5 files changed, 38 insertions, 28 deletions
diff --git a/drivers/dummy/rasterizer_dummy.h b/drivers/dummy/rasterizer_dummy.h
index e39ec915fc..0381d3f0c1 100644
--- a/drivers/dummy/rasterizer_dummy.h
+++ b/drivers/dummy/rasterizer_dummy.h
@@ -789,6 +789,10 @@ public:
 	void end_frame(bool p_swap_buffers) {}
 	void finalize() {}
 
+	static Error is_viable() {
+		return OK;
+	}
+
 	static Rasterizer *_create_current() {
 		return memnew(RasterizerDummy);
 	}
diff --git a/drivers/gles2/rasterizer_gles2.cpp b/drivers/gles2/rasterizer_gles2.cpp
index c926f2bcc4..76ee80aa07 100644
--- a/drivers/gles2/rasterizer_gles2.cpp
+++ b/drivers/gles2/rasterizer_gles2.cpp
@@ -136,26 +136,21 @@ RasterizerScene *RasterizerGLES2::get_scene() {
 	return scene;
 }
 
-void RasterizerGLES2::initialize() {
-
-	print_verbose("Using GLES2 video driver");
+Error RasterizerGLES2::is_viable() {
 
 #ifdef GLAD_ENABLED
 	if (!gladLoadGL()) {
 		ERR_PRINT("Error initializing GLAD");
+		return ERR_UNAVAILABLE;
 	}
 
 // GLVersion seems to be used for both GL and GL ES, so we need different version checks for them
 #ifdef OPENGL_ENABLED // OpenGL 2.1 Profile required
-	if (GLVersion.major < 2) {
-#else // OpenGL ES 3.0
+	if (GLVersion.major < 2 || (GLVersion.major == 2 && GLVersion.minor < 1)) {
+#else // OpenGL ES 2.0
 	if (GLVersion.major < 2) {
 #endif
-		ERR_PRINT("Your system's graphic drivers seem not to support OpenGL 2.1 / OpenGL ES 2.0, sorry :(\n"
-				  "Try a drivers update, buy a new GPU or try software rendering on Linux; Godot will now crash with a segmentation fault.");
-		OS::get_singleton()->alert("Your system's graphic drivers seem not to support OpenGL 2.1 / OpenGL ES 2.0, sorry :(\n"
-								   "Godot Engine will self-destruct as soon as you acknowledge this error message.",
-				"Fatal error: Insufficient OpenGL / GLES driver support");
+		return ERR_UNAVAILABLE;
 	}
 
 #ifdef GLES_OVER_GL
@@ -181,14 +176,21 @@ void RasterizerGLES2::initialize() {
 			glGetFramebufferAttachmentParameteriv = glGetFramebufferAttachmentParameterivEXT;
 			glGenerateMipmap = glGenerateMipmapEXT;
 		} else {
-			ERR_PRINT("Your system's graphic drivers seem not to support GL_ARB(EXT)_framebuffer_object OpenGL extension, sorry :(\n"
-					  "Try a drivers update, buy a new GPU or try software rendering on Linux; Godot will now crash with a segmentation fault.");
-			OS::get_singleton()->alert("Your system's graphic drivers seem not to support GL_ARB(EXT)_framebuffer_object OpenGL extension, sorry :(\n"
-									   "Godot Engine will self-destruct as soon as you acknowledge this error message.",
-					"Fatal error: Insufficient OpenGL / GLES driver support");
+			return ERR_UNAVAILABLE;
 		}
 	}
 #endif
+
+#endif // GLAD_ENABLED
+
+	return OK;
+}
+
+void RasterizerGLES2::initialize() {
+
+	print_verbose("Using GLES2 video driver");
+
+#ifdef GLAD_ENABLED
 	if (true || OS::get_singleton()->is_stdout_verbose()) {
 		if (GLAD_GL_ARB_debug_output) {
 			glEnable(_EXT_DEBUG_OUTPUT_SYNCHRONOUS_ARB);
@@ -198,7 +200,6 @@ void RasterizerGLES2::initialize() {
 			print_line("OpenGL debugging not supported!");
 		}
 	}
-
 #endif // GLAD_ENABLED
 
