Allow alternative form for refract().

Bug: 27266906
Change-Id: Ib24c8d065d922a987feb0271f397d83b837ae936

diff --git a/modules/glshared/glsBuiltinPrecisionTests.cpp b/modules/glshared/glsBuiltinPrecisionTests.cpp
index d32a373..fee0c53 100644 (file)
--- a/modules/glshared/glsBuiltinPrecisionTests.cpp
+++ b/modules/glshared/glsBuiltinPrecisionTests.cpp
@@ -3127,6 +3127,49 @@ protected:
        }
 };
 
+template<int Size, typename Ret, typename Arg0, typename Arg1>
+struct ApplyRefract
+{
+       static ExprP<Ret> apply (ExpandContext&                 ctx,
+                                                        const ExprP<Arg0>&             i,
+                                                        const ExprP<Arg1>&             n,
+                                                        const ExprP<float>&    eta)
+       {
+               const ExprP<float>      dotNI   = bindExpression("dotNI", ctx, dot(n, i));
+               const ExprP<float>      k               = bindExpression("k", ctx, constant(1.0f) - eta * eta *
+                                                                                                (constant(1.0f) - dotNI * dotNI));
+
+               return cond(k < constant(0.0f),
+                                       genXType<float, Size>(constant(0.0f)),
+                                       i * eta - n * (eta * dotNI + sqrt(k)));
+       };
+};
+
+template<typename Ret, typename Arg0, typename Arg1>
+struct ApplyRefract<1, Ret, Arg0, Arg1>
+{
+       static ExprP<Ret> apply (ExpandContext&                 ctx,
+                                                        const ExprP<Arg0>&             i,
+                                                        const ExprP<Arg1>&             n,
+                                                        const ExprP<float>&    eta)
+       {
+               const ExprP<float>      dotNI   = bindExpression("dotNI", ctx, dot(n, i));
+               const ExprP<float>      k1              = bindExpression("k1", ctx, constant(1.0f) - eta * eta *
+                                                                                               (constant(1.0f) - dotNI * dotNI));
+
+               const ExprP<float>      k2              = bindExpression("k2", ctx,
+                                                                                               (((dotNI * (-dotNI)) + constant(1.0f)) * eta)
+                                                                                               * (-eta) + constant(1.0f));
+
+               return alternatives(cond(k1 < constant(0.0f),
+                                                               genXType<float, 1>(constant(0.0f)),
+                                                               i * eta - n * (eta * dotNI + sqrt(k1))),
+                                                       cond(k2 < constant(0.0f),
+                                                               genXType<float, 1>(constant(0.0f)),
+                                                               i * eta - n * (eta * dotNI + sqrt(k2))));
+       };
+};
+
 template <int Size>
 class Refract : public DerivedFunc<
        Signature<typename ContainerOf<float, Size>::Container,
@@ -3151,13 +3194,8 @@ protected:
                const ExprP<Arg0>&      i               = args.a;
                const ExprP<Arg1>&      n               = args.b;
                const ExprP<float>&     eta             = args.c;
-               const ExprP<float>      dotNI   = bindExpression("dotNI", ctx, dot(n, i));
-               const ExprP<float>      k               = bindExpression("k", ctx, constant(1.0f) - eta * eta *
-                                                                                                (constant(1.0f) - dotNI * dotNI));
 
-               return cond(k < constant(0.0f),
-                                       genXType<float, Size>(constant(0.0f)),
-                                       i * eta - n * (eta * dotNI + sqrt(k)));
+               return ApplyRefract<Size, Ret, Arg0, Arg1>::apply(ctx, i, n, eta);
        }
 };