Minor fixes to texture anisotropy handling

[libs/gl.git] / source / extension.h

diff --git a/source/extension.h b/source/extension.h
index d6eb75f6a396eccec9c17cd7e6a111e3cb7406aa..cf824e24b0a189b65fc88de30adc6dc862fb5e09 100644 (file)
--- a/source/extension.h
+++ b/source/extension.h
@@ -1,34 +1,102 @@
-/* $Id$
-
-This file is part of libmspgl
-Copyright © 2007  Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
-
 #ifndef MSP_GL_EXTENSION_H_
 #define MSP_GL_EXTENSION_H_
 
-#include <msp/core/except.h>
+#include <string>
 
 namespace Msp {
 namespace GL {
 
-typedef void ExtFunc();
+enum GLApi
+{
+       OPENGL,
+       OPENGL_ES2
+};
+
+enum GLProfile
+{
+       CORE_PROFILE,
+       COMPATIBILITY_PROFILE
+};
+
+
+struct Version
+{
+       unsigned short major;
+       unsigned short minor;
+
+       Version();
+       Version(unsigned short, unsigned short);
+       Version(const std::string &);
+
+       bool operator>=(const Version &) const;
+       bool operator<(const Version &o) const { return !(*this>=o); }
+       operator bool() const { return major || minor; }
+};
+
 
 /**
-Indicates whether an extension is supported.  If this returns true, the
-functions of that extension are safe to use.
+Holds metadata about an extension.  Evaluates to true if the extension is
+supported.
 */
+class Extension
+{
+public:
+       enum SupportLevel
+       {
+               UNSUPPORTED,
+               EXTENSION,
+               CORE
+       };
+
+       typedef SupportLevel (*InitFunc)();
+
+private:
+       const char *name;
+       InitFunc init_func;
+       mutable bool init_done;
+       mutable SupportLevel support;
+
+public:
+       Extension(const char *, InitFunc);
+
+       const char *get_name() const { return name; }
+       operator bool() const;
+};
+
+
+struct Require
+{
+       Require(const Extension &);
+};
+
+
+typedef void ExtFunc();
+
+/** Checks for extension support.  Only intended for internal use. */
 bool is_supported(const std::string &);
 
-/**
-Checks that an extension is supported and throws if it isn't.
-*/
-void require_extension(const std::string &);
+/** Checks for OpenGL version support.  Only intended for internal use. */
+bool is_supported(const Version &, const Version & = Version());
 
-/**
-Returns the address of an extension function.
-*/
+/** Indicates whether an extension has been disabled, either explicitly through
+the MSPGL_DISABLE_EXTENSIONS environment variable or implicitly as a workaround
+for a driver bug.  Only intended for internal use. */
+bool is_disabled(const std::string &);
+
+/** Returns the API for which the library was compiled. */
+GLApi get_gl_api();
+
+/** Returns the OpenGL profile for the active context. */
+GLProfile get_gl_profile();
+
+/** Returns the OpenGL version number, as reported by the implementation. */
+const Version &get_gl_version();
+
+/** Returns the GLSL version number, as reported by the implementation. */
+const Version &get_glsl_version();
+
+/** Returns the address of an extension function.  Only indended for internal
+use. */
 ExtFunc *get_proc_address(const std::string &);
 
 } // namespace GL