demo or test roms to show color emphasis

demo or test roms to show color emphasis
by mattmatteh on 2007-09-01 (#26630)

i was looking to see that i am emulation color emphasis correctly and was looking for a test or demo game. i was trying copper bars by quietust but dont think that it is working correcty. any one know of another ?

thanks

matt

by blargg on 2007-09-02 (#26634)

If your emulator does rendering while the PPU is off, use one of my two full palette demos. Linked one shows all colors in a horizontal strip, repeated 8 times down the screen with each combination of color emphasis.

by mattmatteh on 2007-09-03 (#26686)

thanks blargg. i though i had rendering while the ppu was off but the code is not working. i get blues lines. i searched the forums for rendering while the ppu was off but didnt get much, or at least anything i didnt know. could you explain the code please?

also, do you know of a demo or test that works while the ppu is on ?

thanks
matt

by Disch on 2007-09-03 (#26687)

Code:
if( ppu_off )
{
if( (ppu_addr & 0x3F00) == 0x3F00 )
{
Output_Pixel( palette[ ppu_addr & 0x1F ] );
}
else
{
Output_Pixel( palette[ 0 ] );
}
}

Blargg's palette demo changes the address several times midscanline by reading/writing $2007 (I forget which). The auto increment changes the address and thus makes it point to a different palette entry, changing the color that gets rendered onscreen.

The only game I can think of offhand that cycles through color emphasis modes is Final Fantasy -- which it does during the battle transition for the flashy effect.

by mattmatteh on 2007-09-03 (#26689)

got it working !!
thanks !!!

matt

by Zepper on 2007-09-06 (#26772)

There's an old demo from C.Covell of a water flooding a wall. The transparency effect is cool.

EDIT - about the piece of code, shouldn't be (addr & 0x7F00) == 0x3F00 ?

by Disch on 2007-09-06 (#26773)

Fx3 wrote:
EDIT - about the piece of code, shouldn't be (addr & 0x7F00) == 0x3F00 ?

No.

VRAM is only 16K. $4000-FFFF mirrors $0000-3FFF