XPLM_API void       XPLMDrawString(
                         float *              inColorRGB,
                         int                  inXOffset,
                         int                  inYOffset,
                         char *               inChar,
                         int *                inWordWrapWidth,    /* Can be NULL */
                         XPLMFontID           inFontID);

This routine draws a NULL terminated string in a given font. Pass in the lower left pixel that the character is to be drawn onto. Also pass the character and font ID. This function returns the x offset plus the width of all drawn characters. The color to draw in is specified as a pointer to an array of three floating point colors, representing RGB intensities from 0.0 to 1.0.