/**************************************************************/
/*                                                            */
/* prepare_colormap - Prepare the client_data structure.      */
/*                    The client_data structure               */
/*                    communicates pixel data between the     */
/*                    SE_stream_execute function and your     */
/*                    callback function.                      */
/*                                                            */
/*              arguments:                                    */
/*                                                            */
/*              client_data <CLIENT_DATA*> - Pointer to the   */
/*                                           client data      */
/*                                           structure.       */
/*              pixel_type <LONG> - The pixel bit depth.      */
/*              pixelwidth <LONG> - The width of the image    */
/*                                  specified in pixels.      */
/*              filename <CHAR*> - The name of the BSQ file.  */
/*                                                            */
/**************************************************************/

void prepare_colormap ( SE_COLORMAP_TYPE  *colormap_type,
                        SE_COLORMAP_DATA_TYPE *colormap_data_type, 
                        LONG *num_colormap_entries, 
                        UCHAR *colormap_data) {

	LONG i;

	/* Create an 8-bit RedGreenBlue colormap with 256 entries. */

	*colormap_type = SE_COLORMAP_RGB;
	*colormap_data_type = SE_COLORMAP_DATA_BYTE;
	*num_colormap_entries = 256;

	/* Populate the the RGB color map a range of data from  */
	/* black (0,0,0) to white (256,256,256). */

	for (i=0; i<256; i++) {

		/* Red */

		colormap_data[3*i] = (UCHAR)i;

		/* Green */

		colormap_data[(3*i)+1] = (UCHAR)(256-i);
	
		/* Blue */

		colormap_data[(3*i)+2] = (UCHAR)(256%i);

	}

	return;

} /* prepare_colormap */