vector3f.java

java 3d game jme 工程开发源代码

     *            the y value to subtract.
     * @param subtractZ
     *            the z value to subtract.
     * @return the result vector.
     */
    public Vector3f subtract(float subtractX, float subtractY, float subtractZ) {
        return new Vector3f(x - subtractX, y - subtractY, z - subtractZ);
    }

    /**
     * <code>subtractLocal</code> subtracts the provided values from this vector
     * internally, and returns a handle to this vector for easy chaining of
     * calls.
     *
     * @param subtractX
     *            the x value to subtract.
     * @param subtractY
     *            the y value to subtract.
     * @param subtractZ
     *            the z value to subtract.
     * @return this
     */
    public Vector3f subtractLocal(float subtractX, float subtractY, float subtractZ) {
        x -= subtractX;
        y -= subtractY;
        z -= subtractZ;
        return this;
    }

    /**
     * <code>normalize</code> returns the unit vector of this vector.
     *
     * @return unit vector of this vector.
     */
    public Vector3f normalize() {
        float length = length();
        if (length != 0) {
            return divide(length);
        }
        
        return divide(1);        
    }

    /**
     * <code>normalizeLocal</code> makes this vector into a unit vector of
     * itself.
     *
     * @return this.
     */
    public Vector3f normalizeLocal() {
        float length = length();
        if (length != 0) {
            return divideLocal(length);
        }
        
        return this;        
    }

    /**
     * <code>zero</code> resets this vector's data to zero internally.
     */
    public void zero() {
        x = y = z = 0;
    }

    /**
     * <code>angleBetween</code> returns (in radians) the angle between two vectors.
     * It is assumed that both this vector and the given vector are unit vectors (iow, normalized).
     * 
     * @param otherVector a unit vector to find the angle against
     * @return the angle in radians.
     */
    public float angleBetween(Vector3f otherVector) {
        float dotProduct = dot(otherVector);
        float angle = FastMath.acos(dotProduct);
        return angle;
    }
    
    /**
     * Sets this vector to the interpolation by changeAmnt from this to the finalVec
     * this=(1-changeAmnt)*this + changeAmnt * finalVec
     * @param finalVec The final vector to interpolate towards
     * @param changeAmnt An amount between 0.0 - 1.0 representing a precentage
     *  change from this towards finalVec
     */
    public void interpolate(Vector3f finalVec, float changeAmnt) {
        this.x=(1-changeAmnt)*this.x + changeAmnt*finalVec.x;
        this.y=(1-changeAmnt)*this.y + changeAmnt*finalVec.y;
        this.z=(1-changeAmnt)*this.z + changeAmnt*finalVec.z;
    }

    /**
     * Sets this vector to the interpolation by changeAmnt from beginVec to finalVec
     * this=(1-changeAmnt)*beginVec + changeAmnt * finalVec
     * @param beginVec the beging vector (changeAmnt=0)
     * @param finalVec The final vector to interpolate towards
     * @param changeAmnt An amount between 0.0 - 1.0 representing a precentage
     *  change from beginVec towards finalVec
     */
    public void interpolate(Vector3f beginVec,Vector3f finalVec, float changeAmnt) {
        this.x=(1-changeAmnt)*beginVec.x + changeAmnt*finalVec.x;
        this.y=(1-changeAmnt)*beginVec.y + changeAmnt*finalVec.y;
        this.z=(1-changeAmnt)*beginVec.z + changeAmnt*finalVec.z;
    }

    /**
     * Check a vector... if it is null or its floats are NaN or infinite,
     * return false.  Else return true.
     * @param vector the vector to check
     * @return true or false as stated above.
     */
    public static boolean isValidVector(Vector3f vector) {
      if (vector == null) return false;
      if (Float.isNaN(vector.x) ||
          Float.isNaN(vector.y) ||
          Float.isNaN(vector.z)) return false;
      if (Float.isInfinite(vector.x) ||
          Float.isInfinite(vector.y) ||
          Float.isInfinite(vector.z)) return false;
      return true;
    }

    public static void generateOrthonormalBasis(Vector3f u, Vector3f v, Vector3f w) {
        w.normalizeLocal();
        generateComplementBasis(u, v, w);
    }

    public static void generateComplementBasis(Vector3f u, Vector3f v,
            Vector3f w) {
        float fInvLength;

        if (FastMath.abs(w.x) >= FastMath.abs(w.y)) {
            // w.x or w.z is the largest magnitude component, swap them
            fInvLength = FastMath.invSqrt(w.x * w.x + w.z * w.z);
            u.x = -w.z * fInvLength;
            u.y = 0.0f;
            u.z = +w.x * fInvLength;
            v.x = w.y * u.z;
            v.y = w.z * u.x - w.x * u.z;
            v.z = -w.y * u.x;
        } else {
            // w.y or w.z is the largest magnitude component, swap them
            fInvLength = FastMath.invSqrt(w.y * w.y + w.z * w.z);
            u.x = 0.0f;
            u.y = +w.z * fInvLength;
            u.z = -w.y * fInvLength;
            v.x = w.y * u.z - w.z * u.y;
            v.y = -w.x * u.z;
            v.z = w.x * u.y;
        }
    }

