GLSL backend now emits "#version 120" to legally access invariant keyword and gl_PointCoord built-in variable.
BUG=35
Review URL: http://codereview.appspot.com/2341043
git-svn-id: https://angleproject.googlecode.com/svn/trunk@448 736b8ea6-26fd-11df-bfd4-992fa37f6226
diff --git a/src/compiler/VersionGLSL.h b/src/compiler/VersionGLSL.h
new file mode 100644
index 0000000..64d002b
--- /dev/null
+++ b/src/compiler/VersionGLSL.h
@@ -0,0 +1,50 @@
+//
+// Copyright (c) 2002-2010 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+
+#ifndef COMPILER_VERSIONGLSL_H_
+#define COMPILER_VERSIONGLSL_H_
+
+#include "GLSLANG/ShaderLang.h"
+#include "compiler/intermediate.h"
+
+// Traverses the intermediate tree to return the minimum GLSL version
+// required to legally access all built-in features used in the shader.
+// GLSL 1.1 which is mandated by OpenGL 2.0 provides:
+// - #version and #extension to declare version and extensions.
+// - built-in functions refract, exp, and log.
+// - updated step() to compare x < edge instead of x <= edge.
+// GLSL 1.2 which is mandated by OpenGL 2.1 provides:
+// - many changes to reduce differences when compared to the ES specification.
+// - invariant keyword and its support.
+// - c++ style name hiding rules.
+// - built-in variable gl_PointCoord for fragment shaders.
+//
+class TVersionGLSL : public TIntermTraverser {
+public:
+ TVersionGLSL(ShShaderType type);
+
+ // Returns 120 if "invariant" keyword or "gl_PointCoord" is used
+ // in the shader. Else 110 is returned.
+ int getVersion() { return mVersion; }
+
+ virtual void visitSymbol(TIntermSymbol*);
+ virtual void visitConstantUnion(TIntermConstantUnion*);
+ virtual bool visitBinary(Visit, TIntermBinary*);
+ virtual bool visitUnary(Visit, TIntermUnary*);
+ virtual bool visitSelection(Visit, TIntermSelection*);
+ virtual bool visitAggregate(Visit, TIntermAggregate*);
+ virtual bool visitLoop(Visit, TIntermLoop*);
+ virtual bool visitBranch(Visit, TIntermBranch*);
+
+protected:
+ void updateVersion(int version);
+
+private:
+ ShShaderType mShaderType;
+ int mVersion;
+};
+
+#endif // COMPILER_VERSIONGLSL_H_