From 45d9158ce14d4132f888c9ca29141700fbe17a04 Mon Sep 17 00:00:00 2001
From: Anne Marije v/d Meer <anne.marije.meer@quintor.nl>
Date: Mon, 12 Nov 2018 11:22:37 +0100
Subject: [PATCH] CHeck for opengl version, minimum require 3, and only enable
 debugging when supported

---
 src/Main.cpp | 47 ++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 38 insertions(+), 9 deletions(-)

diff --git a/src/Main.cpp b/src/Main.cpp
index 13af30b..d277130 100644
--- a/src/Main.cpp
+++ b/src/Main.cpp
@@ -122,11 +122,18 @@ ST::string s_rootPath;
 
 imVfs s_vfs;
 SDL_Window *s_display;
-
+SDL_GLContext s_glContext
 FILE *s_logFile = stderr;
 
 PFNGLCOMPRESSEDTEXIMAGE2DARBPROC GLX_CompressedTexImage2D = 0;
 
+void cleanup() {
+    SDL_GL_DeleteContext(s_glContext);
+    SDL_DestroyWindow(s_display);
+
+    SDL_Quit();
+}
+
 #ifdef WIN32
 int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    LPSTR lpCmdLine, int nCmdShow)
@@ -242,11 +249,21 @@ int main(int argc, char *argv[])
 
 
     // Create a window for the game
+<<<<<<< HEAD
     s_display = SDL_CreateWindow("imaginaryMyst Alpha", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, winWidth,
                                  winHeight, SDL_WINDOW_OPENGL);
 
 
     SDL_GLContext glContext = SDL_GL_CreateContext(s_display);
+=======
+    s_display = SDL_CreateWindow("imaginaryMyst Alpha",
+                                 SDL_WINDOWPOS_CENTERED,
+                                 SDL_WINDOWPOS_CENTERED,
+                                 winWidth, winHeight,
+                                 SDL_WINDOW_OPENGL);
+    s_glContext = SDL_GL_CreateContext(s_display);
+
+>>>>>>> CHeck for opengl version, minimum require 3, and only enable debugging when supported
     glewExperimental = true;
     if (glewInit() != GLEW_OK) {
         fprintf(stderr, "Failed to initialize GLEW\n");
@@ -254,10 +271,25 @@ int main(int argc, char *argv[])
     }
     glEnable(GL_DEBUG_OUTPUT);
     glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
-    glDebugMessageCallback(openglCallbackFunction, nullptr);
-    glDebugMessageControl(
-            GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, NULL, true
-    );
+
+    int glMajorVersion;
+    int glMinorVersion;
+    SDL_GL_GetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, &glMajorVersion);
+    SDL_GL_GetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, &glMinorVersion);
+
+    if (glMajorVersion < 3) {
+        fprintf(stderr,
+                "ERROR OoenGL version too low, only OpenGL 3 or higher are supported. Opengl version detected %d.%d.",
+                glMajorVersion, glMinorVersion);
+        cleanup();
+        return 1;
+    }
+    if (glMajorVersion > 4 || (glMajorVersion == 4 && glMinorVersion >= 3)) {
+        glDebugMessageCallback(openglCallbackFunction, nullptr);
+        glDebugMessageControl(
+                GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, NULL, true
+        );
+    }
 
     glEnable(GL_BLEND);
     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
@@ -304,9 +336,6 @@ int main(int argc, char *argv[])
 
     SDL_GL_SwapWindow(s_display);
     SDL_Delay(3000);
-    SDL_GL_DeleteContext(glContext);
-    SDL_DestroyWindow(s_display);
-
-    SDL_Quit();
+cleanup();
     return 0;
 }