/*
- * Copyright (C) 2009-201
0 Andy Spencer <andy753421@gmail.com>
+ * Copyright (C) 2009-201
1 Andy Spencer <andy753421@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
*/
/**
- * SECTION:gis-util
+ * SECTION:grits-util
* @short_description: Geographic utilities
*
* Miscellaneous utility functions, these deal mostly with coordinate
#include <glib.h>
#include <math.h>
+#include <stdio.h>
-#include "gis-util.h"
+#include "grits-util.h"
-/************
- * GisPoint *
- ************/
+/**************
+ * GritsPoint *
+ **************/
/**
- * gis_point_set_lle:
+ * grits_point_set_lle:
* @point: the point to modify
* @lat: the new latitude
* @lon: the new longitude
*
* Set the latitude, longitude, and elevation for a point.
*/
-void gis_point_set_lle(GisPoint *point, gdouble lat, gdouble lon, gdouble elev)
+void grits_point_set_lle(GritsPoint *point, gdouble lat, gdouble lon, gdouble elev)
{
point->lat = lat;
point->lon = lon;
}
-/*************
- * GisBounds *
- *************/
+/***************
+ * GritsBounds *
+ ***************/
/**
- * gis_bounds_set_bounds:
+ * grits_bounds_set_bounds:
* @n: the north edge
* @s: the south edge
* @e: the east edge
*
* Set the north, south, east, and west edges of the bounding box
*/
-void gis_bounds_set_bounds(GisBounds *bounds,
+void grits_bounds_set_bounds(GritsBounds *bounds,
gdouble n, gdouble s, gdouble e, gdouble w)
{
bounds->n = n;
}
return avg;
}
+
+/**
+ * crossd3:
+ * @a: the left point
+ * @b: the center point
+ * @c: the right point
+ * @out: the cross product
+ *
+ * Calculate the cross product of three points
+ */
+void crossd3(gdouble *a, gdouble *b, gdouble *c, gdouble *out)
+{
+ double ba[3], bc[3];
+
+ ba[0] = a[0] - b[0];
+ ba[1] = a[1] - b[1];
+ ba[2] = a[2] - b[2];
+
+ bc[0] = c[0] - b[0];
+ bc[1] = c[1] - b[1];
+ bc[2] = c[2] - b[2];
+
+ crossd(ba, bc, out);
+}
+
+/**
+ * crossd:
+ * @a: the first vector
+ * @b: the second vector
+ * @c: the cross product
+ *
+ * Calculate the cross product of two vectors
+ */
+void crossd(gdouble *a, gdouble *b, gdouble *out)
+{
+ out[0] = a[1] * b[2] - a[2] * b[1];
+ out[1] = a[2] * b[0] - a[0] * b[2];
+ out[2] = a[0] * b[1] - a[1] * b[0];
+}
+
+/**
+ * lengthd:
+ * @a: the vector
+ *
+ * Calculate the length (magnitude) of a vector.
+ *
+ * Returns: the length
+ */
+gdouble lengthd(gdouble *a)
+{
+ return sqrt(a[0] * a[0] +
+ a[1] * a[1] +
+ a[2] * a[2]);
+}
+
+/**
+ * normd:
+ * @a: the first longitude
+ *
+ * Normalize a vector to a mangitude of 1
+ */
+void normd(gdouble *a)
+{
+ gdouble total = lengthd(a);
+ a[0] = a[0] / total;
+ a[1] = a[1] / total;
+ a[2] = a[2] / total;
+}
+
+/**
+ * parse_points:
+ * @string: String representation of the points
+ * @group_sep: Group separator
+ * @point_sep: Point separator
+ * @coord_sep: Coordinate separator
+ * @bounds: The bounding box of all the points, or NULL
+ * @center: The center of the @bounds, or NULL
+ *
+ * Parse a string of the form:
+ * string -> group [@group_sep group] ...
+ * group -> point [@point_sep point] ...
+ * point -> latitude @coord_sep longitude [@coord_sep elevation]
+ *
+ * For example
+ * parse_points("30,-80 30,-120 50,-120 50,-80", "\t", " ", ",");
+ *
+ * Returns: zero-terminated array of groups of points
+ */
+GritsPoints *parse_points(const gchar *string,
+ const gchar *group_sep, const gchar *point_sep, const gchar *coord_sep,
+ GritsBounds *bounds, GritsPoint *center)
+{
+ /* Split and count groups */
+ gchar **sgroups = g_strsplit(string, group_sep, -1);
+ int ngroups = g_strv_length(sgroups);
+
+ GritsBounds _bounds = {-90, 90, -180, 180};
+ gdouble (**groups)[3] = (gpointer)g_new0(double*, ngroups+1);
+ for (int pi = 0; pi < ngroups; pi++) {
+ /* Split and count coordinates */
+ gchar **scoords = g_strsplit(sgroups[pi], point_sep, -1);
+ int ncoords = g_strv_length(scoords);
+
+ /* Create binary coords */
+ gdouble (*coords)[3] = (gpointer)g_new0(gdouble, 3*(ncoords+1));
+ for (int ci = 0; ci < ncoords; ci++) {
+ gdouble lat, lon;
+ sscanf(scoords[ci], "%lf,%lf", &lat, &lon);
+ if (bounds || center) {
+ if (lat > _bounds.n) _bounds.n = lat;
+ if (lat < _bounds.s) _bounds.s = lat;
+ if (lon > _bounds.e) _bounds.e = lon;
+ if (lon < _bounds.w) _bounds.w = lon;
+ }
+ lle2xyz(lat, lon, 0,
+ &coords[ci][0],
+ &coords[ci][1],
+ &coords[ci][2]);
+ }
+
+ /* Insert coords into line array */
+ groups[pi] = coords;
+ g_strfreev(scoords);
+ }
+ g_strfreev(sgroups);
+
+ /* Output */
+ if (bounds)
+ *bounds = _bounds;
+ if (center) {
+ center->lat = (_bounds.n + _bounds.s)/2;
+ center->lon = lon_avg(_bounds.e, _bounds.w);
+ center->elev = 0;
+ }
+ return groups;
+}
+
+/**
+ * free_points:
+ * @points: Array of points allocated by parse_points()
+ *
+ * Frees all data allocated by parse_points
+ */
+void free_points(GritsPoints *points)
+{
+ gdouble (**_points)[3] = points;
+ for (int i = 0; _points[i]; i++)
+ g_free(_points[i]);
+ g_free(_points);
+}
projects / grits / blobdiff