OpenGL: Blender 2.8 on X11 requires GL 3.0

Implements the Linux part of T49012.

Simplify the options for context creation. No options for legacy GL or EGL or ES2. Select 3.2 CORE or COMPATIBILITY profile at build time.

If that fails, use a GL 3.0 context. This keeps Mesa supported while we work on full 3.2 core elsewhere in the code.

2 files changed, 47 insertions, 77 deletions

diff --git a/intern/ghost/intern/GHOST_ContextGLX.cpp b/intern/ghost/intern/GHOST_ContextGLX.cpp
index 9ac61db4041..2d49894a5c2 100644
--- a/intern/ghost/intern/GHOST_ContextGLX.cpp
+++ b/intern/ghost/intern/GHOST_ContextGLX.cpp
@@ -255,9 +255,6 @@ const bool GLXEW_ARB_create_context_robustness =
 		if (m_contextMajorVersion != 0) {
 			attribs[i++] = GLX_CONTEXT_MAJOR_VERSION_ARB;
 			attribs[i++] = m_contextMajorVersion;
-		}
-
-		if (m_contextMinorVersion != 0) {
 			attribs[i++] = GLX_CONTEXT_MINOR_VERSION_ARB;
 			attribs[i++] = m_contextMinorVersion;
 		}
@@ -300,8 +297,8 @@ const bool GLXEW_ARB_create_context_robustness =
 		}
 	}
 	else {
-		/* Create legacy context */
-		m_context = glXCreateContext(m_display, m_visualInfo, s_sharedContext, True);
+		/* Don't create legacy context */
+		fprintf(stderr, "Warning! GLX_ARB_create_context not available.\n");
 	}
 
 	GHOST_TSuccess success;
@@ -328,8 +325,14 @@ const bool GLXEW_ARB_create_context_robustness =
 
 		version = glGetString(GL_VERSION);
 
-		if (!version || version[0] < '2' || ((version[0] == '2') &&  (version[2] < '1'))) {
-			fprintf(stderr, "Error! Blender requires OpenGL 2.1 to run. Try updating your drivers.\n");
+#if 0 // enable this when Blender switches to 3.2 core profile
+		if (!version || version[0] < '3' || ((version[0] == '3') && (version[2] < '2'))) {
+			fprintf(stderr, "Error! Blender requires OpenGL 3.2 to run. Try updating your drivers.\n");
+#else
+		// with Mesa, the closest thing to 3.2 compatibility profile is 3.0
+		if (!version || version[0] < '3') {
+			fprintf(stderr, "Error! Blender requires OpenGL 3.0 (soon 3.2) to run. Try updating your drivers.\n");
+#endif
 			fflush(stderr);
 			/* ugly, but we get crashes unless a whole bunch of systems are patched. */
 			exit(0);
diff --git a/intern/ghost/intern/GHOST_WindowX11.cpp b/intern/ghost/intern/GHOST_WindowX11.cpp
index fd002cec80c..3694bd53881 100644
--- a/intern/ghost/intern/GHOST_WindowX11.cpp
+++ b/intern/ghost/intern/GHOST_WindowX11.cpp
@@ -1301,33 +1301,24 @@ GHOST_WindowX11::
 GHOST_Context *GHOST_WindowX11::newDrawingContext(GHOST_TDrawingContextType type)
 {
 	if (type == GHOST_kDrawingContextTypeOpenGL) {
-#if !defined(WITH_GL_EGL)
 
