Add Quaternion.mul(scalar) (#316)

src/org/joml/Quaterniond.java

@@ -796,6 +796,27 @@ public Quaterniond mul(double qx, double qy, double qz, double qw, Quaterniond d
                         Math.fma(w, qw, Math.fma(-x, qx, Math.fma(-y, qy, -z * qz))));
     }
 
+    /**
+     * Multiply this quaternion by the given scalar.
+     * <p>
+     * This method multiplies all of the four components by the specified scalar.
+     * 
+     * @param f
+     *          the factor to multiply all components by
+     * @return this
+     */
+    public Quaterniond mul(double f) {
+        return mul(f, this);
+    }
+
+    public Quaterniond mul(double f, Quaterniond dest) {
+        dest.x = x * f;
+        dest.y = y * f;
+        dest.z = z * f;
+        dest.w = w * f;
+        return dest;
+    }
+
     /**
      * Pre-multiply this quaternion by <code>q</code>.
      * <p>

src/org/joml/Quaterniondc.java

@@ -232,6 +232,19 @@ public interface Quaterniondc {
      */
     Quaterniond mul(double qx, double qy, double qz, double qw, Quaterniond dest);
 
+    /**
+     * Multiply this quaternion by the given scalar and store the result in <code>dest</code>.
+     * <p>
+     * This method multiplies all of the four components by the specified scalar.
+     * 
+     * @param f
+     *          the factor to multiply all components by
+     * @param dest
+     *            will hold the result
+     * @return dest
+     */
+    Quaterniond mul(double f, Quaterniond dest);
+
     /**
      * Pre-multiply this quaternion by <code>q</code> and store the result in <code>dest</code>.
      * <p>

src/org/joml/Quaternionf.java

@@ -996,6 +996,27 @@ public Quaternionf mul(float qx, float qy, float qz, float qw, Quaternionf dest)
                         Math.fma(w, qw, Math.fma(-x, qx, Math.fma(-y, qy, -z * qz))));
     }
 
+    /**
+     * Multiply this quaternion by the given scalar.
+     * <p>
+     * This method multiplies all of the four components by the specified scalar.
+     * 
+     * @param f
+     *          the factor to multiply all components by
+     * @return this
+     */
+    public Quaternionf mul(float f) {
+        return mul(f, this);
+    }
+
+    public Quaternionf mul(float f, Quaternionf dest) {
+        dest.x = x * f;
+        dest.y = y * f;
+        dest.z = z * f;
+        dest.w = w * f;
+        return dest;
+    }
+
     /**
      * Pre-multiply this quaternion by <code>q</code>.
      * <p>

src/org/joml/Quaternionfc.java

@@ -320,6 +320,19 @@ public interface Quaternionfc {
      */
     Quaternionf mul(float qx, float qy, float qz, float qw, Quaternionf dest);
 
+    /**
+     * Multiply this quaternion by the given scalar and store the result in <code>dest</code>.
+     * <p>
+     * This method multiplies all of the four components by the specified scalar.
+     * 
+     * @param f
+     *          the factor to multiply all components by
+     * @param dest
+     *            will hold the result
+     * @return dest
+     */
+    Quaternionf mul(float f, Quaternionf dest);
+
     /**
      * Pre-multiply this quaternion by <code>q</code> and store the result in <code>dest</code>.
      * <p>