winnie, thank you very much. The codes worked fine on Android. When you find an expert like you in graphics; There is another issue I would like to ask in line with the phrase "Since,then, the One Who creates knows, surely the One Who knows will speak.";
I have geometric problems such as the closest point of the point to the line and the lines that cut the area, and I have very unstable solutions for them.
Do you have a clear resource recommendation on the subject?