I am able to draw morphic primitives with the alpha channel working properly by overriding #drawOn: in my subclass. I am not able to make it work for an ImageMorph.
I'm running squeak 3.9-7067 on XP. Thanks again, Steve On 4/23/07, Bert Freudenberg <[EMAIL PROTECTED]> wrote:
Try drawing something other than an image. I have a hunch the alpha- bitblt is wrong ... Btw, which platform are you on? Which VM? - Bert - On Apr 23, 2007, at 9:32 , Steven Greenberg wrote: > Following Bert's advice, I see that HaloMorph overrides > #drawSubmorphsOn: and calls its Canvas using > asAlphaBlendingCanvas. That seems like a good place to start. > > I tried subclassing ImageMorph and adding this method: > > drawOn: aCanvas > ^ super drawOn: (aCanvas asAlphaBlendingCanvas: alphaValue). > > Unfortunately, it didn't display anything at all. I tried alpha > values of 0.5 and 1.0. If I remove the alpha blending stuff, and > simply call: > > ^ super drawOn: aCanvas. > > it works like a normal ImageMorph, so at least I know it isn't > broken someplace else. > > Any suggestions on how to get asAlphaBlendingCanvas to blend some > alphas? > > > > > On 4/23/07, Steven Greenberg <[EMAIL PROTECTED]> wrote: > Thanks for the pointer! I didn't try that code in the workspace, > but if you enable "haloTransitions" using the Preferences browser > then the halos fade in and out. > > Thanks, > Steve > > > > > On 4/22/07, Bert Freudenberg <[EMAIL PROTECTED] > wrote: > On Apr 23, 2007, at 0:44 , Steven Greenberg wrote: > > > I have a PNG image that I'd like to display fading out. I tried > > the BitBlt method suggested by "Team RAR" to fade the image, but I > > can't make it work. > > > > The image loads properly from a file and displays fine as an > > ImageMorph. I have been able to use a TransformationMorph to > > rotate and scale it, and PNG transparency is working properly. > > > > Is the "Team RAR" BitBlt method the only way, or are there > > alternatives? > > > > I'm running a 3.9 image, and my display depth is set to 32 bits. > > > > Normally you would just use an alpha-blending canvas. See HaloMorph > fadeIn/fadeOut and draw methods. To try those halos, enable this: > > Preferences enable: #haloTransitions > > Now when I tried then the halo icons do not actually show until alpha > is one. No idea why that is. > > - Bert - _______________________________________________ Beginners mailing list [email protected] http://lists.squeakfoundation.org/mailman/listinfo/beginners
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