flicker with transparent overlays

[peterbone]

I want to have several transparent overlays on top of each other and 1 of them will be being redrawn. I can't stop the flicker - anyone know how?

Peter

[Alimonster]

Could you give a little more information please? Do you mean transparent (on/off appearance, like alpha testing or TBitmap.Transparent) or translucency (alpha blending)? Also, what API is this in (GDI, OpenGL, D3D)?

If it's standard Windows stuff then you can look at the obvious methods (DoubleBuffered = true and draw in the OnPaint method, manually double buffer your bitmaps where possible, use Graphics32, handle WM_EraseBkgnd, and so on).

[peterbone]

I'm trying to use several TImage's with transparent set to true. There will be a single object on each overlay so that when one object has to move, only that object has to be redrawn and not all the other objects as well, because the objects might overlap. I've tried all the usual tricks of reducing flicker that normally work but they don't work with transparent TImage's.