 	// For debugging
diff --git a/drivers/gles2/rasterizer_gles2.h b/drivers/gles2/rasterizer_gles2.h
index f727af39dd..98c73b776b 100644
--- a/drivers/gles2/rasterizer_gles2.h
+++ b/drivers/gles2/rasterizer_gles2.h
@@ -61,9 +61,10 @@ public:
 	virtual void end_frame(bool p_swap_buffers);
 	virtual void finalize();
 
+	static Error is_viable();
 	static void make_current();
-
 	static void register_config();
+
 	RasterizerGLES2();
 	~RasterizerGLES2();
 };
diff --git a/drivers/gles3/rasterizer_gles3.cpp b/drivers/gles3/rasterizer_gles3.cpp
index 0d42635194..e4824695d5 100644
--- a/drivers/gles3/rasterizer_gles3.cpp
+++ b/drivers/gles3/rasterizer_gles3.cpp
@@ -136,28 +136,32 @@ typedef void (*DEBUGPROCARB)(GLenum source,
 
 typedef void (*DebugMessageCallbackARB)(DEBUGPROCARB callback, const void *userParam);
 
-void RasterizerGLES3::initialize() {
-
-	print_verbose("Using GLES3 video driver");
+Error RasterizerGLES3::is_viable() {
 
 #ifdef GLAD_ENABLED
 	if (!gladLoadGL()) {
 		ERR_PRINT("Error initializing GLAD");
+		return ERR_UNAVAILABLE;
 	}
 
 // GLVersion seems to be used for both GL and GL ES, so we need different version checks for them
 #ifdef OPENGL_ENABLED // OpenGL 3.3 Core Profile required
-	if (GLVersion.major < 3 && GLVersion.minor < 3) {
+	if (GLVersion.major < 3 || (GLVersion.major == 3 && GLVersion.minor < 3)) {
 #else // OpenGL ES 3.0
 	if (GLVersion.major < 3) {
 #endif
-		ERR_PRINT("Your system's graphic drivers seem not to support OpenGL 3.3 / OpenGL ES 3.0, sorry :(\n"
-				  "Try a drivers update, buy a new GPU or try software rendering on Linux; Godot will now crash with a segmentation fault.");
-		OS::get_singleton()->alert("Your system's graphic drivers seem not to support OpenGL 3.3 / OpenGL ES 3.0, sorry :(\n"
-								   "Godot Engine will self-destruct as soon as you acknowledge this error message.",
-				"Fatal error: Insufficient OpenGL / GLES driver support");
+		return ERR_UNAVAILABLE;
 	}
 
+#endif // GLAD_ENABLED
+	return OK;
+}
+
+void RasterizerGLES3::initialize() {
+
+	print_verbose("Using GLES3 video driver");
+
+#ifdef GLAD_ENABLED
 	if (OS::get_singleton()->is_stdout_verbose()) {
 		if (GLAD_GL_ARB_debug_output) {
 			glEnable(_EXT_DEBUG_OUTPUT_SYNCHRONOUS_ARB);
@@ -167,7 +171,6 @@ void RasterizerGLES3::initialize() {
 			print_line("OpenGL debugging not supported!");
 		}
 	}
-
 #endif // GLAD_ENABLED
 
 	/* // For debugging
diff --git a/drivers/gles3/rasterizer_gles3.h b/drivers/gles3/rasterizer_gles3.h
index f4449ac0f9..0a264caf8f 100644
--- a/drivers/gles3/rasterizer_gles3.h
+++ b/drivers/gles3/rasterizer_gles3.h
@@ -62,9 +62,10 @@ public:
 	virtual void end_frame(bool p_swap_buffers);
 	virtual void finalize();
 
+	static Error is_viable();
 	static void make_current();
-
 	static void register_config();
+
 	RasterizerGLES3();
 	~RasterizerGLES3();
 };