new amiga 500 doom like !

[Gorf]

Originally Posted by sandruzzo

I did a test with blitter, and it's possible to do with it cp2 via line drawing. By setting interleaved bitplane you can do it. And since you can drive blitter with copper, the only thing that cpu have to do is feeding blitter register with 4, 16 colors chunky pixels!

still not clear to me here...

could you elaborate this with some (pseudo) code?

[roondar]

Isn't that too slow to be useful? Remember, the Blitter only draws a single pixel@1 bitplane in 8 CPU cycles when in line mode.

[sandruzzo]

Originally Posted by Gorf

still not clear to me here...

could you elaborate this with some (pseudo) code?

Interleaved bitplanes is some sort of chunky but into y directions since you have:

line0 plane0
line1 plane1
line2 plane2
line3 plane3

Chunky bitmap islike this: p0p1p2p3 - p0p1p2p3 - ......

If you get first 4pixel (p0p1p2p3p4), and use it as a patter for blitters' line draw, and you draw a vertical line, you'll get straight cp2, since with blitter you're rotating that 4 pixels

[sandruzzo]

Originally Posted by roondar

Isn't that too slow to be useful? Remember, the Blitter only draws a single pixel@1 bitplane in 8 CPU cycles when in line mode.

it can do 1 milion of pixels per seconds.

[sandruzzo]

Since lines are fixed on ray-casting game, we could even have a game with "flat" walls, but faster and whitout cp2. Maybe evene 1x1 a lot faster..

Copper list won't be so huge, and you'll have cpu free to do other stuffs

[Gorf]

Originally Posted by sandruzzo

it can do 1 milion of pixels per seconds.

that gives you only 16 fps for 320*200 and a single bitplane..

if you have 4 bitplanes interleaved you have a theoretical field of 320*800, that would be 256.000 plixels ... leaving you with 4 frame per second.
8 if you go down to 160*200 and 16 for 160*100.

Not really a big advantage, is it?

[roondar]

Originally Posted by sandruzzo

it can do 1 milion of pixels per seconds.

That is 1 million pixels per second@1 bitplane, so you must divide that by the number of bitplanes to get an accurate figure. Meaning for a 4 bitplane screen it's 250.000 pixels per second, not 1 million.

Assuming 320x200, there's 64.000 pixels in a frame. Which translates to a fill rate of about 4FPS. This also assumes you're not doing anything other than blitting, which seems unreasonable.

[sandruzzo]

Originally Posted by roondar

That is 1 million pixels per second@1 bitplane, so you must divide that by the number of bitplanes to get an accurate figure. Meaning for a 4 bitplane screen it's 250.000 pixels per second, not 1 million.

Assuming 320x200, there's 64.000 pixels in a frame. Which translates to a fill rate of about 4FPS. This also assumes you're not doing anything other than blitting, which seems unreasonable.

Ok, but they arent' using 1x1 at 320x200 pixel, no way you can do on A500 S
stock

[roondar]

The point is that even at 160x100 the theoretical maximum frame rate when you're not doing anything except drawing with the Blitter is not far from the one the current CPU drawing routines get (16fps vs around 12 IIRC). Start adding all the stuff that is in the game now and I'm pretty sure you'll end up at the same or lower FPS as just using the CPU.

That said, it is an interesting idea.

[sandruzzo]

Originally Posted by roondar

The point is that even at 160x100 the theoretical maximum frame rate when you're not doing anything except drawing with the Blitter is not far from the one the current CPU drawing routines get (16fps vs around 12 IIRC). Start adding all the stuff that is in the game now and I'm pretty sure you'll end up at the same or lower FPS as just using the CPU.

That said, it is an interesting idea.

Maybe you can free cpu to do more...

[DanScott]

Originally Posted by sandruzzo

Maybe you can free cpu to do more...

Post your "test" demo as an ADF, let's see how it works

[roondar]

Look, I genuinely like your out-of-the-box thinking. But this just doesn't seem like a very realistic solution.

I'm not saying it definitely can't be done, but you're essentially suggesting someone who is rather close to completing a game rewrite the entire rendering part (which is not as simple as just drawing a few bobs for a game like this) to try and see if it may get better results using your idea.

Wouldn't it be better to create a full doom/wolf like 3D rendering environment using this technique yourself first? That would serve as a proof of concept so we can actually see if it's worthwhile. That seems to me to be a much better way of doing things, considering how far along this project already is.

[sandruzzo]

I'll try to do a demo were i'll use blitter to do cp2 160x100 and see how much fps we can get. I'm not suggesting to change it's rendering engine, I don't see why doing only "texture" walls at 2x2 or worse. Why don't consider just "flat" rendering on A500 and having better visual outcome?

Back in the day, even though I fully understood Amiga limits, I never liked 2x2 rendering

[sandruzzo]

Originally Posted by DanScott

Post your "test" demo as an ADF, let's see how it works

http://eab.abime.net/showthread.php?...ight=sandruzzo


I'll try to set a demo.

[roondar]

I can respect not liking 2x2 rendering, but it considering what's being attempted here I don't see any other option. Remember, even Doom did 2x2 rendering for the main part of the screen in low-quality mode on PC (though overlays etc were kept at full-resolution).

By the way it's certainly possible I misread your intent, we're both non-native English speakers and that can cause confusion

[DamienD]

Originally Posted by roondar

Look, I genuinely like your out-of-the-box thinking. But this just doesn't seem like a very realistic solution.

I'm not saying it definitely can't be done, but you're essentially suggesting someone who is rather close to completing a game rewrite the entire rendering part (which is not as simple as just drawing a few bobs for a game like this) to try and see if it may get better results using your idea.

Not the first time sandruzzo or Trachu for that matter, have done this

Instead of telling others how to program / manage their games; let's see yours

[sandruzzo]

Originally Posted by roondar

I can respect not liking 2x2 rendering, but it considering what's being attempted here I don't see any other option. Remember, even Doom did 2x2 rendering for the main part of the screen in low-quality mode on PC (though overlays etc were kept at full-resolution).

By the way it's certainly possible I misread your intent, we're both non-native English speakers and that can cause confusion

My fault on English. The point is: why doing somenthing (I'm not talking about this project) that don't suits Amigas' HW well and having an not so visual good outcome?

[sandruzzo]

Originally Posted by DamienD

Not the first time sandruzzo or Trachu for that matter, have done this

Instead of telling others how to program / manage their games; let's see yours

Every time same old music? How much time I've spent allmost begging for Rygars' OCS gfx? I thought it was close this matter... Please

I allmost finished CHIP game, a simple puzzle game, but guess what? That guy disappeared...Allmost finished

[DamienD]

Originally Posted by sandruzzo

Every time same old music?

Same old music; yes most definitely from you

Originally Posted by sandruzzo

How much time I've spent allmost begging for Rygars' OCS gfx? I thought it was close this matter... Please

What's that got to do with you trying to shove your ideas down the authors' throats of every new project???

[Gorf]

Originally Posted by sandruzzo

Maybe you can free cpu to do more...

i somehow doubt that ... since you need the Blitter and Copper to work at full time to draw the lines. After Denise DMA fetch for 4 bitplanes and Copper list (next in priority), what non cpu-blocking slots do you have left for the line-drawing?
I fear you need Blitter-nasty to get to the 1 million pixels per second, but then the CPU is totally blocked without FastRAM

Do you have some calculations here?