Misc: Made it accepted to call SetMouseCursor() with any out-of-bound value, as a way to allow hacking in custom cursors if desirable.

docs/CHANGELOG.txt

@@ -70,6 +70,8 @@ Other changes:
   (e.g. in our testing, handling of a 1 MB text buffer is now 3 times faster in VS2022 Debug build).
   This is the first step toward more refactorig. (#7925) [@alektron, @ocornut]
 - InputText: added CJK double-width punctuation to list of separators considered for CTRL+Arrow.
+- Misc: Made it accepted to call SetMouseCursor() with any out-of-bound value, as a way to allow
+  hacking in custom cursors if desirable.
 - Fonts: fixed ellipsis "..." rendering width miscalculation bug introduced in 1.91.0. (#7976) [@DDeimos]
 - TextLinkOpenURL(): modified tooltip to display a verb "Open 'xxxx'". (#7885, #7660)
 - Backends: SDL2: use SDL_Vulkan_GetDrawableSize() when available. (#7967, #3190) [@scribam]

imgui.cpp

@@ -3702,7 +3702,8 @@ void ImGui::RenderNavHighlight(const ImRect& bb, ImGuiID id, ImGuiNavHighlightFl
 void ImGui::RenderMouseCursor(ImVec2 base_pos, float base_scale, ImGuiMouseCursor mouse_cursor, ImU32 col_fill, ImU32 col_border, ImU32 col_shadow)
 {
     ImGuiContext& g = *GImGui;
-    IM_ASSERT(mouse_cursor > ImGuiMouseCursor_None && mouse_cursor < ImGuiMouseCursor_COUNT);
+    if (mouse_cursor <= ImGuiMouseCursor_None || mouse_cursor >= ImGuiMouseCursor_COUNT) // We intentionally accept out of bound values.
+        mouse_cursor = ImGuiMouseCursor_Arrow;
     ImFontAtlas* font_atlas = g.DrawListSharedData.Font->ContainerAtlas;
     for (ImGuiViewportP* viewport : g.Viewports)
     {
@@ -6198,7 +6199,7 @@ static int ImGui::UpdateWindowManualResize(ImGuiWindow* window, const ImVec2& si
         ButtonBehavior(resize_rect, resize_grip_id, &hovered, &held, ImGuiButtonFlags_FlattenChildren | ImGuiButtonFlags_NoNavFocus);
         //GetForegroundDrawList(window)->AddRect(resize_rect.Min, resize_rect.Max, IM_COL32(255, 255, 0, 255));
         if (hovered || held)
-            g.MouseCursor = (resize_grip_n & 1) ? ImGuiMouseCursor_ResizeNESW : ImGuiMouseCursor_ResizeNWSE;
+            SetMouseCursor((resize_grip_n & 1) ? ImGuiMouseCursor_ResizeNESW : ImGuiMouseCursor_ResizeNWSE);
 
         if (held && g.IO.MouseDoubleClicked[0])
         {
@@ -6244,7 +6245,7 @@ static int ImGui::UpdateWindowManualResize(ImGuiWindow* window, const ImVec2& si
         if (hovered && g.HoveredIdTimer <= WINDOWS_RESIZE_FROM_EDGES_FEEDBACK_TIMER)
             hovered = false;
         if (hovered || held)
-            g.MouseCursor = (axis == ImGuiAxis_X) ? ImGuiMouseCursor_ResizeEW : ImGuiMouseCursor_ResizeNS;
+            SetMouseCursor((axis == ImGuiAxis_X) ? ImGuiMouseCursor_ResizeEW : ImGuiMouseCursor_ResizeNS);
         if (held && g.IO.MouseDoubleClicked[0])
         {
             // Double-clicking bottom or right border auto-fit on this axis
@@ -9296,6 +9297,9 @@ ImGuiMouseCursor ImGui::GetMouseCursor()
     return g.MouseCursor;
 }
 
+// We intentionally accept values of ImGuiMouseCursor that are outside our bounds, in case users needs to hack-in a custom cursor value.
+// Custom cursors may be handled by custom backends. If you are using a standard backend and want to hack in a custom cursor, you may
+// handle it before the backend _NewFrame() call and temporarily set ImGuiConfigFlags_NoMouseCursorChange during the backend _NewFrame() call.
 void ImGui::SetMouseCursor(ImGuiMouseCursor cursor_type)
 {
     ImGuiContext& g = *GImGui;

imgui_demo.cpp

@@ -7490,7 +7490,8 @@ static void ShowDemoWindowInputs()
             IM_ASSERT(IM_ARRAYSIZE(mouse_cursors_names) == ImGuiMouseCursor_COUNT);
 
             ImGuiMouseCursor current = ImGui::GetMouseCursor();
-            ImGui::Text("Current mouse cursor = %d: %s", current, mouse_cursors_names[current]);
+            const char* cursor_name = (current >= ImGuiMouseCursor_Arrow) && (current < ImGuiMouseCursor_COUNT) ? mouse_cursors_names[current] : "N/A";
+            ImGui::Text("Current mouse cursor = %d: %s", current, cursor_name);
             ImGui::BeginDisabled(true);
             ImGui::CheckboxFlags("io.BackendFlags: HasMouseCursors", &io.BackendFlags, ImGuiBackendFlags_HasMouseCursors);
             ImGui::EndDisabled();

imgui_tables.cpp

@@ -4409,7 +4409,7 @@ void ImGui::EndColumns()
             {
                 ButtonBehavior(column_hit_rect, column_id, &hovered, &held);
                 if (hovered || held)
-                    g.MouseCursor = ImGuiMouseCursor_ResizeEW;
+                    SetMouseCursor(ImGuiMouseCursor_ResizeEW);
                 if (held && !(column->Flags & ImGuiOldColumnFlags_NoResize))
                     dragging_column = n;
             }

imgui_widgets.cpp

@@ -4438,7 +4438,7 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
     }
     const bool hovered = ItemHoverable(frame_bb, id, g.LastItemData.InFlags);
     if (hovered)
-        g.MouseCursor = ImGuiMouseCursor_TextInput;
+        SetMouseCursor(ImGuiMouseCursor_TextInput);
 
     // We are only allowed to access the state if we are already the active widget.
     ImGuiInputTextState* state = GetInputTextState(id);