I don't know how OCV works, I have never used it. Of course you can have multiple OpenGL windows. OGL link a rendering context to each window's device context, thus the OGL calls will redirect to...
If you want to draw something in the image you should use PhotoShop, OGL can't interact with other windows that aren't OGL ones, or if the application uses OGL for drawing maybe you can write a...
As Mitsukai said you can manipulate the pixels array of the image. If you do not want to see the image you can draw it at XY(-10000,-10000) and then read the pixels since glReadPixels need pixels...
I do not understand your code, what's that Draw(x, y)? What are x and y in that function? The center of draw? Anyway, try to call glLoadIdentity at the beginning of every shape.draw() and remove that...
Yves is right, I think your list is too much long, if you're not studying to implement new algorithms, analize them, solve math problems with innovative algorithms like Dr. Knuth did with "The art of...
Editors exist to semplify the life, imagine to create a monster by specify each vertex manually, it's impossible. Within the engine are implemented the algorithms to load and display levels,...