Use RAII checks for extensions and versions

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

diff --git a/source/extension.h b/source/extension.h
index d6eb75f6a396eccec9c17cd7e6a111e3cb7406aa..4410cc3c316e244ec7ecd934e4668befffb6126d 100644 (file)
--- a/source/extension.h
+++ b/source/extension.h
@@ -13,6 +13,12 @@ Distributed under the LGPL
 namespace Msp {
 namespace GL {
 
+struct Version
+{
+       unsigned short major;
+       unsigned short minor;
+};
+
 typedef void ExtFunc();
 
 /**
@@ -21,11 +27,38 @@ functions of that extension are safe to use.
 */
 bool is_supported(const std::string &);
 
+/**
+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();
+
 /**
 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.
+*/
+struct RequireExtension
+{
+       RequireExtension(const std::string &e) { require_extension(e); }
+};
+
+/**
+Checks that the OpenGL version is at least a.b and throws if it isn't.
+*/
+void require_version(unsigned a, unsigned b);
+
+/**
+RAII version of require_version.  Useful as a static local variable.
+*/
+struct RequireVersion
+{
+       RequireVersion(unsigned a, unsigned b) { require_version(a, b); }
+};
+
 /**
 Returns the address of an extension function.
 */