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Backends: OpenGL3: Reverted use of glBufferSubData(). (#4468, #4504, #3381, #2981, #4825, #4832, #5127)

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ocornut
2022-11-09 15:57:54 +01:00
parent f0ad810553
commit b8b0f9d02e
2 changed files with 14 additions and 3 deletions
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14
backends/imgui_impl_opengl3.cpp
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@@ -14,6 +14,7 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2022-11-09: OpenGL: Reverted use of glBufferSubData(), too many corruptions issues + old issues seemingly can't be reproed with Intel drivers nowadays (revert 2021-12-15 and 2022-05-23 changes).
// 2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
// 2022-09-27: OpenGL: Added ability to '#define IMGUI_IMPL_OPENGL_DEBUG'.
// 2022-05-23: OpenGL: Reworking 2021-12-15 "Using buffer orphaning" so it only happens on Intel GPU, seems to cause problems otherwise. (#4468, #4825, #4832, #5127).
@@ -272,12 +273,15 @@ bool ImGui_ImplOpenGL3_Init(const char* glsl_version)
}
bd->GlVersion = (GLuint)(major * 100 + minor * 10);
bd->UseBufferSubData = false;
/*
// Query vendor to enable glBufferSubData kludge
#ifdef _WIN32
if (const char* vendor = (const char*)glGetString(GL_VENDOR))
if (strncmp(vendor, "Intel", 5) == 0)
bd->UseBufferSubData = true;
#endif
*/
#else
bd->GlVersion = 200; // GLES 2
#endif
@@ -495,9 +499,13 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
const ImDrawList* cmd_list = draw_data->CmdLists[n];
// Upload vertex/index buffers
// - On Intel windows drivers we got reports that regular glBufferData() led to accumulating leaks when using multi-viewports, so we started using orphaning + glBufferSubData(). (See https://github.com/ocornut/imgui/issues/4468)
// - On NVIDIA drivers we got reports that using orphaning + glBufferSubData() led to glitches when using multi-viewports.
// - OpenGL drivers are in a very sorry state in 2022, for now we are switching code path based on vendors.
// - OpenGL drivers are in a very sorry state nowadays....
// During 2021 we attempted to switch from glBufferData() to orphaning+glBufferSubData() following reports
// of leaks on Intel GPU when using multi-viewports on Windows.
// - After this we kept hearing of various display corruptions issues. We started disabling on non-Intel GPU, but issues still got reported on Intel.
// - We are now back to using exclusively glBufferData(). So bd->UseBufferSubData IS ALWAYS FALSE in this code.
// We are keeping the old code path for a while in case people finding new issues may want to test the bd->UseBufferSubData path.
// - See https://github.com/ocornut/imgui/issues/4468 and please report any corruption issues.
const GLsizeiptr vtx_buffer_size = (GLsizeiptr)cmd_list->VtxBuffer.Size * (int)sizeof(ImDrawVert);
const GLsizeiptr idx_buffer_size = (GLsizeiptr)cmd_list->IdxBuffer.Size * (int)sizeof(ImDrawIdx);
if (bd->UseBufferSubData)