Fix race condition

Values are accessed from main thread and cell preloader threads.

components/terrain/material.cpp

@@ -12,66 +12,150 @@
 
 #include <components/shader/shadermanager.hpp>
 
+#include <mutex>
+
+namespace
+{
+    class BlendmapTexMat
+    {
+    public:
+        static const osg::ref_ptr<osg::TexMat>& value(const int blendmapScale)
+        {
+            static BlendmapTexMat instance;
+            return instance.get(blendmapScale);
+        }
+
+        const osg::ref_ptr<osg::TexMat>& get(const int blendmapScale)
+        {
+            const std::lock_guard<std::mutex> lock(mMutex);
+            auto texMat = mTexMatMap.find(blendmapScale);
+            if (texMat == mTexMatMap.end())
+            {
+                osg::Matrixf matrix;
+                float scale = (blendmapScale/(static_cast<float>(blendmapScale)+1.f));
+                matrix.preMultTranslate(osg::Vec3f(0.5f, 0.5f, 0.f));
+                matrix.preMultScale(osg::Vec3f(scale, scale, 1.f));
+                matrix.preMultTranslate(osg::Vec3f(-0.5f, -0.5f, 0.f));
+                // We need to nudge the blendmap to look like vanilla.
+                // This causes visible seams unless the blendmap's resolution is doubled, but Vanilla also doubles the blendmap, apparently.
+                matrix.preMultTranslate(osg::Vec3f(1.0f/blendmapScale/4.0f, 1.0f/blendmapScale/4.0f, 0.f));
+
+                texMat = mTexMatMap.insert(std::make_pair(blendmapScale, new osg::TexMat(matrix))).first;
+            }
+            return texMat->second;
+        }
+
+    private:
+        std::mutex mMutex;
+        std::map<float, osg::ref_ptr<osg::TexMat>> mTexMatMap;
+    };
+
+    class LayerTexMat
+    {
+    public:
+        static const osg::ref_ptr<osg::TexMat>& value(const float layerTileSize)
+        {
+            static LayerTexMat instance;
+            return instance.get(layerTileSize);
+        }
+
+        const osg::ref_ptr<osg::TexMat>& get(const float layerTileSize)
+        {
+            const std::lock_guard<std::mutex> lock(mMutex);
+            auto texMat = mTexMatMap.find(layerTileSize);
+            if (texMat == mTexMatMap.end())
+            {
+                texMat = mTexMatMap.insert(std::make_pair(layerTileSize,
+                    new osg::TexMat(osg::Matrix::scale(osg::Vec3f(layerTileSize, layerTileSize, 1.f))))).first;
+            }
+            return texMat->second;
+        }
+
+    private:
+        std::mutex mMutex;
+        std::map<float, osg::ref_ptr<osg::TexMat>> mTexMatMap;
+    };
+
+    class EqualDepth
+    {
+    public:
+        static const osg::ref_ptr<osg::Depth>& value()
+        {
+            static EqualDepth instance;
+            return instance.mValue;
+        }
+
+    private:
+        osg::ref_ptr<osg::Depth> mValue;
+
+        EqualDepth()
+            : mValue(new osg::Depth)
+        {
+            mValue->setFunction(osg::Depth::EQUAL);
+        }
+    };
+
+    class LequalDepth
+    {
+    public:
+        static const osg::ref_ptr<osg::Depth>& value()
+        {
+            static LequalDepth instance;
+            return instance.mValue;
+        }
+
+    private:
+        osg::ref_ptr<osg::Depth> mValue;
+
+        LequalDepth()
+            : mValue(new osg::Depth)
+        {
+            mValue->setFunction(osg::Depth::LEQUAL);
+        }
+    };
+
+    class BlendFunc
+    {
+    public:
+        static const osg::ref_ptr<osg::BlendFunc>& value()
+        {
+            static BlendFunc instance;
+            return instance.mValue;
+        }
+
+    private:
+        osg::ref_ptr<osg::BlendFunc> mValue;
+
+        BlendFunc()
+            : mValue(new osg::BlendFunc)
+        {
+            mValue->setFunction(osg::BlendFunc::SRC_ALPHA, osg::BlendFunc::ONE);
+        }
+    };
+
+    class TexEnvCombine
+    {
+    public:
+        static const osg::ref_ptr<osg::TexEnvCombine>& value()
+        {
+            static TexEnvCombine instance;
+            return instance.mValue;
+        }
+
+    private:
+        osg::ref_ptr<osg::TexEnvCombine> mValue;
+
+        TexEnvCombine()
+            : mValue(new osg::TexEnvCombine)
+        {
+            mValue->setCombine_RGB(osg::TexEnvCombine::REPLACE);
+            mValue->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
+        }
+    };
+}
 
