Based on feedback, only use OB (library) or obmm if no Python (#1602)

* Based on feedback, only use OB (library) or obmm if no Python

The new Python energy scripts are preferred
- more flexible (e.g., Open Babel or RDKit)
- can use requirements via pip / conda

Signed-off-by: Geoff Hutchison <geoff.hutchison@gmail.com>

Author: ghutchis

avogadro/qtplugins/forcefield/forcefield.cpp

@@ -65,18 +65,19 @@ Forcefield::Forcefield(QObject* parent_)
   m_gradientTolerance = settings.value("gradientTolerance", 1.0e-4).toDouble();
   settings.endGroup();
 
+  // prefer to use Python interface scripts if available
+  refreshScripts();
+
   // add the openbabel calculators in case they don't exist
 #ifdef BUILD_GPL_PLUGINS
   // These directly use Open Babel and are fast
+  qDebug() << " registering GPL plugins";
   Calc::EnergyManager::registerModel(new OBEnergy("MMFF94"));
   Calc::EnergyManager::registerModel(new OBEnergy("UFF"));
   Calc::EnergyManager::registerModel(new OBEnergy("GAFF"));
-#endif
-
-  refreshScripts();
-
-#ifndef BUILD_GPL_PLUGINS
-  // These call obmm and can be slow
+#else
+  // These call obmm and can be slower
+  qDebug() << " registering obmm plugins";
   Calc::EnergyManager::registerModel(new OBMMEnergy("MMFF94"));
   Calc::EnergyManager::registerModel(new OBMMEnergy("UFF"));
   Calc::EnergyManager::registerModel(new OBMMEnergy("GAFF"));

avogadro/qtplugins/forcefield/obenergy.cpp

@@ -18,6 +18,7 @@
 #include <openbabel/obconversion.h>
 #include <openbabel/obiter.h>
 
+#include <QCoreApplication>
 #include <QDebug>
 #include <QDir>
 
@@ -43,12 +44,25 @@ OBEnergy::OBEnergy(const std::string& method)
   : m_identifier(method), m_name(method), m_molecule(nullptr)
 {
   d = new Private;
+
+  // make sure we set the Open Babel variables for data files
+#ifdef _WIN32
+  QByteArray dataDir =
+    QString(QCoreApplication::applicationDirPath() + "/data").toLocal8Bit();
+  qputenv("BABEL_DATADIR", dataDir);
+#endif
   // Ensure the plugins are loaded
   OBPlugin::LoadAllPlugins();
 
   d->m_forceField = static_cast<OBForceField*>(
     OBPlugin::GetPlugin("forcefields", method.c_str()));
 
+  qDebug() << "OBEnergy: method: " << method.c_str();
+  if (d->m_forceField == nullptr) {
+    qDebug() << "OBEnergy: method not found: " << method.c_str();
+    qDebug() << OBPlugin::ListAsString("forcefields").c_str();
+  }
+
   if (method == "UFF") {
     m_description = tr("Universal Force Field");
     m_elements.reset();