Support frustum clipping against z = -1.

This allows performing the depth range adjustment only once as part of the
viewport transform and not have it be affected by transform feedback.

Change-Id: I89fba3b131c234bea064b1b65f50b62261f4c307
Reviewed-on: https://swiftshader-review.googlesource.com/5421
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
diff --git a/src/Shader/VertexRoutine.hpp b/src/Shader/VertexRoutine.hpp
index eadd795..4aec45f 100644
--- a/src/Shader/VertexRoutine.hpp
+++ b/src/Shader/VertexRoutine.hpp
@@ -63,7 +63,8 @@
 		void computeClipFlags();
 		void postTransform();
 		void writeCache(Pointer<Byte> &cacheLine);
-		void writeVertex(const Pointer<Byte> &vertex, Pointer<Byte> &cacheLine, const UInt &primitiveNumber, const UInt &indexInPrimitive);
+		void writeVertex(const Pointer<Byte> &vertex, Pointer<Byte> &cacheLine);
+		void transformFeedback(const Pointer<Byte> &vertex, const UInt &primitiveNumber, const UInt &indexInPrimitive);
 	};
 }