/****************************************************************************
*
* MODULE:       r.out.vtk  
*   	    	
* AUTHOR(S):    Original author 
*               Soeren Gebbert soerengebbert@gmx.de
* 		08 23 2005 Berlin
* PURPOSE:      Converts raster maps 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/raster.h>
#include <grass/glocale.h>
#include <grass/config.h>
#include "globaldefs.h"

/*local prototypes */
static double get_raster_value_as_double(int maptype, void *ptr,
					 double nullval);


/* ************************************************************************* */
/* Get the value of the current raster pointer as double ******************* */
/* ************************************************************************* */
double get_raster_value_as_double(int MapType, void *ptr, double nullval)
{
    double val = nullval;

    if (MapType == CELL_TYPE) {
	if (Rast_is_null_value(ptr, MapType)) {
	    val = nullval;
	}
	else {
	    val = *(CELL *) ptr;
	}
    }
    if (MapType == FCELL_TYPE) {
	if (Rast_is_null_value(ptr, MapType)) {
	    val = nullval;
	}
	else {
	    val = *(FCELL *) ptr;
	}
    }
    if (MapType == DCELL_TYPE) {
	if (Rast_is_null_value(ptr, MapType)) {
	    val = nullval;
	}
	else {
	    val = *(DCELL *) ptr;
	}
    }

    return val;
}

/* ************************************************************************* */
/* Write the default VTK Header, Elevation  is not supportet *************** */
/* ************************************************************************* */
void
write_vtk_normal_header(FILE * fp, struct Cell_head region, double elevation,
			int type)
{
    G_debug(3, _("write_vtk_normal_header: Writing VTK-Header"));

    /*Simple vtk ASCII header */
    fprintf(fp, "# vtk DataFile Version 3.0\n");
    fprintf(fp, "GRASS GIS 7 Export\n");
    fprintf(fp, "ASCII\n");
    fprintf(fp, "DATASET STRUCTURED_POINTS\n");	/*We are using the structured point dataset. */

    if (type)
	fprintf(fp, "DIMENSIONS %i %i %i\n", region.cols, region.rows, 1);
    else
	fprintf(fp, "DIMENSIONS %i %i %i\n", region.cols + 1, region.rows + 1,
		1);

    fprintf(fp, "SPACING %lf %lf %lf\n", region.ew_res, region.ns_res, 0.0);

    if (type)
	fprintf(fp, "ORIGIN %lf %lf %lf\n",
		(region.west + region.ew_res / 2) - x_extent,
		(region.south + region.ns_res / 2) - y_extent, elevation);
    else
	fprintf(fp, "ORIGIN %lf %lf %lf\n", region.west - x_extent,
		region.south - y_extent, elevation);

}


/* ************************************************************************* */
/* Write the Elevation VTK Header, Elevation is supportet ****************** */
/* ************************************************************************* */
void write_vtk_structured_elevation_header(FILE * fp, struct Cell_head region)
{
    G_debug(3,
	    _("write_vtk_structured_elevation_header: Writing VTK-Header"));

    /*Simple vtk ASCII header */
    fprintf(fp, "# vtk DataFile Version 3.0\n");
    fprintf(fp, "GRASS GIS 7 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, 1);
    fprintf(fp, "POINTS %i float\n", region.cols * region.rows);	/*The Coordinates */
}

/* ************************************************************************* */
/* Write the Rectilinear Elevtaion VTK Header, Elevation is supportet ****** */
/* ************************************************************************* */
void write_vtk_polygonal_elevation_header(FILE * fp, struct Cell_head region)
{
    G_debug(3, _("write_vtk_polygonal_elevation_header: Writing VTK-Header"));

    /*Simple vtk ASCII header */
    fprintf(fp, "# vtk DataFile Version 3.0\n");
    fprintf(fp, "GRASS GIS 7 Export\n");
    fprintf(fp, "ASCII\n");
    fprintf(fp, "DATASET POLYDATA\n");	/*We are using polydataset. */
    fprintf(fp, "POINTS %i float\n", region.cols * region.rows);
}

