From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 17 Oct 2014 10:36:54 +0000 (+0300)
Subject: Add facilities to disable extensions and force lower versions
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=72efb2325bcac4ba2bfc243fe4766357681868a5

Add facilities to disable extensions and force lower versions

Useful for testing some exotic combinations without actually having to
dig up suitable hardware.
---

diff --git a/source/extension.cpp b/source/extension.cpp
index d0361665..fdbefb53 100644
--- 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()
@@ -106,7 +122,16 @@ const Version &get_gl_version()
 inline Version _get_glsl_version()
 {
 	string glsl_ver = reinterpret_cast<const char *>(glGetString(GL_SHADING_LANGUAGE_VERSION));
-	return Version(glsl_ver.substr(0, glsl_ver.find(' ')));
+	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()