Transparency In DrectX

Hi everyone

I am a newbie Smile

Smile

. I have a few questions regarding DirectX and GDI+. Here we go.

Description: The application i am developing is using C# .NET, there is a main "Form" on which there are controls i.e. buttons etc. Then, there is a child form on which i draw lines and circles (using drawArc). I have tested both DirectX and GDI+. My requirement is to update the screen after like every 10-20milliseconds. Another requirement is that the child form (on which i am drawing things) should be transparent.

1. Is there any switcme procedure to optimize my Display rate (its not updating as it should be). I have tried Invalidate region as well, it makes performance better but still its not realtime.

2. DirectX is supposed to be real fast, i used DirectX on the child form, but enables transparency as well. What happened was that it became too slow.

So, my question is "Is there any possibilit of GDI+ meeting my requrements, i don't see any. If DirectX can meet my requrements, as it should, how can i make the tranperency feature work. Because when i enable transparancy on DirectX the results are too poor."

Thanks a lot for your help .

Sayed Zeeshan.

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Transparency In DrectX

Thomo2
I don't personally know about GDI (or GDI+) under .Net, but in my experience of it in C++ it is not really a good choice if you want high 50hz+ response times. DirectX is perfectly capable of doing this...

With one slight issue... if you're using it in a complicated desktop environment (where Direct3D is in windowed mode) the runtimes will be forced to "play nice" with other Windows applications. This can mean that performance will suffer - although it should still be possible to achieve acceptable performance.

If I understand your comments on transparency correctly, you're making the container/background of the D3D-based application transparent, not the actual geometry/pixels that Direct3D is rendering There is a subtle difference...

Taking a bit of a guess here, Direct3D will have to display it's internal representation to the GUI, and then GDI+ (or possibly just .Net) will have to make that image transparent based on what is underneath it. So, you might not realise it, but you could be invoking functionality from the "basic" parts of Windows/.Net graphics implicitly. This feeds back into what I was saying about performance suffering when you try to get Direct3D to play nice with all the other Windows GUI citizens

hth
Jack
DenisSheshko
Hi Jack

By transparency i mean setting the form transparency, on which the DirectX is rendering.
I think in that way DirectX is involving GDI+ which is lowering the performance.

Is there any way to synchronise GDI+ and DirectX for a better performance. or is there any way to optimize GDI+ for graphics of 50+ hz refresh rate.

Thanks a lot

Sayed Zeeshan
James McGilp
I can't say for definite, but it wouldn't surprise me if GDI+ and DirectX were operating in their own little worlds and as such didn't know that they were co-existing. DirectX is just rendering away to a hDC as requested, and GDI+ is taking the hDC/hWND and blending it as appropriate.

So trying to synchronize them and/or combine their functionality probably wouldn't work too well.

You might want to try posting this question in one of the more .Net/GDI+ oriented groups - my area of speciality is DirectX, so I'm probably not the best person to answer a question on the finer points of tuning .NET and GDI+

hth
Jack
badseed2379
Thanks a lot for your feedback.

It seems that there is no good way to combine them both. Maybe i should stick to DirectX for now.

Sayed Zeeshan.
Transparency In DrectX

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