vector3f.java

java 3d game jme 工程开发源代码

     */
    public Vector3f cross(float otherX, float otherY, float otherZ, Vector3f result) {
        if (result == null) result = new Vector3f();
        float resX = ((y * otherZ) - (z * otherY)); 
        float resY = ((z * otherX) - (x * otherZ));
        float resZ = ((x * otherY) - (y * otherX));
        result.set(resX, resY, resZ);
        return result;
    }

    /**
     * <code>crossLocal</code> calculates the cross product of this vector
     * with a parameter vector v.
     *
     * @param v
     *            the vector to take the cross product of with this.
     * @return this.
     */
    public Vector3f crossLocal(Vector3f v) {
        return crossLocal(v.x, v.y, v.z);
    }

    /**
     * <code>crossLocal</code> calculates the cross product of this vector
     * with a parameter vector v.
     *
     * @param otherX
     *            x component of the vector to take the cross product of with this.
     * @param otherY
     *            y component of the vector to take the cross product of with this.
     * @param otherZ
     *            z component of the vector to take the cross product of with this.
     * @return this.
     */
    public Vector3f crossLocal(float otherX, float otherY, float otherZ) {
        float tempx = ( y * otherZ ) - ( z * otherY );
        float tempy = ( z * otherX ) - ( x * otherZ );
        z = (x * otherY) - (y * otherX);
        x = tempx;
        y = tempy;
        return this;
    }

    /**
     * <code>length</code> calculates the magnitude of this vector.
     *
     * @return the length or magnitude of the vector.
     */
    public float length() {
        return FastMath.sqrt(lengthSquared());
    }

    /**
     * <code>lengthSquared</code> calculates the squared value of the
     * magnitude of the vector.
     *
     * @return the magnitude squared of the vector.
     */
    public float lengthSquared() {
        return x * x + y * y + z * z;
    }

    /**
     * <code>distanceSquared</code> calculates the distance squared between
     * this vector and vector v.
     *
     * @param v the second vector to determine the distance squared.
     * @return the distance squared between the two vectors.
     */
    public float distanceSquared(Vector3f v) {
        double dx = x - v.x;
        double dy = y - v.y;
        double dz = z - v.z;
        return (float) (dx * dx + dy * dy + dz * dz);
    }

    /**
     * <code>distance</code> calculates the distance between this vector and
     * vector v.
     *
     * @param v the second vector to determine the distance.
     * @return the distance between the two vectors.
     */
    public float distance(Vector3f v) {
        return FastMath.sqrt(distanceSquared(v));
    }

    /**
     *
     * <code>mult</code> multiplies this vector by a scalar. The resultant
     * vector is returned.
     *
     * @param scalar
     *            the value to multiply this vector by.
     * @return the new vector.
     */
    public Vector3f mult(float scalar) {
        return new Vector3f(x * scalar, y * scalar, z * scalar);
    }

    /**
     *
     * <code>mult</code> multiplies this vector by a scalar. The resultant
     * vector is supplied as the second parameter and returned.
     *
     * @param scalar the scalar to multiply this vector by.
     * @param product the product to store the result in.
     * @return product
     */
    public Vector3f mult(float scalar, Vector3f product) {
        if (null == product) {
            product = new Vector3f();
        }

        product.x = x * scalar;
        product.y = y * scalar;
        product.z = z * scalar;
        return product;
    }

    /**
     * <code>multLocal</code> multiplies this vector by a scalar internally,
     * and returns a handle to this vector for easy chaining of calls.
     *
     * @param scalar
     *            the value to multiply this vector by.
     * @return this
     */
    public Vector3f multLocal(float scalar) {
        x *= scalar;
        y *= scalar;
        z *= scalar;
        return this;
    }

    /**
     * <code>multLocal</code> multiplies a provided vector to this vector
     * internally, and returns a handle to this vector for easy chaining of
     * calls. If the provided vector is null, null is returned.
     *
     * @param vec
     *            the vector to mult to this vector.
     * @return this
     */
    public Vector3f multLocal(Vector3f vec) {
        if (null == vec) {
            logger.warning("Provided vector is null, null returned.");
            return null;
        }
        x *= vec.x;
        y *= vec.y;
        z *= vec.z;
        return this;
    }


    /**
     * <code>multLocal</code> multiplies a provided vector to this vector
     * internally, and returns a handle to this vector for easy chaining of
     * calls. If the provided vector is null, null is returned.
     *
     * @param vec
     *            the vector to mult to this vector.
     * @return this
     */
    public Vector3f mult(Vector3f vec) {
        if (null == vec) {
            logger.warning("Provided vector is null, null returned.");
            return null;
        }
        return mult(vec, null);
    }

