org.pepsoft.util.MathUtils Maven / Gradle / Ivy
The newest version!
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package org.pepsoft.util;
import javax.vecmath.Vector3d;
/**
*
* @author pepijn
*/
public final class MathUtils {
private MathUtils() {
// Prevent instantiation
}
/**
* Positive integer powers.
*/
public static int pow(int x, int y) {
if ((x >= 0) && (x < 50) && (y >= 0) && (y < 50)) {
return INTEGER_POWERS[x][y];
} else {
switch (y) {
case 0:
return 1;
case 1:
return x;
case 2:
return x * x;
case 3:
return x * x * x;
default:
if (y < 0) {
throw new IllegalArgumentException("y " + y + " < 0");
} else {
for (int i = 1; i < y; i++) {
x *= x;
}
return x;
}
}
}
}
/**
* Calculates x modulo y. This is different than the Java remainder operator
* (%) in that it always returns a positive value.
*
* @param a The operand.
* @param b The modulus.
* @return x modulo y
*/
public static float mod(float a, float b) {
if (a < 0) {
return a + (float) Math.ceil(-a / b) * b;
} else if (a >= b) {
return a - (float) Math.floor(a / b) * b;
} else {
return a;
}
}
/**
* Calculates x modulo y. This is different than the Java remainder operator
* (%) in that it always returns a positive value.
*
* @param a The operand.
* @param b The modulus.
* @return x modulo y
*/
public static double mod(double a, double b) {
if (a < 0) {
return a + Math.ceil(-a / b) * b;
} else if (a >= b) {
return a - Math.floor(a / b) * b;
} else {
return a;
}
}
/**
* Calculates x modulo y. This is different than the Java remainder operator
* (%) in that it always returns a positive value.
*
* @param a The operand.
* @param b The modulus.
* @return x modulo y
*/
public static int mod(int a, int b) {
if (a < 0) {
return (a % b + b) % b;
} else {
return a % b;
}
}
/**
* Calculates the distance between two points in two dimensional space. Uses
* a lookup table for distances below 300 for speed.
*
* @param x1 The X coordinate of the first point.
* @param y1 The Y coordinate of the first point.
* @param x2 The X coordinate of the second point.
* @param y2 The Y coordinate of the second point.
* @return The distance between the two points.
*/
public static float getDistance(int x1, int y1, int x2, int y2) {
return getDistance(x2 - x1, y2 - y1);
}
/**
* Calculates the distance between two points in three dimensional space.
* Uses a lookup table for distances below 50 for speed.
*
* @param x1 The X coordinate of the first point.
* @param y1 The Y coordinate of the first point.
* @param z1 The Z coordinate of the first point.
* @param x2 The X coordinate of the second point.
* @param y2 The Y coordinate of the second point.
* @param z2 The Z coordinate of the second point.
* @return The distance between the two points.
*/
public static float getDistance(int x1, int y1, int z1, int x2, int y2, int z2) {
return getDistance(x2 - x1, y2 - y1, z2 - z1);
}
/**
* Calculates the distance between two points. Uses a lookup table for
* distances below 300 for speed.
*
* @param dx The difference along the x axis between the two points.
* @param dy The difference along the y axis between the two points.
* @return The distance between the two points.
*/
public static float getDistance(int dx, int dy) {
dx = Math.abs(dx);
dy = Math.abs(dy);
if ((dx <= 300) && (dy <= 300)) {
return DISTANCES_2D[dx][dy];
} else {
return (float) Math.sqrt(dx * dx + dy * dy);
}
}
/**
* Calculates the distance between two points in 2D space.
*
* @param dx The difference along the x axis between the two points.
* @param dy The difference along the y axis between the two points.
* @return The distance between the two points.
*/
public static float getDistance(float dx, float dy) {
return (float) Math.sqrt(dx * dx + dy * dy);
}
/**
* Calculates the distance between two points in 3D space.
*
* @param dx The difference along the x axis between the two points.
* @param dy The difference along the y axis between the two points.
* @param dz The difference along the z axis between the two points.
* @return The distance between the two points.
*/
public static float getDistance(float dx, float dy, float dz) {
final double d = Math.sqrt(dx * dx + dy * dy);
return (float) Math.sqrt(d * d + dz * dz);
}
/**
* Calculates the distance between two points in 3D space.
*
* @param dx The difference along the x axis between the two points.
