#24469 - sgeos - Wed Aug 04, 2004 7:29 am
Has the 656K of VRAM been confirmed at this point? That seems like a huge amount. (It looks like enough to double buffer the at least one screen.) Does it seem likely that each screen with have registers and vram enough to operate as an independant GBA screen?
The potentially bogus leaked spec lists a 6:6:6 color format for a total of 262144 colors. Has this been confirmed? It seems silly to use 18 bits for color. That would double the amount of palette ram need. Worse, it would double the amount of ram need for bitmap modes, unless a 5:5:5 mode is available. (Chop the bottom bit?)
-Brendan
#24471 - FluBBa - Wed Aug 04, 2004 9:06 am
Didn't it say the LCD had 6:6:6 output and the graphics chip was still 5:5:5?
Maybe it can be usefull when using blending operations and things like that or they maybe can use some kind of a gamma corrector before final output?
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#24474 - ampz - Wed Aug 04, 2004 10:17 am
| sgeos wrote: |
Has the 656K of VRAM been confirmed at this point? That seems like a huge amount. (It looks like enough to double buffer the at least one screen.) Does it seem likely that each screen with have registers and vram enough to operate as an independant GBA screen?
The potentially bogus leaked spec lists a 6:6:6 color format for a total of 262144 colors. Has this been confirmed? It seems silly to use 18 bits for color. That would double the amount of palette ram need. Worse, it would double the amount of ram need for bitmap modes, unless a 5:5:5 mode is available. (Chop the bottom bit?)
-Brendan |
Why is 18bits silly? 18bit colors does not require twice the ram. Simply make the graphics hardware (including memory) 18bit wide.
#24489 - Teasy - Wed Aug 04, 2004 3:36 pm
Slightly OT, but how much VRAM did N64 have compared to the 656K VRAM in DS?
#24493 - techtech - Wed Aug 04, 2004 4:18 pm
The N64 had a rather flexible framebuffer.
You could tell it where (anywhere in the 4MB of RAM) to have the
framebuffer. The size depended on what kind of mode you set up
(16/32bit, selectable resolution, choose PAL/NTSC (I think)).
#24496 - dagamer34 - Wed Aug 04, 2004 4:25 pm
| sgeos wrote: |
Has the 656K of VRAM been confirmed at this point? That seems like a huge amount. (It looks like enough to double buffer the at least one screen.) Does it seem likely that each screen with have registers and vram enough to operate as an independant GBA screen?
The potentially bogus leaked spec lists a 6:6:6 color format for a total of 262144 colors. Has this been confirmed? It seems silly to use 18 bits for color. That would double the amount of palette ram need. Worse, it would double the amount of ram need for bitmap modes, unless a 5:5:5 mode is available. (Chop the bottom bit?)
-Brendan |
Yeah, 18-bits seems odd. And that's a lot of overhead when copying for 2 extra bits, lots of wasted memory.
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#24500 - sgeos - Wed Aug 04, 2004 5:06 pm
| ampz wrote: |
| Why is 18bits silly? 18bit colors does not require twice the ram. Simply make the graphics hardware (including memory) 18bit wide. |
Even if the graphics hardware uses memory that is 18 bits wide, I'll need to store color info using u32 or some packed format.
| FluBBa wrote: |
| Didn't it say the LCD had 6:6:6 output and the graphics chip was still 5:5:5? |
My bad. According to the doc, the LCD is 6:6:6. I did not see anything about the format the graphics chip uses. The 2D section just lists the max BG and OBJ count. The 3D section lists the max polygon count, max pixel count and something else in kanji that I can't be bothered to look up right now.
-Brendan
#24506 - tepples - Wed Aug 04, 2004 6:27 pm
My immediate thought: Perhaps the textures are still 15-bit or 8-bit or 4-bit like on the PS1, but the result after lighting is 18-bit.
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