hw sprites era end.

Página 1/2
| 2

Por PingPong

Prophet (3987)

imagem de PingPong

26-03-2022, 19:04

https://www.youtube.com/watch?v=A8LXC5tXb-Y.

with a decent blitter one can do more flexible sprites than those provided by hw itself even if in the V9990 hw sprites are relatively good.

Entrar ou registrar-se para comentar

Por Parn

Paladin (809)

imagem de Parn

27-03-2022, 01:23

I'd like to see the blitter working in a 64 color mode, since P1 can have up to 64 colors with sprites and patterns.

Por PingPong

Prophet (3987)

imagem de PingPong

27-03-2022, 15:48

the video shows a bitmapped not a pattern mode.

Por Parn

Paladin (809)

imagem de Parn

28-03-2022, 16:15

Yes, I know. It's just that all demos and games I've seen using the blitter run in B1 at 16 colors, despite P1 being more colorful. I'm just wondering how it would perform in a 64 color mode. Note I'm not saying no one uses the blitter in B1 at more than 16 colors, just that I haven't seen it. Wink

Por Manel46

Paladin (673)

imagem de Manel46

28-03-2022, 17:44

If the graphics are in BD8 mode, 8 bits/pixel (screen 8), we have 256 colors.
https://mega.nz/file/D9sADCDK#KFgEbjzpDnABTa3JsMH7W4IKF9iJ1Q...

Por erpirao

Paragon (1292)

imagem de erpirao

28-03-2022, 18:40

metal dragon from kai magazine is b1 8bpp (256 colors)

Por PingPong

Prophet (3987)

imagem de PingPong

28-03-2022, 19:58

Parn wrote:

Yes, I know. It's just that all demos and games I've seen using the blitter run in B1 at 16 colors, despite P1 being more colorful. I'm just wondering how it would perform in a 64 color mode. Note I'm not saying no one uses the blitter in B1 at more than 16 colors, just that I haven't seen it. Wink

the blitter is slower in P1 or P2 modes due to the higher bandwidth that those modes require, with sprites and multilayer or higher resolution. however it should be enough to efficiently move the nametable.
However, one thing i do not know, in those modes there is a chance that the CPU can overrun the vdp especially with r800. i no not know also if the wait pin is connected.

Por Parn

Paladin (809)

imagem de Parn

28-03-2022, 20:20

Thanks for reminding me of Metal Dragon. It really has 256 colors available, but I bet it doesn't use them all, since the palette is fixed, which for me is the greatest weakness of the BD8 color mode. I wonder if BP6 would have looked better, with more freedom to choose colors from. The example given by @Manel46, for instance, doesn't seem to make use of more than 64 colors itself (I took some screenshots at random and they hovered around 55 unique colors).

EDIT: Now it would be quite disappointing if P1 can't keep up with R800 or even Z80.

Por Manel46

Paladin (673)

imagem de Manel46

28-03-2022, 22:13

The number of colors depends on the ones that the source bmp has.
I use bmp2g9b with the -f parameter, which gives me a g9b file, in BD8 mode, which can have up to 256 colors.

Por PingPong

Prophet (3987)

imagem de PingPong

28-03-2022, 23:03

in p1 mode the blitter speed is greatly reduced because sprites and nametable management waste a lot of memory cycles. i think that the cpu could override the vdp because the speed is rougly the same of the v9938 blitter in those modes.
somewhere there is a chart about the speed on pattern modes but i cannot find it anymore.

Por Parn

Paladin (809)

imagem de Parn

29-03-2022, 00:15

Manel46 wrote:

The number of colors depends on the ones that the source bmp has.
I use bmp2g9b with the -f parameter, which gives me a g9b file, in BD8 mode, which can have up to 256 colors.

I understand that, but just think about it. Those 256 colors are fixed. Yes, there can be a situation where you may use all those specific 256 colors, but most of the time you won't be using all of them. And since you can't select your colors freely from the V9990 32k color space, you'll be restricted to an unoptimized palette, instead of selecting whatever 64 colors are closer to your source image. But hey, don't take my word for it, just try it for yourself: take a random Agony screenshot directly from the Amiga, and compare converting it to 256 colors with a fixed palette and converting it to 64 colors with a custom palette, and see which looks better.

PingPong wrote:

in p1 mode the blitter speed is greatly reduced because sprites and nametable management waste a lot of memory cycles. i think that the cpu could override the vdp because the speed is rougly the same of the v9938 blitter in those modes.
somewhere there is a chart about the speed on pattern modes but i cannot find it anymore.

I don't think there's much advantage in trying to use P1 as if it were B1. Just use its strong points, which are patterns and sprites, and I believe it would perform very well even if we don't use the blitter. But then, the blitter could be useful to, say, update every pattern at once, if needed.

Página 1/2
| 2