Fix an incorrect negation

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

diff --git a/source/extension.h b/source/extension.h
index 4072869cc25662d8c76fe2d4ab94c5700515f2a3..cf824e24b0a189b65fc88de30adc6dc862fb5e09 100644 (file)
--- a/source/extension.h
+++ b/source/extension.h
@@ -6,60 +6,97 @@
 namespace Msp {
 namespace GL {
 
+enum GLApi
+{
+       OPENGL,
+       OPENGL_ES2
+};
+
+enum GLProfile
+{
+       CORE_PROFILE,
+       COMPATIBILITY_PROFILE
+};
+
+
 struct Version
 {
        unsigned short major;
        unsigned short minor;
-};
 
-typedef void ExtFunc();
+       Version();
+       Version(unsigned short, unsigned short);
+       Version(const std::string &);
 
-/**
-Indicates whether an extension is supported.  If this returns true, the
-functions of that extension are safe to use.
-*/
-bool is_supported(const std::string &);
+       bool operator>=(const Version &) const;
+       bool operator<(const Version &o) const { return !(*this>=o); }
+       operator bool() const { return major || minor; }
+};
 
-/**
-Checks that an extension is supported and throws if it isn't.
-*/
-void require_extension(const std::string &);
 
 /**
-RAII version of require_extension.  Useful as a static local variable.
+Holds metadata about an extension.  Evaluates to true if the extension is
+supported.
 */
-struct RequireExtension
+class Extension
 {
-       RequireExtension(const std::string &e) { require_extension(e); }
-};
+public:
+       enum SupportLevel
+       {
+               UNSUPPORTED,
+               EXTENSION,
+               CORE
+       };
 
-/**
-Returns the OpenGL version number, as reported by the implementation.
-Functions up to the returned version are safe to use.
-*/
-const Version &get_gl_version();
+       typedef SupportLevel (*InitFunc)();
 
-/**
-Indicates whether the OpenGL version is at least a.b.
-*/
-bool is_version_at_least(unsigned a, unsigned b);
+private:
+       const char *name;
+       InitFunc init_func;
+       mutable bool init_done;
+       mutable SupportLevel support;
 
-/**
-Checks that the OpenGL version is at least a.b and throws if it isn't.
-*/
-void require_version(unsigned a, unsigned b);
+public:
+       Extension(const char *, InitFunc);
 
-/**
-RAII version of require_version.  Useful as a static local variable.
-*/
-struct RequireVersion
+       const char *get_name() const { return name; }
+       operator bool() const;
+};
+
+
+struct Require
 {
-       RequireVersion(unsigned a, unsigned b) { require_version(a, b); }
+       Require(const Extension &);
 };
 
-/**
-Returns the address of an extension function.  Only indended for internal use.
-*/
+
+typedef void ExtFunc();
+
+/** Checks for extension support.  Only intended for internal use. */
+bool is_supported(const std::string &);
+
+/** Checks for OpenGL version support.  Only intended for internal use. */
+bool is_supported(const Version &, const Version & = Version());
+
+/** 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