Function gmt_map_setup

src/gmt_map.c:9926–10004

! . */

/*! . */
int gmt_map_setup (struct GMT_CTRL *GMT, double wesn[]) {
	unsigned int i;
	int error;
	bool search, double_auto[6];
	bool test_pole[2] = {true, true}, separate_intervals = false;
	double scale, i_scale;

	if ((error = gmt_proj_setup (GMT, wesn)) != GMT_NOERROR) goto gmt_map_setup_end;

	gmt_set_undefined_defaults (GMT, sqrt (GMT->current.map.width * GMT->current.map.height), false);	/* We must change any undefined defaults given max plot dimension */

	search = GMT->current.proj.search;

	/* If intervals are not set specifically, round them to some "nice" values
	 * Remember whether frame items in both directions were automatically set */
	for (i = 0; i < 6; i++)
		double_auto[i] = gmt_M_is_geographic (GMT, GMT_IN) && GMT->current.map.frame.set_both &&
		GMT->current.map.frame.axis[GMT_X].item[i].active && GMT->current.map.frame.axis[GMT_X].item[i].interval == 0.0 &&
		GMT->current.map.frame.axis[GMT_Y].item[i].active && GMT->current.map.frame.axis[GMT_Y].item[i].interval == 0.0;

	gmt_auto_frame_interval (GMT, GMT_X, GMT_ANNOT_UPPER);
	gmt_auto_frame_interval (GMT, GMT_Y, GMT_ANNOT_UPPER);
	gmt_auto_frame_interval (GMT, GMT_Z, GMT_ANNOT_UPPER);
	gmt_auto_frame_interval (GMT, GMT_X, GMT_ANNOT_LOWER);
	gmt_auto_frame_interval (GMT, GMT_Y, GMT_ANNOT_LOWER);
	gmt_auto_frame_interval (GMT, GMT_Z, GMT_ANNOT_LOWER);

	/* Then check if one or both poles are inside map.  If they are then the longitude range will be 360
	 * and depending on the latitude extent it may not make sense to use the coarse longitude-spacing determined
	 * also for the latitude spacing.  We check this and if a pole is inside and if the latitude range is < 1/4
	 * of that of the longitude (e.g., 90 degrees for a 0-360 global map) we go separate. */

	if (GMT->current.proj.projection_GMT == GMT_AZ_EQDIST) {	/* Must be careful since if a pole equals an antipode we get NaNs as coordinates */
		double x, y;
		gmt_geo_to_xy (GMT, GMT->current.proj.central_meridian, -90.0, &x, &y);
		if (gmt_M_is_dnan (x) && gmt_M_is_dnan (y)) test_pole[0] = false;
		gmt_geo_to_xy (GMT, GMT->current.proj.central_meridian, +90.0, &x, &y);
		if (gmt_M_is_dnan (x) && gmt_M_is_dnan (y)) test_pole[1] = false;
	}
	if (test_pole[0] && !gmt_map_outside (GMT, GMT->current.proj.central_meridian, -90.0)) GMT->current.proj.pole_in_map[0] = separate_intervals = true;
	if (test_pole[1] && !gmt_map_outside (GMT, GMT->current.proj.central_meridian, +90.0)) GMT->current.proj.pole_in_map[1] = separate_intervals = true;
	if (separate_intervals && (GMT->common.R.wesn[YHI] - GMT->common.R.wesn[YLO]) / (GMT->common.R.wesn[XHI] - GMT->common.R.wesn[XLO]) > 0.25)
		separate_intervals = false;	/* E.g, for a whole global hemisphere we keep them the same, else we adjust individually */

	/* Now set the pairs of automatically set intervals to be the same in both x- and y-direction, except when a geographic pole is inside an oblique map frame */
	for (i = 0; i < 6; i++) {
		if (double_auto[i] && !separate_intervals) GMT->current.map.frame.axis[GMT_X].item[i].interval = GMT->current.map.frame.axis[GMT_Y].item[i].interval =
		MAX (GMT->current.map.frame.axis[GMT_X].item[i].interval, GMT->current.map.frame.axis[GMT_Y].item[i].interval);
	}

	if (!GMT->current.map.n_lon_nodes) GMT->current.map.n_lon_nodes = urint (GMT->current.map.width / GMT->current.setting.map_line_step);
	if (!GMT->current.map.n_lat_nodes) GMT->current.map.n_lat_nodes = urint (GMT->current.map.height / GMT->current.setting.map_line_step);

	GMT->current.map.dlon = (GMT->common.R.wesn[XHI] - GMT->common.R.wesn[XLO]) / GMT->current.map.n_lon_nodes;
	GMT->current.map.dlat = (GMT->common.R.wesn[YHI] - GMT->common.R.wesn[YLO]) / GMT->current.map.n_lat_nodes;

	if (GMT->current.map.width > 400.0 && gmt_M_is_grdmapproject (GMT)) {	/* ***project calling with true scale, probably  */
		search = false;	/* Safe-guard that prevents region search below for (map|grd)project and others (400 inch = ~> 10 meters) */