metal: initial work on windowing and instance creation

src/modules/graphics/Graphics.h

@@ -151,7 +151,7 @@ public:
 	enum Renderer
 	{
 		RENDERER_OPENGL = 0,
-		RENDERER_OPENGLES,
+		RENDERER_METAL,
 		RENDERER_MAX_ENUM
 	};
 
@@ -797,6 +797,11 @@ public:
 	 **/
 	virtual Renderer getRenderer() const = 0;
 
+	/**
+	 * Whether shaders will use GLSL ES or not (mobile shaders).
+	 **/
+	virtual bool usesGLSLES() const = 0;
+
 	/**
 	 * Returns system-dependent renderer information.
 	 * Returned strings can vary greatly between systems! Do not rely on it for
@@ -853,6 +858,8 @@ public:
 		return (T *) scratchBuffer.data();
 	}
 
+	static Graphics *createInstance(const std::vector<Renderer> &renderers);
+
 	static bool getConstant(const char *in, DrawMode &out);
 	static bool getConstant(DrawMode in, const char *&out);
 	static std::vector<std::string> getConstants(DrawMode);