    @Override
    public Vector3f clone() {
        try {
            return (Vector3f) super.clone();
        } catch (CloneNotSupportedException e) {
            throw new AssertionError(); // can not happen
        }
    }

    /**
     * Saves this Vector3f into the given float[] object.
     * 
     * @param floats
     *            The float[] to take this Vector3f. If null, a new float[3] is
     *            created.
     * @return The array, with X, Y, Z float values in that order
     */
    public float[] toArray(float[] floats) {
        if (floats == null) {
            floats = new float[3];
        }
        floats[0] = x;
        floats[1] = y;
        floats[2] = z;
        return floats;
    }

    /**
     * are these two vectors the same? they are is they both have the same x,y,
     * and z values.
     *
     * @param o
     *            the object to compare for equality
     * @return true if they are equal
     */
    public boolean equals(Object o) {
        if (!(o instanceof Vector3f)) { return false; }

        if (this == o) { return true; }

        Vector3f comp = (Vector3f) o;
        if (Float.compare(x,comp.x) != 0) return false;
        if (Float.compare(y,comp.y) != 0) return false;
        if (Float.compare(z,comp.z) != 0) return false;
        return true;
    }

    /**
     * <code>hashCode</code> returns a unique code for this vector object based
     * on it's values. If two vectors are logically equivalent, they will return
     * the same hash code value.
     * @return the hash code value of this vector.
     */
    public int hashCode() {
        int hash = 37;
        hash += 37 * hash + Float.floatToIntBits(x);
        hash += 37 * hash + Float.floatToIntBits(y);
        hash += 37 * hash + Float.floatToIntBits(z);
        return hash;
    }

    /**
     * <code>toString</code> returns the string representation of this vector.
     * The format is:
     *
     * org.jme.math.Vector3f [X=XX.XXXX, Y=YY.YYYY, Z=ZZ.ZZZZ]
     *
     * @return the string representation of this vector.
     */
    public String toString() {
        return "com.jme.math.Vector3f [X=" + x + ", Y=" + y + ", Z=" + z + "]";
    }


    /**
     * Used with serialization.  Not to be called manually.
     * @param in input
     * @throws IOException
     * @throws ClassNotFoundException
     * @see java.io.Externalizable
     */
    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
        x=in.readFloat();
        y=in.readFloat();
        z=in.readFloat();
    }

    /**
     * Used with serialization.  Not to be called manually.
     * @param out output
     * @throws IOException
     * @see java.io.Externalizable
     */
    public void writeExternal(ObjectOutput out) throws IOException {
        out.writeFloat(x);
        out.writeFloat(y);
        out.writeFloat(z);
    }

    public void write(JMEExporter e) throws IOException {
        OutputCapsule capsule = e.getCapsule(this);
        capsule.write(x, "x", 0);
        capsule.write(y, "y", 0);
        capsule.write(z, "z", 0);
    }

    public void read(JMEImporter e) throws IOException {
        InputCapsule capsule = e.getCapsule(this);
        x = capsule.readFloat("x", 0);
        y = capsule.readFloat("y", 0);
        z = capsule.readFloat("z", 0);
    }
    
    public Class<? extends Vector3f> getClassTag() {
        return this.getClass();
    }

    public float getX() {
        return x;
    }

    public void setX(float x) {
        this.x = x;
    }

    public float getY() {
        return y;
    }

    public void setY(float y) {
        this.y = y;
    }

    public float getZ() {
        return z;
    }

    public void setZ(float z) {
        this.z = z;
    }
    
    /**
     * @param index
     * @return x value if index == 0, y value if index == 1 or z value if index ==
     *         2
     * @throws IllegalArgumentException
     *             if index is not one of 0, 1, 2.
     */
    public float get(int index) {
        switch (index) {
            case 0:
                return x;
            case 1:
                return y;
            case 2:
                return z;
        }
        throw new IllegalArgumentException("index must be either 0, 1 or 2");
    }
    
    /**
     * @param index
     *            which field index in this vector to set.
     * @param value
     *            to set to one of x, y or z.
     * @throws IllegalArgumentException
     *             if index is not one of 0, 1, 2.
     */
    public void set(int index, float value) {
        switch (index) {
            case 0:
                x = value;
                return;
            case 1:
                y = value;
                return;
            case 2:
                z = value;
                return;
        }
        throw new IllegalArgumentException("index must be either 0, 1 or 2");
    }
}