09jyoung

hello... i'm writing a C++/Win32 connect four program... its still in development... but the source can be found here[link]... i'm doing alright... except with updating the board... I used InvalidateRect(hWnd,NULL,true) to update it... the problem is that this updates the entire screen and causes it to flicker... does anyone know any better methods to keep it form flickering??? Any help would be greatly appreciated.

Jimbo

Don't double post in the future please.

I'd suggest you look into double buffering if you haven't already.

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09jyoung

double buffering??? ok... thanks... i'll look it up

lectricpharaoh

Another thing besides double buffering is proper use of InvalidateRect(). The purpose of this function is to invalidate (ie mark as not up-to-date) a rectangle within your window. As such, if you pass the entire window (or more precisely, the entire client area), you will get more flicker than if you invalidate the smallest region possible.

With something like your game, it should only be updating a small region (about 1/16th of the client area) with each move, and this will probably lead to less flicker. Even if you get the flicker issue solved with double buffering, you should do this; it doesn't make sense to blit sixteen times the pixels you need to.

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grumpy

This is more a windows programming (or, a graphics programming) question, which is independent of programming language, and has no place in a C++ forum.

win32 specific answer follows.....

When using InvalidateRect(), it is also necessary for the WM_PAINT handler for the window to determine (using means specific to the application) whether it has been invoked in response to one or more invalidated regions or in response to a requirement to redraw the whole window. Failure to do this means that, by default, the WM_PAINT must update the whole window .... which sort of counteracts the benefits of using InvalidateRect() in the first place [one of the symptoms will be window flicker, as the entire window may be refreshed every time a region within the window is invalidated]. Look up the documentation on the WM_PAINT message (eg here) for more information.

Ancient Dragon

Where do you suggest we put it? (Please, don't say "Up Mine" )

grumpy

Up yours.

Generically, I'd normally suggest it go into a win32 programming area or into a graphics programming area. Catch is, neither of those exist in PFO.

The problem with putting it into a C++ area is that it is really not C++. And the problem is independent of programming language: it is a win32 problem that exists, and has the same solution, if it comes up in any win32 context (eg Delphi, VB, Digital Fortran, ....)

09jyoung

thanks and i soved the problem... heres the code if ya want it...
http://h1.ripway.com/jyoung0922/Temp.zip

09jyoung

sorry... no one answered me in the other one