How to draw rectangle on a RGB Image ??

Hi,

Well I'm currently writing a module to display a rectangle on a RGB Image (bmp file).

I'm using TMS320DM6437 & Code Composer Studio-CSS 3.3v for Coding.

Within BSP(provided for TMS320DM6437 ) there is a function which draws Rectangle i.e. GRAPHICS_DrawRectangle.

void GRAPHICS_DrawRect(volatile u16* pDstBuf, volatile Uint16 x1, volatile Uint16 y1, volatile Uint16 x2, volatile Uint16 y2, volatile Uint16 color, volatile Bool fill, volatile u8 bufindex);

I can draw the rectangle only on binary images (bmp file) properly, but i'm facing problem to draw it on RGB image.

Image size is - 640 x 480

pls guide suggesting any alterative / sloution to draw rectangle on RGB Image.

Presently code is in simulation mode only.

Regards,

Pratibha