New Sprite type supporting alpha channel

[Tarzan1163]

Problem
In my project a have sprite that holds some antialiased graphic. Part of this graphic is repainted with transparent color (masked). However when i push this sprite to another sprite, then part with alpha is already premultiplied and thus antialiased parts are useles.
I cannot paint directly into destination sprite because of that masking step.

Use case

1. create Sprite with transparent background
2. paint some antialiased graphic with opaque color (e.g. fillSmoothCircle())
3. use pushSprite() or pushToSprite()
4. see properly blended graphics (antialiased parts)

Solution
Introduce sprite that holds alpha and blending with background color is done only when pushSprite() or pustToSprite() is called.

Would it be possible to add such sprite type into library?

[Bodmer]

Adding an alpha channel to sprites is on the TO DO list but it will be some time before it gets added. This capability would then allow masking/transparency/opacity features.

[MR-XieXuan]

Expect

[DoctorU]

I've been thinking on this.

You could create two sprites, one for your image, and a grayscale one, from alpha channel, for your mask. Then interpolate.

I'll give it some more thought and try to create a demo.