/****************************************************************************
*
* MODULE:       r3.out.vtk  
*   	    	
* AUTHOR(S):    Original author 
*               Soeren Gebbert soerengebbert at gmx de
* 		27 Feb 2006 Berlin
* PURPOSE:      Converts 3D raster maps (G3D) into the VTK-Ascii format  
*
* COPYRIGHT:    (C) 2005 by the GRASS Development Team
*
*               This program is free software under the GNU General Public
*   	    	License (>=v2). Read the file COPYING that comes with GRASS
*   	    	for details.
*
*****************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <grass/gis.h>
#include <grass/G3d.h>
#include <grass/glocale.h>
#include "globalDefs.h"
#include "writeVTKHead.h"
#include "parameters.h"
#include "errorHandling.h"



/* ************************************************************************* */
/* Writes the strcutured points Header ************************************* */
/* ************************************************************************* */
void writeVTKStructuredPointHeader(FILE * fp, char *vtkFile, G3D_Region region,
				   int dp)
{
    double scale;

    scale = atof(param.elevscale->answer);
    G_debug(3,
	    _
	    ("writeVTKStructuredPointHeader: Writing VTKStructuredPoint-Header"));

    /*Simple vtk ASCII header */

    fprintf(fp, "# vtk DataFile Version 3.0\n");
    fprintf(fp, "GRASS 6 Export\n");
    fprintf(fp, "ASCII\n");
    fprintf(fp, "DATASET STRUCTURED_POINTS\n");	/*We are using the structured point dataset. */

    if (param.point->answer)
	fprintf(fp, "DIMENSIONS %i %i %i\n", region.cols, region.rows,
		region.depths);
    else
	fprintf(fp, "DIMENSIONS %i %i %i\n", region.cols + 1, region.rows + 1,
		region.depths + 1);

    fprintf(fp, "SPACING %.*f %.*f %.*f\n", dp, region.ew_res, dp,
	    region.ns_res, dp, (region.tb_res * scale));

    if (param.point->answer) {
	if (param.origin->answer)
	    fprintf(fp, "ORIGIN %.*f %.*f %.*f\n", dp,
		    (region.west + region.ew_res / 2) - x_extent, dp,
		    (region.south + region.ns_res / 2) - y_extent, dp,
		    region.bottom * scale + (region.tb_res * scale) / 2);
	else
	    fprintf(fp, "ORIGIN %.*f %.*f %.*f\n", dp,
		    (region.west + region.ew_res / 2) - x_extent, dp,
		    (region.south + region.ns_res / 2) - y_extent, dp,
		    region.bottom + (region.tb_res * scale) / 2);
    }
    else {
	if (param.origin->answer)
	    fprintf(fp, "ORIGIN %.*f %.*f %.*f\n", dp, region.west - x_extent, dp,
		    region.south - y_extent, dp, region.bottom * scale);
	else
	    fprintf(fp, "ORIGIN %.*f %.*f %.*f\n", dp, region.west - x_extent, dp,
		    region.south - y_extent, dp, region.bottom);
    }

    if (param.point->answer)
	fprintf(fp, "POINT_DATA %i\n", region.cols * region.rows * region.depths);	/*We have pointdata */
    else
	fprintf(fp, "CELL_DATA %i\n", region.cols * region.rows * region.depths);	/*We have celldata */

    return;
}


/* ************************************************************************* */
/* Writes the strcutured grid header **************************************** */
/* ************************************************************************* */
void writeVTKStructuredGridHeader(FILE * fp, char *vtkFile, G3D_Region region)
{
    G_debug(3,
	    _
	    ("writeVTKStructuredGridHeader: Writing VTKStructuredGrid-Header"));
    fprintf(fp, "# vtk DataFile Version 3.0\n");
    fprintf(fp, "GRASS 6 Export\n");
    fprintf(fp, "ASCII\n");
    fprintf(fp, "DATASET STRUCTURED_GRID\n");	/*We are using the structured grid dataset. */
    fprintf(fp, "DIMENSIONS %i %i %i\n", region.cols, region.rows,
	    region.depths);
    /*Only point data is available */
    fprintf(fp, "POINTS %i float\n", region.cols * region.rows * region.depths);

    return;
}

/* ************************************************************************* */
/* Writes the unstrcutured grid header ************************************* */
/* ************************************************************************* */
void writeVTKUnstructuredGridHeader(FILE * fp, char *vtkFile, G3D_Region region)
{
    G_debug(3,
	    _
	    ("writeVTKUnstructuredGridHeader: Writing VTKUnstructuredGrid-Header"));
    fprintf(fp, "# vtk DataFile Version 3.0\n");
    fprintf(fp, "GRASS 6 Export\n");
    fprintf(fp, "ASCII\n");
    fprintf(fp, "DATASET UNSTRUCTURED_GRID\n");	/*We are using the unstructured grid dataset. */
    /*Only cell data is available, because we creating a hexaeder/vtk-voxel for every voxel */
    fprintf(fp, "POINTS %i float\n", region.cols * region.rows * region.depths * 8);	/*a Voxel has 8 points */

    return;
}