Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Differences in D4 and D6 TImage component?  Getting flicker in D6.

Posted on 2004-04-02
3
Medium Priority
?
264 Views
Last Modified: 2010-04-05
I have an application that I wrote in Delphi 4 a few years ago.  It generates a Mandelbrot image and displays the image as it's rendered.  I recompiled under Delphi 6, and now the TImage component flickers like crazy while it displays.  This is extremely annoying.  What changed between these two version to cause this?

Here is the code in the main loop:

  for i := 0 to iMandel.Height do
  begin
    for r := 0 to iMandel.Width do
    begin
      iMandel.Picture.Bitmap.Canvas.Pixels[r, i] :=
        ChooseColor(MandelComputeAndTest(MinX + (r * deltaR), MinY + (i * deltaI)));
    end;
    iMandel.Refresh;
    Application.ProcessMessages;
    if StopRender then
      Break;
  end;

iMandel in the TImage component.
MandelComputeAndTest computes a value for the point passed in.
ChooseColor maps that returned value into a color.

I tried commenting out the "iMandel.Refresh" and the "Application.ProcessMessages".  Neither of these stopped the flicker.

I just tried Delphi 7 and it doesn't flicker.  However, I prefer D6 to D7, so if anyone can help I would greatly appreciate it.

Thanks
0
Comment
Question by:edsteele
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
3 Comments
 
LVL 26

Expert Comment

by:Russell Libby
ID: 10746223
I have a feeling (based on the following link), that Delphi6 will need the  DoubleBuffered property set to True for the image's parent:

see:

http://www.delphiforfun.org/Programs/Delphi_Techniques/Testing_Delphi_Versions.htm

Try setting the TImage's parent (normally the form) DoubleBuffered property to True, and then run the test.

-----------------------

Hope this helps,
Russell


0
 
LVL 11

Accepted Solution

by:
ZhaawZ earned 1000 total points
ID: 10746528
You can also try to set iMandel.Stretch to True
0
 
LVL 1

Author Comment

by:edsteele
ID: 10752058
Setting the DoubleBuffered property to true actually made things worse.

However, setting Stretch to true fixed it.  I'm a little perplexed as to why that would help.
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

The uses clause is one of those things that just tends to grow and grow. Most of the time this is in the main form, as it's from this form that all others are called. If you have a big application (including many forms), the uses clause in the in…
In my programming career I have only very rarely run into situations where operator overloading would be of any use in my work.  Normally those situations involved math with either overly large numbers (hundreds of thousands of digits or accuracy re…
In this brief tutorial Pawel from AdRem Software explains how you can quickly find out which services are running on your network, or what are the IP addresses of servers responsible for each service. Software used is freeware NetCrunch Tools (https…
This tutorial will teach you the special effect of super speed similar to the fictional character Wally West aka "The Flash" After Shake : http://www.videocopilot.net/presets/after_shake/ All lightning effects with instructions : http://www.mediaf…
Suggested Courses

715 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question