/* 
	StepperTable.java
	creates a text file containg a formated int array
	
	The array values correspond to the slope of 90 deg of a sine wave
*/

import javax.swing.*;
import java.io.*;
import java.util.*;

public class DiffTable{
	public static void main(String[] args){
		
		Scanner in = new Scanner(System.in);		// console input
		PrintWriter out = null;						// file output stream
		File file = new File( "./sinescale.txt" );	// file name
		
		if( file == null ) System.exit(1);			// error
		else System.out.println(file.getName());	// print file name to console
		
		try
		{
			out = new PrintWriter(file);
		}
		catch( FileNotFoundException e )
		{
			System.err.println( e );
			System.exit(1);
		}
		
		int table_size = 64;						// default table size
		String table_name = "sine";					// default array name
				
		try
		{	// get user input
//			System.out.print("Enter table name: ");
//			table_name = in.next();
//			System.out.println(table_name);
			System.out.print("Enter table size: ");
			table_size = in.nextInt();
			System.out.println(table_size);
		}
		catch(	InputMismatchException e )
		{
			System.err.println( e );
			System.exit(1);
		}
		catch(	NoSuchElementException e )
		{
			System.err.println( e );
			System.exit(1);
		}

		// internal array: table[i] = {angle, sin(angle), slope}
		double table[][] = new double[table_size][3];	
		
		// calculate 90 degrees of a sine table
		for(int i = 0; i < table_size; i++)
		{
			table[i][0] = Math.toRadians(i * 90 / (table_size - 1)); // angle in degrees
			table[i][1] = Math.sin( table[i][0] );
			if( i > 0 )
			{
				table[i][2] = (table[i][1] - table[i-1][1]) / (table[i][0] - table[i-1][0]);
				if( Double.isNaN( table[i][2] ) )
					table[i][2] = table[i-1][2];
			}
			else
				table[i][2] = 1;
		}
		
		//print the table
		out.print("PROGMEM prog_uint16_t " + table_name + "[] = " + "{");
		for( int i = 0; i < table_size; i++)
		{
			int x = (int)Math.round( (1 / table[i][2]) );
			System.out.println( table[i][0] +"\t"+ table[i][1] +"\t"+ table[i][2] +
								"\t" + (1 / table[i][2]) +"\t"+ x );
			out.print( x );
			if( table_size - i > 1 )
				out.print(", ");
		}
		out.println("};");
		out.close();
	}
	
	// not used
//	static File fileChooser()
//	{
//		JFileChooser fc = new JFileChooser("./init");
//		int v = fc.showSaveDialog(null);
//		if( v == fc.APPROVE_OPTION)
//			return fc.getSelectedFile();
//		else
//			return null;
//	}
}