+		// During development:
+		//   try 3.2 compatibility profile
+		//   fall back to 3.0 if needed
+		//
+		// Final Blender 2.8:
+		//   try 3.2 core profile
+		//   no fallbacks
+
+		const int profile_mask =
 #if defined(WITH_GL_PROFILE_CORE)
-		GHOST_Context *context = new GHOST_ContextGLX(
-		        m_wantStereoVisual,
-		        m_wantNumOfAASamples,
-		        m_window,
-		        m_display,
-		        m_visualInfo,
-		        (GLXFBConfig)m_fbconfig,
-		        GLX_CONTEXT_CORE_PROFILE_BIT_ARB,
-		        3, 2,
-		        GHOST_OPENGL_GLX_CONTEXT_FLAGS | (m_is_debug_context ? GLX_CONTEXT_DEBUG_BIT_ARB : 0),
-		        GHOST_OPENGL_GLX_RESET_NOTIFICATION_STRATEGY);
-#elif defined(WITH_GL_PROFILE_ES20)
-		GHOST_Context *context = new GHOST_ContextGLX(
-		        m_wantStereoVisual,
-		        m_wantNumOfAASamples,
-		        m_window,
-		        m_display,
-		        m_visualInfo,
-		        (GLXFBConfig)m_fbconfig,
-		        GLX_CONTEXT_ES2_PROFILE_BIT_EXT,
-		        2, 0,
-		        GHOST_OPENGL_GLX_CONTEXT_FLAGS | (m_is_debug_context ? GLX_CONTEXT_DEBUG_BIT_ARB : 0),
-		        GHOST_OPENGL_GLX_RESET_NOTIFICATION_STRATEGY);
+			GLX_CONTEXT_CORE_PROFILE_BIT_ARB;
 #elif defined(WITH_GL_PROFILE_COMPAT)
+			GLX_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB;
+#else
+#  error // must specify either core or compat at build time
+#endif
+
 		GHOST_Context *context = new GHOST_ContextGLX(
 		        m_wantStereoVisual,
 		        m_wantNumOfAASamples,
@@ -1335,58 +1326,34 @@ GHOST_Context *GHOST_WindowX11::newDrawingContext(GHOST_TDrawingContextType type
 		        m_display,
 		        m_visualInfo,
 		        (GLXFBConfig)m_fbconfig,
-		        0, // profile bit
-		        0, 0,
+		        profile_mask,
+		        3, 2,
 		        GHOST_OPENGL_GLX_CONTEXT_FLAGS | (m_is_debug_context ? GLX_CONTEXT_DEBUG_BIT_ARB : 0),
 		        GHOST_OPENGL_GLX_RESET_NOTIFICATION_STRATEGY);
-#else
-#  error
-#endif
 
-#else
-
-#if defined(WITH_GL_PROFILE_CORE)
-		GHOST_Context *context = new GHOST_ContextEGL(
-		        m_wantStereoVisual,
-		        m_wantNumOfAASamples,
-		        m_window,
-		        m_display,
-		        EGL_CONTEXT_OPENGL_CORE_PROFILE_BIT,
-		        3, 2,
-		        GHOST_OPENGL_EGL_CONTEXT_FLAGS,
-		        GHOST_OPENGL_EGL_RESET_NOTIFICATION_STRATEGY,
-		        EGL_OPENGL_API);
-#elif defined(WITH_GL_PROFILE_ES20)
-		GHOST_Context *context = new GHOST_ContextEGL(
-		        m_wantStereoVisual,
-		        m_wantNumOfAASamples,
-		        m_window,
-		        m_display,
-		        0, // profile bit
-		        2, 0,
-		        GHOST_OPENGL_EGL_CONTEXT_FLAGS,
-		        GHOST_OPENGL_EGL_RESET_NOTIFICATION_STRATEGY,
-		        EGL_OPENGL_ES_API);
-#elif defined(WITH_GL_PROFILE_COMPAT)
-		GHOST_Context *context = new GHOST_ContextEGL(
-		        m_wantStereoVisual,
-		        m_wantNumOfAASamples,
-		        m_window,
-		        m_display,
-		        0, // profile bit
-		        0, 0,
-		        GHOST_OPENGL_EGL_CONTEXT_FLAGS,
-		        GHOST_OPENGL_EGL_RESET_NOTIFICATION_STRATEGY,
-		        EGL_OPENGL_API);
-#else
-#  error
-#endif
-
-#endif
 		if (context->initializeDrawingContext())
 			return context;
-		else
+		else {
 			delete context;
+
+			// since that failed try 3.0 (mostly for Mesa, which doesn't implement compatibility profile)
+			context = new GHOST_ContextGLX(
+			        m_wantStereoVisual,
+			        m_wantNumOfAASamples,
+			        m_window,
+			        m_display,
+			        m_visualInfo,
+			        (GLXFBConfig)m_fbconfig,
+			        0, // no profile bit
+			        3, 0,
+			        GHOST_OPENGL_GLX_CONTEXT_FLAGS | (m_is_debug_context ? GLX_CONTEXT_DEBUG_BIT_ARB : 0),
+			        GHOST_OPENGL_GLX_RESET_NOTIFICATION_STRATEGY);
+
+			if (context->initializeDrawingContext())
+				return context;
+			else
+				delete context;
+		}
 	}
 
 	return NULL;