From 7b9764254d9cf24f74ea013bb56fc4530f17bfe6 Mon Sep 17 00:00:00 2001
From: itsmattkc <itsmattkc@gmail.com>
Date: Fri, 12 Jun 2020 03:44:23 +1000
Subject: [PATCH] math: generate alpha channel only if multiplying a texture by
 a matrix

---
 app/node/math/math/math.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/app/node/math/math/math.cpp b/app/node/math/math/math.cpp
index 6c656b369..ab5867f5c 100644
--- a/app/node/math/math/math.cpp
+++ b/app/node/math/math/math.cpp
@@ -319,6 +319,9 @@ NodeValueTable MathNode::Value(NodeValueDatabase &value) const
       if (GetOperation() != kOpMultiply
           || number_val.data().value<QMatrix4x4>().isIdentity()) {
         operation_is_noop = true;
+      } else {
+        // It's likely an alpha channel will result from this operation
+        job.SetAlphaChannelRequired(true);
       }
     }