    /**
     * <code>multLocal</code> multiplies a provided vector to this vector
     * internally, and returns a handle to this vector for easy chaining of
     * calls. If the provided vector is null, null is returned.
     *
     * @param vec
     *            the vector to mult to this vector.
     * @param store result vector (null to create a new vector)
     * @return this
     */
    public Vector3f mult(Vector3f vec, Vector3f store) {
        if (null == vec) {
            logger.warning("Provided vector is null, null returned.");
            return null;
        }
        if (store == null) store = new Vector3f();
        return store.set(x * vec.x, y * vec.y, z * vec.z);
    }


    /**
     * <code>divide</code> divides the values of this vector by a scalar and
     * returns the result. The values of this vector remain untouched.
     *
     * @param scalar
     *            the value to divide this vectors attributes by.
     * @return the result <code>Vector</code>.
     */
    public Vector3f divide(float scalar) {
        scalar = 1f/scalar;
        return new Vector3f(x * scalar, y * scalar, z * scalar);
    }

    /**
     * <code>divideLocal</code> divides this vector by a scalar internally,
     * and returns a handle to this vector for easy chaining of calls. Dividing
     * by zero will result in an exception.
     *
     * @param scalar
     *            the value to divides this vector by.
     * @return this
     */
    public Vector3f divideLocal(float scalar) {
        scalar = 1f/scalar;
        x *= scalar;
        y *= scalar;
        z *= scalar;
        return this;
    }


    /**
     * <code>divide</code> divides the values of this vector by a scalar and
     * returns the result. The values of this vector remain untouched.
     *
     * @param scalar
     *            the value to divide this vectors attributes by.
     * @return the result <code>Vector</code>.
     */
    public Vector3f divide(Vector3f scalar) {
        return new Vector3f(x / scalar.x, y / scalar.y, z / scalar.z);
    }

    /**
     * <code>divideLocal</code> divides this vector by a scalar internally,
     * and returns a handle to this vector for easy chaining of calls. Dividing
     * by zero will result in an exception.
     *
     * @param scalar
     *            the value to divides this vector by.
     * @return this
     */
    public Vector3f divideLocal(Vector3f scalar) {
        x /= scalar.x;
        y /= scalar.y;
        z /= scalar.z;
        return this;
    }

    /**
     *
     * <code>negate</code> returns the negative of this vector. All values are
     * negated and set to a new vector.
     *
     * @return the negated vector.
     */
    public Vector3f negate() {
        return new Vector3f(-x, -y, -z);
    }

    /**
     *
     * <code>negateLocal</code> negates the internal values of this vector.
     *
     * @return this.
     */
    public Vector3f negateLocal() {
        x = -x;
        y = -y;
        z = -z;
        return this;
    }

    /**
     *
     * <code>subtract</code> subtracts the values of a given vector from those
     * of this vector creating a new vector object. If the provided vector is
     * null, null is returned.
     *
     * @param vec
     *            the vector to subtract from this vector.
     * @return the result vector.
     */
    public Vector3f subtract(Vector3f vec) {
        return new Vector3f(x - vec.x, y - vec.y, z - vec.z);
    }

    /**
     * <code>subtractLocal</code> subtracts a provided vector to this vector
     * internally, and returns a handle to this vector for easy chaining of
     * calls. If the provided vector is null, null is returned.
     *
     * @param vec
     *            the vector to subtract
     * @return this
     */
    public Vector3f subtractLocal(Vector3f vec) {
        if (null == vec) {
            logger.warning("Provided vector is null, null returned.");
            return null;
        }
        x -= vec.x;
        y -= vec.y;
        z -= vec.z;
        return this;
    }

    /**
     *
     * <code>subtract</code>
     *
     * @param vec
     *            the vector to subtract from this
     * @param result
     *            the vector to store the result in
     * @return result
     */
    public Vector3f subtract(Vector3f vec, Vector3f result) {
        if(result == null) {
            result = new Vector3f();
        }
        result.x = x - vec.x;
        result.y = y - vec.y;
        result.z = z - vec.z;
        return result;
    }

    /**
     *
     * <code>subtract</code> subtracts the provided values from this vector,
     * creating a new vector that is then returned.
     *
     * @param subtractX
     *            the x value to subtract.
     * @param subtractY