Mame Palette (intensity Bit)

[Franxis]

This post is dedicated to DaveC...

I use the following #define to get the colors of the palette:
#define GP_RGB24(r,g,b) ((((((r>>3))&0x1f)<<11)|((((g>>3))&0x1f)<<6)|((((b>>3))&0x1f)<<1))&0xfffe)

Then the intensity bit is set to 0, then i don't know why DaveC says that the gamma is too high...

Also i change the MAME palette with the following code:
GP_PALETTEENTRY colorgp;
colorgp = GP_RGB24(r,g,b);
GpPaletteEntryChange(i,1,&colorgp,GPC_PAL_ASYNC_REALIZE);

In other way, the palette of the images in the frontend has been created with GP32 Converter with intensity bit set to 0 (i have checked black color as 0x0 in the generated .h file). In this cases I assign the palette directly from the .h file without any conversion:
for (c=0;c<256;c++) {
GpPaletteEntryChange(c,1,&gp32splash_Pal[c],0);
}


Then, i'm doing something bad??? Why the gamma is too high???
Is there any way to modify the gamma in the gp32???

Regards.

 

[rlyeh]

#define RGBA(R,G,B,A) (((R&0xF8)<<8)|((G&0xF8)<)|((B&0xF8)>>2)|A)

set A to 0

 

[DaveC]

I wish I could help code wise Franxis. I am not a coder unfortunately I would look at the source and play with it if I was. There must be something weird with the SDK that sets the bit somewhere that you haven't found yet.

All I know is the "black" background is too light. It is like that in the frontend AND the emulation. I don't know what is causing it. It is very noticeable on the BLU. I really wish I could help with the code. All I can do is test the emu and tell you when I notice that it is fixed. I would be glad to test for you.

Rlyeh, maybe you could look at the MultiPac source that Franxis has posted on this site. It has the same intensity bit problem, if you could spot the problem there maybe it would be the same fix for MAME.

All of your work is great and appreciated, thanks Franxis, Rlyeh.

Regards.

 

[Franxis]

#define RGBA(R,G,B,A) (((R&0xF8)<<8)|((G&0xF8)<)|((B&0xF8)>>2)|A)

set A to 0

​

Thanks peaso Rlyeh, i will test it !

 

[gaterooze]

No offence, DaveC, but in all honesty I don't notice a problem with the gamma... Is it just you, or do other folks share the same view?

Maybe I'm just focused on the great game I'm playing to worry about the background?

 

[Franxis]

No offence, DaveC, but in all honesty I don't notice a problem with the gamma... Is it just you, or do other folks share the same view?

Maybe I'm just focused on the great game I'm playing to worry about the background?

​

I don't notice it too... but DaveC says that the image will be better with the correct gamma... I will test it...

 

[EvilDragon]

Guess, you two have BLUs, eh?
The gamma is slightly different on FLU, I guess that's why

 

[DaveC]

No offence, DaveC, but in all honesty I don't notice a problem with the gamma... Is it just you, or do other folks share the same view?

Maybe I'm just focused on the great game I'm playing to worry about the background?

​

I don't notice it too... but DaveC says that the image will be better with the correct gamma... I will test it...

​

You won't notice much of a difference, if any at all, on your FLU. You need a BLU to notice. With a BLU the difference is significant because of the way the screen is lit. If you will let me test it I will tell you if there is a difference with your update as I have a BLU.

 

[Franxis]

DaveC i have compiled the new binary with Rlyeh suggestion and i have send it to you... I think there is no difference... but tell me if you see any difference...

Regards.

 

[DaveC]

DaveC i have compiled the new binary with Rlyeh suggestion and i have send it to you... I think there is no difference... but tell me if you see any difference...

Regards.

​

No there is no difference. It is the same from title screen to emu. It is exactly the same as before It must be setting the bit somewhere else or something I don't know. If Rlyeh looked at the source maybe he could spot the problem. Since neither of you guys have BLUs (maybe you could get one, the contrast is so nice ) it is probably hard to test.

I just noticed something else. Xcade has the same problem, light background. SIemu (space inv emu) though does not. Most non-arcade emus don't have this problem on my unit either. I wonder if it is something in the MAME code that is bumping up the background gamma like a separate gamma setting in MAME? Maybe code from the PC has a default setting that does it? Not sure why Rlyeh's code had no effect though, I would have thought it would have SOME effect.

Thanks for trying though

Picture taken with same GP32 and same lighting conditions (dark room):