CGX 4 and P96 SDK

[Karlos]

I don´t know the Amiga APIs or libraries well enough to understand this concept

How, in this "vision" is support for various buses and cards achieved in your mind? I would think that this would be delegated to a driver that know the chipset. The next problem is that this chipset can reside on a zorro bus, pci bus - or heaven forbid usb bus - LOL

The key to this, I think, is one of abstraction. This "new" graphics.library would itself be agnostic to the underlying hardware and thus need to sit on top of something lower level, in my mind. The additional functionality presented by existing rtg libraries would sit on top of the same layer and just expose the relevant features of it that the new graphics.library doesn't.

This lower layer would be responsible for detecting/managing the hardware bus and memory space, thus providing a consistent API for actual chip drivers, such that it doesn't matter if your graphics chip is attached by zorro or PCI. For the most part I see bus and memory management as different aspects of the same task - essentially how  you map the device's memory/register space into the system memory map such that the chip driver knows where the hardware registers/memory are located as well as the graphics.library's BitMap allocator knowing where to get video memory from.

I think a lot more thought is required though

[arnljot]

Maybe a good place to start is to doodle some design documentation, just for the heck of it. To get a mental picture of what the new system would be like. Perhaps a google code page, or a soureforge page?

Then when we know what it´ll look like we´ll know if we can attract a bounty for it and a coder or three?

[Karlos]

TBH, I would suggest the first thing should be to gauge the level of interest.

[arnljot]

Perhaps you´re right. But I think that it would be easier to gather support if people knew what they were taking a position on. And also pie in the sky dreams could be grounded first so that the project could have a hint of realism.

But either way, the nay sayers could perhaps overrun the project and discourage coders before it takes off.

Would you be interested in participating with design or code? I don´t know Amiga APIs or C coding, but I´d be happy to contribute with sourcing documentation and doing other leg work as needed or instructed to

[Karlos]

Interested, yes. Able, maybe not. I really don't seem to find the time for anything like this any more :-/

[Jose]

To me only thing that comes to mind regarding layers is that they are very dangerous to performance, just like the current bottleneck for 3D in OS4 IIRC was the extra 2D layer (i.e. MiniGL constantly calling P96).
Not saying that it can't be done or anything similar, it just reminds me of that right away...

[arnljot]

What does the CGX superlayers do? That is one of the CGX P96 differences?

[Karlos]

What does the CGX superlayers do? That is one of the CGX P96 differences?

I think it's an optimisation made to the handling of layers to reduce the amount of blitting/copying when refreshing many overlapping areas. Don't quote me on that, though.

[arnljot]

I remember that CGX put forwards the layers as their strong point.

What did P96 use as their selling point? Any features, or was it "just faster and better"? Something that both can claim.

I´m not trying to identify one as better or inferrior, just trying to get a rough idea of the feature matrix.

[Gulliver]

Okay, I had to create a thread, to create a poll to gauge interest. Please explain a bit more on that thread what this is about, and I invite you to continue discussing this issue on that thread.

Thanks


PS: If we want things to get done, we actually need to do something about it

[Karlos]

One of P96's features was that it supported CGX software too. Certainly everything I ever wrote for CGX (not including video overlay which I never investigated) also worked on P96.

I haven't really tried the other way around.

[arnljot]

Yes, I remember the P96 compatability mode for CGX. But I remember that software that used overlay (like video playback software) was initially in two versions, one for CGX4 and one for P96.

It´s a long time ago, so my memory might trip me on this one.

Back then I was a user who followed the RTG of my card, first P96 with my P-IV, then CGX4 with my CyberStormPPC.

@Gavillan, I´ll certainly vote. But I only have a half formed idea at the moment what this is about.

[Karlos]

My graphics card didn't even have a video overlay. It was faked using texture mapping, by the looks of things.

[buzz]

I read the emails sent. I wondered perhaps the p96 developer, might compromise with a source license for the SDK where he retains full copyright/ownership etc, but allow drivers build on it to be fully open ? I just wondered if they got scared off by the wording.

However, I am not surprised permission wasn't granted. Only for the fact that this is Amiga land, where the idea of sharing information, and helping each other doesnt exist! (mostly)

[ChaosLord]

What does the CGX superlayers do? That is one of the CGX P96 differences?

Code: [Select]

IF (GfxCardDetected and BlittingToGfxCardScreen) THEN
   BlitIntelligentlyUsingGfxCardBlitter();
ELSE_IF (BlittingToAGAScreen) THEN
   BlitIntelligentlyUsingCPU();
END_IF


[Piru]

What does the CGX superlayers do?

It replaces layers.library with a faster one. Also the replacement has support for simple (1-bit) transparency.

Superlayers and layers.library itself isn't related to blitting at all.