1 files changed, 40 insertions, 0 deletions

diff --git a/src/export/convert_coords.c b/src/export/convert_coords.c
new file mode 100644
index 0000000..37d780a
--- /dev/null
+++ b/src/export/convert_coords.c
@@ -0,0 +1,40 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+int main(int argc, char *argv[])
+{
+        double x, y;
+        char buf[64];
+        int in;
+        while( fgets( buf, sizeof(buf), stdin ) )
+        {
+            if( sscanf( buf, "%lf %lf", &x, &y ) == 2 ) {
+                double R   = 6365000;
+                double fe  = 5200000;
+                double fn  = 1200000;
+                double ph0 = 0.5235977; // 30deg
+                double ph1 = 0.7853980; // 45deg
+                double ph2 = 0.9599309; // 55deg
+                double l0  = 0.1745329; // 10deg
+
+                double xs = (x-fe)/R;
+                double ys = (y-fn)/R;
+                double ph0_s = 0.25*M_PI+0.5*ph0;
+                double ph1_s = 0.25*M_PI+0.5*ph1;
+                double ph2_s = 0.25*M_PI+0.5*ph2;
+
+                double n  = log(cos(ph1)/cos(ph2))/log(tan(ph2_s)/tan(ph1_s));
+                double F  = cos(ph1)*pow(tan(ph1_s),n)/n;
+                double r0 = F / pow(tan(ph0_s),n);
+                double r  = sqrt(pow(xs,2)+pow(r0-ys,2));
+                double th = atan(xs/(r0-ys));
+
+                double lon = l0+th/n;
+                double lat = 2.0*atan(pow(F/r,1.0/n))-0.5*M_PI;
+
+                printf("%lf\t%lf\n", lat*180.0/M_PI, lon*180.0/M_PI);
+            } else
+                printf("\t\n");
+        }
+        return 0;
+}