/* ************************************************************************* */
/* Write the CellDataHeader ************************************************ */
/* ************************************************************************* */
void write_vtk_celldata_header(FILE * fp, struct Cell_head region)
{
    G_debug(3, _("write_vtk_celldata_header: Writing VTK-DataHeader"));
    fprintf(fp, "CELL_DATA %i\n", region.cols * region.rows);
}

/* ************************************************************************* */
/* Write the PointDataHeader ************************************************ */
/* ************************************************************************* */
void write_vtk_pointdata_header(FILE * fp, struct Cell_head region)
{
    G_debug(3, _("writeVTKPointHeader: Writing VTK-DataHeader"));
    fprintf(fp, "POINT_DATA %i\n", region.cols * region.rows);
}


/* ************************************************************************* */
/* Write the VTK Structured Coordinates ************************************ */
/* ************************************************************************* */
void
write_vtk_structured_coordinates(int fd, FILE * fp, char *varname,
				 struct Cell_head region, int out_type,
				 char *null_value, double scale, int dp)
{
    int ncols = region.cols;
    int nrows = region.rows;
    int row, col;
    int rowcount = 0, colcount = 0;
    double nspos = 0.0, ewpos = 0.0;
    double nullvalue, value;
    void *ptr, *raster;

    G_debug(3, _("write_vtk_structured_coordinates: Writing Coordinates"));

    /*the nullvalue */
    if (!sscanf(null_value, "%lf", &nullvalue)) {
	G_warning("Null value is not valid, using 0 instead.");
	nullvalue = 0;
    }

    raster = Rast_allocate_buf(out_type);

    rowcount = 0;
    for (row = nrows - 1; row >= 0; row--) {
	colcount = 0;
	G_percent((row - nrows) * (-1), nrows, 2);

	Rast_get_row(fd, raster, row, out_type);

	nspos = region.ns_res / 2 + region.south + rowcount * region.ns_res;
	nspos -= y_extent;

	for (col = 0, ptr = raster; col < ncols;
	     col++, ptr = G_incr_void_ptr(ptr, Rast_cell_size(out_type))) {
	    ewpos =
		region.ew_res / 2 + region.west + colcount * region.ew_res;
	    ewpos -= x_extent;

	    value = get_raster_value_as_double(out_type, ptr, nullvalue);
	    fprintf(fp, "%.*f %.*f %.*f\n", dp, ewpos, dp, nspos, dp,
		    value * scale);

	    colcount++;
	}
	rowcount++;
    }
    return;
}

/* ************************************************************************* */
/* Write Polygonal Coordinates ********************************************* */
/* ************************************************************************* */
void
write_vtk_polygonal_coordinates(int fd, FILE * fp, char *varname,
				struct Cell_head region, int out_type,
				char *null_value, double scale, int polytype,
				int dp)
{
    int ncols = region.cols;
    int nrows = region.rows;
    int row, col;
    int rowcount = 0, colcount = 0;
    double nspos = 0.0, ewpos = 0.0;
    double value, nullvalue;
    void *ptr, *raster;
    int i, j, count;

    G_debug(3,
	    _("write_vtk_polygonal_coordinates: Writing VTK Polygonal data"));

    /*the nullvalue */
    if (!sscanf(null_value, "%lf", &nullvalue)) {
	G_warning("Null value is not valid, using 0 instead.");
	nullvalue = 0;
    }


    /*First we are writing the coordinate points, the elevation cell is only used for the z coordinate */
    raster = Rast_allocate_buf(out_type);

    rowcount = 0;
    for (row = nrows - 1; row >= 0; row--) {
	colcount = 0;
	G_percent((row - nrows) * (-1), nrows, 10);

