www.pudn.com > MobiCraft_src.rar > MyMath.java

// style: tabs, tabsize=4, style=ANSI 
//+----------------------------------------------------------------------+ 
// Copyleft 2007. MobiCraft Team. GNU GPL license. 
// Made by Andrew Denisov and Zahar Semenov 
//+----------------------------------------------------------------------+ 
// Filename: MyMath.java 
//+----------------------------------------------------------------------+ 
// Comment: Math in "int" numbers. 
// Based on DieWorld's code. Thanks to him for it. 
//+----------------------------------------------------------------------+ 
 
package app; 
 
public class MyMath 
{ 
	//значение синусов и квадратов синусов для углов от 0 до 89 градусов 
	private final static int sinval[] = 
	{ 
		  0,  17,  35,  52,  70,  87, 105, 122, 139, 156, 
		174, 191, 208, 225, 242, 259, 276, 292, 309, 326, 
		342, 358, 375, 391, 407, 423, 438, 454, 469, 485, 
		500, 515, 530, 545, 559, 574, 588, 602, 616, 629, 
		643, 656, 669, 682, 695, 707, 719, 731, 743, 755, 
		766, 777, 788, 799, 809, 819, 829, 839, 848, 857, 
		866, 875, 883, 891, 899, 906, 914, 921, 927, 934, 
		940, 946, 951, 956, 961, 966, 970, 974, 978, 982, 
		985, 988, 990, 993, 995, 996, 998, 999, 999, 1000}; 
	private final static int sin2val[] ={0, 305, 1218, 2739, 4866, 7596, 10926, 14852, 19369, 24472, 30154, 36408, 43227, 50603, 58526, 66987, 75976, 85481, 95491, 105995, 116978, 128428, 140330, 152671, 165435, 178606, 192169, 206107, 220404, 235040, 250000, 265264, 280814, 296632, 312697, 328990, 345491, 362181, 379039, 396044, 413176, 430413, 447736, 465122, 482550, 500000, 517450, 534878, 552264, 569587, 586824, 603956, 620961, 637819, 654508, 671010, 687303, 703368, 719186, 734736, 750000, 764960, 779596, 793893, 807831, 821394, 834565, 847329, 859670, 871572, 883022, 894005, 904508, 914519, 924024, 933013, 941474, 949397, 956773, 963592, 969846, 975528, 980631, 985148, 989074, 992404, 995134, 997261, 998782, 999695}; 
 
 
	// Синус. аргумент передаётся в градусах. MyMath.wsin(x) = 1000*Math.sin(x/180*PI) 
	public static int wsin(int arg)  
	{ 
		int q = 1; 
		if (arg < 0) {arg = -arg; q = -1;} 
		while (arg >= 360) {arg -= 360;} 
		if (arg >= 0 && arg < 90)    {return q*sinval[arg];} 
		if (arg >= 90 && arg < 180)  {return q*sinval[179 - arg];} 
		if (arg >= 180 && arg < 270) {return -q*sinval[arg - 180];} 
		if (arg >= 270 && arg < 360) {return -q*sinval[359 - arg];} 
		return 1001; 
	} 
	// Косинус 
	public static int wcos(int arg)  
	{ 
		return wsin(90 - arg);  
	} 
	// Тангенс 
	public static int wtg(int arg) 
	{ 
		return wsin(arg)/wcos(arg); 
	} 
 
	// Котангенс 
	public static int wctg(int arg) 
	{ 
		return wcos(arg)/wsin(arg); 
	} 
	// Точный угол по двум катетам 0..360; 361, если х=у=0  
	public static int wangle(int x, int y)  
	{ 
		long wx = x; 
		long wy = y; 
		if (x == 0 && y == 0) {	return 361;} 
		 
		long katet2 = (10000*wy*wy); 
		long hypo2 = (wx*wx + wy*wy); 
		long sin2a = (katet2 / hypo2); 
		sin2a *= 100; 
		int alpha = 0; 
		int i; 
		for (i = 0; i < 89; i++) 
		{ 
			if (sin2a >= sin2val[i] && sin2a <= sin2val[i+1]) 
			{ 
				alpha = i; 
				break; 
			} 
		} 
		 
		if (alpha == 0 && i == 89) { 
			alpha = 90; 
		} 
		 
		//alpha = 90 - alpha; 
		 
		if (x >= 0 && y >= 0){ 
			return alpha; 
		} 
		if (x < 0 && y >= 0){ 
			return 180 - alpha; 
		} 
		if (x < 0 && y < 0){ 
			return 180 + alpha; 
		} 
		if (x >= 0 && y < 0){ 
			return 360 - alpha; 
		} 
			 
		return 361; 
	} 
	 
	// Квадратный корень 
	public static int sqrt(int iX) 
	{ 
		int iGuess = 0; 
		int iBit = 0x8000; 
		int iBitShift = 15; 
		do 
		{ 
			// 2*Bit*Guess + Bit^2 
			int iForwardGuess = (iGuess + iGuess + iBit) << iBitShift; 
			// Verify if the bit should be toggled or not 
			if (iX >= iForwardGuess) 
			{ 
				iGuess |= iBit; 
				iX -= iForwardGuess; 
			} 
			iBitShift--; 
			iBit >>= 1; 
		} 
		while (iBit != 0); 
		return iGuess; 
	} 
/*	 
	// Квадратный корень в целых числах 
	public static int sqrt(int L) 
	{ 
		int div, rslt = L; 
		if (L <= 0) 
			return 0; 
		else if ((L & 0xFFFF0000) != 0) 
			if ((L & 0xFF000000) != 0) 
				div = 0x3FFF; 
			else 
				div = 0x7FF; 
		else if ((L & 0x0FF00) != 0) 
			div = 0x3F; 
		else 
			div = 0x7; 
		while (true) 
		{ 
			div = div + L / div; 
			div = (div & 1) + (div >> 1); 
			if (rslt > div) 
				rslt = div; 
			else 
			{ 
				if (L / rslt == rslt - 1 && L % rslt == 0) 
					rslt--; 
				return rslt; 
			} 
		} 
	} 
*/ 
	public static int sgn(int i) 
	{ 
		if (i > 0) 
			return 1; 
		if (i < 0) 
			return -1; 
		return 0; 
	} 
 
	public static int abs(int i) 
	{ 
		if (i < 0) 
			return -i; 
		else 
			return i; 
	} 
 
	public static int min(int i, int j) 
	{ 
		if (i < j) 
			return i; 
		else 
			return j; 
	} 
	public static int max(int i, int j) 
	{ 
		if (i > j) 
			return i; 
		else 
			return j; 
	} 
 
	// Степень. i^power 
	public static int power(int i, int power) 
	{ 
		int k = i; 
		for (int z = 0; z < power; z++) 
			k*=i; 
		return k; 
	}	                
}