Changed default ImTextureID_Invalid value to -1 instead of 0 +added comments. (#9293, #8745, #8465, #7090)

docs/CHANGELOG.txt

@@ -41,6 +41,12 @@ HOW TO UPDATE?
 
 Breaking Changes:
 
+ - Changed default ImTextureID_Invalid value to -1 instead of 0 if not #define-d.
+    (#9293, #8745, #8465, #7090)
+   - It seems like a better default since it will work with backends storing
+     indices or memory offsets inside ImTextureID, where 0 might be a valid value.
+   - If this is causing problem with e.g your custom ImTextureID definition, you can
+     add '#define ImTextureID_Invalid 0' to your imconfig.h + PLEASE report this to GitHub.
  - Separator(): fixed a legacy quirk where Separator() was submitting a zero-height
    item for layout purpose, even though it draws a 1-pixel separator.
    The fix could affect code e.g. computing height from multiple widgets in order to

imgui.cpp

@@ -394,6 +394,9 @@ IMPLEMENTING SUPPORT for ImGuiBackendFlags_RendererHasTextures:
  When you are not sure about an old symbol or function name, try using the Search/Find function of your IDE to look for comments or references in all imgui files.
  You can read releases logs https://github.com/ocornut/imgui/releases for more details.
 
+ - 2026/03/12 (1.92.7) - Changed default ImTextureID_Invalid to -1 instead of 0 if not #define-d. (#9293, #8745, #8465, #7090)
+                         It seems like a better default since it will work with backends storing indices or memory offsets inside ImTextureID, where 0 might be a valid value.
+                         If this is causing problem with e.g. your custom ImTextureID definition, you can add '#define ImTextureID_Invalid 0' to your imconfig.h + PLEASE report this to GitHub.
  - 2026/02/26 (1.92.7) - Separator: fixed a legacy quirk where Separator() was submitting a zero-height item for layout purpose, even though it draws a 1-pixel separator.
                          The fix could affect code e.g. computing height from multiple widgets in order to allocate vertical space for a footer or multi-line status bar. (#2657, #9263)
                          The "Console" example had such a bug:
@@ -402,8 +405,7 @@ IMPLEMENTING SUPPORT for ImGuiBackendFlags_RendererHasTextures:
                          Should be:
                             float footer_height = style.ItemSpacing.y + style.SeparatorSize + ImGui::GetFrameHeightWithSpacing();
                             BeginChild("ScrollingRegion", { 0, -footer_height });
-   When such idiom was used and assuming zero-height Separator, it is likely that
+                         When such idiom was used and assuming zero-height Separator, it is likely that in 1.92.7 the resulting window will have unexpected 1 pixel scrolling range.
-   in 1.92.7 the resulting window will have unexpected 1 pixel scrolling range.
  - 2026/02/23 (1.92.7) - Commented out legacy signature for Combo(), ListBox(), signatures which were obsoleted in 1.90 (Nov 2023), when the getter callback type was changed.
                          - Old getter type:   bool (*getter)(void* user_data, int idx, const char** out_text)   // Set label + return bool. False replaced label with placeholder.
                          - New getter type:   const char* (*getter)(void* user_data, int idx)                   // Return label or NULL/empty label if missing

imgui.h

@@ -30,7 +30,7 @@
 // Library Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals, e.g. '#if IMGUI_VERSION_NUM >= 12345')
 #define IMGUI_VERSION       "1.92.7 WIP"
-#define IMGUI_VERSION_NUM   19264
+#define IMGUI_VERSION_NUM   19265
 #define IMGUI_HAS_TABLE             // Added BeginTable() - from IMGUI_VERSION_NUM >= 18000
 #define IMGUI_HAS_TEXTURES          // Added ImGuiBackendFlags_RendererHasTextures - from IMGUI_VERSION_NUM >= 19198
 
@@ -340,9 +340,11 @@ IM_MSVC_RUNTIME_CHECKS_RESTORE
 typedef ImU64 ImTextureID;      // Default: store up to 64-bits (any pointer or integer). A majority of backends are ok with that.
 #endif
 
-// Define this if you need 0 to be a valid ImTextureID for your backend.
+// Define this if you need to change the invalid value for your backend.
+// - in v1.92.7 (2025/03/12): we changed default value from 0 to -1 as it is a better default, which supports storing offsets/indices.
+// - If this is causing problem with your custom ImTextureID definition, you can add '#define ImTextureID_Invalid' to your imconfig + please report this to GitHub.
 #ifndef ImTextureID_Invalid
-#define ImTextureID_Invalid     ((ImTextureID)0)
+#define ImTextureID_Invalid     ((ImTextureID)-1)
 #endif
 
 // ImTextureRef = higher-level identifier for a texture. Store a ImTextureID _or_ a ImTextureData*.
@@ -3906,8 +3908,10 @@ inline ImTextureID ImTextureRef::GetTexID() const
 // Using an indirection to avoid patching ImDrawCmd after a SetTexID() call (but this could be an alternative solution too)
 inline ImTextureID ImDrawCmd::GetTexID() const
 {
-    // If you are getting this assert: A renderer backend with support for ImGuiBackendFlags_RendererHasTextures (1.92)
+    // If you are getting this assert with ImTextureID_Invalid == 0 and your ImTextureID is used to store an index:
-    // must iterate and handle ImTextureData requests stored in ImDrawData::Textures[].
+    // - You can add '#define ImTextureID_Invalid ((ImTextureID)-1)' in your imconfig file.
+    // If you are getting this assert with a renderer backend with support for ImGuiBackendFlags_RendererHasTextures (1.92+):
+    // - You must correctly iterate and handle ImTextureData requests stored in ImDrawData::Textures[]. See docs/BACKENDS.md.
     ImTextureID tex_id = TexRef._TexData ? TexRef._TexData->TexID : TexRef._TexID; // == TexRef.GetTexID() above.
     if (TexRef._TexData != NULL)
         IM_ASSERT(tex_id != ImTextureID_Invalid && "ImDrawCmd is referring to ImTextureData that wasn't uploaded to graphics system. Backend must call ImTextureData::SetTexID() after handling ImTextureStatus_WantCreate request!");