nesdev.org

Clever

psycopathicteen wrote:I have another youtube account as Aaendi.

I just saw your gunstar demo, and it's very well done ..
thanks to prove that snes's CPU is not as slow as some guys want it to be

And how sprites rotation is done in alisha ??

Ok i see now, thanks for explanantions :wink: The biggest problem is not changing the scroll value but calculating the values to use in each line in the first place (and nothing is going to help you here, that's a game logic issue, not a hardware one). yes of course, i said by difficult for game log...

MD does must go with vsram for all kind of vertical scrolls ?? If so, this why some heavy vertical lines scroll are complicated to do, no ?? If i understand correctly, you have 18 slots per line when active display and it's tight to change Vscroll on each line with interrupt . I'm not saying it's im...

It amazes me how 3 enemies can bring about a 12 MHz 68000 to its knees. I wonder how the code looks...

doesn't looks at the first cps2 shmups then

The programmers weren't lazy, or incompetent.

No, but i think they made bad programming habits because to work on powerful systems .

But how did they know their methods of doing stuff? It seems like an awful lot of the large companies actually weren't the most efficient programmers. Because they are used to works on arcade machines which have more horse power than you can dream, this why you can code like a pig without (almost) ...

That's what I mean't I'm just stupid.

don't worry

Wait how would you handle backwards velocity?

With a negative value i think .

yes, i think so

sbv

Where ??
I don't see that in his code,bvs and bvc yes .

You can have 8.8 velocity but at least you require 16.8 positions don't you agree Yes, if you want, but it's required to add velocity to all entire sprites of your game .. it's required for player and some sprites, and you can use easily the ZP for that . And even if the 68k is faster,it's by 20/30...

Also can you explain me why my collision code have no use in a game ? could you make it faster by the way ? i spoke to have so much velocity in a game, i took this example on sega-16, when you comparing with tomaitheous the efficiency of 65xxx (as you described crappy) and 68k, strangely it was 24b...

It is on topic, because were talking about optimizations and we shouldn't waste cycles unless there's a benefeit, and I don't see any difference in having a range of -32768 to 32767 compared to a range of 0 to 65535. stef is a professional of examples which have no use in a game or a 2D machine .. ...

so we can consider about a bit less than 35 cycles for the mean

yes in the better case for 68k, but if collision accur for the first test, 68k is far behind (it's 192 cycles) ..

Except for the 16 bits stuff the 65816 ISA can't really help here, i will try to convert the code myself...
About the Hu6280, i don't see how it can actually do in less cycles than a 6502, i would even say it can only do worth here !

Damn, i'm always forget that you doesn't add any box in it

Definitely not... i think you can only reduce by a limited amount of cycles but you can try to prove me the contrary ;) In you code exemple it's all the adc and sbc who's take the whole of cycles, you can divide it by to with native 16 bits operations . Plus your code is not optimal, and you can pr...