Misc: Added an explicit compile-time test for non-scoped IM_ASSERT() macros to redirect users to a solution + fixed our stb wrappers.

+ Nav: Use nav layer enum, comments.

Author: ocornut

docs/CHANGELOG.txt

@@ -69,6 +69,8 @@ Other Changes:
 - Window: Fixed a bug with child window inheriting ItemFlags from their parent when the child
   window also manipulate the ItemFlags stack. (#3024) [@Stanbroek]
 - Font: Fixed non-ASCII space occasionally creating unnecessary empty polygons.
+- Misc: Added an explicit compile-time test for non-scoped IM_ASSERT() macros to redirect users
+  to a solution rather than encourage people to add braces in the codebase.
 - Misc: Added additional checks in EndFrame() to verify that io.KeyXXX values have not been
   tampered with between NewFrame() and EndFrame().
 - Misc, Freetype: Fixed support for IMGUI_STB_RECT_PACK_FILENAME compile time directive

examples/imgui_impl_win32.h

@@ -17,9 +17,9 @@ IMGUI_IMPL_API void     ImGui_ImplWin32_NewFrame();
 //#define IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
 //#define IMGUI_IMPL_WIN32_DISABLE_LINKING_XINPUT
 
-// Win32 message handler
-// - Intentionally commented out in a '#if 0' block to avoid dragging dependencies on <windows.h>
-// - You can COPY this line into your .cpp code to forward declare the function.
+// Win32 message handler your application need to call.
+// - Intentionally commented out in a '#if 0' block to avoid dragging dependencies on <windows.h> from this helper.
+// - You should COPY the line below into your .cpp code to forward declare the function and then you can call it.
 #if 0
 extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 #endif

imgui.cpp

@@ -6718,6 +6718,14 @@ static void ImGui::ErrorCheckNewFrameSanityChecks()
 {
     ImGuiContext& g = *GImGui;
 
+    // Check user IM_ASSERT macro
+    // (IF YOU GET A WARNING OR COMPILE ERROR HERE: it means you assert macro is incorrectly defined!
+    //  If your macro uses multiple statements, it NEEDS to be surrounded by a 'do { ... } while (0)' block.
+    //  This is a common C/C++ idiom to allow multiple statements macros to be used in control flow blocks.)
+    // #define IM_ASSERT(EXPR)   SomeCode(EXPR); SomeMoreCode();                    // Wrong!
+    // #define IM_ASSERT(EXPR)   do { SomeCode(EXPR); SomeMoreCode(); } while (0)   // Correct!
+    if (true) IM_ASSERT(1); else IM_ASSERT(0);
+
     // Check user data
     // (We pass an error message in the assert expression to make it visible to programmers who are not using a debugger, as most assert handlers display their argument)
     IM_ASSERT(g.Initialized);
@@ -7631,7 +7639,7 @@ void ImGui::ClosePopupToLevel(int remaining, bool restore_focus_to_window_under_
         }
         else
         {
-            if (g.NavLayer == 0 && focus_window)
+            if (g.NavLayer == ImGuiNavLayer_Main && focus_window)
                 focus_window = NavRestoreLastChildNavWindow(focus_window);
             FocusWindow(focus_window);
         }
@@ -8110,7 +8118,7 @@ static bool ImGui::NavScoreItem(ImGuiNavMoveResult* result, ImRect cand)
     // 2017/09/29: FIXME: This now currently only enabled inside menu bars, ideally we'd disable it everywhere. Menus in particular need to catch failure. For general navigation it feels awkward.
     // Disabling it may lead to disconnected graphs when nodes are very spaced out on different axis. Perhaps consider offering this as an option?
     if (result->DistBox == FLT_MAX && dist_axial < result->DistAxial)  // Check axial match
-        if (g.NavLayer == 1 && !(g.NavWindow->Flags & ImGuiWindowFlags_ChildMenu))
+        if (g.NavLayer == ImGuiNavLayer_Menu && !(g.NavWindow->Flags & ImGuiWindowFlags_ChildMenu))
             if ((g.NavMoveDir == ImGuiDir_Left && dax < 0.0f) || (g.NavMoveDir == ImGuiDir_Right && dax > 0.0f) || (g.NavMoveDir == ImGuiDir_Up && day < 0.0f) || (g.NavMoveDir == ImGuiDir_Down && day > 0.0f))
             {
                 result->DistAxial = dist_axial;
@@ -8221,7 +8229,7 @@ void ImGui::NavMoveRequestForward(ImGuiDir move_dir, ImGuiDir clip_dir, const Im
 void ImGui::NavMoveRequestTryWrapping(ImGuiWindow* window, ImGuiNavMoveFlags move_flags)
 {
     ImGuiContext& g = *GImGui;
-    if (g.NavWindow != window || !NavMoveRequestButNoResultYet() || g.NavMoveRequestForward != ImGuiNavForward_None || g.NavLayer != 0)
+    if (g.NavWindow != window || !NavMoveRequestButNoResultYet() || g.NavMoveRequestForward != ImGuiNavForward_None || g.NavLayer != ImGuiNavLayer_Main)
         return;
     IM_ASSERT(move_flags != 0); // No points calling this with no wrapping
     ImRect bb_rel = window->NavRectRel[0];
@@ -8466,7 +8474,7 @@ static void ImGui::NavUpdate()
     // Store our return window (for returning from Layer 1 to Layer 0) and clear it as soon as we step back in our own Layer 0
     if (g.NavWindow)
         NavSaveLastChildNavWindowIntoParent(g.NavWindow);
-    if (g.NavWindow && g.NavWindow->NavLastChildNavWindow != NULL && g.NavLayer == 0)
+    if (g.NavWindow && g.NavWindow->NavLastChildNavWindow != NULL && g.NavLayer == ImGuiNavLayer_Main)
         g.NavWindow->NavLastChildNavWindow = NULL;
 
