🚀 go-pugleaf

Matthew Hurd <MatthewHurd@OzEmailDOTcom.au> wrote:
>Aaron Spink wrote in message ...
>>
>>If the info is correct and the Rasterization engine contains 4MB of
>>embedded dram, then the possible resulutions are as follows.
>>
>>All assuming 32bit color(8b,8r,8g,8a) and  16, 24, 32 bits of Z
>>
>> 16 24 32
>>640x480 1.8MB 2.1MB 2.5MB
>>800x600 2.88MB 3.36MB 3.84MB
>>1024x768 4.7MB 5.5MB 6.29MB
>>
>>I'm going to assume that they will support roughly
>>800x600x32x32 or 640x480x32x32.  Anything higher than
>>800x600 is wishfull thinking unless you want bad quality or
>>want to pay ~2k per PSX2.
>
>The spec for the graphic chip lists DTV and 1280x1024 VESA
>capability.
>
>You could get better RAM usage than this with a polygon
>hardware sort and z-frame like the POWER VR stuff does.

You can forget the sort/z-frame entirely, if needs be, using
just a simple sort and hoping to avoid clipping errors. It
wouldn't be a lot of use for most games, but for things like
menus it'd be fine.

>I don't know if they do this though. Still doesn't give you
>1280x1024 with 32 bit colour, but 24/23 bit would be OK
>with 16/15 bit colour and 8 bit alpha.

Why would you need an alpha value for the frame buffer?
In pretty much every case, it would be supplied as part of
the drawing operation (eg: as 1-srcalpha).

That's then 1280x1024x15 = 2.5mb. Since there's only
room for one frame at this resolution, the display might
have to be interlaced (or, the front buffer might be in a
seperate area of memory, since pretty much all drawing
is to the back buffer).

Given that it's 100% compatible with the PSX1, it will have
to support 15 and 24-bit screen depths (along with no
z-buffer) and 4/8-bit paletted textures. It's possible that
these will only be in a compatibility mode, but it's more
likely that they will be available to all games.

>Anything higher than 800x600 doesn't make much sense for a
>tv though.

Yup.

---
Russ