D6: TImage flickering at canvas operations

[Harald Werr]

Hello

I noticed that performing any operation on the canvas of a TImage in
Delphi 6 causes the whole Image to flicker.
This was NOT the case in earlier Versions of Delphi (we used D1 to D4).
The flickering makes some "animations" on the screen, where many drawing
operations take place at a time, looking very ugly.

Even performing the graphical operations on a internal Bitmap and
copying it to the Image.Canvas will not help since Canvas.CopyRect also
causes the flickering. I could try StretchDraw instead (don't know if
flickering would stop then), but I wonder why the flickering occurs at
all. Adding csOpaque to ControlStyle, as recommended in the Borland help
site, didn't change anything.

Seems to me the flickering occurs on ALL graphical changes on the
canvas, e.g. drawing an ellipse, a rectangle, copying from another
bmp...

The difference between D4 and D6 can easily be shown by a little demo
program added to the delphi pack (Default installation path:
C:\Programme\Borland\Delphi6\Demos\Doc\Graphex.dpr). It can be compiled
in D4 and in D6 as well.

Somebody found a workaround, e.g. a TImage descendant?

Harry

[marcello farina]

Hi Harald,

see reply to question 44950 by George Pistikos

Marcello

[Patrick Quinn]

I use the TImage32 from (free) Graphics32 library - excellent and TOTALLY
flicker free - from:

http://www.g32.org/

Drawing etc is much faster, and it supports layers too.

Hope that helps

Patrick

Harald Werr <we...@avk.fraunhofer.de> wrote in message
news:3C3DA90A...@avk.fraunhofer.de...

[Harald Werr]

Ciao Marcello,

I don't know how to access a posting by its number within my Netscape
Messenger, but anyway:

I found the same posting in the UseNet newsgroup archive via efg's
graphics homepage. I set property stretch to True and Proportional to
False, and flickering stopped!

Mille grazie

Harry

marcello farina schrieb:

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