Tezz Posted November 28, 2007 Share Posted November 28, 2007 There are some real benefits, when using hires (some may name it "bad" but its only "in the eye of the observer" )a) when changing one colour, you have two colours changed b) one can change colours "everywhere" without taking care about the border which still has it's own colour. .... and .... maybe.... : If still some cycles are free, midline changes still can be done... ingame... I agree with that and I like the use of hi-res with overlays like the bombjack levels I worked out only using simple dli overlays in the g'n'g thread a few weeks back, the use of hi-res is not to everyones taste it seems ( I do understand the preference and equally like the use of the usual multicolured 2:1 ratio modes). It's all good to me. These Spectrum "remakes" that XXL is creating is bringing a lot of titles across that otherwise wouldn't see the light of day on the Atari. I think it's a great thing and would have been very happy to see this done back in the 80's. Here's one of the (enhanced) spectrum screens I did earlier for BJ, I have all the 5 backdrops done also. Regards to all, Tezz Quote Link to comment Share on other sites More sharing options...
emkay Posted November 28, 2007 Share Posted November 28, 2007 This time I am lucky to have a provement for my "ideas" ... since the conversion of Jetpac In LN2 you have to deal with *overlapping* of sprites. I don't see such overlapping sprites in Jetboy. ??? The sprites do overlap with themselves and other objects. They keep the object behind and they do not use EOR routines. The 3.5MHz for the Zilog are very needed. It has some good memory saving commands, but the commands need more cpu cycles. With optimized code, the ATARI easily can be faster than the Z80 inside the speccy. The Z80 takes 11 clocks for a 16-bit addition; the popular 6502 needs around 20 cycles to do the same thing using 8-bit operations. Using "typical" clocks of 4MHz versus 1MHz respectively (i.e. similarly fast memory chips), this translates into the Z80 being approximately seven times as fast as the 6502 for this particular operation (20/(11/4) ≈ 7). (Wikipedia http://en.wikipedia.org/wiki/Zilog_Z80 -> Notes and references 6) Do you have exact numbers for your claims? At least here, you should look at what you are copying from... The ATARI clocks at 1.79MHz and the Speccy clocks a 3.5MHz And: Machine code works with more than 16Bit additions. This reminds me about the fact that the Core 2 Duo Prozessors do complete "load data/ progress /save data" in one cycle. Caused by this fact, really all programs should be 5-10 times faster compared to an old Pentium or Athlon. But all you recognize is some 10-40% advantage which is mostly caused by the overall architecture and a bigger 2nd level cache. Quote Link to comment Share on other sites More sharing options...
emkay Posted November 28, 2007 Share Posted November 28, 2007 http://www.worldofspectrum.org/faq/referen...e.htm#CBOpcodes What a cycle wasting... Quote Link to comment Share on other sites More sharing options...
Chrodegang Posted November 28, 2007 Share Posted November 28, 2007 (edited) The sprites do overlap with themselves and other objects. Off course I noticed the p/m overlap with graphics. By the word 'sprites' I meant software sprites (p/m = hardware sprites). At least here, you should look at what you are copying from...The ATARI clocks at 1.79MHz and the Speccy clocks a 3.5MHz You should read what I post: there is at least one case where a Z80 cpu is much faster than a 6502 processor which contradicts to your rather general statement With optimized code, the ATARI easily can be faster than the Z80 inside the speccy. In the case of 16bit additon the 6502 cannot be faster than the Z80. Do you understand that? And: Machine code works with more than 16Bit additions. Can you elaborate on this, please? Edited November 29, 2007 by Chrodegang Quote Link to comment Share on other sites More sharing options...
Heaven/TQA Posted November 28, 2007 Share Posted November 28, 2007 as far as i remember the z80 is clocked at higher speed but sometimes the 6502 code is shorter and therefore can compensate the 2x-3x faster clock.... i guess that was common sense in the 80s... last ninja does need not only sprite overlay but needs as well masking/clipping with his 3d iso which is NOT trivial as it might look at the first look. remember our old discussions when we talked about 2d-iso diablo stuff... if we had several layers like gameboy then its far more simple... so i would assume that most of the speccy games can be done on a8 except maybe the 3d-games where the 16bit features of the z80 might be usefull... the speccy's video hardware is very simple... Quote Link to comment Share on other sites More sharing options...
emkay Posted November 28, 2007 Share Posted November 28, 2007 last ninja does need not only sprite overlay but needs as well masking/clipping with his 3d iso which is NOT trivial as it might look at the first look. Why not creating subroutines that handle objects where the "sprite" stands behind as a "fixed" sprite. Probably it is faster to draw the small range over the softwaresprite (to be in front of the moving sprite) than to compare pixel by pixel? Rember, that the A8 has a very good hires iso 3D game (Amaurote), which was reduced to a "top-view 2D scroller with sprites" on the C64. Quote Link to comment Share on other sites More sharing options...
analmux Posted November 28, 2007 Share Posted November 28, 2007 Rember, that the A8 has a very good hires iso 3D game (Amaurote), which was reduced to a "top-view 2D scroller with sprites" on the C64. ...but, also remember that on A8 it's a terribly slow engine. Playability / fun suffers a lot from that i.m.h.o. Quote Link to comment Share on other sites More sharing options...
emkay Posted November 29, 2007 Share Posted November 29, 2007 Rember, that the A8 has a very good hires iso 3D game (Amaurote), which was reduced to a "top-view 2D scroller with sprites" on the C64. ...but, also remember that on A8 it's a terribly slow engine. Playability / fun suffers a lot from that i.m.h.o. ...but, also remember that the Last Ninja only looks isometric. The whole engine works with simple sprite collission, while Amaurote is a "real" isometric engine. Quote Link to comment Share on other sites More sharing options...
