Creating the trigonometric functions

Trig class

A class that contains the trigonometric functions used by the application for the environmental 3D audio.

1. Create the Trig class file.

2. Import the required classes.

   package com.nokia.mid.mansion;
   
   

3. Create the Trig class and define the trigonometric function estimates.

   /**
    * Trigonometrical function estimates.
    *
    */
   public class Trig{
       private final static int SIN[]=
       {   
   		0, 174, 342, 500, 643, 766, 866, 940, 985, 1000, 985, 940, 866, 766,
   		643, 500, 342, 174, 0, -174, -342, -500, -643, -766, -866, -940, -985,
   		-1000, -985, -940, -866, -766, -643, -500, -342, -174 
   	};
   
       private final static int COS[]= 
       {
   		1000, 985, 940, 866, 766, 643, 500, 342, 174, 0, -174, -342, -500, -643,
   		-766, -866, -940, -985, -1000, -985, -940, -866, -766, -643, -500, -342,
   		-174, 0, 174, 342, 500, 643, 766, 866, 940, 985 
   	};
   
   

4. Create the Sine and Cosine estimator methods.

       /**
        * Sine estimator
        *
        * @param alpha in deci-degrees, between 0 and 35
        * @return in thousandths
        */
       private static int sin(int alpha) {
       	return SIN[alpha];
       }
       
       /**
        * Cosine estimator
        *
        * @param alpha in deci-degrees, between 0 and 35
        * @return in thousandths
        */
       private static int cos(int alpha) {
       	return COS[alpha];
       }  
   
   

5. Create methods for calculating the rotation for x and y coordinates.

       /**
        * Calculates the rotation
        *
        * @param theta in deci-degrees, between 0 and 35
        * @return new x 
        */
       public static int transX(int x, int y, int theta){
       	return (x * cos(theta) - y * sin(theta))/1000;
       }
   
       /**
        * Calculates the rotation
        *
        * @param theta in deci-degrees, between 0 and 35
        * @return new y
        */
       public static int transY(int x, int y, int theta){
   		// minus because of y-coordinate of the screen upside down(?)
   		return -(x * sin(theta) + y * cos(theta))/1000;
       }
   
   

6. Create methods for calculating the rotation for the screen x and y coordinates directly.

      /**
        * Calculates the rotation for the screen coordinates directly
        *
        * @param theta in deci-degrees, between 0 and 35
        * @return new x 
        */
       public static int transXS(int x, int y, int theta){
       	return -(x * cos(theta) - y * sin(theta))/50000;
       }
   
       /**
        * Calculates the rotation for the screen coordinates directly
        *
        * @param theta in deci-degrees, between 0 and 35
        * @return new y
        */
       public static int transYS(int x, int y, int theta){
   		// minus because of y-coordinate of the screen upside down(?)
   		return (x * sin(theta) + y * cos(theta))/50000;
       }
   }