Using ofGraphics functions on images

Is there a way to use those functions ( in ofGraphics i.e. ofCircle ) on images ??
I would be thankfull if it would be even another object that isn’t image but I could access pixel data and send them to image .

you can draw a image on to the screen,
then you can draw a circle or what ever shape you like on top of that image,
then you grab the pixels from what you’ve drawn on the screen using grabScreen()…-grabScreen

think there is an example app provided with openframeworks distribution that shows you how to take a portion of the screen and use it as a texture.


I know I can do it that way ,but I need a method to do this without drawing on screen. My point is that I want to avoid any flickering or other un wanted effects from using grabScreen ( I can do a fast image draw,draw shape , grabscreen and skip 1 frame forward )

You can use FBOs (search the forum) to draw into an offscreen buffer, or use some other liraries, such as Antigrain Geometry ( or perhaps cairo (