+ /** @param font Font ID, or empty to use the default
+ * @param italic true for italic text
+ * @param bold true for bold text
+ * @param underline true for underlined text
+ * @param colour Colour of the text
+ * @param size Size in points as if the screen height is 11 inches, so a 72pt font would be 1/11th of the screen height
+ * @param aspect_adjust greater than 1 to stretch text to be wider, less than 1 to shrink text to be narrower (must be between 0.25 and 4)
+ * @param in start time
+ * @param out finish time
+ * @param h_position Horizontal position as a fraction of the screen width (between 0 and 1) from h_align
+ * @param h_align Horizontal alignment point
+ * @param v_position Vertical position as a fraction of the screen height (between 0 and 1) from v_align
+ * @param v_align Vertical alignment point
+ * @param z_position Z position as a proportion of the primary picture width between -1 and +1;
+ * +ve moves the image away from the viewer, -ve moves it toward the viewer, 0 is in the plane of the screen.
+ * @param direction Direction of text
+ * @param text The text to display
+ * @param effect Effect to use
+ * @param effect_colour Colour of the effect
+ * @param fade_up_time Time to fade the text in
+ * @param fade_down_time Time to fade the text out
+ * @param space_before Space to add before this string, in ems (could be negative to remove space).
+ */