	Rast_get_row(fd, raster, row, out_type);

	nspos = region.ns_res / 2 + region.south + rowcount * region.ns_res;
	nspos -= y_extent;

	for (col = 0, ptr = raster; col < ncols;
	     col++, ptr = G_incr_void_ptr(ptr, Rast_cell_size(out_type))) {
	    ewpos =
		region.ew_res / 2 + region.west + colcount * region.ew_res;
	    ewpos -= x_extent;

	    value = get_raster_value_as_double(out_type, ptr, nullvalue);
	    fprintf(fp, "%.*f %.*f %.*f\n", dp, ewpos, dp, nspos, dp,
		    value * scale);

	    colcount++;
	}
	rowcount++;
    }

    /*Now we need to write the Connectivity between the points */

    if (polytype == QUADS) {	/*The default */
	/*If Datafiltering should be supportet, we use Polygons to represent the grid */
	fprintf(fp, "POLYGONS %i %i\n", (region.rows - 1) * (region.cols - 1),
		5 * (region.rows - 1) * (region.cols - 1));

	/*We creat a grid of quads, the corners of the quads are the datapoints */
	for (i = 0; i < region.rows - 1; i++) {
	    for (j = 0; j < region.cols - 1; j++) {
		fprintf(fp, "4 %i %i %i %i \n", i * region.cols + j,
			i * region.cols + j + 1,
			(i + 1) * region.cols + j + 1,
			(i + 1) * region.cols + j);
	    }
	}
    }


    if (polytype == TRIANGLE_STRIPS) {
	/*TriangleStrips, take a look ate www.vtk.org for the definition of triangle_strips in vtk */
	/*If we use triangelestrips, the number of points per strip is equal to the double number of cols we have */
	fprintf(fp, "TRIANGLE_STRIPS %i %i\n", region.rows - 1,
		(region.rows - 1) + (region.rows - 1) * (2 * region.cols));

	/*For every Row-1 make a strip */
	for (i = 0; i < region.rows - 1; i++) {

	    /*Number of Points */
	    fprintf(fp, "%i ", region.cols * 2);

	    /*Write the points */
	    for (j = 0; j < region.cols; j++) {
		fprintf(fp, "%i %i ", i * region.cols + j,
			(i + 1) * region.cols + j);
	    }
	    fprintf(fp, "\n");
	}
    }

    if (polytype == VERTICES) {
	/*If the Data should be Triangulated by VTK, we use vertices to represent the grid */
	fprintf(fp, "VERTICES %i %i\n", region.rows,
		region.rows + (region.rows) * (region.cols));

	count = 0;
	for (i = 0; i < region.rows; i++) {
	    fprintf(fp, "%i ", (region.cols));
	    for (j = 0; j < region.cols; j++) {
		fprintf(fp, "%i ", count);
		count++;
	    }
	    fprintf(fp, "\n");
	}
    }

    return;
}

/* ************************************************************************* */
/* Write the VTK Data ****************************************************** */
/* ************************************************************************* */
void
write_vtk_data(int fd, FILE * fp, char *varname, struct Cell_head region,
	       int out_type, char *null_value, int dp)
{
    int ncols = region.cols;
    int nrows = region.rows;
    int row, col;
    double value, nullvalue;
    void *ptr, *raster;

    G_debug(3, _("write_vtk_data: Writing VTK-Data"));

    /*the nullvalue */
    if (!sscanf(null_value, "%lf", &nullvalue)) {
	G_warning("Null value is not valid, using 0 instead.");
	nullvalue = 0;
    }

    fprintf(fp, "SCALARS %s float 1\n", varname);
    fprintf(fp, "LOOKUP_TABLE default\n");


    raster = Rast_allocate_buf(out_type);

    for (row = nrows - 1; row >= 0; row--) {
	G_percent((row - nrows) * (-1), nrows, 10);

	Rast_get_row(fd, raster, row, out_type);

	for (col = 0, ptr = raster; col < ncols;
	     col++, ptr = G_incr_void_ptr(ptr, Rast_cell_size(out_type))) {

	    value = get_raster_value_as_double(out_type, ptr, nullvalue);
	    fprintf(fp, "%.*f ", dp, value);

	}
	fprintf(fp, "\n");
    }
    return;

