Performance issue with animations on top of image layers

[Farshid-Monhaseri]

Issue Title

Performance issue with animations on top of image layers

Describe the bug

The animation operation on top of the image widget seems to create some sort of performance issues

To Reproduce

This issue was detected on one of the low-end arm devices (imx6ull) but It would be expected on other low-end devices too (e.g. single core armv7 sub-1GHz CPU, no GPU) Create a simple app with one or several image widget at background then add a simple leaner animation on top of them.

Expected behavior

The animation should work smoothly like when there are no images at the bottom layer.

Devices:

Please complete the following information:

• Device: imx6ull (armv7, no GPU)
• OS:
• OS Version:
• TotalCross Version: 6.1.1

Additional context

It would be some alpha masking issue or similar one at TotalCrossVM