     // Update CTRL+TAB and Windowing features (hold Square to move/resize/etc.)
@@ -8503,7 +8511,7 @@ static void ImGui::NavUpdate()
             if (!(g.OpenPopupStack.back().Window->Flags & ImGuiWindowFlags_Modal))
                 ClosePopupToLevel(g.OpenPopupStack.Size - 1, true);
         }
-        else if (g.NavLayer != 0)
+        else if (g.NavLayer != ImGuiNavLayer_Main)
         {
             // Leave the "menu" layer
             NavRestoreLayer(ImGuiNavLayer_Main);
@@ -8625,7 +8633,7 @@ static void ImGui::NavUpdate()
     g.NavMoveResultOther.Clear();
 
     // When we have manually scrolled (without using navigation) and NavId becomes out of bounds, we project its bounding box to the visible area to restart navigation within visible items
-    if (g.NavMoveRequest && g.NavMoveFromClampedRefRect && g.NavLayer == 0)
+    if (g.NavMoveRequest && g.NavMoveFromClampedRefRect && g.NavLayer == ImGuiNavLayer_Main)
     {
         ImGuiWindow* window = g.NavWindow;
         ImRect window_rect_rel(window->InnerRect.Min - window->Pos - ImVec2(1,1), window->InnerRect.Max - window->Pos + ImVec2(1,1));
@@ -8688,7 +8696,7 @@ static void ImGui::NavUpdateMoveResult()
     IM_ASSERT(g.NavWindow && result->Window);
 
     // Scroll to keep newly navigated item fully into view.
-    if (g.NavLayer == 0)
+    if (g.NavLayer == ImGuiNavLayer_Main)
     {
         ImVec2 delta_scroll;
         if (g.NavMoveRequestFlags & ImGuiNavMoveFlags_ScrollToEdge)
@@ -8727,7 +8735,7 @@ static float ImGui::NavUpdatePageUpPageDown()
     ImGuiContext& g = *GImGui;
     if (g.NavMoveDir != ImGuiDir_None || g.NavWindow == NULL)
         return 0.0f;
-    if ((g.NavWindow->Flags & ImGuiWindowFlags_NoNavInputs) || g.NavWindowingTarget != NULL || g.NavLayer != 0)
+    if ((g.NavWindow->Flags & ImGuiWindowFlags_NoNavInputs) || g.NavWindowingTarget != NULL || g.NavLayer != ImGuiNavLayer_Main)
         return 0.0f;
 
     ImGuiWindow* window = g.NavWindow;

imgui_draw.cpp

@@ -120,7 +120,7 @@ namespace IMGUI_STB_NAMESPACE
 #ifndef STB_RECT_PACK_IMPLEMENTATION                        // in case the user already have an implementation in the _same_ compilation unit (e.g. unity builds)
 #ifndef IMGUI_DISABLE_STB_RECT_PACK_IMPLEMENTATION
 #define STBRP_STATIC
-#define STBRP_ASSERT(x)     IM_ASSERT(x)
+#define STBRP_ASSERT(x)     do { IM_ASSERT(x); } while (0)
 #define STBRP_SORT          ImQsort
 #define STB_RECT_PACK_IMPLEMENTATION
 #endif
@@ -135,7 +135,7 @@ namespace IMGUI_STB_NAMESPACE
 #ifndef IMGUI_DISABLE_STB_TRUETYPE_IMPLEMENTATION
 #define STBTT_malloc(x,u)   ((void)(u), IM_ALLOC(x))
 #define STBTT_free(x,u)     ((void)(u), IM_FREE(x))
-#define STBTT_assert(x)     IM_ASSERT(x)
+#define STBTT_assert(x)     do { IM_ASSERT(x); } while(0)
 #define STBTT_fmod(x,y)     ImFmod(x,y)
 #define STBTT_sqrt(x)       ImSqrt(x)
 #define STBTT_pow(x,y)      ImPow(x,y)

imgui_widgets.cpp

@@ -6178,7 +6178,7 @@ void ImGui::EndMainMenuBar()
     // When the user has left the menu layer (typically: closed menus through activation of an item), we restore focus to the previous window
     // FIXME: With this strategy we won't be able to restore a NULL focus.
     ImGuiContext& g = *GImGui;
-    if (g.CurrentWindow == g.NavWindow && g.NavLayer == 0 && !g.NavAnyRequest)
+    if (g.CurrentWindow == g.NavWindow && g.NavLayer == ImGuiNavLayer_Main && !g.NavAnyRequest)
         FocusTopMostWindowUnderOne(g.NavWindow, NULL);
 
     End();

misc/freetype/imgui_freetype.cpp

@@ -280,7 +280,7 @@ namespace
 
 #ifndef STB_RECT_PACK_IMPLEMENTATION                        // in case the user already have an implementation in the _same_ compilation unit (e.g. unity builds)
 #ifndef IMGUI_DISABLE_STB_RECT_PACK_IMPLEMENTATION
-#define STBRP_ASSERT(x)     IM_ASSERT(x)
+#define STBRP_ASSERT(x)     do { IM_ASSERT(x); } while (0)
 #define STBRP_STATIC
 #define STB_RECT_PACK_IMPLEMENTATION
 #endif