From 8b149bf8f43e0f1b4185517289b039c09ffb70b2 Mon Sep 17 00:00:00 2001
From: Attila Uygun <auygun@opera.com>
Date: Thu, 2 Nov 2023 21:48:39 +0100
Subject: [PATCH] Fix for flickering imgui when switching renderer

Use the geometry from last frame in ImguiBackend::CreateRenderResources if
available.
---
 src/engine/imgui_backend.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/engine/imgui_backend.cc b/src/engine/imgui_backend.cc
index 969694c..c70939e 100644
--- a/src/engine/imgui_backend.cc
+++ b/src/engine/imgui_backend.cc
@@ -80,7 +80,10 @@ void ImguiBackend::Shutdown() {
 void ImguiBackend::CreateRenderResources(Renderer* renderer) {
   renderer_ = renderer;
   shader_->SetRenderer(renderer);
+
   geometries_.clear();
+  if (ImGui::GetCurrentContext() && ImGui::GetDrawData())
+    Render();
 
   auto source = std::make_unique<ShaderSource>();
   if (source->Load("engine/imgui.glsl")) {