Detect AGA

[Steffest]

Hey!
I'm an experienced webdeveloper but totally new to C.
As an educational project I want to create a (simple) game that compiles from the same source from Amiga kickstart 1.3 to kickstart 3.1 and beyond to other platforms like modern webbrowsers, scaling up things like colors and sprite-sizes depending on the host capabilities.

My question: How do you detect what features like AGA are present on the host?
Is it just a matter of trying to open a library using IExec->OpenLibrary starting from version 50 going up until one works?

As a non-C guy, this looks a bit weird to me.
Are there any other methods?

Thanks!

[phx]

Originally Posted by Steffest

from Amiga kickstart 1.3 to kickstart 3.1

...

Is it just a matter of trying to open a library using IExec->OpenLibrary starting from version 50 going up until one works?

Using the Exec-Interface (IExec) works with V50 (OS4.x) only. Do you want to support 1.3 to 3.x (M68k) or 4.x (PPC), or both?

My question: How do you detect what features like AGA are present on the host?

Open graphics.library. Cast the returned library-pointer to "struct GfxBase *" and don't forget to include "graphics/gfxbase.h".

Now you can check GfxBase->ChipRevBits0. When GFXF_AA_ALICE is set, you are most likely running on an AGA system.

IIRC, ChipRevBits0 didn't exist before V39. So you better open graphics.library for V39. When your ROM is older then there is certainly also no AGA chipset present (first AGA Amigas had V39).

[Steffest]

Aha!
Thanks phx.

Yes, I want to support 1.3 too.
GfxBase->ChipRevBits0 sounds perfect. I will try it out.

Thanks, nudges like these are super useful in this phase.