implemented external xml/shader loading for transitions as well as regular nodes

Transitions are nodes but have a few parameters that are programmatic and always
required. This lets people write external code for transitions as well.

app/node/block/transition/CMakeLists.txt

@@ -19,6 +19,8 @@ add_subdirectory(diptoblack)
 
 set(OLIVE_SOURCES
   ${OLIVE_SOURCES}
+  node/block/transition/externaltransition.h
+  node/block/transition/externaltransition.cpp
   node/block/transition/transition.h
   node/block/transition/transition.cpp
   PARENT_SCOPE

app/node/block/transition/externaltransition.cpp

@@ -0,0 +1,64 @@
+#include "externaltransition.h"
+
+ExternalTransition::ExternalTransition(const QString &xml_meta_filename) :
+  meta_(xml_meta_filename)
+{
+  foreach (NodeInput* input, meta_.inputs()) {
+    AddInput(input);
+  }
+}
+
+Node *ExternalTransition::copy() const
+{
+  return new ExternalTransition(meta_.filename());
+}
+
+QString ExternalTransition::Name() const
+{
+  return meta_.Name();
+}
+
+QString ExternalTransition::id() const
+{
+  return meta_.id();
+}
+
+QString ExternalTransition::Category() const
+{
+  return meta_.Category();
+}
+
+QString ExternalTransition::Description() const
+{
+  return meta_.Description();
+}
+
+void ExternalTransition::Retranslate()
+{
+  meta_.Retranslate();
+}
+
+bool ExternalTransition::IsAccelerated() const
+{
+  return true;
+}
+
+QString ExternalTransition::AcceleratedCodeVertex() const
+{
+  return meta_.vert_code();
+}
+
+QString ExternalTransition::AcceleratedCodeFragment() const
+{
+  return meta_.frag_code();
+}
+
+int ExternalTransition::AcceleratedCodeIterations() const
+{
+  return meta_.iterations();
+}
+
+NodeInput *ExternalTransition::AcceleratedCodeIterativeInput() const
+{
+  return meta_.iteration_input();
+}

app/node/block/transition/externaltransition.h

@@ -0,0 +1,32 @@
+#ifndef EXTERNALTRANSITION_H
+#define EXTERNALTRANSITION_H
+
+#include "transition.h"
+
+#include "node/metareader.h"
+
+class ExternalTransition : public TransitionBlock
+{
+public:
+  ExternalTransition(const QString& xml_meta_filename);
+
+  virtual Node* copy() const override;
+
+  virtual QString Name() const override;
+  virtual QString id() const override;
+  virtual QString Category() const override;
+  virtual QString Description() const override;
+
+  virtual void Retranslate() override;
+
+  virtual bool IsAccelerated() const override;
+  virtual QString AcceleratedCodeVertex() const override;
+  virtual QString AcceleratedCodeFragment() const override;
+  virtual int AcceleratedCodeIterations() const override;
+  virtual NodeInput* AcceleratedCodeIterativeInput() const override;
+
+private:
+  NodeMetaReader meta_;
+};
+
+#endif // EXTERNALTRANSITION_H