--- a
+++ b/trunk/Plugin/edisc.c
@@ -0,0 +1,64 @@
+/*
+    Apophysis Plugin
+
+    Copyright (C) 2007-2009 Joel Faber
+    Copyright (C) 2007-2009 Michael Faber
+
+    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
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+// Must define this structure before we include apoplugin.h
+typedef struct
+{
+	double edisc_vvar;
+} Variables;
+
+#define _USE_MATH_DEFINES
+#define APO_NOVARIABLES
+#define APO_VIRTUALVAR
+#include "apoplugin.h"
+
+// Set the name of this plugin
+APO_PLUGIN("edisc");
+
+// You must call the argument "vp".
+int PluginVarPrepare(Variation* vp)
+{
+	VAR(edisc_vvar) = VVAR / 11.57034632;
+    return TRUE; // Always return TRUE.
+}
+
+// You must call the argument "vp".
+int PluginVarCalc(Variation* vp)
+{
+	double tmp = FTy * FTy + FTx * FTx + 1.0;
+	double tmp2 = 2.0 * FTx;
+	double r1 = sqrt(tmp + tmp2);
+	double r2 = sqrt(tmp - tmp2);
+	double xmax = (r1 + r2) * 0.5;
+	double snv, csv, snhu, cshu;
+	double expu, expuinv;
+
+    fsincos(log(xmax + sqrt(xmax - 1.0)), &snv, &csv);
+    sinhcosh(-acos(FTx / xmax), &snhu, &cshu);
+
+    if (FTy > 0.0)
+        snv = -snv;
+
+    FPx += VAR(edisc_vvar) * cshu * csv;
+    FPy += VAR(edisc_vvar) * snhu * snv;
+
+    return TRUE;
+}