#include <grass/gis.h>
#include <grass/Vect.h>
#include "local.h"

#define debug stderr

struct Cell_head region, page;

static union
{
    CELL **cell;
    DCELL **dcell;
} raster;
static int max_rows;
static int at_row;
static CELL cat;
static DCELL dcat;
static int cur_x, cur_y;
static int format;
static CELL *cell;
static DCELL *dcell;
static char **null_flags;
static char isnull;

static int cell_dot (int,int);
static int dcell_dot (int,int);
static int cont (int,int);
static int move (int,int);

static int (*dot)();

int 
begin_rasterization (int nrows, int f)
{
    int i,size;
    int pages;

    G_suppress_warnings(1);
    /* otherwise get complaints about window changes */
        
    format = f;

    max_rows = nrows;
    if (max_rows <= 0)
	max_rows = 512;

    G_get_set_window (&region);
    G_get_set_window (&page);

    pages = (region.rows + max_rows - 1) / max_rows;

    if (max_rows > region.rows)
	max_rows = region.rows;

    size = max_rows * region.cols;
    switch (format)
    {
    case USE_CELL:
	raster.cell = (CELL **)G_calloc(max_rows * sizeof(char), sizeof(CELL *));
	raster.cell[0] = (CELL *)G_calloc(size * sizeof(char), sizeof(CELL));
	for (i = 1; i < max_rows; i++)
	    raster.cell[i] = raster.cell[i-1] + region.cols;
	dot = cell_dot;
	break;

    case USE_DCELL:
	raster.dcell = (DCELL **)G_calloc(max_rows * sizeof(char), sizeof(DCELL *));
	raster.dcell[0] = (DCELL *)G_calloc(size * sizeof(char), sizeof(DCELL));
	for (i = 1; i < max_rows; i++)
	    raster.dcell[i] = raster.dcell[i-1] + region.cols;
	dot = dcell_dot;
	break;
    }

    null_flags = (char **)G_calloc(max_rows * sizeof(char), sizeof(char *));
    null_flags[0] = (char *)G_calloc(size * sizeof(char), sizeof(char));
    for (i = 1; i < max_rows; i++)
	null_flags[i] = null_flags[i-1] + region.cols;

    at_row = 0;
    configure_plot();

    return pages;
}

#define DONE 1
#define ERROR -1
#define AGAIN 0

int 
configure_plot (void)
{
    int i,j;
    int nrows;
    int ncols;

    nrows = region.rows - at_row;
    if (nrows <= 0)
	return DONE;

    if (nrows > max_rows)
	nrows = max_rows;
    
    ncols = region.cols;

/* zero the raster */
    switch (format)
    {
    case USE_CELL:
	for (i = 0; i < nrows; i++)
	    for (j = 0; j < ncols; j++)
		raster.cell[i][j] = 0;
	break;
    case USE_DCELL:
	for (i = 0; i < nrows; i++)
	    for (j = 0; j < ncols; j++)
		raster.dcell[i][j] = 0;
	break;
    }

    for (i = 0; i < nrows; i++)
	for (j = 0; j < ncols; j++)
	    null_flags[i][j] = 1;

/* change the region */
    page.north = region.north - at_row * region.ns_res;
    page.south = page.north - nrows * region.ns_res;
    G_set_window (&page);

/* configure the plot routines */
    G_setup_plot (-0.5, page.rows-0.5, -0.5, page.cols-0.5, move, cont);

    return AGAIN;
}

int 
output_raster (int fd)
{
    int i;

    for (i = 0; i < page.rows; i++, at_row++)
    {
	switch (format)
	{
	case USE_CELL:
	    cell = raster.cell[i];
	    /* insert the NULL values */
	    G_insert_c_null_values (cell, null_flags[i], page.cols);
	    if (G_put_c_raster_row (fd, cell) < 0)  return ERROR;
	    break;

	case USE_DCELL:
	    dcell = raster.dcell[i];
	    /* insert the NULL values */
	    G_insert_d_null_values (dcell, null_flags[i], page.cols);
	    if (G_put_d_raster_row (fd, dcell) < 0)  return ERROR;
	    break;
	}
    }
    return configure_plot();
}

int set_cat (CELL x)
{
    cat = x;
    if ( (isnull = ISNULL(&cat)) ) cat = 0;
    return 0;
}

int set_dcat (DCELL x)
{
    dcat = x;
    if ( (isnull = ISDNULL(&dcat)) ) dcat = 0;
    return 0;
}

int raster_dot (int x, int y)
{
    dot(x,y);
    return 0;
}

static int move (int x, int y)
{
    cur_x = x;
    cur_y = y;

    return 0;
}

static int cont (int x, int y)
{
    if(cur_x < 0 && x < 0) goto set;
    if(cur_y < 0 && y < 0) goto set;
    if(cur_x >= page.cols && x >= page.cols) goto set;
    if(cur_y >= page.rows && y >= page.rows) goto set;

    G_bresenham_line (cur_x, cur_y, x, y, dot);

set:
    move (x, y);

    return 0;
}

static int cell_dot (int x, int y)
{
    if (x >= 0 && x < page.cols && y >= 0 && y < page.rows) {
	raster.cell[y][x] = cat;
	null_flags[y][x] = isnull;
    }
    return 0;
}

static int dcell_dot (int x, int y)
{
    if (x >= 0 && x < page.cols && y >= 0 && y < page.rows) {
	raster.dcell[y][x] = dcat;
	null_flags[y][x] = isnull;
    }
    return 0;
}