AlphaAppleDemo and 16Bit Workbench-Screen

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fingus
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AlphaAppleDemo and 16Bit Workbench-Screen

Post by fingus »

I got only a black box around the Apple of the AlphaAppleDemo with a 16Bit Workbench on Amiga OS4.1.3. I´m not sure if this is really a Hollywood-Problem, but someone mentioned some time ago that there´s an error in the Alpha-function of Workbench in 16Bit (Workbench-Shadows also missing with composing enabled).

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airsoftsoftwair
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Re: AlphaAppleDemo and 16Bit Workbench-Screen

Post by airsoftsoftwair »

That's not a bug. Alpha transparency is of course only possible on 32-bit screenmodes because 16-bit doesn't have any room for an alpha channel.

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fingus
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Re: AlphaAppleDemo and 16Bit Workbench-Screen

Post by fingus »

Thats not true!

I have figured out that the Alpha-Apple-Demo is working in 16Bit AND 32Bit-Mode ONLY if Compositing is turned On in GUI-Prefs!

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airsoftsoftwair
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Re: AlphaAppleDemo and 16Bit Workbench-Screen

Post by airsoftsoftwair »

Yes, it needs compositing because otherwise it would be much too slow. If it's really working in 16bit mode too, then OS4 is doing some tricks here and it will eat up more memory than 16bits per pixel because 16bits don't have any room for any alpha information (5bits red + 6bits green + 5bits blue).

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