GLX: try to get an OpenGL 3.3 core context

2 files changed, 81 insertions, 49 deletions

diff --git a/Source/Core/VideoBackends/OGL/GLInterface/GLX.cpp b/Source/Core/VideoBackends/OGL/GLInterface/GLX.cpp
index 12912b0f5d..900a74b0c8 100644
--- a/Source/Core/VideoBackends/OGL/GLInterface/GLX.cpp
+++ b/Source/Core/VideoBackends/OGL/GLInterface/GLX.cpp
@@ -9,9 +9,22 @@
 #include "VideoCommon/RenderBase.h"
 #include "VideoCommon/VideoConfig.h"
 
+#define GLX_CONTEXT_MAJOR_VERSION_ARB       0x2091
+#define GLX_CONTEXT_MINOR_VERSION_ARB       0x2092
+
+typedef GLXContext (*PFNGLXCREATECONTEXTATTRIBSPROC)(Display*, GLXFBConfig, GLXContext, Bool, const int*);
 typedef int ( * PFNGLXSWAPINTERVALSGIPROC) (int interval);
+
+static PFNGLXCREATECONTEXTATTRIBSPROC glXCreateContextAttribs = nullptr;
 static PFNGLXSWAPINTERVALSGIPROC glXSwapIntervalSGI = nullptr;
 
+static bool s_glxError;
+static int ctxErrorHandler(Display *dpy, XErrorEvent *ev)
+{
+    s_glxError = true;
+    return 0;
+}
+
 void cInterfaceGLX::SwapInterval(int Interval)
 {
 	if (glXSwapIntervalSGI)
@@ -33,68 +46,86 @@ void cInterfaceGLX::Swap()
 // Call browser: Core.cpp:EmuThread() > main.cpp:Video_Initialize()
 bool cInterfaceGLX::Create(void *window_handle)
 {
-	int glxMajorVersion, glxMinorVersion;
-
-	// attributes for a single buffered visual in RGBA format with at least
-	// 8 bits per color
-	int attrListSgl[] = {GLX_RGBA, GLX_RED_SIZE, 8,
-		GLX_GREEN_SIZE, 8,
-		GLX_BLUE_SIZE, 8,
-		None};
-
-	// attributes for a double buffered visual in RGBA format with at least
-	// 8 bits per color
-	int attrListDbl[] = {GLX_RGBA, GLX_DOUBLEBUFFER,
-		GLX_RED_SIZE, 8,
-		GLX_GREEN_SIZE, 8,
-		GLX_BLUE_SIZE, 8,
-		None };
-
-	int attrListDefault[] = {
-		GLX_RGBA,
-		GLX_RED_SIZE, 1,
-		GLX_GREEN_SIZE, 1,
-		GLX_BLUE_SIZE, 1,
-		GLX_DOUBLEBUFFER,
-		None };
-
 	dpy = XOpenDisplay(nullptr);
 	int screen = DefaultScreen(dpy);
 
+	// checking glx version
+	int glxMajorVersion, glxMinorVersion;
 	glXQueryVersion(dpy, &glxMajorVersion, &glxMinorVersion);
-	NOTICE_LOG(VIDEO, "glX-Version %d.%d", glxMajorVersion, glxMinorVersion);
+	if (glxMajorVersion < 1 || (glxMajorVersion == 1 && glxMinorVersion < 4))
+	{
+		ERROR_LOG(VIDEO, "glX-Version %d.%d detected, but need at least 1.4",
+		          glxMajorVersion, glxMinorVersion);
+		return false;
+	}
 
