+Expression* extensionSupportedParser(const SGPropertyNode* exp,
+ expression::Parser* parser)
+{
+ if (exp->getType() == props::STRING
+ || exp->getType() == props::UNSPECIFIED) {
+ ExtensionSupportedExpression* esp
+ = new ExtensionSupportedExpression(exp->getStringValue());
+ int location = parser->getBindingLayout().addBinding("__contextId",
+ expression::INT);
+ VariableExpression<int>* contextExp
+ = new VariableExpression<int>(location);
+ esp->addOperand(contextExp);
+ return esp;
+ }
+ throw expression::ParseError("extension-supported expression has wrong type");
+}
+
+expression::ExpParserRegistrar
+extensionSupportedRegistrar("extension-supported", extensionSupportedParser);
+
+class GLShaderLanguageExpression : public GeneralNaryExpression<float, int>
+{
+public:
+ void eval(float& value, const expression::Binding* b) const
+ {
+ value = 0.0f;
+ int contextId = getOperand(0)->getValue(b);
+ GL2Extensions* extensions
+ = GL2Extensions::Get(static_cast<unsigned>(contextId), true);
+ if (!extensions)
+ return;
+ if (!extensions->isGlslSupported())
+ return;
+ value = extensions->getLanguageVersion();
+ }
+};
+
+Expression* shaderLanguageParser(const SGPropertyNode* exp,
+ expression::Parser* parser)
+{
+ GLShaderLanguageExpression* slexp = new GLShaderLanguageExpression;
+ int location = parser->getBindingLayout().addBinding("__contextId",
+ expression::INT);
+ VariableExpression<int>* contextExp = new VariableExpression<int>(location);
+ slexp->addOperand(contextExp);
+ return slexp;
+}
+
+expression::ExpParserRegistrar shaderLanguageRegistrar("shader-language",
+ glVersionParser);
+
+