I bet this is one of those "oh man that was simple" things.. I have a RECT which I use to draw an ellipse (not necessarilly circle). my ellipse gets drag handles on the north/east/south/west edges and I determine those simply with the mid position of the sides of the RECT.
How can I calculate the x/y coordinates of the "corners of the circle" - that is, the NE, SE, SW and NW points along the circumference? Conceptually, if I could take that same RECT and rotate it 45deg I could then simply take the center points again, and that would give me the corners along the circumference.
but how do I rotate a rect?