From 681026ba1c2bbeca29a0ff2a9671fb509d689706 Mon Sep 17 00:00:00 2001
From: AnyOldName3 <krizdjali@gmail.com>
Date: Wed, 8 Mar 2023 00:28:48 +0000
Subject: [PATCH] Ensure shader requirements are pushed at least once for
 subgraph

Shaders, if deemed necessary, get attached to the node mentioned by the
top of the requirements stack. Previously an empty stack was incorrectly
assumed to mean no shaders were required, but we found out that was
wrong. We need to put shaders *somewhere*, and the root of the subgraph
we're modifying should be the best place.
---
 components/shader/shadervisitor.cpp | 71 ++++++++++++++---------------
 1 file changed, 34 insertions(+), 37 deletions(-)

diff --git a/components/shader/shadervisitor.cpp b/components/shader/shadervisitor.cpp
index 7a949aac80..18ba0e6569 100644
--- a/components/shader/shadervisitor.cpp
+++ b/components/shader/shadervisitor.cpp
@@ -185,15 +185,17 @@ namespace Shader
 
     void ShaderVisitor::apply(osg::Node& node)
     {
-        if (node.getStateSet())
+        bool needPop = false;
+        if (node.getStateSet() || mRequirements.empty())
         {
+            needPop = true;
             pushRequirements(node);
-            applyStateSet(node.getStateSet(), node);
-            traverse(node);
-            popRequirements();
+            if (node.getStateSet())
+                applyStateSet(node.getStateSet(), node);
         }
-        else
-            traverse(node);
+        traverse(node);
+        if (needPop)
+            popRequirements();
     }
 
     osg::StateSet* getWritableStateSet(osg::Node& node)
@@ -820,12 +822,12 @@ namespace Shader
 
     void ShaderVisitor::apply(osg::Geometry& geometry)
     {
-        bool needPop = (geometry.getStateSet() != nullptr);
-        if (geometry.getStateSet()) // TODO: check if stateset affects shader permutation before pushing it
-        {
+        bool needPop = geometry.getStateSet() || mRequirements.empty();
+        if (needPop)
             pushRequirements(geometry);
+
+        if (geometry.getStateSet()) // TODO: check if stateset affects shader permutation before pushing it
             applyStateSet(geometry.getStateSet(), geometry);
-        }
 
         if (!mRequirements.empty())
         {
@@ -844,7 +846,7 @@ namespace Shader
 
     void ShaderVisitor::apply(osg::Drawable& drawable)
     {
-        bool needPop = drawable.getStateSet();
+        bool needPop = drawable.getStateSet() || mRequirements.empty();
 
         if (needPop)
         {
@@ -854,37 +856,32 @@ namespace Shader
                 applyStateSet(drawable.getStateSet(), drawable);
         }
 
-        if (!mRequirements.empty())
-        {
-            const ShaderRequirements& reqs = mRequirements.back();
-            createProgram(reqs);
+        const ShaderRequirements& reqs = mRequirements.back();
+        createProgram(reqs);
 
-            if (auto rig = dynamic_cast<SceneUtil::RigGeometry*>(&drawable))
+        if (auto rig = dynamic_cast<SceneUtil::RigGeometry*>(&drawable))
+        {
+            osg::ref_ptr<osg::Geometry> sourceGeometry = rig->getSourceGeometry();
+            if (sourceGeometry && adjustGeometry(*sourceGeometry, reqs))
+                rig->setSourceGeometry(sourceGeometry);
+        }
+        else if (auto morph = dynamic_cast<SceneUtil::MorphGeometry*>(&drawable))
+        {
+            osg::ref_ptr<osg::Geometry> sourceGeometry = morph->getSourceGeometry();
+            if (sourceGeometry && adjustGeometry(*sourceGeometry, reqs))
+                morph->setSourceGeometry(sourceGeometry);
+        }
+        else if (auto osgaRig = dynamic_cast<SceneUtil::RigGeometryHolder*>(&drawable))
+        {
+            osg::ref_ptr<SceneUtil::OsgaRigGeometry> sourceOsgaRigGeometry = osgaRig->getSourceRigGeometry();
+            osg::ref_ptr<osg::Geometry> sourceGeometry = sourceOsgaRigGeometry->getSourceGeometry();
+            if (sourceGeometry && adjustGeometry(*sourceGeometry, reqs))
             {
-                osg::ref_ptr<osg::Geometry> sourceGeometry = rig->getSourceGeometry();
-                if (sourceGeometry && adjustGeometry(*sourceGeometry, reqs))
-                    rig->setSourceGeometry(sourceGeometry);
-            }
-            else if (auto morph = dynamic_cast<SceneUtil::MorphGeometry*>(&drawable))
-            {
-                osg::ref_ptr<osg::Geometry> sourceGeometry = morph->getSourceGeometry();
-                if (sourceGeometry && adjustGeometry(*sourceGeometry, reqs))
-                    morph->setSourceGeometry(sourceGeometry);
-            }
-            else if (auto osgaRig = dynamic_cast<SceneUtil::RigGeometryHolder*>(&drawable))
-            {
-                osg::ref_ptr<SceneUtil::OsgaRigGeometry> sourceOsgaRigGeometry = osgaRig->getSourceRigGeometry();
-                osg::ref_ptr<osg::Geometry> sourceGeometry = sourceOsgaRigGeometry->getSourceGeometry();
-                if (sourceGeometry && adjustGeometry(*sourceGeometry, reqs))
-                {
-                    sourceOsgaRigGeometry->setSourceGeometry(sourceGeometry);
-                    osgaRig->setSourceRigGeometry(sourceOsgaRigGeometry);
-                }
+                sourceOsgaRigGeometry->setSourceGeometry(sourceGeometry);
+                osgaRig->setSourceRigGeometry(sourceOsgaRigGeometry);
             }
 
         }
-        else
-            ensureFFP(drawable);
 
         if (needPop)
             popRequirements();