source: java/client_3D/src/pl/vorg/mowa/core/graphics/Vec2.java @ 66

package pl.vorg.mowa.core.graphics;

/**
 * A vector in 2d space.
 * 
 * @author vorg
 */
public class Vec2 {
        private float[] v = {0,0};
        
        public Vec2() {
                
        }
        
        public Vec2(float x, float y) {
                v[0] = x;
                v[1] = y;
        }
        
        public Vec2(Vec2 vec) {
                float[] w = vec.getVector();
                v[0] = w[0];
                v[1] = w[1];
        }
        
        public Vec2(float[] vec) {
                v[0] = vec[0];
                v[1] = vec[1];
        }
        
        @Override
        public boolean equals(java.lang.Object obj) {
                float[] w = ((Vec2)obj).getVector();
                return (v[0] == w[0]) && (v[1] == w[1]); 
        }
        
        public float getX() {
                return v[0];
        }
        
        public float getY() {
                return v[1];
        }
        
        public float getS() {
                return v[0];
        }
        
        public float getT() {
                return v[1];
        }
        
        public void setX(float x) {
                v[0] = x;
        }
        
        public void setY(float y) {
                v[1] = y;
        }
        
        public void setS(float s) {
                v[0] = s;
        }
        
        public void setT(float t) {
                v[1] = t;
        }
        
        public float[] getVector() {
                return v;
        }
        
        public void normalize() {
                float length = length();
                if (length > 0) {
                        v[0] /= length;
                        v[1] /= length;
                }
        }
        
        public float length() {
                return (float)Math.sqrt(v[0]*v[0]+v[1]*v[1]);
        }
        
        public float dot(Vec2 a) {
                float[] va = a.getVector();
                return v[0]*va[0] + v[1]*va[1];
        }
        
        public float angle(Vec2 a) {
                float len = length();
                float alen = a.length();
                if ((len == 0) || (alen == 0)) {
                        return 0;
                }
                return (float)Math.acos(this.dot(a)/(len*alen));
        }
        
        public static float angle(Vec2 a, Vec2 b) {
                return a.angle(b);
        }
        
        public static float angleTan(Vec2 a, Vec2 b) {
                double angle = Math.atan2(a.getY(),a.getX()) - Math.atan2(b.getY(),b.getX());
                return (float)angle;
        }
}