1 files changed, 34 insertions, 0 deletions
diff --git a/src/cmd/map/libmap/simpleconic.c b/src/cmd/map/libmap/simpleconic.c
new file mode 100644
index 00000000..1ed1d1aa
--- /dev/null
+++ b/src/cmd/map/libmap/simpleconic.c
@@ -0,0 +1,34 @@
+#include <u.h>
+#include <libc.h>
+#include "map.h"
+
+static double r0, a;
+
+static int
+Xsimpleconic(struct place *place, double *x, double *y)
+{
+	double r = r0 - place->nlat.l;
+	double t = a*place->wlon.l;
+	*x = -r*sin(t);
+	*y = -r*cos(t);
+	return 1;
+}
+
+proj
+simpleconic(double par0, double par1)
+{
+	struct coord lat0;
+	struct coord lat1;
+	deg2rad(par0,&lat0);
+	deg2rad(par1,&lat1);
+	if(fabs(lat0.l+lat1.l)<.01)
+		return rectangular(par0);
+	if(fabs(lat0.l-lat1.l)<.01) {
+		a = lat0.s/lat0.l;
+		r0 = lat0.c/lat0.s + lat0.l;
+	} else {
+		a = (lat1.c-lat0.c)/(lat0.l-lat1.l);
+		r0 = ((lat0.c+lat1.c)/a + lat1.l + lat0.l)/2;
+	}
+	return Xsimpleconic;
+}