20 February 2015, 18:42 | #141 |
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regarding using blitter to faster fill 3D, one color, polygons in games - does anybody have experience with this? There was lot of talks about this but I am not sure if anybody do this in game?
How much blitter would improve 3D games frame per seconds over CPU only version? |
20 February 2015, 20:00 | #142 |
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The Falcon 030 review from ex-Atari owner: http://www.amigareport.com/ar119/p1-9.html
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20 February 2015, 22:46 | #143 | ||
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Mostly not done in games, since ST influenced game development on Amiga. Gameplay often required scenes of 40-80 polygons, so to get decent framerates on ST, they shrunk the screen buffer to "very small" to make the polygons smaller; at tiny polygon sizes, the CPU can beat unsophisticated Blitter routines. (Unfortunately, most 3D games using the CPU were therefore made without regard to faster CPUs, and this affected the Amiga. Because they plot to the screen memory directly, there is much less gain than otherwise possible on a faster CPU with fastmem.) Therefore, using the Blitter for what it was designed for in 3D games remained largely unexplored. In demos it was, but high polycount fast fullscreen 3D remained elusive since the inclination was always towards simplifying the scene to make a slick production. On A1200 the Blitter was not upgraded, so on A1200 it doesn't pay off to write a sophisticated 3D routine using the Blitter, except in special cases. |
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20 February 2015, 23:12 | #144 |
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@Photon
Except maybe Thomas Landspurg work especially Virtual World. Explanation of it's techno here : http://landspurg.net/tomsoft/Demos/V...lds/index.html Kamelito |
21 February 2015, 00:00 | #145 |
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I love his demos (just linked Trip to Mars in the oldschool group on Facebook an hour ago as it happens ). But that doesn't mean his (or others') demos deliver the performance expected from exploring the Blitter fillrate. Here, he uses the Blitter because he basically has to (because of adding low-poly objects on top of Richter's backgrounds; re-using the palette). A CPU routine would be something like 3-4x slower than the Blitter on top of a picture that you have to restore.
This is why I wrote about reduced slick scenes in my previous post, in demos the tendency was to not solve the problem of fast complex Blitter 3D but to put together an enjoyable presentation instead. Vector Preview by Tai-Pan was a better attempt at a Blitter 3D engine, but it doesn't have scenes comparable to contemporary 3D games. |
22 February 2015, 13:24 | #146 | |||
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Side to this i've wrote - Atari (buying Atari assets, TTL bough Atari Amiga contract) was able to use Lorraine, later this was confirmed in lawsuit (Atari claim that chips (3) are ready and designed for Atari). Quote:
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If you are right then it is even more surprising why ST is so limited - why so inflexible display circuit was used ?!? (idea that ST was designed in rush, in situation where enemy competitor acquired superior technology can explain this rush - if this is not the case then sorry but i have no explanation). |
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22 February 2015, 14:19 | #147 | |
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Low End Computers -> [ Show youtube player ] |
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22 February 2015, 15:51 | #148 | |
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Well - this is not explanation of anything - i can understand 9 bit CLUT (lower pin count on IC, Amiga is 12 pins but still there is nothing difficult to add 5'th bit and as such to have 15 bits but this mean 3 additional pins on IC and no longer 48 Pin DIL sufficient etc). However lack of hardware pointer (single sprite) for mouse cursor in GUI is hard to explain - blitter can be explain as bigger problem - need to be synchronized, working concurrently with CPU and VDC etc Mentioned HW scroll, lack of overscan... Once again - ST have graphics comparable to CGA + HGC - nothing fancy i would say. |
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22 February 2015, 20:20 | #149 |
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^ please stop conversation about amiga/atari.
I will open new thread shortly! since I also want to hear more opinion about it. |
22 February 2015, 22:35 | #150 | |
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But the lack of hardware scrolling is very strange... Edit: Atari ST modes: 320x200 16 colors, 640x200 4 colors, 640x400 2 colors (requires special monitor), palette of 512 (3-3-3 R-G-B) CGA modes: 160x200 16 colors*, 320x200 4 colors, 640x200 2 colors, palette of 16** (1-1-1-1 R-G-B-I) (* actually an undocumented text mode, no commonly used) (** actually this is even less impressive as the colors aren't freely selectable - hence the characteristic "CGA look") Last edited by Megol; 22 February 2015 at 22:54. |
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22 February 2015, 22:42 | #151 | |
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22 February 2015, 23:41 | #152 | |
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does anybody have any numbers? e.g. Elite II was written on Amiga. David B. could use Amiga blitter for filling polygons and CPU on ST. But he did not. Why? He does not have time or there was no speed gain? so: does anybody have numbers? |
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22 February 2015, 23:55 | #153 |
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Or simply: Does it pay off to improve the performance on the Amiga or would people still buy the game without the extra effort put in?
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23 February 2015, 00:27 | #154 | ||
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but still, does anybody have any numbers how much faster 3D fill would be with blitter (or slower)? Last edited by TCD; 23 February 2015 at 00:33. Reason: Back-to-back posts merged. |
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23 February 2015, 00:35 | #155 |
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Can we lay off the off-topic stuff on this forum please? If you want to discuss the Falcon vs A1200 performance here that's fine, but please leave all speculative discussions that lead nowhere 30 years later out of it.
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23 February 2015, 09:38 | #156 | |
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On contrari: I always hear argument "it is Atari port so it does not use blitter" (we could read same argument here in this thread). I would like if someone could support this argument with facts. But you are right, I will open another thread with this topic. Stay tuned... |
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23 February 2015, 09:46 | #157 |
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Sorry, I should have quoted you and stated that I meant the 'Jack Tramiel and Lorraine' part. Feel free to make another thread about the blitter comparison
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23 February 2015, 10:13 | #158 | |
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here is new thread about "Using blitter for filling 3D polygons": http://eab.abime.net/showthread.php?t=77162 |
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23 February 2015, 12:00 | #159 | |
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You don't know your classics heh ? |
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23 February 2015, 14:02 | #160 | |
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"Braben originally programmed the game for the Amiga in 68000 assembly language. It had roughly 250,000 lines of code, which were ported from 68000 assembler to the PC's 80286 assembler by Chris Sawyer."
https://en.wikipedia.org/wiki/Fronti...nt_and_release Quote:
btw more sensible explanation than "it is ST game port so there is no blitter use" is that blitter is not used since Elite II appear in time when there were more powerfull machines than plain ST or A500 where blitter is slower than main CPU. and where did you find that "David Braben was an ST fanboy"? As I read, he was more BBS/Archimedes fan since best, most complete, version of Elite 1 is for Archimedes. Zarch is also writen first Archimedes... Last edited by kovacm; 23 February 2015 at 14:08. |
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