Function gmtplot_plot_vector_head_fill

src/gmt_plot.c:5061–5126

}

GMT_LOCAL void gmtplot_plot_vector_head_fill (struct GMT_CTRL *GMT, double *xp, double *yp, uint64_t n, struct GMT_SYMBOL *S) {
	/* PW: Plots the polygon that makes up a vector head.  Because sometimes these head stick
	 * across a periodic boundary we must check if that is the case and plot the two parts separately.
	 * When that is the case we cannot draw the outline of the two new polygons since we wish to show
	 * the heads as "clipped" by the boundary; hence all the rigamarole below. */
	uint64_t start = 0, nin = 0;
	unsigned int n_use, *pin = NULL;	/* Copy of the pen moves */
	unsigned int cap = GMT->PSL->internal.line_cap;
	double *xin = NULL, *yin = NULL;	/* Temp vector with possibly clipped x,y line returned by gmt_geo_to_xy_line */
	if ((GMT->current.plot.n = gmt_geo_to_xy_line (GMT, xp, yp, n)) == 0) return;	/* All outside, or use plot.x|y array */
	PSL_setlinecap (GMT->PSL, PSL_SQUARE_CAP);	/* In case there are clipped heads and we want to do the best we can with the lines */
	n = GMT->current.plot.n;	/* Possibly fewer points */
	if (PSL_vec_outline (S->v.status)) {
		bool close = (GMT->current.plot.n > 2 && gmt_polygon_is_open (GMT, GMT->current.plot.x, GMT->current.plot.y, GMT->current.plot.n));
		nin = n;
		PSL_command (GMT->PSL, "O0\n");	/* Temporary turn off outline; must draw outline separately when head is split */
		if (close) nin++;
		xin = gmt_M_memory (GMT, NULL, nin, double);
		yin = gmt_M_memory (GMT, NULL, nin, double);
		pin = gmt_M_memory (GMT, NULL, nin, unsigned int);
		gmt_M_memcpy (xin, GMT->current.plot.x, n, double);
		gmt_M_memcpy (yin, GMT->current.plot.y, n, double);
		gmt_M_memcpy (pin, GMT->current.plot.pen, n, unsigned int);
		if (close) {	/* Explicitly close the polygon outline */
			xin[n] = xin[0];
			yin[n] = yin[0];
		}
	}

	if ((*GMT->current.map.will_it_wrap) (GMT, GMT->current.plot.x, GMT->current.plot.y, GMT->current.plot.n, &start)) {	/* Polygon does indeed wrap */
		double *xtmp = NULL, *ytmp = NULL;	/* Temp vector for map truncating */
		GMT_Report (GMT->parent, GMT_MSG_DEBUG, "Vector head polygon will wrap at periodic boundary and will be split into two sections\n");
		xtmp = gmt_M_memory (GMT, NULL, n, double);
		ytmp = gmt_M_memory (GMT, NULL, n, double);
		gmt_M_memcpy (xtmp, GMT->current.plot.x, n, double);
		gmt_M_memcpy (ytmp, GMT->current.plot.y, n, double);
		/* First truncate against left border */
		GMT->current.plot.n = gmt_map_truncate (GMT, xtmp, ytmp, n, start, -1);
		n_use = (unsigned int)gmt_compact_line (GMT, GMT->current.plot.x, GMT->current.plot.y, GMT->current.plot.n, false, 0);
		PSL_beginclipping (GMT->PSL, GMT->current.plot.x, GMT->current.plot.y, (int)n_use, GMT->session.no_rgb, 3);
		PSL_plotpolygon (GMT->PSL, GMT->current.plot.x, GMT->current.plot.y, (int)n_use);
		if (PSL_vec_outline (S->v.status)) gmt_plot_line (GMT, xin, yin, pin, nin, PSL_LINEAR);
		PSL_endclipping (GMT->PSL, 1);
		/* Then truncate against right border */
		GMT->current.plot.n = gmt_map_truncate (GMT, xtmp, ytmp, n, start, +1);
		n_use = (unsigned int)gmt_compact_line (GMT, GMT->current.plot.x, GMT->current.plot.y, GMT->current.plot.n, false, 0);
		PSL_beginclipping (GMT->PSL, GMT->current.plot.x, GMT->current.plot.y, (int)n_use, GMT->session.no_rgb, 3);
		PSL_plotpolygon (GMT->PSL, GMT->current.plot.x, GMT->current.plot.y, (int)n_use);
		if (PSL_vec_outline (S->v.status)) gmt_plot_line (GMT, xin, yin, pin, nin, PSL_LINEAR);
		PSL_endclipping (GMT->PSL, 1);
		gmt_M_free (GMT, xtmp);		gmt_M_free (GMT, ytmp);
	}
	else {	/* No wrapping but may be clipped */
		PSL_beginclipping (GMT->PSL, GMT->current.plot.x, GMT->current.plot.y, (int)GMT->current.plot.n, GMT->session.no_rgb, 3);
		PSL_plotpolygon (GMT->PSL, GMT->current.plot.x, GMT->current.plot.y, (int)GMT->current.plot.n);
		if (PSL_vec_outline (S->v.status)) gmt_plot_line (GMT, xin, yin, pin, nin, PSL_LINEAR);
		PSL_endclipping (GMT->PSL, 1);
	}