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More than 4 colors

More than 4 colors
by on (#111851)
I just have made a screenshot of Tom and Jerry from the emulator:

Image

I only refer to the background palette now. If you look at the colors on the palette and on the screen, on the screen there are definetly more than 4 color, I count:
- yellow
- brown
- black
- light grey
- dark grey
- light purple
- dark purple

That's 7 colors. How is that possible? Of course it can use the attribute bits to map the rest of the colors from the palette, but then if it scrolls and the next image that floats in wants to use another set of 4 group colors from palette? My assumption would be that it changes the attribute bits runtime, is it a technic widely used? Seems to me a nightmare to program that.

Also, is there an enumator that could show me used attribute bits for each 4 group tiles?
Re: More than 4 colors
by on (#111852)
It selects one of the 4 palettes. The PPU Viewer only displays with 1 pallet. Right click to switch palettes used to display.
Re: More than 4 colors
by on (#111854)
A neat feature of no$nes's debugger (in comparison to FCEUX's) is that it remembers the last palette used for each tile and updates the pattern table dump accordingly.
Re: More than 4 colors
by on (#111855)
3gengames wrote:
It selects one of the 4 palettes. The PPU Viewer only displays with 1 pallet. Right click to switch palettes used to display.


sorry that is not what i meant, another example:

Image

in this small portion of the screen there are at least 7 different colors at the same time!?
Re: More than 4 colors
by on (#111856)
No there isn't, there's 16x16 blocks where the colors can be selected from one of the four 3-color pallets. That's how it works, that is just at a boundary where they're really close.
Re: More than 4 colors
by on (#111858)
3gengames wrote:
No there isn't, there's 16x16 blocks where the colors can be selected from one of the four 3-color pallets. That's how it works, that is just at a boundary where they're really close.


Ok, now I understand. I had a wrong concept of the attribute bit. thanks
Re: More than 4 colors
by on (#111863)
lidnariq wrote:
A neat feature of no$nes's debugger (in comparison to FCEUX's) is that it remembers the last palette used for each tile and updates the pattern table dump accordingly.

That's a cool idea...!
Re: More than 4 colors
by on (#111864)
Instrumentation never ceases to surprise me with how useful it can be without having to be very smart or complex.
Re: More than 4 colors
by on (#111870)
lidnariq wrote:
A neat feature of no$nes's debugger (in comparison to FCEUX's) is that it remembers the last palette used for each tile and updates the pattern table dump accordingly.

Does it turn solid tiles and (say) the cloudbushes of Super Mario Bros. into seizure hell?
Re: More than 4 colors
by on (#111871)
I always found the feature of NO$GBA where it shows the actively used colors for a tile to be utterly annoying, because there is no way to turn it off. I often see holes in the tiles, and everything that isn't on the screen becomes solid black. You'd expect a VRAM viewer to show you all of VRAM, not just what is currently visible on a background. I liked VisualBoyAdvance's VRAM viewer more because you could simply select what palette you wanted to view all of VRAM with, and it would show you everything.
Re: More than 4 colors
by on (#111872)
Dwedit wrote:
I always found the feature of NO$GBA where it shows the actively used colors for a tile to be utterly annoying, because there is no way to turn it off.

I can see why that would be annoying. I found the idea pretty good, but you definitely should be able to override the emulator's choices, and even pick a "neutral" (grayscale?) palette or define your own. Being forced to use one of the active palettes can get in the way of debugging sometimes, like during fade sequences and all palettes are black.
Re: More than 4 colors
by on (#111874)
tepples wrote:
Does it turn solid tiles and (say) the cloudbushes of Super Mario Bros. into seizure hell?
No; the tiles appear onscreen in a stable order, so the coloring chosen is too:
Attachment:
no$nes-vram-viewer.png
no$nes-vram-viewer.png [ 10.51 KiB | Viewed 2487 times ]


Apparently I misremembered, and it doesn't actually cache the MRU palette per tile, just shows the current utilization.

The "Color Attribute" radio buttons provide you with an "assume ascending/descending luminance" override.
Re: More than 4 colors
by on (#111959)
tokumaru wrote:
a "neutral" (grayscale?) palette

Grayscale is good for 2 or 4 colors, but you probably don't want it for more. For 16 colors personally I'd prefer the CGA/EGA palette (without the dark yellow to brown hack) which not only has distinct colors but actually has a good variety by itself. No idea what I'd use on something like 256 colors though =S
Re: More than 4 colors
by on (#111965)
Sik wrote:
Grayscale is good for 2 or 4 colors, but you probably don't want it for more. For 16 colors personally I'd prefer the CGA/EGA palette

I depends on what you want to do, I guess... To identify tiles, grayscale is always better IMO, because palettes are often arranged according to brightness (you'd need increasing and decreasing grayscale palettes to cover these 2 common cases), "random" colors just throw you off. However, if your goal is to analyze the actual color indices being used, the CGA/EGA color would make sense, because we have already memorized their indices.
Re: More than 4 colors
by on (#111966)
Sik wrote:
No idea what I'd use on something like 256 colors though =S
I kinda like the MCGA default palette. (16 CGA, then 16 grey, then 3 luminosity x 3 saturation x 24 hues, and 8 unallocated). It's a little easier for me to look at a color and remember where it is in the lookup than something like a conventional RGB332 "fake truecolor" array.