* @param dy The difference along the y axis between the two points.
* @param dz The difference along the z axis between the two points.
* @return The distance between the two points.
*/
public static double getDistance(double dx, double dy, double dz) {
final double d = Math.sqrt(dx * dx + dy * dy);
return Math.sqrt(d * d + dz * dz);
}
public static float getDistance(int dx, int dy, int dz) {
dx = Math.abs(dx);
dy = Math.abs(dy);
dz = Math.abs(dz);
if ((dx <= 50) && (dy <= 50) && (dz <= 50)) {
return DISTANCES_3D[dx][dy][dz];
} else {
return (float) Math.sqrt(dx * dx + dy * dy + dz * dz);
}
}
public static int clamp(int min, int value, int max) {
return (value < min) ? min : ((value > max) ? max : value);
}
public static float clamp(float min, float value, float max) {
return (value < min) ? min : ((value > max) ? max : value);
}
public static double clamp(double min, double value, double max) {
return (value < min) ? min : ((value > max) ? max : value);
}
/**
* Rotate a vector counterclockwise around an axis.
*
* @param vector The vector to rotate.
* @param axis The axis around which to rotate it.
* @param angle How many radians to rotate it counterclockwise.
* @return The rotated vector.
*/
public static Vector3d rotateVectorCC(Vector3d vector, Vector3d axis, double angle){
double x = vector.x, y = vector.y, z = vector.z;
double u = axis.x, v = axis.y, w = axis.z;
double cosAngle = Math.cos(angle);
double sinAngle = Math.sin(angle);
double product = u * x + v * y + w * z;
double xPrime = u * product * (1d - cosAngle) + x * cosAngle + (-w * y + v * z) * sinAngle;
double yPrime = v * product * (1d - cosAngle) + y * cosAngle + (w * x - u * z) * sinAngle;
double zPrime = w * product * (1d - cosAngle) + z * cosAngle + (-v * x + u * y) * sinAngle;
return new Vector3d(xPrime, yPrime, zPrime);
}
/**
* Calculates the shortest distance of a point to a line segment.
*
* @param px The X coordinate of the point.
* @param py The Y coordinate of the point.
* @param vx The X coordinate of the start of the line segment.
* @param vy The Y coordinate of the start of the line segment.
* @param wx The X coordinate of the end of the line segment.
* @param wy The Y coordinate of the end of the line segment.
* @return The shortest distance of the specified point to the specified
* line segment.
*/
public static double distanceToLineSegment(int px, int py, int vx, int vy, int wx, int wy) {
return Math.sqrt(distToSegmentSquared(px, py, vx, vy, wx, wy));
}
private static double dist2(double x1, double y1, double x2, double y2) {
return (x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2);
}
private static double distToSegmentSquared(long vx, long vy, long wx, long wy, long px, long py) {
double l2 = dist2(vx, vy, wx, wy);
if (l2 == 0) {
return dist2(px, py, vx, vy);
}
double t = ((px - vx) * (wx - vx) + (py - vy) * (wy - vy)) / l2;
t = Math.max(0, Math.min(1, t));
return dist2(px, py, vx + t * (wx - vx), vy + t * (wy - vy));
}
public static final double TWO_PI = Math.PI * 2;
private static final float[][] DISTANCES_2D = new float[301][301];
private static final float[][][] DISTANCES_3D = new float[51][51][51];
private static final int[][] INTEGER_POWERS = new int[50][50];
static {
for (int dx = 0; dx <= 300; dx++) {
for (int dy = 0; dy <= 300; dy++) {
DISTANCES_2D[dx][dy] = (float) Math.sqrt(dx * dx + dy * dy);
}
}
for (int dx = 0; dx <= 50; dx++) {
for (int dy = 0; dy <= 50; dy++) {
for (int dz = 0; dz <= 50; dz++) {
DISTANCES_3D[dx][dy][dz] = (float) Math.sqrt(dx * dx + dy * dy + dz * dz);
}
}
}
for (int x = 0; x < 50; x++) {
for (int y = 0; y < 50; y++) {
long n = 1;
for (int i = 0; i < y; i++) {
n *= x;
if (n > Integer.MAX_VALUE) {
n = Integer.MAX_VALUE;
break;
}
}
INTEGER_POWERS[x][y] = (int) n;
}
}
}
}© 2015 - 2025 Weber Informatics LLC | Privacy Policy