Description of the problem:
I want to use the brushing tool or a corresponding mouse routine to draw on an image presented in the background. Both the brush tool as well as the mouse routine (copied from Michele Svanera / demo_drawing · GitLab) work perfectly online, as long as I do not add a picture stimulus to the experiment. However, whenever I add a picture stimulus to the experiment, I am only able to draw polygons (below left) instead of point-by-point lines (below right).
I tried changed the order of brush and picture and even (just to explore whats going on) put them in separate trials. Moreover, I used a png instead of a jpg and changes transparency. But nothing worked.
Any help would be appreciated!