Add helper functions to update DifferentialPair (#2547)

1 files changed, 18 insertions, 0 deletions

diff --git a/source/slang/diff.meta.slang b/source/slang/diff.meta.slang
index 033c173ab..a97ab9eaf 100644
--- a/source/slang/diff.meta.slang
+++ b/source/slang/diff.meta.slang
@@ -92,6 +92,24 @@ struct DifferentialPair : IDifferentiable
     }
 };
 
+[ForceInline]
+void updatePrimal<T : IDifferentiable>(inout DifferentialPair<T> p, T newPrimal)
+{
+    p = DifferentialPair<T>(newPrimal, p.d);
+}
+
+[ForceInline]
+void updateDiff<T : IDifferentiable>(inout DifferentialPair<T> p, T.Differential newDiff)
+{
+    p = DifferentialPair<T>(p.p, newDiff);
+}
+
+[ForceInline]
+void updatePair<T : IDifferentiable>(inout DifferentialPair<T> p, T newPrimal, T.Differential newDiff)
+{
+    p = DifferentialPair<T>(newPrimal, newDiff);
+}
+
 
 #define VECTOR_MAP_D_UNARY(TYPE, COUNT, D_FUNC, VALUE) \
     vector<TYPE, COUNT> result; \