render(bitmap, string, x, y[, color[, flags]])
Draws the text 'string' on 'bitmap' at the position (x, y).
If color is supplied, it draws the text with that color, otherwise it draws the text white.
Note that in versions before 0.9c, color was specified as three parameters. This has been deprecated.
flags can be a sum of these values: Font.None : No flags (default). Font.CenterV : Center the text vertically with y at the middle. Font.CenterH : Center the text horizontally with x at the middle. Font.Shadow : Draw a shadow under the text. Font.Formatting : Draw the text with formatting.