From 91da461caa9e419f0d24596456a3ee56e716e6a1 Mon Sep 17 00:00:00 2001
From: Jeffrey Crowell <github@crowell.biz>
Date: Mon, 30 May 2022 12:03:14 -0400
Subject: [PATCH] Use OpenGL2 on MacOS instead of OpenGL3

---
 libultraship/Makefile                           |  2 ++
 .../Lib/ImGui/backends/imgui_impl_opengl3.cpp   |  4 ++--
 libultraship/libultraship/SohImGuiImpl.cpp      | 17 +++++++++++++++++
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/libultraship/Makefile b/libultraship/Makefile
index 9f269ea61..b1bc0f691 100644
--- a/libultraship/Makefile
+++ b/libultraship/Makefile
@@ -56,6 +56,7 @@ CXX_FILES := \
 	$(shell find libultraship/Lib/Fast3D -name *.cpp) \
 	$(shell find libultraship -maxdepth 1 -name *.cpp) \
 	$(shell find libultraship/Lib/ImGui -maxdepth 1 -name *.cpp) \
+	libultraship/Lib/ImGui/backends/imgui_impl_opengl2.cpp \
 	libultraship/Lib/ImGui/backends/imgui_impl_opengl3.cpp \
 	libultraship/Lib/ImGui/backends/imgui_impl_sdl.cpp \
 	libultraship/Lib/StrHash64.cpp \
@@ -80,6 +81,7 @@ INC_DIRS := $(addprefix -I, \
 	libultraship/Lib/Fast3D/U64 \
 	libultraship/Lib/spdlog \
 	libultraship/Lib/spdlog/include \
+	libultraship/Lib/ImGui \
 	libultraship \
 )
 
diff --git a/libultraship/libultraship/Lib/ImGui/backends/imgui_impl_opengl3.cpp b/libultraship/libultraship/Lib/ImGui/backends/imgui_impl_opengl3.cpp
index 9ff0e80c2..c1d182c07 100644
--- a/libultraship/libultraship/Lib/ImGui/backends/imgui_impl_opengl3.cpp
+++ b/libultraship/libultraship/Lib/ImGui/backends/imgui_impl_opengl3.cpp
@@ -220,9 +220,9 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
     if (imgl3wInit() != 0)
     {
         fprintf(stderr, "Failed to initialize OpenGL loader!\n");
-#ifndef __APPLE__ // this is ok due to shared library cache
+//#ifndef __APPLE__ // this is ok due to shared library cache
         return false;
-#endif
+//#endif
     }
 #endif
 
diff --git a/libultraship/libultraship/SohImGuiImpl.cpp b/libultraship/libultraship/SohImGuiImpl.cpp
index 8e4becaab..84149fcfc 100644
--- a/libultraship/libultraship/SohImGuiImpl.cpp
+++ b/libultraship/libultraship/SohImGuiImpl.cpp
@@ -27,8 +27,13 @@
 #include "Utils/StringHelper.h"
 
 #ifdef ENABLE_OPENGL
+#ifdef __APPLE__
+#include "Lib/ImGui/backends/imgui_impl_opengl2.h"
+#include "Lib/ImGui/backends/imgui_impl_sdl.h"
+#else
 #include "Lib/ImGui/backends/imgui_impl_opengl3.h"
 #include "Lib/ImGui/backends/imgui_impl_sdl.h"
+#endif
 
 #endif
 
@@ -153,7 +158,11 @@ namespace SohImGui {
     void ImGuiBackendInit() {
         switch (impl.backend) {
         case Backend::SDL:
+#ifdef __APPLE__
+            ImGui_ImplOpenGL2_Init();
+#else
             ImGui_ImplOpenGL3_Init("#version 120");
+#endif
             break;
 
 #if defined(ENABLE_DX11) || defined(ENABLE_DX12)
@@ -199,7 +208,11 @@ namespace SohImGui {
     void ImGuiBackendNewFrame() {
         switch (impl.backend) {
         case Backend::SDL:
+#ifdef __APPLE__
+            ImGui_ImplOpenGL2_NewFrame();
+#else
             ImGui_ImplOpenGL3_NewFrame();
+#endif
             break;
 #if defined(ENABLE_DX11) || defined(ENABLE_DX12)
         case Backend::DX11:
@@ -214,7 +227,11 @@ namespace SohImGui {
     void ImGuiRenderDrawData(ImDrawData* data) {
         switch (impl.backend) {
         case Backend::SDL:
+#ifdef __APPLE__
+            ImGui_ImplOpenGL2_RenderDrawData(data);
+#else
             ImGui_ImplOpenGL3_RenderDrawData(data);
+#endif
             break;
 #if defined(ENABLE_DX11) || defined(ENABLE_DX12)
         case Backend::DX11: