In DX9 backend InvalidateDeviceObjects can release already released texture #8977
Description
Version/Branch of Dear ImGui:
Version 1.92.3, Branch: 3 week old docking with features/string_view applied, but I reproduced it on current master
Back-ends:
imgui_impl_dx9.cpp
Compiler, OS:
Windows 11, Visual Studio Build Tools 2022
Full config/build information:
No response
Details:
My Issue/Question:
For sake of simplicity I decided to call
ImGui_ImplDX9_InvalidateDeviceObjects();
direct3DDevice->Reset(&direct3DParams);
ImGui_ImplDX9_CreateDeviceObjects();after arrival of WM_SIZE with wParam != SIZE_MINIMIZED.
This change lead to missing font glyphs or crashes after window resize.
After some investigation I noticed that the problem arises when aforementioned block of code is called multiple times in a row.
The problem is that in function ImGui_ImplDX9_InvalidateDeviceObjects following loop:
for (ImTextureData* tex : ImGui::GetPlatformIO().Textures)
if (tex->RefCount == 1)
{
tex->SetStatus(ImTextureStatus_WantDestroy);
ImGui_ImplDX9_UpdateTexture(tex);
}can release already destroyed textures as in ImGui_ImplDX9_UpdateTexture:
LPDIRECT3DTEXTURE9 backend_tex = (LPDIRECT3DTEXTURE9)tex->TexID;
if (backend_tex == nullptr)
return;
IM_ASSERT(tex->TexID == (ImTextureID)(intptr_t)backend_tex);
backend_tex->Release();
// Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
tex->SetTexID(ImTextureID_Invalid);
tex->SetStatus(ImTextureStatus_Destroyed);backend_tex is not set to nullptr.
Locally I changed if statement to if (tex->RefCount == 1 && tex->Status != ImTextureStatus_Destroyed) and it works, but I'm not sure if this is desired solution.
Screenshots/Video:
No response
Minimal, Complete and Verifiable Example code:
In examples\example_win32_directx9\main.cpp change WM_SIZE handling to:
case WM_SIZE:
if (wParam == SIZE_MINIMIZED)
return 0;
g_d3dpp.BackBufferWidth = (UINT)LOWORD(lParam);
g_d3dpp.BackBufferHeight = (UINT)HIWORD(lParam);
ResetDevice();
return 0;