(Breaking) Backends: DX12: removed support for legacy `ImGui_ImplDX12_Init()` signature obsoleted in 1.91.6. (#9487)

Amend 40b2286d1, 142827f7, eefe5d5aa.
diff --git a/backends/imgui_impl_dx12.cpp b/backends/imgui_impl_dx12.cpp
index 0348828..04516ee 100644
--- a/backends/imgui_impl_dx12.cpp
+++ b/backends/imgui_impl_dx12.cpp
@@ -20,6 +20,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2026-08-05: DirectX12: *BREAKING CHANGE* Removed support for legacy `ImGui_ImplDX12_Init()` signature obsoleted in 1.91.6 (2024-11-15) because it needed to forcefully disable support for ImGuiBackendFlags_RendererHasTextures. (#9487)
 //  2026-04-23: Added support for standard draw callbacks (in platform_io): DrawCallback_ResetRenderState, DrawCallback_SetSamplerLinear, DrawCallback_SetSamplerNearest. (#9378)
 //  2025-10-11: DirectX12: Reuse texture upload buffer and grow it only when necessary. (#9002)
 //  2025-09-29: DirectX12: Rework synchronization logic. (#8961)
@@ -956,37 +957,6 @@
     return true;
 }
 
-#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
-// Legacy initialization API Obsoleted in 1.91.5
-// font_srv_cpu_desc_handle and font_srv_gpu_desc_handle are handles to a single SRV descriptor to use for the internal font texture, they must be in 'srv_descriptor_heap'
-bool ImGui_ImplDX12_Init(ID3D12Device* device, int num_frames_in_flight, DXGI_FORMAT rtv_format, ID3D12DescriptorHeap* srv_descriptor_heap, D3D12_CPU_DESCRIPTOR_HANDLE font_srv_cpu_desc_handle, D3D12_GPU_DESCRIPTOR_HANDLE font_srv_gpu_desc_handle)
-{
-    ImGui_ImplDX12_InitInfo init_info;
-    init_info.Device = device;
-    init_info.NumFramesInFlight = num_frames_in_flight;
-    init_info.RTVFormat = rtv_format;
-    init_info.SrvDescriptorHeap = srv_descriptor_heap;
-    init_info.LegacySingleSrvCpuDescriptor = font_srv_cpu_desc_handle;
-    init_info.LegacySingleSrvGpuDescriptor = font_srv_gpu_desc_handle;
-
-    D3D12_COMMAND_QUEUE_DESC queueDesc = {};
-    queueDesc.Type = D3D12_COMMAND_LIST_TYPE_DIRECT;
-    queueDesc.Flags = D3D12_COMMAND_QUEUE_FLAG_NONE;
-    queueDesc.NodeMask = 1;
-    HRESULT hr = device->CreateCommandQueue(&queueDesc, IID_PPV_ARGS(&init_info.CommandQueue));
-    IM_ASSERT(SUCCEEDED(hr));
-
-    bool ret = ImGui_ImplDX12_Init(&init_info);
-    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
-    bd->commandQueueOwned = true;
-
-    ImGuiIO& io = ImGui::GetIO();
-    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasTextures; // Using legacy ImGui_ImplDX12_Init() call with 1 SRV descriptor we cannot support multiple textures.
-
-    return ret;
-}
-#endif
-
 void ImGui_ImplDX12_Shutdown()
 {
     ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
diff --git a/backends/imgui_impl_dx12.h b/backends/imgui_impl_dx12.h
index b8be8db..dfb327f 100644
--- a/backends/imgui_impl_dx12.h
+++ b/backends/imgui_impl_dx12.h
@@ -59,13 +59,6 @@
 IMGUI_IMPL_API void     ImGui_ImplDX12_NewFrame();
 IMGUI_IMPL_API void     ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandList* graphics_command_list);
 
-#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
-// Legacy initialization API Obsoleted in 1.91.5
-// - font_srv_cpu_desc_handle and font_srv_gpu_desc_handle are handles to a single SRV descriptor to use for the internal font texture, they must be in 'srv_descriptor_heap'
-// - When we introduced the ImGui_ImplDX12_InitInfo struct we also added a 'ID3D12CommandQueue* CommandQueue' field.
-IMGUI_IMPL_API bool     ImGui_ImplDX12_Init(ID3D12Device* device, int num_frames_in_flight, DXGI_FORMAT rtv_format, ID3D12DescriptorHeap* srv_descriptor_heap, D3D12_CPU_DESCRIPTOR_HANDLE font_srv_cpu_desc_handle, D3D12_GPU_DESCRIPTOR_HANDLE font_srv_gpu_desc_handle);
-#endif
-
 // Use if you want to reset your rendering device without losing Dear ImGui state.
 IMGUI_IMPL_API bool     ImGui_ImplDX12_CreateDeviceObjects();
 IMGUI_IMPL_API void     ImGui_ImplDX12_InvalidateDeviceObjects();
@@ -82,6 +75,14 @@
     ID3D12GraphicsCommandList*  CommandList;
 };
 
+#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
+// Legacy initialization API Obsoleted in 1.91.5
+// - font_srv_cpu_desc_handle and font_srv_gpu_desc_handle are handles to a single SRV descriptor to use for the internal font texture, they must be in 'srv_descriptor_heap'
+// - When we introduced the ImGui_ImplDX12_InitInfo struct we also added a 'ID3D12CommandQueue* CommandQueue' field.
+// - DOES NOT SUPPORT ImGuiBackendFlags_RendererHasTextures.
+//IMGUI_IMPL_API bool     ImGui_ImplDX12_Init(ID3D12Device* device, int num_frames_in_flight, DXGI_FORMAT rtv_format, ID3D12DescriptorHeap* srv_descriptor_heap, D3D12_CPU_DESCRIPTOR_HANDLE font_srv_cpu_desc_handle, D3D12_GPU_DESCRIPTOR_HANDLE font_srv_gpu_desc_handle);
+#endif
+
 #if defined(__clang__)
 #pragma clang diagnostic pop
 #endif
diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index 3197f28..a4ed837 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt
@@ -45,6 +45,10 @@
   favor of `style.CurveTesselationMaxError` (default 1.12)` which is in Pixels unit. It is
   easier to tweak + this allows us to easily scale error threshold on high density screens.
   - style.CurveTesselationMaxError == sqrf(style.CurveTessellationTol).
+- Backends:
+  - DirectX12: Removed support for legacy `ImGui_ImplDX12_Init()` signature, which was
+    obsoleted in 1.91.6 (December 2014), because it needed to forcefully disable support
+    for `ImGuiBackendFlags_RendererHasTextures`. Use the new signature! (#9487)
 
 Other Changes: