Making a painting - how to add information to previous frame


I’m all new to the OF, and have been browsing this forum for the last couple of days. It has been very inspiring, and OF seems to be a very fun tool to use.

I currently have a project, in which I want to create a painting depending on different things. Until now, I have focused just on how emotions etc contribute to the painting, but now I’m ready to start with the code. I have made a brush, which will move around and draw on the screen.
The problem is, every frame is created with a background, and a circle with a radius at the point of the brush. What I want, is to add this circle to the previous frame, so that I will be able to make, let’s say a line. Can I save the previous frame, and to that just add the new circle, and this new frame is then used in the next frame? I don’t really know how to do that, and I would be grateful for any kind of help.

You can make a ofSetBackgroundAuto(false) on the setup, so previous frames will stay onscreen.

Hehe, I just found that out. Just threw the setting of color for background to testApp::setup, and added ofSetBackgroundAuto(false);

But thanks anyway =)

The next problem is blending colors, but that is a later problem when I’m heading into shaders