My task is the following. I show a picture and the participants are supposed to indicate where in the picture they see the object. The best way to do this would be by having something like a lasso feature, to free-handedly draw a shape around the object while keeping the mouse button pressed. Alternatives are to draw the shape by clicking several times in a row and connecting the dots by straight lines. Or, which im trying to implement at the moment, to just draw an ellipse with the mouse button pressed.
So far, I'm managing to have the participant draw the ellipse by making two clicks, capturing the click positions and altering the position variables of the ellipse accordingly.
Having it work with with an ellipse, mouse down to start, then drag the ellipse with a 'preview' of its shape and then mouse release would already be great. The rest is bonus. The current version with two clicks and no 'preview' of the shape in between is just very unintuitive.
I would be very happy for any kind of help or suggestions.
Thanks a lot!