 namespace Terrain
 {
-
-    osg::ref_ptr<osg::TexMat> getBlendmapTexMat(int blendmapScale)
-    {
-        static std::map<int, osg::ref_ptr<osg::TexMat> > texMatMap;
-        osg::ref_ptr<osg::TexMat> texMat = texMatMap[blendmapScale];
-        if (!texMat)
-        {
-            osg::Matrixf matrix;
-            float scale = (blendmapScale/(static_cast<float>(blendmapScale)+1.f));
-            matrix.preMultTranslate(osg::Vec3f(0.5f, 0.5f, 0.f));
-            matrix.preMultScale(osg::Vec3f(scale, scale, 1.f));
-            matrix.preMultTranslate(osg::Vec3f(-0.5f, -0.5f, 0.f));
-            // We need to nudge the blendmap to look like vanilla.
-            // This causes visible seams unless the blendmap's resolution is doubled, but Vanilla also doubles the blendmap, apparently.
-            matrix.preMultTranslate(osg::Vec3f(1.0f/blendmapScale/4.0f, 1.0f/blendmapScale/4.0f, 0.f));
-
-            texMat = new osg::TexMat(matrix);
-
-            texMatMap[blendmapScale] = texMat;
-        }
-        return texMat;
-    }
-
-    osg::ref_ptr<osg::TexMat> getLayerTexMat(float layerTileSize)
-    {
-        static std::map<float, osg::ref_ptr<osg::TexMat> > texMatMap;
-        osg::ref_ptr<osg::TexMat> texMat = texMatMap[layerTileSize];
-        if (!texMat)
-        {
-            texMat = new osg::TexMat(osg::Matrix::scale(osg::Vec3f(layerTileSize,layerTileSize,1.f)));
-
-            texMatMap[layerTileSize] = texMat;
-        }
-        return texMat;
-    }
-
-    osg::ref_ptr<osg::Depth> getEqualDepth()
-    {
-        static osg::ref_ptr<osg::Depth> depth;
-        if (!depth)
-        {
-            depth = new osg::Depth;
-            depth->setFunction(osg::Depth::EQUAL);
-        }
-        return depth;
-    }
-    osg::ref_ptr<osg::Depth> getLequalDepth()
-    {
-        static osg::ref_ptr<osg::Depth> depth;
-        if (!depth)
-        {
-            depth = new osg::Depth;
-            depth->setFunction(osg::Depth::LEQUAL);
-        }
-        return depth;
-    }
-
     std::vector<osg::ref_ptr<osg::StateSet> > createPasses(bool useShaders, bool forcePerPixelLighting, bool clampLighting, Shader::ShaderManager* shaderManager, const std::vector<TextureLayer> &layers,
                                                            const std::vector<osg::ref_ptr<osg::Texture2D> > &blendmaps, int blendmapScale, float layerTileSize)
     {
@@ -87,16 +171,9 @@ namespace Terrain
 
