Have you ever dreamed of rotating points around other points by amounts? Have you also or instead dreamt of drawing a smooth curve between two points the l̶a̶z̶y̶ lazy way? Do you use Unity3D with C#? Then boy do I have a deal for you

gistfile1.txt

using UnityEngine;
using System.Collections;

public class SmoothCurveDraw : MonoBehaviour {

    	public Vector2 curveStart;
	public float curveAngle = 90;
	public int smoothValue = 1;
	public Color rayColor = Color.blue;

	void Update() {
		
		//clamp between zero and 180 because Vector2.Angle doesn't return anything above 180
		//getting around this using a third vector is messy and weird but possible
		curveAngle = Mathf.Clamp(curveAngle, 0, 180);
		
		//draws a curve between the starting point you supply and the angle of the curve
		//as rotated around a pivot point which you also supply
		//by a smoothing value between 0 and 3 which you supply again
		Vector2 endPos = rotatePointAroundPoint(curveStart, Vector2.zero, curveAngle);

		//if smoothness is too high bad things happen
		smoothValue = Mathf.Clamp(smoothValue, 0, 3);

		//no smoothing is pretty straight so just do it here (0 is actually first level smoothing in the draw function below)
		if (smoothValue == 0)
			Debug.DrawRay(curveStart, endPos - curveStart, rayColor);
		else 
			drawCurveBetweenPoints(curveStart, endPos, Vector2.zero, (float)smoothValue-1);
	}

	//this function draws the curve between two points and therefore is named aptly
	void drawCurveBetweenPoints(Vector2 p1, Vector2 p2, Vector2 pivot, float smoothness) {

		Vector2 midpoint = rotatePointAroundPoint(p1, pivot, Vector2.Angle(p1,p2)/2);

		//the idea is splitting it in two every time, and it takes an int, so:
		smoothness -= 0.5f;

		//done smoothing
		if (smoothness < 0) {
			Debug.DrawRay(p1, midpoint-p1, rayColor);
			Debug.DrawRay(midpoint, p2-midpoint, rayColor);
			return;
		}

		//recursion is here
		drawCurveBetweenPoints(p1, midpoint, pivot, smoothness);
		drawCurveBetweenPoints(midpoint, p2, pivot, smoothness);
	}

	//rotates point p1 around a pivot point (p2) by a rotation angle
	Vector2 rotatePointAroundPoint(Vector2 p1, Vector2 p2, float rotAngle) {

		//math
		rotAngle *= Mathf.Deg2Rad;
		return new Vector2 ((Mathf.Cos(-rotAngle) * (p1.x - p2.x)  + 
							 Mathf.Sin(-rotAngle) * (p1.y - p2.y)) + p2.x,
							(Mathf.Sin(-rotAngle) * (p2.x - p1.x)  - 
							 Mathf.Cos(-rotAngle) * (p2.y - p1.y)) + p2.y);
	}
}