I am a very beginner in qt, the problem I've got is that I cann't figure out how to draw a rectangular with 4 points using QCP. Moreover, these rectangular are perhaps overwrite each other, and I wish to give them with different colours.
Anyone has a solution for me, please? It's very difficult for me. I can not find an example in the guide.
Would anyone be kindly put all the code below and with a little explanation, please.
Thank you very much.