Method for Unity to get angle using a start and end points. Code can be improve.

gistfile1.cs

  private float GetAngleFromPosition(float x1, float y1, float x2, float y2){
 		float o = 0;
		float a = 0;
		bool doingA = false;
		bool doingB = false;
		bool doingC = false;
		bool doingD = false;

		if(x1 >= x2 && y1 <= y2){//set for A
			o = x1 - x2;
			a = y2 - y1;
			doingA = true;
		}else if(x1 >= x2 && y1 >= y2) { // set for B
			a = x1 - x2;
			o = y1 - y2;
			doingB = true;
		}else if(x1 <= x2 && y1 >= y2){//set for C
			o = x2 - x1;
			a = y1 - y2;
			doingC = true;
		}else if( x1 <= x2 && y1 <= y2){//set for D 
			o = y2 - y1;
			a = x2 -x1;
			doingD = true;
		}

//		print("o: " + o);
//		print("a: " + a);

		float angle = Mathf.Rad2Deg*Mathf.Atan(o / a);
		angle = Mathf.Ceil(angle);
		
		if(doingB){ angle += 90; }
		else if (doingC) { angle += 180; }		
		else if (doingD) { angle += 270; }

		return angle;
	}