Good graphical math sources?

I'm starting to learning about drawing circles, waves etc. using OpenGL and it involves some math to draw these stuffs and I want to know if there is any source that explains how these things work. For example, this is code for drawing circle.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
void drawCircle(float cx, float cy, float r, float num_segments){
	glBegin(GL_LINE_LOOP);

	for(int i = 0; i < num_segments; i++){
                float theta = 2.0f * PI * i / num_segments;

		float x = r * cosf(theta);
		float y = r * sinf(theta);

		glVertex2f(x + cx, y + cy);
	}

	glEnd();
}


This draw a circle but I want to know how it works. Is there any websites/videos that explains how these stuffs work?
Topic archived. No new replies allowed.