From 4c0a861f91414c26dde1476c6dae24f05c73af6d Mon Sep 17 00:00:00 2001
From: Julien Valentin <mp3butcher@hotmail.com>
Date: Sat, 13 Jan 2018 21:25:47 +0100
Subject: [PATCH] add static helper func in order to generate Samplers of a
 Samplerless StateSet +fix ident

---
 include/osg/Sampler | 15 ++++++++------
 src/osg/Sampler.cpp | 50 +++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 57 insertions(+), 8 deletions(-)

diff --git a/include/osg/Sampler b/include/osg/Sampler
index 1ffdda1ab..6cb4c1192 100644
--- a/include/osg/Sampler
+++ b/include/osg/Sampler
@@ -70,10 +70,10 @@ class OSG_EXPORT Sampler : public osg::StateAttribute
           * filtering, use normal filtering (equivalent to a max anisotropy
           * value of 1.0. Valid range is 1.0f upwards.  The maximum value
           * depends on the graphics system. */
-          void setMaxAnisotropy(float anis);
+        void setMaxAnisotropy(float anis);
 
-          /** Gets the maximum anisotropy value. */
-          inline float getMaxAnisotropy() const { return _maxAnisotropy; }
+        /** Gets the maximum anisotropy value. */
+        inline float getMaxAnisotropy() const { return _maxAnisotropy; }
 
         void setMinLOD(float anis);
 
@@ -90,6 +90,9 @@ class OSG_EXPORT Sampler : public osg::StateAttribute
         /** Gets the maximum anisotropy value. */
         inline float getLODBias() const { return _lodbias; }
 
+        /** helper method to generate Sampler from Texture's sampling parameters (except shadow_texture_mode left to NONE) */
+        static void generateSamplerObjects(StateSet&);
+
         virtual void apply(State& state) const;
 
         virtual void compileGLObjects(State&) const;
@@ -107,12 +110,12 @@ class OSG_EXPORT Sampler : public osg::StateAttribute
         Texture::ShadowTextureMode _shadow_texture_mode;
         Vec4d _borderColor;
 
-        Texture::FilterMode      _min_filter;
-        Texture::FilterMode      _mag_filter;
+        Texture::FilterMode _min_filter;
+        Texture::FilterMode _mag_filter;
         float _maxAnisotropy, _minlod, _maxlod, _lodbias;
 
         mutable buffered_value<GLuint> _PCsampler;
-        mutable buffered_value<uint8_t>   _PCdirtyflags;
+        mutable buffered_value<uint8_t> _PCdirtyflags;
 };
 }
 #endif
diff --git a/src/osg/Sampler.cpp b/src/osg/Sampler.cpp
index d33d725a9..c5597acd8 100644
--- a/src/osg/Sampler.cpp
+++ b/src/osg/Sampler.cpp
@@ -225,13 +225,14 @@ void Sampler::compileGLObjects(State& state) const
             extensions->glSamplerParameterf(samplerobject, GL_TEXTURE_MAX_ANISOTROPY_EXT, _maxAnisotropy);
         }
 
-        if(_maxlod - _minlod > 0)
+        if(_maxlod - _minlod >= 0)
         {   // if range is valid
             extensions->glSamplerParameterf(samplerobject, GL_TEXTURE_MIN_LOD, _minlod);
             extensions->glSamplerParameterf(samplerobject, GL_TEXTURE_MAX_LOD, _maxlod);
         }
 
         extensions->glSamplerParameterf(samplerobject, GL_TEXTURE_LOD_BIAS, _lodbias);
+
         _PCdirtyflags[contextID]=false;
     }
 }
@@ -244,7 +245,7 @@ void Sampler::apply(State&state) const
     unsigned int contextID = state.getContextID();
     if(  _PCdirtyflags[contextID] )
         compileGLObjects(state);
-    
+
     state.get<GLExtensions>()->glBindSampler( state.getActiveTextureUnit(), _PCsampler[contextID] );
 }
 
@@ -274,3 +275,48 @@ int Sampler::compare(const StateAttribute& sa) const
     COMPARE_StateAttribute_Parameter(_lodbias)
     return 0; // passed all the above comparison macros, must be equal.
 }
+
+void Sampler::generateSamplerObjects(StateSet& ss)
+{
+    const osg::StateSet::TextureAttributeList& texAttributes = ss.getTextureAttributeList();
+    for(unsigned int unit=0; unit<texAttributes.size(); ++unit)
+    {
+        StateSet::RefAttributePair attmode;
+        Sampler * sampler = 0;
+        const StateSet::AttributeList& tex_attributes = texAttributes[unit];
+        for(StateSet::AttributeList::const_iterator aitr = tex_attributes.begin();
+            aitr!=tex_attributes.end();
+            ++aitr)
+        {
+            if( aitr->second.first.get()->getType() != StateAttribute::TEXTURE )
+            {
+                if( aitr->second.first.get()->getType() == StateAttribute::SAMPLER)
+                    sampler = static_cast< Sampler* > (aitr->second.first.get());
+            }
+            else attmode= aitr->second;
+        }
+
+        if( attmode.first.valid() )
+        {
+            if( !sampler )
+            {
+                ///create new Sampler and add it to this
+                sampler = new Sampler();
+                Texture * tex = attmode.first->asTexture();
+                sampler->setFilter( Texture::MIN_FILTER, tex->getFilter(Texture::MIN_FILTER) );
+                sampler->setFilter( Texture::MAG_FILTER, tex->getFilter(Texture::MAG_FILTER) );
+                sampler->setWrap( Texture::WRAP_S, tex->getWrap(Texture::WRAP_S) );
+                sampler->setWrap( Texture::WRAP_T, tex->getWrap(Texture::WRAP_T) );
+                sampler->setWrap( Texture::WRAP_R, tex->getWrap(Texture::WRAP_R) );
+                sampler->setMaxAnisotropy( tex->getMaxAnisotropy() );
+                sampler->setShadowCompareFunc( tex->getShadowCompareFunc() );
+                //sampler->setShadowTextureMode( tex->getShadowTextureMode() ); default LUMINANCE tex param incompatible with default NONE Sampler param
+                sampler->setBorderColor( tex->getBorderColor() );
+                sampler->setLODBias( tex->getLODBias() );
+                sampler->setMinLOD( tex->getMinLOD() );
+                sampler->setMaxLOD( tex->getMaxLOD() );
+                ss.setTextureAttributeAndModes(unit,sampler,attmode.second);
+            }
+        }
+    }
+}