Copper gradient in RTG?

[wiz12]

Is it possible to have a copper gradient background effect in workbench windows like the tools Copper Demon or WBGradient provide but in RTG screenmodes?

[Thomas Richter]

Yes, obviously. Just use a hi-color or true-color screen mode, and an appropriate picture as desktop background.

[kriz]

Using a picture would not create the same effect, with copper gradient you can have it as background on other pub screens also like Dopus ..

[Thomas Richter]

Then select a proper picture for DOpus as well...

[wiz12]

I'm using a picture of the copper gradient as a background and this is a good substitute but I was hoping there might be tool similar to Daemon Tools that would work for RTG screenmodes because while Daemon tools works well for native screenmodes it just shows a plain grey picture on RTG resolutions?

[Daedalus]

While RTG can show every colour on screen that a copper gradient can, it doesn't work in the same way as those copper tricks do, which is to change one single colour down the screen. This is why it shows through on window backgrounds, inactive window borders, and anywhere else the given pen (usually 0 for the background) is used, and why the effect is relative to the display, not the window position. An image isn't the same thing at all, and because an RTG screen works in a fundamentally different way to natives screens, the same trick simply doesn't work.

There's no RTG equivalent that I'm aware of.

[kriz]

You can not put a picture behind Dopus or other applications on their own pub screen the same way as the copper effect does ...

It is Aga only (i see one application called stripes on aminet for wb1.x but not tried it http://aminet.net/package/misc/antiq/Stripes )..

Example of how it looks with Dopus:

[Thomas Richter]

Originally Posted by kriz

You can not put a picture behind Dopus or other applications on their own pub screen the same way as the copper effect does ...

That depends on the version of DOpus. On this ancient version, of course not. No, generally, you cannot. There is no copper on RTG screens. The copper was offering a mechanism to overcome limitations of the small bandwidth of the chipset back then when the Amiga was designed, but as RTG offers you to select the color of every pixel from millions of colors, rather than 32 or 256 as on the Amiga - there is generally no need for it anymore.

[pixie]

Is there a way to simulate the way gradients behave the same in RTG?

[Thomas Richter]

Everything that can be said about this had been already said. There is no copper on RTG, but there is true-color, so you can give every pixel its own color from a 16 or 24 bit color space. That gives you enough freedom to define a background image in the way you like, including gradients. That gradient is of course in the image and it does not affect other images or windows on the screen.

Thus, you have a lot more flexibility on RTG - gradients can also be horizontal, not vertical, and you are not restricted to bars at all, but can pick any image you like.

[Karlos]

Originally Posted by pixie

Is there a way to simulate the way gradients behave the same in RTG?

If you want a fast*, hardware accelerated gradient on an RTG screen, you might consider using something like W3D or GL to fill it if you have capable hardware. You could use a basic Gouraud shaded triangle strip for that, full screen width, with vertices for every defined colour band (assuming there aren't many and they are spaced at different points vertically down the screen).

That works if you are just drawing a background to an RGB bitmap, but if you wanted to do something that gave a similar effect to an actual copper gradient on a suitable bitmap that already has graphics on it, you'd need to perform this rendering with chroma testing enabled to isolate the pixels (by colour) that you want to replace. Chroma testing is a defined feature in W3D and GL but implementation quality varies. I can say it works on Permedia and Radeon though.

This doesn't go over the bigger problem that your screen would be a seizure inducing flickerfest unless you could guarantee to only draw on the screen bitmap during blanking or found a way to double buffer it all.

*terms and conditions apply. This will be fast when all that is happening is filling. The moment you need to chromatest against pixels already in the buffer, you have a read/write cycle.

[pixie]

Originally Posted by Thomas Richter

Everything that can be said about this had been already said. There is no copper on RTG, but there is true-color, so you can give every pixel its own color from a 16 or 24 bit color space. That gives you enough freedom to define a background image in the way you like, including gradients. That gradient is of course in the image and it does not affect other images or windows on the screen.

Thus, you have a lot more flexibility on RTG - gradients can also be horizontal, not vertical, and you are not restricted to bars at all, but can pick any image you like.

I know that RTG can give me 24bit, what I am asking is if it possible to do the effect of MagiCCopper. From what I understand you're talking, and I may be wrong, you're talking of a 24bit gradient that once applied it is fixed on windows.

There was once a trick used by an OS1.3 app where background and windows background were used as genlock, that's what I am asking if it is possible on RTG to do something of the like. I am submitting a video where it shows what I aim at.

The app was named SimGen and you can see it in action on 12:45 [ Show youtube player ]

[Karlos]

Originally Posted by pixie

I know that RTG can give me 24bit, what I am asking is if it possible to do the effect of MagiCCopper. From what I understand you're talking, and I may be wrong, you're talking of a 24bit gradient that once applied it is fixed on windows.

There was once a trick used by an OS1.3 app where background and windows background were used as genlock, that's what I am asking if it is possible on RTG to do something of the like. I am submitting a video where it shows what I aim at.

The app was named SimGen and you can see it in action on 12:45 [ Show youtube player ]

That looks like it's just doing what WBPattern Prefs does, except that it positions the image in each window to have the same absolute offset in screen space, making it look like a genlocked signal.

[pixie]

Originally Posted by Karlos

That looks like it's just doing what WBPattern Prefs does, except that it positions the image in each window to have the same absolute offset in screen space, making it look like a genlocked signal.

Birdie also does it on windows, but I guess the key is in your wording: "absolute offset"

[Karlos]

Originally Posted by pixie

Birdie also does it on windows, but I guess the key is in your wording: "absolute offset"

What I mean there is, basing the image top left offset on the window top left position on screen, including any menu bar adjustment or whatever.

[pixie]

Originally Posted by Karlos

What I mean there is, basing the image top left offset on the window top left position on screen, including any menu bar adjustment or whatever.

I've also discovered that it is possible to use in WinUAE the genlock, one can even have animations running in the background!

I guess the UAE RTG doesn't have anything that allows it