Improve company productivity with a Business Account.Sign Up

x
?
Solved

Clipping a Layered Window

Posted on 2006-06-30
2
Medium Priority
?
617 Views
Last Modified: 2013-11-20
I have a layered pop-up window which contains several child dialogs.  the children should not be of concern to this question.  The outer corners of the pop-up are rounded, I have been using standard windows clipping regions to clip them however they produc a somewhat undesired jagged edge (no anti-aliasing).  If I make the region big enough to show the anti-aliased corner I get a crappy border around the pop-up (and you can still see the pixelation in it).  It is my understanding that the color-key of a layered window defines a color that will not be rendered to the desktop (transparent).  

I use SetLayeredWindowAttributes() to fade the popup in and out.  This works very well, so the function calls are being made.

In OnPaint(), I use GDI+ Graphics::Clear() to set the entire background to the desired 'transparent' color, I then procede to draw the pop-ups frame and interior.  But when it's all done, the transparent color is not very transparent (doesn't work).

// initial set layered window in the override of CreateEx() (after everything is created and verified)
// dont mind the '0' alpha, the pop-up initially fades in
SetLayeredWindowAttributes(RGB(0,0,255),0,LWA_COLORKEY|LWA_ALPHA);

So... ... How do I get my pop-up edges 'smoothly' transparent?

Thank you in advance.
0
Comment
Question by:r2far
  • 2
2 Comments
 
LVL 22

Accepted Solution

by:
mahesh1402 earned 1200 total points
ID: 17019336
>>How do I get my pop-up edges 'smoothly' transparent?

UpdateLayeredWindow() has the additional advantage that the image defining the window shape can have per-pixel transparency.  Each pixel has an alpha value of 0-255, from total transparency (invisible) to total opacity..

UpdateLayeredWindow() allows you to gradually make the  edge of the window more and more transparent, as you move toward the edge.  This lets the edge blend into the background, no matter if the background is light or dark.  The edge is thus very smooth and non-pixellated.

Have a look at this article :
Per Pixel Alpha Blend : http://www.codeproject.com/gdi/pxalphablend.asp

-MAHESH
0
 
LVL 22

Expert Comment

by:mahesh1402
ID: 17019363
I think article above at codeproject with src is exactly what you are looking for..use UpdateLayeredWindow() and check.

-MAHESH
0

Featured Post

Get your problem seen by more experts

Be seen. Boost your question’s priority for more expert views and faster solutions

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

In this article, I'll describe -- and show pictures of -- some of the significant additions that have been made available to programmers in the MFC Feature Pack for Visual C++ 2008.  These same feature are in the MFC libraries that come with Visual …
Have you tried to learn about Unicode, UTF-8, and multibyte text encoding and all the articles are just too "academic" or too technical? This article aims to make the whole topic easy for just about anyone to understand.
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
When you have multiple client accounts to manage, it often feels like there aren’t enough hours in the day. With too many applications to juggle, you can’t focus on your clients, much less your growing to-do list. But that doesn’t have to be the cas…

606 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