Add facilities to disable extensions and force lower versions

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

diff --git a/source/extension.cpp b/source/extension.cpp
index 41b06b217f79c9df88c83498eb595d41cbecaca9..fdbefb5336407e402ba0985985804ba4d527c241 100644 (file)
--- a/source/extension.cpp
+++ b/source/extension.cpp
@@ -85,6 +85,13 @@ bool is_supported(const string &ext)
                        buffer. */
                        extensions.erase("GL_NV_primitive_restart");
 
+               if(const char *disable_ptr = getenv("MSPGL_DISABLE_EXTENSIONS"))
+               {
+                       vector<string> disable = split(disable_ptr);
+                       for(vector<string>::const_iterator i=disable.begin(); i!=disable.end(); ++i)
+                               extensions.erase(*i);
+               }
+
                init_done = true;
        }
 
@@ -94,7 +101,16 @@ bool is_supported(const string &ext)
 inline Version _get_gl_version()
 {
        string gl_ver = reinterpret_cast<const char *>(glGetString(GL_VERSION));
-       return Version(gl_ver.substr(0, gl_ver.find(' ')));
+       Version ver(gl_ver.substr(0, gl_ver.find(' ')));
+
+       if(const char *force_ver_ptr = getenv("MSPGL_FORCE_VERSION"))
+       {
+               Version force_ver(force_ver_ptr);
+               if(!(force_ver>=ver))
+                       ver = force_ver;
+       }
+
+       return ver;
 }
 
 const Version &get_gl_version()
@@ -103,6 +119,27 @@ const Version &get_gl_version()
        return version;
 }
 
+inline Version _get_glsl_version()
+{
+       string glsl_ver = reinterpret_cast<const char *>(glGetString(GL_SHADING_LANGUAGE_VERSION));
+       Version ver(glsl_ver.substr(0, glsl_ver.find(' ')));
+
+       if(const char *force_ver_ptr = getenv("MSPGL_FORCE_GLSL_VERSION"))
+       {
+               Version force_ver(force_ver_ptr);
+               if(!(force_ver>=ver))
+                       ver = force_ver;
+       }
+
+       return ver;
+}
+
+const Version &get_glsl_version()
+{
+       static Version version = _get_glsl_version();
+       return version;
+}
+
 bool is_version_at_least(unsigned a, unsigned b)
 {
        return get_gl_version()>=Version(a, b);