Refactor version number extraction and checks

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

diff --git a/source/extension.cpp b/source/extension.cpp
index 56f96d4ecee2136dcde2d42f5fbdfa7bbf8b421b..41b06b217f79c9df88c83498eb595d41cbecaca9 100644 (file)
--- a/source/extension.cpp
+++ b/source/extension.cpp
@@ -14,6 +14,31 @@ using namespace std;
 namespace Msp {
 namespace GL {
 
+Version::Version()
+{
+       major = 0;
+       minor = 0;
+}
+
+Version::Version(unsigned short a, unsigned short i)
+{
+       major = a;
+       minor = i;
+}
+
+Version::Version(const string &s)
+{
+       vector<string> parts = split(s, '.');
+       major = lexical_cast<unsigned>(parts[0]);
+       minor = lexical_cast<unsigned>(parts[1]);
+}
+
+bool Version::operator>=(const Version &other) const
+{
+       return major>other.major || (major==other.major && minor>=other.minor);
+}
+
+
 Extension::Extension(const char *n, InitFunc f):
        name(n),
        init_func(f),
@@ -66,28 +91,21 @@ bool is_supported(const string &ext)
        return extensions.count(ext);
 }
 
-const Version &get_gl_version()
+inline Version _get_gl_version()
 {
-       static Version version;
-       static bool init_done = false;
-
-       if(!init_done)
-       {
-               string gl_ver = reinterpret_cast<const char *>(glGetString(GL_VERSION));
-               vector<string> parts = split(gl_ver.substr(0, gl_ver.find(' ')), '.');
-               version.major = lexical_cast<unsigned>(parts[0]);
-               version.minor = lexical_cast<unsigned>(parts[1]);
-
-               init_done = true;
-       }
+       string gl_ver = reinterpret_cast<const char *>(glGetString(GL_VERSION));
+       return Version(gl_ver.substr(0, gl_ver.find(' ')));
+}
 
+const Version &get_gl_version()
+{
+       static Version version = _get_gl_version();
        return version;
 }
 
 bool is_version_at_least(unsigned a, unsigned b)
 {
-       const Version &ver = get_gl_version();
-       return (ver.major>a || (ver.major==a && ver.minor>=b));
+       return get_gl_version()>=Version(a, b);
 }
 
 ExtFunc *get_proc_address(const string &name)