implemented demonstrative dip to black transition

app/node/block/transition/crossdissolve/crossdissolve.cpp

@@ -1,10 +1,5 @@
 #include "crossdissolve.h"
 
-CrossDissolveTransition::CrossDissolveTransition()
-{
-
-}
-
 Node *CrossDissolveTransition::copy() const
 {
   CrossDissolveTransition* c = new CrossDissolveTransition();

app/node/block/transition/crossdissolve/crossdissolve.h

@@ -6,7 +6,7 @@
 class CrossDissolveTransition : public TransitionBlock
 {
 public:
-  CrossDissolveTransition();
+  CrossDissolveTransition() = default;
 
   virtual Node* copy() const override;
 

app/node/block/transition/diptoblack/diptoblack.cpp

@@ -1,6 +1,35 @@
 #include "diptoblack.h"
 
-DipToBlackTransition::DipToBlackTransition()
+Node *DipToBlackTransition::copy() const
 {
+  DipToBlackTransition* c = new DipToBlackTransition();
 
+  CopyParameters(this, c);
+
+  return c;
+}
+
+QString DipToBlackTransition::Name() const
+{
+  return tr("Dip to Black");
+}
+
+QString DipToBlackTransition::id() const
+{
+  return "org.olivevideoeditor.Olive.diptoblack";
+}
+
+QString DipToBlackTransition::Description() const
+{
+  return tr("A smooth dip to transparency and back into another clip.");
+}
+
+bool DipToBlackTransition::IsAccelerated() const
+{
+  return true;
+}
+
+QString DipToBlackTransition::CodeFragment() const
+{
+  return ReadFileAsString(":/shaders/diptoblack.frag");
 }

app/node/block/transition/diptoblack/diptoblack.h

@@ -6,7 +6,16 @@
 class DipToBlackTransition : public TransitionBlock
 {
 public:
-  DipToBlackTransition();
+  DipToBlackTransition() = default;
+
+  virtual Node* copy() const override;
+
+  virtual QString Name() const override;
+  virtual QString id() const override;
+  virtual QString Description() const override;
+
+  virtual bool IsAccelerated() const override;
+  virtual QString CodeFragment() const override;
 };
 
 #endif // DIPTOBLACKTRANSITION_H