001    package net.minecraft.src;
002    
003    import cpw.mods.fml.common.Side;
004    import cpw.mods.fml.common.asm.SideOnly;
005    import java.util.Random;
006    
007    public class MathHelper
008    {
009        /**
010         * A table of sin values computed from 0 (inclusive) to 2*pi (exclusive), with steps of 2*PI / 65536.
011         */
012        private static float[] SIN_TABLE = new float[65536];
013    
014        /**
015         * sin looked up in a table
016         */
017        public static final float sin(float par0)
018        {
019            return SIN_TABLE[(int)(par0 * 10430.378F) & 65535];
020        }
021    
022        /**
023         * cos looked up in the sin table with the appropriate offset
024         */
025        public static final float cos(float par0)
026        {
027            return SIN_TABLE[(int)(par0 * 10430.378F + 16384.0F) & 65535];
028        }
029    
030        public static final float sqrt_float(float par0)
031        {
032            return (float)Math.sqrt((double)par0);
033        }
034    
035        public static final float sqrt_double(double par0)
036        {
037            return (float)Math.sqrt(par0);
038        }
039    
040        /**
041         * Returns the greatest integer less than or equal to the float argument
042         */
043        public static int floor_float(float par0)
044        {
045            int var1 = (int)par0;
046            return par0 < (float)var1 ? var1 - 1 : var1;
047        }
048    
049        @SideOnly(Side.CLIENT)
050    
051        /**
052         * returns par0 cast as an int, and no greater than Integer.MAX_VALUE-1024
053         */
054        public static int truncateDoubleToInt(double par0)
055        {
056            return (int)(par0 + 1024.0D) - 1024;
057        }
058    
059        /**
060         * Returns the greatest integer less than or equal to the double argument
061         */
062        public static int floor_double(double par0)
063        {
064            int var2 = (int)par0;
065            return par0 < (double)var2 ? var2 - 1 : var2;
066        }
067    
068        /**
069         * Long version of floor_double
070         */
071        public static long floor_double_long(double par0)
072        {
073            long var2 = (long)par0;
074            return par0 < (double)var2 ? var2 - 1L : var2;
075        }
076    
077        public static float abs(float par0)
078        {
079            return par0 >= 0.0F ? par0 : -par0;
080        }
081    
082        public static int abs_int(int par0)
083        {
084            return par0 >= 0 ? par0 : -par0;
085        }
086    
087        public static int ceiling_float_int(float par0)
088        {
089            int var1 = (int)par0;
090            return par0 > (float)var1 ? var1 + 1 : var1;
091        }
092    
093        public static int ceiling_double_int(double par0)
094        {
095            int var2 = (int)par0;
096            return par0 > (double)var2 ? var2 + 1 : var2;
097        }
098    
099        /**
100         * Returns the value of the first parameter, clamped to be within the lower and upper limits given by the second and
101         * third parameters.
102         */
103        public static int clamp_int(int par0, int par1, int par2)
104        {
105            return par0 < par1 ? par1 : (par0 > par2 ? par2 : par0);
106        }
107    
108        @SideOnly(Side.CLIENT)
109    
110        /**
111         * Returns the value of the first parameter, clamped to be within the lower and upper limits given by the second and
112         * third parameters
113         */
114        public static float clamp_float(float par0, float par1, float par2)
115        {
116            return par0 < par1 ? par1 : (par0 > par2 ? par2 : par0);
117        }
118    
119        /**
120         * Maximum of the absolute value of two numbers.
121         */
122        public static double abs_max(double par0, double par2)
123        {
124            if (par0 < 0.0D)
125            {
126                par0 = -par0;
127            }
128    
129            if (par2 < 0.0D)
130            {
131                par2 = -par2;
132            }
133    
134            return par0 > par2 ? par0 : par2;
135        }
136    
137        @SideOnly(Side.CLIENT)
138    
139        /**
140         * Buckets an integer with specifed bucket sizes.  Args: i, bucketSize
141         */
142        public static int bucketInt(int par0, int par1)
143        {
144            return par0 < 0 ? -((-par0 - 1) / par1) - 1 : par0 / par1;
145        }
146    
147        @SideOnly(Side.CLIENT)
148    
149        /**
150         * Tests if a string is null or of length zero
151         */
152        public static boolean stringNullOrLengthZero(String par0Str)
153        {
154            return par0Str == null || par0Str.length() == 0;
155        }
156    
157        public static int getRandomIntegerInRange(Random par0Random, int par1, int par2)
158        {
159            return par1 >= par2 ? par1 : par0Random.nextInt(par2 - par1 + 1) + par1;
160        }
161    
162        public static double average(long[] par0ArrayOfLong)
163        {
164            long var1 = 0L;
165            long[] var3 = par0ArrayOfLong;
166            int var4 = par0ArrayOfLong.length;
167    
168            for (int var5 = 0; var5 < var4; ++var5)
169            {
170                long var6 = var3[var5];
171                var1 += var6;
172            }
173    
174            return (double)var1 / (double)par0ArrayOfLong.length;
175        }
176    
177        /**
178         * the angle is reduced to an angle between -180 and +180 by mod, and a 360 check
179         */
180        public static float wrapAngleTo180_float(float par0)
181        {
182            par0 %= 360.0F;
183    
184            if (par0 >= 180.0F)
185            {
186                par0 -= 360.0F;
187            }
188    
189            if (par0 < -180.0F)
190            {
191                par0 += 360.0F;
192            }
193    
194            return par0;
195        }
196    
197        /**
198         * the angle is reduced to an angle between -180 and +180 by mod, and a 360 check
199         */
200        public static double wrapAngleTo180_double(double par0)
201        {
202            par0 %= 360.0D;
203    
204            if (par0 >= 180.0D)
205            {
206                par0 -= 360.0D;
207            }
208    
209            if (par0 < -180.0D)
210            {
211                par0 += 360.0D;
212            }
213    
214            return par0;
215        }
216    
217        static
218        {
219            for (int var0 = 0; var0 < 65536; ++var0)
220            {
221                SIN_TABLE[var0] = (float)Math.sin((double)var0 * Math.PI * 2.0D / 65536.0D);
222            }
223        }
224    }