raster2.c

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/********************************************************************
 * code in this file is designed to send raster data to the graphics
 * driver. It handles raster->color lookup translation, as well as
 * loading appropriate colormaps into the driver and the sending of
 * raster data to the plotter. The loading of colors is designed to
 * never send more colors than the hardware can support - even though
 * the GRASS drivers will allocate virtual colormaps to pretend there are more
 * This code effectively disables that driver feature/mistake.
 *
 * To simply plot raster data:
 *
 * to specify if overlay mode is to be used
 *   D_set_overlay_mode(flag)
 *      int flag;              /1=yes,0=no/
 *
 * to select a raster color for line drawing
 *   D_color (cat, colors)
 *      CELL cat
 *      struct Colors *colors; /color info/
 *
 *   D_color_of_type(raster, colors, data_type);
 *      void *raster;
 *      struct Colors *colors; /color info/
 *      RASTER_MAP_TYPE data_type;
 *
 * Note: the same Colors structure must be passed to all routines.
 *
 */
#include <stdlib.h>
#include <grass/gis.h>
#include <grass/display.h>
#include <grass/raster.h>

int D__overlay_mode = 0;        /* external for now, but to be fixed later */


int D_set_overlay_mode(int n)
{
    D__overlay_mode = (n != 0);

    return 0;
}


/* this routine modifies the hardware colormap
 * provided that we are not using fixed mode colors.
 * For use by programs such as d.colors
 *
 * returns:
 *    0 error - in fixed mode,
 *              or cat not in min:max color range
 *    1 ok
 */

int D_color(CELL cat, struct Colors *colors)
{
    return D_c_color(cat, colors);
}

/* select color for line drawing */
int D_c_color(CELL cat, struct Colors *colors)
{
    return D_color_of_type(&cat, colors, CELL_TYPE);
}

/* select color for line drawing */

int D_d_color(DCELL val, struct Colors *colors)
{
    return D_color_of_type(&val, colors, DCELL_TYPE);
}

/* select color for line drawing */

int D_f_color(FCELL val, struct Colors *colors)
{
    return D_color_of_type(&val, colors, FCELL_TYPE);
}


int D_color_of_type(const void *raster,
                    struct Colors *colors, RASTER_MAP_TYPE data_type)
{
    int r, g, b;

    G_get_raster_color(raster, &r, &g, &b, colors, data_type);
    R_RGB_color((unsigned char)r, (unsigned char)g, (unsigned char)b);

    return 0;
}