Merge branch 'master' into examples_refactor

imgui.cpp

@@ -257,6 +257,7 @@
                        - you may pass a ImFontAtlas* pointer to CreateContext() to share a font atlas between contexts. Otherwhise CreateContext() will create its own font atlas instance.
                        - removed allocator parameters from CreateContext(), they are now setup with SetAllocatorFunctions(), and shared by all contexts.
                        - removed the default global context and font atlas instance, which were confusing for users of DLL reloading and users of multiple contexts.
+ - 2018/01/31 (1.60) - moved sample TTF files from extra_fonts/ to misc/fonts/. If you loaded files directly from the imgui repo you may need to update your paths.
  - 2018/01/11 (1.60) - obsoleted IsAnyWindowHovered() in favor of IsWindowHovered(ImGuiHoveredFlags_AnyWindow). Kept redirection function (will obsolete).
  - 2018/01/11 (1.60) - obsoleted IsAnyWindowFocused() in favor of IsWindowFocused(ImGuiFocusedFlags_AnyWindow). Kept redirection function (will obsolete).
  - 2018/01/03 (1.60) - renamed ImGuiSizeConstraintCallback to ImGuiSizeCallback, ImGuiSizeConstraintCallbackData to ImGuiSizeCallbackData.
@@ -547,11 +548,15 @@
 
  Q: How can I load a different font than the default? (default is an embedded version of ProggyClean.ttf, rendered at size 13)
  A: Use the font atlas to load the TTF/OTF file you want:
-
       ImGuiIO& io = ImGui::GetIO();
       io.Fonts->AddFontFromFileTTF("myfontfile.ttf", size_in_pixels);
       io.Fonts->GetTexDataAsRGBA32() or GetTexDataAsAlpha8()
 
+    New programmers: remember that in C/C++ and most programming languages if you want to use a backslash \ in a string literal you need to write a double backslash "\\":
+      io.Fonts->AddFontFromFileTTF("MyDataFolder\MyFontFile.ttf", size_in_pixels);   // WRONG
+      io.Fonts->AddFontFromFileTTF("MyDataFolder\\MyFontFile.ttf", size_in_pixels);  // CORRECT
+      io.Fonts->AddFontFromFileTTF("MyDataFolder/MyFontFile.ttf", size_in_pixels);   // ALSO CORRECT
+
  Q: How can I easily use icons in my application?
  A: The most convenient and practical way is to merge an icon font such as FontAwesome inside you main font. Then you can refer to icons within your 
     strings. Read 'How can I load multiple fonts?' and the file 'misc/fonts/README.txt' for instructions and useful header files.
@@ -2636,6 +2641,7 @@ ImGuiContext* ImGui::CreateContext(ImFontAtlas* shared_font_atlas)
     ImGuiContext* ctx = IM_NEW(ImGuiContext)(shared_font_atlas);
     if (GImGui == NULL)
         SetCurrentContext(ctx);
+    Initialize(ctx);
     return ctx;
 }
 
@@ -3280,6 +3286,7 @@ void ImGui::NewFrame()
 
     // Check user data
     // (We pass an error message in the assert expression as a trick to get it visible to programmers who are not using a debugger, as most assert handlers display their argument)
+    IM_ASSERT(g.Initialized);
     IM_ASSERT(g.IO.DeltaTime >= 0.0f                                    && "Need a positive DeltaTime (zero is tolerated but will cause some timing issues)");
     IM_ASSERT(g.IO.DisplaySize.x >= 0.0f && g.IO.DisplaySize.y >= 0.0f  && "Invalid DisplaySize value");
     IM_ASSERT(g.IO.Fonts->Fonts.Size > 0                                && "Font Atlas not built. Did you call io.Fonts->GetTexDataAsRGBA32() / GetTexDataAsAlpha8() ?");
@@ -3294,9 +3301,13 @@ void ImGui::NewFrame()
     if (g.IO.NavFlags & ImGuiNavFlags_EnableKeyboard)
         IM_ASSERT(g.IO.KeyMap[ImGuiKey_Space] != -1 && "ImGuiKey_Space is not mapped, required for keyboard navigation.");
 
-    // Initialize on first frame
-    if (!g.Initialized)
-        Initialize(&g);
+    // Load settings on first frame
+    if (!g.SettingsLoaded)
+    {
+        IM_ASSERT(g.SettingsWindows.empty());
+        LoadIniSettingsFromDisk(g.IO.IniFilename);
+        g.SettingsLoaded = true;
+    }
 
     g.Time += g.IO.DeltaTime;
     g.FrameCount += 1;
@@ -3602,6 +3613,7 @@ static void SettingsHandlerWindow_WriteAll(ImGuiContext* imgui_ctx, ImGuiSetting
 void ImGui::Initialize(ImGuiContext* context)
 {
     ImGuiContext& g = *context;
+    IM_ASSERT(!g.Initialized && !g.SettingsLoaded);
     g.LogClipboard = IM_NEW(ImGuiTextBuffer)();
 
     // Add .ini handle for ImGuiWindow type
@@ -3613,9 +3625,6 @@ void ImGui::Initialize(ImGuiContext* context)
     ini_handler.WriteAllFn = SettingsHandlerWindow_WriteAll;
     g.SettingsHandlers.push_front(ini_handler);
 
-    // Load .ini file
-    IM_ASSERT(g.SettingsWindows.empty());
-    LoadIniSettingsFromDisk(g.IO.IniFilename);
     g.Initialized = true;
 }
 
@@ -3765,6 +3774,7 @@ static void LoadIniSettingsFromMemory(const char* buf_readonly)
         }
     }
     ImGui::MemFree(buf);
+    g.SettingsLoaded = true;
 }
 
 static void SaveIniSettingsToDisk(const char* ini_filename)