Steven Greenberg wrote:

m := Morph new openInWorld. m visible: false. m visible: true.

well.. that's easy!

I would like to know how to fade in and out. I read the BitBlt way, but I haven't tried it yet.

On 4/22/07, *Brad Fuller* <brad@bradfuller.com mailto:brad@bradfuller.com> wrote:

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.
>
along the same lines, how can one make an object disappear, or
invisible? I don't mean delete the morph, but just make it
invisible and
make it visible again.

--

Are you trying to do this via eToys? I don't know whether it's available that way. Try typing that code into a workspace, though, and you should be able to make the Morph visible and invisible. You can also do this in your programs.

On 4/23/07, Brad Fuller brad@bradfuller.com wrote:

Steven Greenberg wrote:

...

m := Morph new openInWorld. m visible: false. m visible: true.

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 greenbes@puzzlingevidence.net 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 bert@freudenbergs.de 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 -

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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 bert@freudenbergs.de 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 greenbes@puzzlingevidence.net 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 <bert@freudenbergs.de > 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 -

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