-	// Get an appropriate visual
-	vi = glXChooseVisual(dpy, screen, attrListDbl);
-	if (vi == nullptr)
+	// loading core context creation function
+	glXCreateContextAttribs = (PFNGLXCREATECONTEXTATTRIBSPROC)GetFuncAddress("glXCreateContextAttribsARB");
+	if (!glXCreateContextAttribs)
 	{
-		vi = glXChooseVisual(dpy, screen, attrListSgl);
-		if (vi != nullptr)
-		{
-			ERROR_LOG(VIDEO, "Only single buffered visual!");
-		}
-		else
-		{
-			vi = glXChooseVisual(dpy, screen, attrListDefault);
-			if (vi == nullptr)
-			{
-				ERROR_LOG(VIDEO, "Could not choose visual (glXChooseVisual)");
-				return false;
-			}
-		}
+		ERROR_LOG(VIDEO, "glXCreateContextAttribsARB not found, do you support GLX_ARB_create_context?");
+		return false;
 	}
-	else
+
+	// choosing framebuffer
+	int visual_attribs[] =
+	{
+		GLX_X_RENDERABLE    , True,
+		GLX_DRAWABLE_TYPE   , GLX_WINDOW_BIT,
+		GLX_X_VISUAL_TYPE   , GLX_TRUE_COLOR,
+		GLX_RED_SIZE        , 8,
+		GLX_GREEN_SIZE      , 8,
+		GLX_BLUE_SIZE       , 8,
+		GLX_DEPTH_SIZE      , 0,
+		GLX_STENCIL_SIZE    , 0,
+		GLX_DOUBLEBUFFER    , True,
+		None
+	};
+	int fbcount = 0;
+	GLXFBConfig* fbc = glXChooseFBConfig(dpy, screen, visual_attribs, &fbcount);
+	if (!fbc || !fbcount)
 	{
-		NOTICE_LOG(VIDEO, "Got double buffered visual!");
+		ERROR_LOG(VIDEO, "Failed to retrieve a framebuffer config");
+		return false;
 	}
+	fbconfig = *fbc;
+	XFree(fbc);
+
+	// Get an appropriate visual
+	vi = glXGetVisualFromFBConfig(dpy, fbconfig);
 
 	// Create a GLX context.
-	ctx = glXCreateContext(dpy, vi, nullptr, GL_TRUE);
-	if (!ctx)
+	// We try to get a 3.3 core profile, else we try it with anything we get.
+	int context_attribs[] =
 	{
-		PanicAlert("Unable to create GLX context.");
-		return false;
+		GLX_CONTEXT_MAJOR_VERSION_ARB, 3,
+		GLX_CONTEXT_MINOR_VERSION_ARB, 3,
+		GLX_CONTEXT_PROFILE_MASK_ARB,  GLX_CONTEXT_CORE_PROFILE_BIT_ARB,
+		GLX_CONTEXT_FLAGS_ARB,         GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB,
+		None
+	};
+	s_glxError = false;
+	XErrorHandler oldHandler = XSetErrorHandler(&ctxErrorHandler);
+	ctx = glXCreateContextAttribs(dpy, fbconfig, 0, True, context_attribs);
+	XSync(dpy, False);
+	if (!ctx || s_glxError)
+	{
+		int context_attribs_legacy[] =
+		{
+			GLX_CONTEXT_MAJOR_VERSION_ARB, 1,
+			GLX_CONTEXT_MINOR_VERSION_ARB, 0,
+			None
+		};
+		s_glxError = false;
+		ctx = glXCreateContextAttribs(dpy, fbconfig, 0, True, context_attribs_legacy);
+		XSync(dpy, False);
+		if (!ctx || s_glxError)
+		{
+			ERROR_LOG(VIDEO, "Unable to create GL context.");
+			return false;
+		}
 	}
+	XSetErrorHandler(oldHandler);
 
 	XWindow.Initialize(dpy);
 
diff --git a/Source/Core/VideoBackends/OGL/GLInterface/GLX.h b/Source/Core/VideoBackends/OGL/GLInterface/GLX.h
index fa97efdabf..8198ea9194 100644
--- a/Source/Core/VideoBackends/OGL/GLInterface/GLX.h
+++ b/Source/Core/VideoBackends/OGL/GLInterface/GLX.h
@@ -18,6 +18,7 @@ private:
 	Window win;
 	GLXContext ctx;
 	XVisualInfo *vi;
+	GLXFBConfig fbconfig;
 public:
 	friend class cX11Window;
 	void SwapInterval(int Interval) override;