Add manual OpenGL context creation.

For SDL2 set attributes for context version.
For SDL1.2 in X11 create own context.
For SDL1.2 and other platforms not implimented for now.

Also try fallback if need to older context versions.

1 files changed, 32 insertions, 0 deletions

diff --git a/src/utils/sdl2helper.cpp b/src/utils/sdl2helper.cpp
index 22c57116c..3b2b988a0 100644
--- a/src/utils/sdl2helper.cpp
+++ b/src/utils/sdl2helper.cpp
@@ -94,4 +94,36 @@ SDL_Thread *SDL::createThread(SDL_ThreadFunction fn,
     return SDL_CreateThread(fn, name, data);
 }
 
+void *SDL::createGLContext(SDL_Window *const window,
+                           const int major,
+                           const int minor)
+{
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, major);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, minor);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK,
+        SDL_GL_CONTEXT_PROFILE_CORE);
+//    SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG);
+    SDL_ClearError();
+    void *context = SDL_GL_CreateContext(window);
+    if (SDL_GetError())
+    {
+        if (!context && (major > 3 || (major == 3 && minor > 3)))
+        {
+            logger->log("Try fallback to OpenGL 3.3 context");
+            SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+            SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
+            SDL_ClearError();
+            context = SDL_GL_CreateContext(window);
+            if (SDL_GetError())
+            {
+                logger->log("Try fallback to OpenGL 3.0 context");
+                SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+                SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
+                context = SDL_GL_CreateContext(window);
+            }
+        }
+    }
+    return context;
+}
+
 #endif  // USE_SDL2