2001)
davidm (19:07 18/7/2001)
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Lee Johnston |
Message #83801, posted by johnstlr at 08:49, 18/7/2001 |
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Posts: 193
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For a laugh I thought I'd try BHP from the TBA collection CD on my RiscStation. To my utter surprise the game actually started up with my car on the grid. I accelerated away and then hit a problem - the moment I tried to turn the 3D graphics completely disappeared leaving me with the background picture and the sound effects. Has anyone else seen this? Also I'm surprised it even got that far because I thought the game made use of the SA only SMULL and UMULL instructions which I figured would have caused a crash (unless they're interpreted as NOPs but then that doesn't explain why the starting grid appears at all). I haven't had a chance to look through the source code yet to see if it does use these commands. The BHP demo that comes with the Holograph suite works fine (if a little slow in some areas). Certainly it must've been doing a good 12 frames per sec (possibly a little more). Not bad for a 56Mhz machine eh? I should point out this was at 320*256 rather than the hi-res mode though. |
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David McEwen |
Message #83802, posted by davidm at 12:56, 18/7/2001, in reply to message #83801 |
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Posts: 100
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Since I only have an SA machine (although I should be getting my hands on a A7000+ at some point) I haven't seen the problem you've mentioned. However I would assume that if the demo worked the game would too... The UMULL/SMULL instructions may indeed be interpreted as NOPs as Descent 2 just doesn't display anything on the lower spec machines as far as I'm aware. I suppose the code that is doing the visibility checking may be using such instructions and thus you are getting nothing shown... but that would be a complete guess. BTW BHP always runs in low res never anything decent like 480x352 or above... I would say that there are better racing games out there to try... but then I remembered this is RISC OS world. |
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Lee Johnston |
Message #83803, posted by johnstlr at 16:27, 18/7/2001, in reply to message #83802 |
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The UMULL/SMULL instructions may indeed be interpreted as NOPs as Descent 2 just doesn't display anything on the lower spec machines as far as I'm aware. I suppose the code that is doing the visibility checking may be using such instructions and thus you are getting nothing shown... but that would be a complete guess. I appreciate the guess - it's something until I look through the code. What is intriguing is that the start grid comes up and I can accelerate down the straight, it's only when I turn the problem comes up. I would've figured that any code that relied on those instructions would have been an integral part of the rendering pipeline. Anyway, no point speculating  BTW BHP always runs in low res never anything decent like 480x352 or above... The instructions claim F7 or F8 sets high res - then again I think this is just standard TAG functionality and the instructions were cut 'n' pasted from the TAG manual. I would say that there are better racing games out there to try... but then I remembered this is RISC OS world. True - I only looked because I was curious as I've never seen it before. |
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David McEwen |
Message #83804, posted by davidm at 19:07, 18/7/2001, in reply to message #83803 |
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Just did a quick search through the code and there isn't a SMULL or UMULL or MLAL to be found. So the problem you are having is even more of a mystery - if I remember I'll ask Martin and see if he has an idea. |
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Acorn Arcade forums: Games: BHP |