             if (!firstLayer)
             {
-                static osg::ref_ptr<osg::BlendFunc> blendFunc;
-                if (!blendFunc)
-                {
-                    blendFunc= new osg::BlendFunc();
-                    blendFunc->setFunction(osg::BlendFunc::SRC_ALPHA, osg::BlendFunc::ONE);
-                }
                 stateset->setMode(GL_BLEND, osg::StateAttribute::ON);
-                stateset->setAttributeAndModes(blendFunc, osg::StateAttribute::ON);
+                stateset->setAttributeAndModes(BlendFunc::value(), osg::StateAttribute::ON);
-
+                stateset->setAttributeAndModes(EqualDepth::value(), osg::StateAttribute::ON);
-                stateset->setAttributeAndModes(getEqualDepth(), osg::StateAttribute::ON);
             }
             // disable fog if we're the first layer of several - supposed to be completely black
             if (firstLayer && blendmaps.size() > 0)
@@ -105,7 +182,7 @@ namespace Terrain
                 fog->setStart(10000000);
                 fog->setEnd(10000000);
                 stateset->setAttributeAndModes(fog, osg::StateAttribute::OFF|osg::StateAttribute::OVERRIDE);
-                stateset->setAttributeAndModes(getLequalDepth(), osg::StateAttribute::ON);
+                stateset->setAttributeAndModes(LequalDepth::value(), osg::StateAttribute::ON);
             }
 
             int texunit = 0;
@@ -115,7 +192,7 @@ namespace Terrain
                 stateset->setTextureAttributeAndModes(texunit, it->mDiffuseMap);
 
                 if (layerTileSize != 1.f)
-                    stateset->setTextureAttributeAndModes(texunit, getLayerTexMat(layerTileSize), osg::StateAttribute::ON);
+                    stateset->setTextureAttributeAndModes(texunit, LayerTexMat::value(layerTileSize), osg::StateAttribute::ON);
 
                 stateset->addUniform(new osg::Uniform("diffuseMap", texunit));
 
@@ -125,8 +202,7 @@ namespace Terrain
                     osg::ref_ptr<osg::Texture2D> blendmap = blendmaps.at(blendmapIndex++);
 
                     stateset->setTextureAttributeAndModes(texunit, blendmap.get());
-
+                    stateset->setTextureAttributeAndModes(texunit, BlendmapTexMat::value(blendmapScale));
-                    stateset->setTextureAttributeAndModes(texunit, getBlendmapTexMat(blendmapScale));
                     stateset->addUniform(new osg::Uniform("blendMap", texunit));
                 }
 
@@ -165,17 +241,8 @@ namespace Terrain
                     stateset->setTextureAttributeAndModes(texunit, blendmap.get());
 
                     // This is to map corner vertices directly to the center of a blendmap texel.
-                    stateset->setTextureAttributeAndModes(texunit, getBlendmapTexMat(blendmapScale));
+                    stateset->setTextureAttributeAndModes(texunit, BlendmapTexMat::value(blendmapScale));
-
+                    stateset->setTextureAttributeAndModes(texunit, TexEnvCombine::value(), osg::StateAttribute::ON);
-                    static osg::ref_ptr<osg::TexEnvCombine> texEnvCombine;
-                    if (!texEnvCombine)
-                    {
-                        texEnvCombine = new osg::TexEnvCombine;
-                        texEnvCombine->setCombine_RGB(osg::TexEnvCombine::REPLACE);
-                        texEnvCombine->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
-                    }
-
-                    stateset->setTextureAttributeAndModes(texunit, texEnvCombine, osg::StateAttribute::ON);
 
                     ++texunit;
                 }
@@ -185,7 +252,7 @@ namespace Terrain
                 stateset->setTextureAttributeAndModes(texunit, tex.get());
 
                 if (layerTileSize != 1.f)
-                    stateset->setTextureAttributeAndModes(texunit, getLayerTexMat(layerTileSize), osg::StateAttribute::ON);
+                    stateset->setTextureAttributeAndModes(texunit, LayerTexMat::value(layerTileSize), osg::StateAttribute::ON);
             }
 
             stateset->setRenderBinDetails(passIndex++, "RenderBin");