Chrodegang Posted November 29, 2007 Share Posted November 29, 2007 Why not creating subroutines that handle objects where the "sprite" stands behind as a "fixed" sprite. There are games that use precalculated sprites overlappings (mostly Jump'n'Run games), but for LN2 this technique cannot be used due to memory constraints - you had to compute and to keep in memory every possible overlap-scenario (quite a lot!). The whole engine works with simple sprite collission, while Amaurote is a "real" isometric engine. First game screen of LN2: the Ninja may partially walk behind the drum, curtains or the front wall. You cannot just copy the sprite onto the screen. Usually this problem is solved either by using z-buffer techniques (way to slow) or by masking (requires masking screen in memory). I am wondering what technique Amaurote is using? but needs as well masking/clipping with his 3d iso which is NOT trivial as it might look at the first look Real 3D-calculations are not necessary. Masking should be sufficient in the case of LN2. I think it's the way it is done in Spectrum and C64. Quote Link to comment Share on other sites More sharing options...
Heaven/TQA Posted November 29, 2007 Share Posted November 29, 2007 Andre, yes... what i ment with "non trivial at first look" is that you can simply say "yes. we do it with masking" but this can be little bit more complicated than just saying "yes. we use masks"... Quote Link to comment Share on other sites More sharing options...
Heaven/TQA Posted November 29, 2007 Share Posted November 29, 2007 haven't we talked about TLN-engine few years ago? please have a look at http://lastninja.lemon64.com/main.htm for the pc editor... Quote Link to comment Share on other sites More sharing options...
xxl Posted November 29, 2007 Author Share Posted November 29, 2007 jsw 64kb 100% done video: http://atari.pl/jsw_end.rar time to optymize, join music and ... Quote Link to comment Share on other sites More sharing options...
emkay Posted November 29, 2007 Share Posted November 29, 2007 Andre, yes... what i ment with "non trivial at first look" is that you can simply say "yes. we do it with masking" but this can be little bit more complicated than just saying "yes. we use masks"... BTW.... Masking... Let's say some weird looking guy is added to the screen... it is walking near the table and stands behind it... or above? Well to have it "behind" or "above" the table.... only the change of one colour register is needed. The used player "masks" the other player by priority and the playfield colour by the used brightness.... Quote Link to comment Share on other sites More sharing options...
Chrodegang Posted November 30, 2007 Share Posted November 30, 2007 BTW.... Masking... Yes emkay, a Ninja is usually wearing a mask. Quote Link to comment Share on other sites More sharing options...
emkay Posted November 30, 2007 Share Posted November 30, 2007 (edited) BTW.... Masking... Yes emkay, a Ninja is usually wearing a mask. Btw: Apples & Pears Speccy can do "7 times" faster 16 bit adding than an 1MHz 6502 Found this today: http://www.youtube.com/watch?v=W3q4SAQ9r7U...feature=related What a mess... Done with "the knowledge of today"... Even the Spectrum's graphicschip has more to offer for such game than antic. Looking a the video and seeing the black lines, I guess that almost 70lines are calculated/drawn with a 32 byte width. Allthough you see big black areas which reduces the handled bytes. You also see "stripes" that are the result of not using screen syncing. This means, the game runs as fast as possible on the spectrum. Is someone interested in coding a Doom Game in coloured hires and a better framerate (even looking better) on the A8 ? The question is not, whether it can be done. The question is, when will it be done. Edited November 30, 2007 by emkay Quote Link to comment Share on other sites More sharing options...
Heaven/TQA Posted November 30, 2007 Share Posted November 30, 2007 can someone give me a quick explanation how in TLN the masking work? i know how the GBA/DS stuff works as you have several layers but a short info would help me esp. for bitmap based machines... (assuming player sprite is hardware sprite). thanks! Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 30, 2007 Share Posted November 30, 2007 I'm thinking on the C-64 it's probably done using a sprite. In Last Ninja 1, goto the budda near the start (keep going right off-screen). Walk under the arch - there are parts of it where a single pixel of grass colour gets priority over the player. I've tried altering VIC regs in the monitor but the game seems to have shadow registers in z-page, and code all over the place that changes them and loads them to VIC. Quote Link to comment Share on other sites More sharing options...
xxl Posted December 1, 2007 Author Share Posted December 1, 2007 last public demo video in final game cheat menu will be removed. Quote Link to comment Share on other sites More sharing options...
Heaven/TQA Posted December 1, 2007 Share Posted December 1, 2007 xxl...looks good. the speed seems to be near original spectrum speed? Quote Link to comment Share on other sites More sharing options...
deathtrappomegranate Posted December 2, 2007 Share Posted December 2, 2007 Very impressive Quote Link to comment Share on other sites More sharing options...
xxl Posted December 2, 2007 Author Share Posted December 2, 2007 xxl...looks good. the speed seems to be near original spectrum speed? a8 version (+music) is little bit faster. compare Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.