Eaten ghosts are not transparent

[MikeDX]

Once a ghost is eaten, it returns to home but instead of being fully transparent, the ghosts wear a "black" suit, covering any tiles over as they pass (most noticeably the dots).

There are a couple of ways of fixing this.

The obvious one is to check for ARGB 0XFF000000 in the gfx_decode_color_palette function around line 2806 or to check for r+g+b==0 around line 2798 and set to 0x0 if true.

Happy to submit a PR for this, depending upon which approach you wish to take.

[floooh]

Damn you are picky 😆
I think I use the same trick as the original game, because I haven't found separate 'eyes' in the sprite ROM. But it might be that the arcade hardware renders 'black' as transparent.

I'm a bit confused, because this code block at the end of palette initialization sets every first slot in an 8-color-block to transparent... and I would assume that the eyes are using such a color palette slot for the 'ghost coat'.

PS: I mean this code block:

pacman.c/pacman.c

Lines 2802 to 2805 in cc56af9

	// first color in each color block is transparent
	if ((i & 3) == 0) {
	state.gfx.color_palette[i] &= 0x00FFFFFF;
	}

Maybe I have a bug or wrong assumption there? (would need to cross-check with the emulator - assuming that I don't have the same bug there: https://github.com/floooh/chips/blob/master/systems/namco.h)

[floooh]

PS: maybe the color code for the eyes is wrong here (?)

pacman.c/pacman.c

Line 236 in cc56af9

COLOR_EYES = 0x19,

...but I'd need to dig into the code base again to understand how the color decoding worked...

[MikeDX]

Damn you are picky 😆

Have to confess, this is only due to having travelled the same road as you and written pacman from the dossier (also my fault for being a massive nerd!)

I think I use the same trick as the original game, because I haven't found separate 'eyes' in the sprite ROM. But it might be that the arcade hardware renders 'black' as transparent.

You are correct. The "eyes" graphic is indeed a regular ghost in a "black" suit. The Colour prom in namco hardware causes all black to be transparent regardless of palette position. This being the case I suspect the correct way is to set all RGB000 to transparent and not just the primary indexes.

I'm a bit confused, because this code block at the end of palette initialization sets every first slot in an 8-color-block to transparent... and I would assume that the eyes are using such a color palette slot for the 'ghost coat'.

You are correct - the sprites all use a 4 colour palette group and not individual colours (not sure what i'm trying to say here!)

Maybe I have a bug or wrong assumption there? (would need to cross-check with the emulator - assuming that I don't have the same bug there: https://github.com/floooh/chips/blob/master/systems/namco.h)

I think I tested your emulator and checked and that did not suffer the same fate (linked from another issue)

Once things aren't quite as chaotic here I plan to submit some further PRs to help with other "accuracy" improvements but rather than just posting problems I prefer to post issues + solutions rather than just poke holes as that is not fair and not nice :)