From a64f9e671936451d7a3a60191dcca6e37e97e585 Mon Sep 17 00:00:00 2001
From: Tavian Barnes <tavianator@gmail.com>
Date: Thu, 9 Jul 2009 21:03:16 +0000
Subject: Implement removing/inserting in the middle of a dmnsn_array*.

---
 libdimension/dimension/array.h       | 28 ++++++++++++++++++++++++++++
 libdimensionxx/dimensionxx/scene.hpp | 11 ++++++++---
 libdimensionxx/scene.cpp             | 17 +++++++++++++++++
 3 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/libdimension/dimension/array.h b/libdimension/dimension/array.h
index c12ff9f..d835d60 100644
--- a/libdimension/dimension/array.h
+++ b/libdimension/dimension/array.h
@@ -139,4 +139,32 @@ dmnsn_array_pop(dmnsn_array *array, void *obj)
   dmnsn_array_resize(array, size - 1);   /* Shrink the array */
 }
 
+/* Insert an item into the middle of the array */
+DMNSN_INLINE void
+dmnsn_array_insert(dmnsn_array *array, size_t i, const void *obj)
+{
+  size_t size = dmnsn_array_size(array);
+  /* Increase the size by 1 */
+  dmnsn_array_resize(array, size + 1);
+  /* Move the elements at and after `i' 1 to the right */
+  memmove((char *)array->ptr + array->obj_size*(i + 1),
+          (char *)array->ptr + array->obj_size*i,
+          array->obj_size*(size - i));
+  /* Insert `obj' at `i' */
+  memcpy((char *)array->ptr + array->obj_size*i, obj, array->obj_size);
+}
+
+/* Remove an item from the middle of the array */
+DMNSN_INLINE void
+dmnsn_array_remove(dmnsn_array *array, size_t i)
+{
+  size_t size = dmnsn_array_size(array);
+  /* Move the array elements after `i' 1 to the left */
+  memmove((char *)array->ptr + array->obj_size*i,
+          (char *)array->ptr + array->obj_size*(i + 1),
+          array->obj_size*(size - i));
+  /* Decrease the size by 1 */
+  dmnsn_array_resize(array, size - 1);
+}
+
 #endif /* DIMENSION_ARRAY_H */
diff --git a/libdimensionxx/dimensionxx/scene.hpp b/libdimensionxx/dimensionxx/scene.hpp
index 73cbc2e..acb2cb1 100644
--- a/libdimensionxx/dimensionxx/scene.hpp
+++ b/libdimensionxx/dimensionxx/scene.hpp
@@ -25,7 +25,7 @@
 
 namespace Dimension
 {
-  // Iterator class for scene objects
+  // Iterator class for scene objects - never invalidated unless removed
   class Scene_Iterator;
 
   // Base scene class.  Wraps a dmnsn_scene*.
@@ -55,6 +55,7 @@ namespace Dimension
     Iterator end();
 
     void push_object(Object& object);
+    void remove_object(Iterator i);
 
     // Access the wrapped C object.
     dmnsn_scene*       dmnsn();
@@ -72,8 +73,10 @@ namespace Dimension
 
   class Scene_Iterator
   {
+    typedef std::list<std::tr1::shared_ptr<Object> >::iterator Iterator;
+
   public:
-    Scene_Iterator(std::list<std::tr1::shared_ptr<Object> >::iterator i)
+    Scene_Iterator(Iterator i)
       : m_i(i) { }
     // Scene_Iterator(const Scene_Iterator& i);
     // ~Scene_Iterator();
@@ -91,8 +94,10 @@ namespace Dimension
     Scene_Iterator& operator--()    { --m_i; return *this; }
     Scene_Iterator  operator--(int) { return Scene_Iterator(m_i--); }
 
+    Iterator iterator() const { return m_i; }
+
   private:
-    std::list<std::tr1::shared_ptr<Object> >::iterator m_i;
+    Iterator m_i;
   };
 }
 
diff --git a/libdimensionxx/scene.cpp b/libdimensionxx/scene.cpp
index 4ff19e1..1bff351 100644
--- a/libdimensionxx/scene.cpp
+++ b/libdimensionxx/scene.cpp
@@ -99,6 +99,23 @@ namespace Dimension
     dmnsn_array_push(dmnsn()->objects, &cobject);
   }
 
+  // Remove an object
+  void
+  Scene::remove_object(Iterator i)
+  {
+    // Find it in the dmnsn_array* of objects and remove it
+    for (unsigned int j = 0; j < dmnsn_array_size(dmnsn()->objects); ++j) {
+      dmnsn_object* cobject;
+      dmnsn_array_get(dmnsn()->objects, j, &cobject);
+      if (cobject == i->dmnsn()) {
+        dmnsn_array_remove(dmnsn()->objects, j);
+        break;
+      }
+    }
+    // Remove it from the std::list
+    m_objects.erase(i.iterator());
+  }
+
   // Access the wrapped C object.
 
   dmnsn_scene*
-- 
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