}



/* ************************************************************************* */
/* Write the VTK RGB Image Data ******************************************** */
/* ************************************************************************* */
void
write_vtk_rgb_image_data(int redfd, int greenfd, int bluefd, FILE * fp,
			 const char *varname, struct Cell_head region,
			 int out_type, int dp)
{
    int ncols = region.cols;
    int nrows = region.rows;
    int row, col;
    void *redptr, *redraster;
    void *greenptr, *greenraster;
    void *blueptr, *blueraster;
    double r = 0.0, g = 0.0, b = 0.0;

    G_debug(3, _("write_vtk_rgb_image_data: Writing VTK-ImageData"));

    fprintf(fp, "COLOR_SCALARS %s 3\n", varname);

    redraster = Rast_allocate_buf(out_type);
    greenraster = Rast_allocate_buf(out_type);
    blueraster = Rast_allocate_buf(out_type);

    for (row = nrows - 1; row >= 0; row--) {
	G_percent((row - nrows) * (-1), nrows, 10);

	Rast_get_row(redfd, redraster, row, out_type);
	Rast_get_row(greenfd, greenraster, row, out_type);
	Rast_get_row(bluefd, blueraster, row, out_type);

	for (col = 0, redptr = redraster, greenptr = greenraster, blueptr =
	     blueraster; col < ncols;
	     col++, redptr =
	     G_incr_void_ptr(redptr, Rast_cell_size(out_type)), greenptr =
	     G_incr_void_ptr(greenptr, Rast_cell_size(out_type)), blueptr =
	     G_incr_void_ptr(blueptr, Rast_cell_size(out_type))) {

	    r = get_raster_value_as_double(out_type, redptr, 0.0);
	    g = get_raster_value_as_double(out_type, greenptr, 0.0);
	    b = get_raster_value_as_double(out_type, blueptr, 0.0);

	    /*Test of valuerange, the data should be 1 byte gray values */
	    if (r > 255 || g > 255 || b > 255 || r < 0 || g < 0 || b < 0) {
		G_warning(_("Wrong map values! Values should in between 0 and 255!\n"));
		fprintf(fp, "0 0 0 \n");
	    }
	    else {
		fprintf(fp, "%.*f %.*f %.*f \n", dp, r / 255, dp, g / 255, dp,
			b / 255);
	    }
	}
    }
    return;

}


/* ************************************************************************* */
/* Write the VTK Vector Data *********************************************** */
/* ************************************************************************* */
void
write_vtk_vector_data(int xfd, int yfd, int zfd, FILE * fp,
		      const char *varname, struct Cell_head region,
		      int out_type, int dp)
{
    int ncols = region.cols;
    int nrows = region.rows;
    int row, col;
    void *xptr, *xraster;
    void *yptr, *yraster;
    void *zptr, *zraster;
    double x = 0.0, y = 0.0, z = 0.0;

    G_debug(3, _("write_vtk_vector_data: Writing VTK-vector data"));

    fprintf(fp, "VECTORS %s float\n", varname);

    xraster = Rast_allocate_buf(out_type);
    yraster = Rast_allocate_buf(out_type);
    zraster = Rast_allocate_buf(out_type);

    for (row = nrows - 1; row >= 0; row--) {
	G_percent((row - nrows) * (-1), nrows, 10);

	Rast_get_row(xfd, xraster, row, out_type);
	Rast_get_row(yfd, yraster, row, out_type);
	Rast_get_row(zfd, zraster, row, out_type);

	for (col = 0, xptr = xraster, yptr = yraster, zptr =
	     zraster; col < ncols;
	     col++, xptr =
	     G_incr_void_ptr(xptr, Rast_cell_size(out_type)), yptr =
	     G_incr_void_ptr(yptr, Rast_cell_size(out_type)), zptr =
	     G_incr_void_ptr(zptr, Rast_cell_size(out_type))) {

	    x = get_raster_value_as_double(out_type, xptr, 0.0);
	    y = get_raster_value_as_double(out_type, yptr, 0.0);
	    z = get_raster_value_as_double(out_type, zptr, 0.0);

	    fprintf(fp, "%.*f %.*f %.*f \n", dp, x, dp, y, dp, z);
	}
    }
    return;

}