vector3d.java

java写的3D程序,src目录下有其源程序.

package myprojects.graph3dapp;

class Vector3d {
	public double x, y, z, h; //(x, y, z)通常表示坐标，h用于齐次坐标相乘，并保持为1
	
	Vector3d() {
		x = 0;		y = 0;
		z = 0;		h = 1;
	}
	
	Vector3d(double x, double y, double z) {
		this.x = x;		this.y = y;
		this.z = z;		this.h = 1;
	}
	
	Vector3d(double vector[]) {
		x = vector[0];	y = vector[1];
		z = vector[2];	h = 1;
	}
	
	Vector3d(Vector3d v) {
		this.x = v.x;		this.y = v.y;
		this.z = v.z;		this.h = 1;
	}
	
	public void add(Vector3d v) {
		x += v.x;
		y += v.y;
		z += v.z;	
	}
	
	public static Vector3d add(Vector3d v0, Vector3d v1) {
		return new Vector3d(v0.x+v1.x, v0.y+v1.y, v0.z+v1.z);	
	}
	
	public void sub(Vector3d v) {
		x -= v.x;
		y -= v.y;
		z -= v.z;	
	}
	
	public static Vector3d sub(Vector3d v0, Vector3d v1) {
		return new Vector3d(v0.x-v1.x, v0.y-v1.y, v0.z-v1.z);	
	}
	
	public void negate() {
		x = -x;		y = -y;
		z = -z;		
	}
	
	public static Vector3d negate(Vector3d v) {
		return new Vector3d(-v.x, -v.y, -v.z);
	}
	
	public double dot(Vector3d v) {
		return x*v.x + y*v.y + z*v.z;
	}
	
	public void cross(Vector3d v) {
		x = y*v.z - z*v.y;
		y = z*v.x - x*v.z;
		z = x*v.y - y*v.x;
	}
	
	public static Vector3d cross(Vector3d v0, Vector3d v1) {
		return new Vector3d(v0.y*v1.z - v0.z*v1.y,
							v0.z*v1.x - v0.x*v1.z,
							v0.x*v1.y - v0.y*v1.x);
	}
	
	public double length() {
		return (double)Math.sqrt(x*x + y*y + z*z);
	}
	
	public void normalize() {
		double length = length();
		
		x /= length;	y /= length;	z /= length;
	}
	
	public static Vector3d normalize(Vector3d v) {
		double length = v.length();
		
		return new Vector3d(v.x/length, v.y/length, v.z/length);
	}
	
	public void scale(double s) {
		x *= s;		y *= s;		z *= s;
	}
	
	public static Vector3d scale(Vector3d v, double s) {
		return new Vector3d(v.x*s, v.y*s, v.z*s);
	}
	
	public void mulMatrix(Matrix3d m) {
		Vector3d vr = new Vector3d();
		vr.x = x*m.matrix[0][0] + y*m.matrix[1][0] + 
			   z*m.matrix[2][0] + h*m.matrix[3][0];	
		vr.y = x*m.matrix[0][1] + y*m.matrix[1][1] + 
			   z*m.matrix[2][1] + h*m.matrix[3][1];	
		vr.z = x*m.matrix[0][2] + y*m.matrix[1][2] + 
			   z*m.matrix[2][2] + h*m.matrix[3][2];	
		vr.h = x*m.matrix[0][3] + y*m.matrix[1][3] + 
			   z*m.matrix[2][3] + h*m.matrix[3][3];	
		if(vr.h < 0.0005f) vr.h = 0.0005f;
		x = vr.x/vr.h;		y = vr.y/vr.h;
		z = vr.z/vr.h;		h = 1;
	}
	
	public static Vector3d mulMatrix(Vector3d v, Matrix3d m) {
		Vector3d vr = new Vector3d();
		vr.x = v.x*m.matrix[0][0] + v.y*m.matrix[1][0] + 
			   v.z*m.matrix[2][0] + v.h*m.matrix[3][0];	
		vr.y = v.x*m.matrix[0][1] + v.y*m.matrix[1][1] + 
			   v.z*m.matrix[2][1] + v.h*m.matrix[3][1];	
		vr.z = v.x*m.matrix[0][2] + v.y*m.matrix[1][2] + 
			   v.z*m.matrix[2][2] + v.h*m.matrix[3][2];	
		vr.h = v.x*m.matrix[0][3] + v.y*m.matrix[1][3] + 
			   v.z*m.matrix[2][3] + v.h*m.matrix[3][3];	
		if(vr.h < 0.0005f) vr.h = 0.0005f;
		vr.x /= vr.h;		vr.y /= vr.h;
		vr.z /= vr.h;		vr.h = 1;
		return vr;
	}
	
	public String toString() {
		return 	String.valueOf(x)+", "+String.valueOf(y)+", "+
				String.valueOf(z)+", "+String.valueOf(h);
	}
}