Examples: DirectX9/10/11: Comments

examples/directx10_example/imgui_impl_dx10.cpp

@@ -484,7 +484,7 @@ void    ImGui_ImplDX10_InvalidateDeviceObjects()
         return;
 
     if (g_pFontSampler) { g_pFontSampler->Release(); g_pFontSampler = NULL; }
-    if (g_pFontTextureView) { g_pFontTextureView->Release(); g_pFontTextureView = NULL; ImGui::GetIO().Fonts->TexID = 0; }
+    if (g_pFontTextureView) { g_pFontTextureView->Release(); g_pFontTextureView = NULL; ImGui::GetIO().Fonts->TexID = NULL; } // We copied g_pFontTextureView to io.Fonts->TexID so let's clear that as well.
     if (g_pIB) { g_pIB->Release(); g_pIB = NULL; }
     if (g_pVB) { g_pVB->Release(); g_pVB = NULL; }
 

examples/directx11_example/imgui_impl_dx11.cpp

@@ -485,7 +485,7 @@ void    ImGui_ImplDX11_InvalidateDeviceObjects()
         return;
 
     if (g_pFontSampler) { g_pFontSampler->Release(); g_pFontSampler = NULL; }
-    if (g_pFontTextureView) { g_pFontTextureView->Release(); g_pFontTextureView = NULL; ImGui::GetIO().Fonts->TexID = 0; }
+    if (g_pFontTextureView) { g_pFontTextureView->Release(); g_pFontTextureView = NULL; ImGui::GetIO().Fonts->TexID = NULL; } // We copied g_pFontTextureView to io.Fonts->TexID so let's clear that as well.
     if (g_pIB) { g_pIB->Release(); g_pIB = NULL; }
     if (g_pVB) { g_pVB->Release(); g_pVB = NULL; }
 

examples/directx9_example/imgui_impl_dx9.cpp

@@ -313,10 +313,11 @@ void ImGui_ImplDX9_InvalidateDeviceObjects()
     }
 
     // At this point note that we set ImGui::GetIO().Fonts->TexID to be == g_FontTexture, so clear both.
+    ImGuiIO& io = ImGui::GetIO();
+    IM_ASSERT(g_FontTexture == io.Fonts->TexID);
     if (g_FontTexture)
         g_FontTexture->Release();
     g_FontTexture = NULL;
-    ImGuiIO& io = ImGui::GetIO();
     io.Fonts->TexID = NULL;
 }