Deploying Alpha Channels to Win 8.1

Targets Windows
1

Good Day:

I am writing notes on a canvas containing a musical staff. The notes are stored a TARGA (.tga) files.

The notes display correctly under Mavericks.

When I deploy to Windows 8.1, the notes do not appear. I tried making .bmp files, but the alpha channels do not work.

What other formats with alpha channels will Windows 8.1 take?

Thanks -Will

2

[quote=203782:@William Bonney]Good Day:

I am writing notes on a canvas containing a musical staff. The notes are stored a TARGA (.tga) files.

The notes display correctly under Mavericks.

When I deploy to Windows 8.1, the notes do not appear. I tried making .bmp files, but the alpha channels do not work.

What other formats with alpha channels will Windows 8.1 take?

Thanks -Will[/quote]

The trick is http://documentation.xojo.com/index.php/Application.UseGDIPlus

3

Sorry, no joy.

#If TargetWin32
beep
App.UseGDIPlus = True
#Endif

When placed in the application’s Open Event Handler makes no change in either .bmp (no alpha)
or .tga (no picture).

Is there further documentation of UseGDIPlus? The docs are sketchy here.

Thanks -Will

4

[quote=203782:@William Bonney]What other formats with alpha channels will Windows 8.1 take?
[/quote]

As far as I know, TGA is not supported. A list of supported formats is at http://documentation.xojo.com/index.php/Picture.Save

Xojo does not support BMP with indexed colors, which as far as I know is the only BMP that supports transparency. I had to create VB .NET DLLs for that last year just to save in that format.

I use Png, it supports alpha very nicely. It should work just fine for what you describe. Oh, important detail : do not set double buffering on for your canvases.

5

Putting the graphic into a .png file did the Trick! Now cross-compiles!

Many thanks -Will

6

[quote=203866:@William Bonney]Putting the graphic into a .png file did the Trick! Now cross-compiles!

Many thanks -Will[/quote]

You’re welcome.