If you understand objective c very well, then just read the last 2 sentences. The rest of this just summarizes the last 2 sentances:
So I have two sprites, the lower arm and the upper arm. I set the anchor points to ccp(0.5f,0.0f) So lets say that the following dashes represent the lower arm, the anchorpoint is the dash in parenthesis: (-)------ . So the object is rotating around this point (the CGPoint at the moment is ccp(100,55)).
What I need is, if the lower arm is rotating around the dash in parenthesis: (-)-----o the circle represents the point I want. I'm basically connecting the two arms and trying to make the movement look nice... Both arms are 17 pixels long (which means that if the lower arm is pointing straight up, the CGPoint of the circle is ccp(100,72), and if the arm was pointing straight down, the circle would be ccp(100,38).
What equation would I use so that I could set the position of the upper arm equal to the position of the lower arm's rotating CGPoint, represented as a circle in the 2nd paragraph of this question. Like... _,/ the _ represents the lower arm, the comma represents the point I want, and the / represent the upper arm.
So lower and upper arm = 17 pixels long, anchor point for both is (0.5f,0.0f), how do I find the point opposite of the anchor point for the lower arm.
x = 100 + 17 * cos(θ)
y = 55 + 17 * sin(θ)