Split SL::Compiler into several files

[libs/gl.git] / source / glsl / evaluate.cpp

diff --git a/source/glsl/evaluate.cpp b/source/glsl/evaluate.cpp
new file mode 100644 (file)
index 0000000..96a80fa
--- /dev/null
+++ b/source/glsl/evaluate.cpp
@@ -0,0 +1,98 @@
+#include "evaluate.h"
+
+namespace Msp {
+namespace GL {
+namespace SL {
+
+ExpressionEvaluator::ExpressionEvaluator():
+       variable_values(0),
+       result(0.0f),
+       result_valid(false)
+{ }
+
+ExpressionEvaluator::ExpressionEvaluator(const ValueMap &v):
+       variable_values(&v),
+       result(0.0f),
+       result_valid(false)
+{ }
+
+void ExpressionEvaluator::visit(Literal &literal)
+{
+       if(literal.token=="true")
+               result = 1.0f;
+       else if(literal.token=="false")
+               result = 0.0f;
+       else
+               result = lexical_cast<float>(literal.token);
+       result_valid = true;
+}
+
+void ExpressionEvaluator::visit(ParenthesizedExpression &parexp)
+{
+       parexp.expression->visit(*this);
+}
+
+void ExpressionEvaluator::visit(VariableReference &var)
+{
+       if(!var.declaration)
+               return;
+
+       if(variable_values)
+       {
+               ValueMap::const_iterator i = variable_values->find(var.declaration);
+               if(i!=variable_values->end())
+                       i->second->visit(*this);
+       }
+       else if(var.declaration->init_expression)
+               var.declaration->init_expression->visit(*this);
+}
+
+void ExpressionEvaluator::visit(UnaryExpression &unary)
+{
+       result_valid = false;
+       unary.expression->visit(*this);
+       if(!result_valid)
+               return;
+
+       if(unary.oper=="!")
+               result = !result;
+       else
+               result_valid = false;
+}
+
+void ExpressionEvaluator::visit(BinaryExpression &binary)
+{
+       result_valid = false;
+       binary.left->visit(*this);
+       if(!result_valid)
+               return;
+
+       float left_result = result;
+       result_valid = false;
+       binary.right->visit(*this);
+       if(!result_valid)
+               return;
+
+       if(binary.oper=="<")
+               result = (left_result<result);
+       else if(binary.oper=="<=")
+               result = (left_result<=result);
+       else if(binary.oper==">")
+               result = (left_result>result);
+       else if(binary.oper==">=")
+               result = (left_result>=result);
+       else if(binary.oper=="==")
+               result = (left_result==result);
+       else if(binary.oper=="!=")
+               result = (left_result!=result);
+       else if(binary.oper=="&&")
+               result = (left_result && result);
+       else if(binary.oper=="||")
+               result = (left_result || result);
+       else
+               result_valid = false;
+}
+
+} // namespace SL
+} // namespace GL
+} // namespace Msp