Second or 'Ghost' Mouse Pointer

Hello all,

I am working on a GUI which contains two axes with different images. I want to create a 'ghost mouse pointer' which appears above axes2 when I move the primary mouse pointer over axes1. The second mouse pointer should move parallel to the primary mouse pointer.

So far I am using the WindowButtonMotionFcn to capture the mouse coordinates. For the second mouse pointer, I use a small grayscale matrix representing a mouse arrow. This image is displayed in a third axes, and the axes is moved by the WindowButtonMotionFcn using set(handles.AxesPointer, 'Position', ...) when the mouse arrow is above axes1. So far so good, however, two problems remain:

1. The 'ghost mouse' is a little slower than the primary mouse (which I could live with).

2. The background of the 'ghost mouse' is black, transparent would be nicer.

Any ideas how I can render my 'ghost mouse' axes transparent, or any other way to achieve the 'ghost mouse'?

Thanks Chris

Answer 1

[Jan]

I suggest to keep the axes, which contains the ghost pointer fixed and move the coordinates of the image instead. I assume, this would be faster.

NaN-Values in the image's CData are displayed transparently.