Removed the dependency on realloc functionality #117 + fixed one alloc in NewFrame()

imgui.cpp

@@ -128,6 +128,7 @@
  Occasionally introducing changes that are breaking the API. The breakage are generally minor and easy to fix.
  Here is a change-log of API breaking changes, if you are using one of the functions listed, expect to have to fix some code.
  
+ - 2015/02/01 (1.31) - removed IO.MemReallocFn (unused)
  - 2015/01/19 (1.30) - renamed ImGuiStorage::GetIntPtr()/GetFloatPtr() to GetIntRef()/GetIntRef() because Ptr was conflicting with actual pointer storage functions.
  - 2015/01/11 (1.30) - big font/image API change! now loads TTF file. allow for multiple fonts. no need for a PNG loader.
               (1.30) - removed GetDefaultFontData(). uses io.Fonts->GetTextureData*() API to retrieve uncompressed pixels.
@@ -537,7 +538,6 @@ ImGuiIO::ImGuiIO()
     // User functions
     RenderDrawListsFn = NULL;
     MemAllocFn = malloc;
-    MemReallocFn = realloc;
     MemFreeFn = free;
     GetClipboardTextFn = GetClipboardTextFn_DefaultImpl;   // Platform dependent default implementations
     SetClipboardTextFn = SetClipboardTextFn_DefaultImpl;
@@ -1484,11 +1484,6 @@ void ImGui::MemFree(void* ptr)
 {
     return GImGui.IO.MemFreeFn(ptr);
 }
-
-void* ImGui::MemRealloc(void* ptr, size_t sz)
-{
-    return GImGui.IO.MemReallocFn(ptr, sz);
-}
     
 static ImGuiIniData* FindWindowSettings(const char* name)
 {
@@ -1754,7 +1749,7 @@ void ImGui::NewFrame()
 
     // No window should be open at the beginning of the frame.
     // But in order to allow the user to call NewFrame() multiple times without calling Render(), we are doing an explicit clear.
-    g.CurrentWindowStack.clear();
+    g.CurrentWindowStack.resize(0);
 
     // Create implicit window - we will only render it if the user has added something to it.
     ImGui::Begin("Debug", NULL, ImVec2(400,400));

imgui.h

@@ -69,10 +69,9 @@ struct ImVec4
 
 namespace ImGui
 {
-    // Proxy functions to access the MemAllocFn/MemFreeFn/MemReallocFn pointers in ImGui::GetIO(). The only reason they exist here is to allow ImVector<> to compile inline.
+    // Proxy functions to access the MemAllocFn/MemFreeFn pointers in ImGui::GetIO(). The only reason they exist here is to allow ImVector<> to compile inline.
     IMGUI_API void*       MemAlloc(size_t sz);
     IMGUI_API void        MemFree(void* ptr);
-    IMGUI_API void*       MemRealloc(void* ptr, size_t sz);
 }
 
 // std::vector<> like class to avoid dragging dependencies (also: windows implementation of STL with debug enabled is absurdly slow, so let's bypass it so our code runs fast in debug). 
@@ -115,8 +114,16 @@ public:
     inline const value_type&    back() const                    { IM_ASSERT(Size > 0); return Data[Size-1]; }
     inline void                 swap(ImVector<T>& rhs)          { const size_t rhs_size = rhs.Size; rhs.Size = Size; Size = rhs_size; const size_t rhs_cap = rhs.Capacity; rhs.Capacity = Capacity; Capacity = rhs_cap; value_type* rhs_data = rhs.Data; rhs.Data = Data; Data = rhs_data; }
 
-    inline void                 reserve(size_t new_capacity)    { Data = (value_type*)ImGui::MemRealloc(Data, new_capacity * sizeof(value_type)); Capacity = new_capacity; }
     inline void                 resize(size_t new_size)         { if (new_size > Capacity) reserve(new_size); Size = new_size; }
+    inline void                 reserve(size_t new_capacity)    
+    { 
+        if (new_capacity <= Capacity) return;
+        T* new_data = (value_type*)ImGui::MemAlloc(new_capacity * sizeof(value_type));
+        memcpy(new_data, Data, Size * sizeof(value_type));
+        ImGui::MemFree(Data);
+        Data = new_data;
+        Capacity = new_capacity; 
+    }
 
     inline void                 push_back(const value_type& v)  { if (Size == Capacity) reserve(Capacity ? Capacity * 2 : 4); Data[Size++] = v; }
     inline void                 pop_back()                      { IM_ASSERT(Size > 0); Size--; }
@@ -523,9 +530,8 @@ struct ImGuiIO
     const char* (*GetClipboardTextFn)();
     void        (*SetClipboardTextFn)(const char* text);
 
-    // Optional: override memory allocations (default to posix malloc/realloc/free). MemFreeFn() may be called with a NULL pointer.
+    // Optional: override memory allocations (default to posix malloc/free). MemFreeFn() may be called with a NULL pointer.
     void*       (*MemAllocFn)(size_t sz);
-    void*       (*MemReallocFn)(void* ptr, size_t sz);
     void        (*MemFreeFn)(void* ptr);
 
     // Optional: notify OS Input Method Editor of the screen position of your cursor for text input position (e.g. when using Japanese/Chinese inputs in Windows)