From 4cfae88f09d4ae5606fcd9cdc5ee494ae2d06801 Mon Sep 17 00:00:00 2001
From: David Murmann <david@23x5.net>
Date: Wed, 12 Jun 2024 10:37:39 +0200
Subject: [PATCH] Fix #122739: mix causes unnecessary evaluation when ints are
 used

Fixes #122739.

I added all five missing conversions that the convert node can do in the svm code to the constant folding.

Pull Request: https://projects.blender.org/blender/blender/pulls/123035
---
 intern/cycles/scene/constant_fold.cpp | 13 ++++++++++
 intern/cycles/scene/constant_fold.h   |  1 +
 intern/cycles/scene/shader_graph.h    |  4 ++++
 intern/cycles/scene/shader_nodes.cpp  | 34 +++++++++++++++++++--------
 4 files changed, 42 insertions(+), 10 deletions(-)

diff --git a/intern/cycles/scene/constant_fold.cpp b/intern/cycles/scene/constant_fold.cpp
index 9739de59014..0be3a23ab1c 100644
--- a/intern/cycles/scene/constant_fold.cpp
+++ b/intern/cycles/scene/constant_fold.cpp
@@ -55,6 +55,19 @@ void ConstantFolder::make_constant(float3 value) const
   graph->disconnect(output);
 }
 
+void ConstantFolder::make_constant(int value) const
+{
+  VLOG_DEBUG << "Folding " << node->name << "::" << output->name() << " to constant (" << value
+             << ").";
+
+  foreach (ShaderInput *sock, output->links) {
+    sock->set(value);
+    sock->constant_folded_in = true;
+  }
+
+  graph->disconnect(output);
+}
+
 void ConstantFolder::make_constant_clamp(float value, bool clamp) const
 {
   make_constant(clamp ? saturatef(value) : value);
diff --git a/intern/cycles/scene/constant_fold.h b/intern/cycles/scene/constant_fold.h
index c97d12e086c..6b50498adea 100644
--- a/intern/cycles/scene/constant_fold.h
+++ b/intern/cycles/scene/constant_fold.h
@@ -31,6 +31,7 @@ class ConstantFolder {
   /* Constant folding helpers */
   void make_constant(float value) const;
   void make_constant(float3 value) const;
+  void make_constant(int value) const;
   void make_constant_clamp(float value, bool clamp) const;
   void make_constant_clamp(float3 value, bool clamp) const;
   void make_zero() const;
diff --git a/intern/cycles/scene/shader_graph.h b/intern/cycles/scene/shader_graph.h
index 82ea2a781c7..b0a2a12bdea 100644
--- a/intern/cycles/scene/shader_graph.h
+++ b/intern/cycles/scene/shader_graph.h
@@ -96,6 +96,10 @@ class ShaderInput {
   {
     ((Node *)parent)->set(socket_type, f);
   }
+  void set(int f)
+  {
+    ((Node *)parent)->set(socket_type, f);
+  }
 
   void disconnect();
 
diff --git a/intern/cycles/scene/shader_nodes.cpp b/intern/cycles/scene/shader_nodes.cpp
index 70e5ab55f2a..6e14b27e1b7 100644
--- a/intern/cycles/scene/shader_nodes.cpp
+++ b/intern/cycles/scene/shader_nodes.cpp
@@ -2123,24 +2123,38 @@ void ConvertNode::constant_fold(const ConstantFolder &folder)
   /* proxy nodes should have been removed at this point */
   assert(special_type != SHADER_SPECIAL_TYPE_PROXY);
 
-  /* TODO(DingTo): conversion from/to int is not supported yet, don't fold in that case */
-
   if (folder.all_inputs_constant()) {
-    if (from == SocketType::FLOAT) {
+    if (from == SocketType::FLOAT || from == SocketType::INT) {
+      float val = value_float;
+      if (from == SocketType::INT) {
+        val = value_int;
+      }
       if (SocketType::is_float3(to)) {
-        folder.make_constant(make_float3(value_float, value_float, value_float));
+        folder.make_constant(make_float3(val, val, val));
+      }
+      else if (to == SocketType::INT) {
+        folder.make_constant((int)val);
+      }
+      else if (to == SocketType::FLOAT) {
+        folder.make_constant(val);
       }
     }
     else if (SocketType::is_float3(from)) {
-      if (to == SocketType::FLOAT) {
+      if (to == SocketType::FLOAT || to == SocketType::INT) {
+        float val;
         if (from == SocketType::COLOR) {
-          /* color to float */
-          float val = folder.scene->shader_manager->linear_rgb_to_gray(value_color);
-          folder.make_constant(val);
+          /* color to scalar */
+          val = folder.scene->shader_manager->linear_rgb_to_gray(value_color);
         }
         else {
-          /* vector/point/normal to float */
-          folder.make_constant(average(value_vector));
+          /* vector/point/normal to scalar */
+          val = average(value_vector);
+        }
+        if (to == SocketType::INT) {
+          folder.make_constant((int)val);
+        }
+        else if (to == SocketType::FLOAT) {
+          folder.make_constant(val);
         }
       }
       else if (SocketType::is_float3(to)) {