Added ImageProcessor interface class and plugin mechnanism for ImageProcessor implementations to osgDB::Registry.

Add NVidiaTextureTools based plugin that provides an ImageProcessor implementation within an nvtt plugin.

include/osgDB/ImageProcessor

@@ -0,0 +1,54 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield 
+ *
+ * This library is open source and may be redistributed and/or modified under  
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
+ * OpenSceneGraph Public License for more details.
+*/
+
+#ifndef OSGDB_IMAGEPROCESSOR
+#define OSGDB_IMAGEPROCESSOR 1
+
+#include <osg/Object>
+
+namespace osgDB {
+
+class ImageProcessor : public osg::Object
+{
+    public:
+
+        ImageProcessor():
+            osg::Object(true) {}
+
+        ImageProcessor(const ImageProcessor& rw,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY):
+            osg::Object(rw,copyop) {}
+
+        virtual ~ImageProcessor() {}
+
+        META_Object(osgDB,ImageProcessor);
+
+        enum CompressionMethod
+        {
+            USE_CPU, /// Use CPU for compression even when GPU compression is available
+            USE_GPU  /// Use GPU for compression when available (i.e CUDA), otherwise fallback to CPU
+        };
+
+        enum CompressionQuality
+        {
+            FASTEST,
+            NORMAL,
+            PRODUCTION,
+            HIGHEST
+        };
+
+        virtual void compress(osg::Image& image, osg::Texture::InternalFormatMode compressedFormat, bool generateMipMap, bool resizeToPowerOfTwo, CompressionMethod method, CompressionQuality quality) {}
+        virtual void generateMipMap(osg::Image& image, bool resizeToPowerOfTwo, CompressionMethod method) {}
+};
+
+}
+#endif

include/osgDB/Registry

@@ -27,6 +27,7 @@
 #include <osgDB/ObjectWrapper>
 #include <osgDB/FileCache>
 #include <osgDB/SharedStateManager>
+#include <osgDB/ImageProcessor>
 
 #include <vector>
 #include <map>
@@ -59,7 +60,6 @@ struct type_wrapper: basic_type_wrapper {
     }
 };
 
-
 /**
     Registry is a singleton factory which stores
     the reader/writers which are linked in
@@ -101,6 +101,9 @@ class OSGDB_EXPORT Registry : public osg::Referenced
         void addReaderWriter(ReaderWriter* rw);
         void removeReaderWriter(ReaderWriter* rw);
 
+        void addImageProcessor(ImageProcessor* ip);
+        void removeImageProcessor(ImageProcessor* ip);
+
         /** create the platform specific library name associated with file.*/
         std::string createLibraryNameForFile(const std::string& fileName);
 
@@ -142,6 +145,21 @@ class OSGDB_EXPORT Registry : public osg::Referenced
         const ReaderWriterList& getReaderWriterList() const { return _rwList; }
  
 
+        typedef std::vector< osg::ref_ptr<ImageProcessor> > ImageProcessorList;
+
+        /** get a image processor if available.*/
+        ImageProcessor* getImageProcessor();
+
+        /** get a image processor which is associated specified extension.*/
+        ImageProcessor* getImageProcessorForExtension(const std::string& ext);
+
+        /** get list of all registered ImageProcessors.*/
+        ImageProcessorList& getImageProcessorList() { return _ipList; }
+
+        /** get const list of all registered ImageProcessors.*/
+        const ImageProcessorList& getImageProcessorList() const { return _ipList; }
+
+
         typedef class osgDB::FindFileCallback FindFileCallback;
         typedef class osgDB::ReadFileCallback ReadFileCallback;
         typedef class osgDB::WriteFileCallback WriteFileCallback;
@@ -555,6 +573,7 @@ class OSGDB_EXPORT Registry : public osg::Referenced
 
         OpenThreads::ReentrantMutex _pluginMutex;
         ReaderWriterList            _rwList;
+        ImageProcessorList          _ipList;
         DynamicLibraryList          _dlList;
 
         bool _openingLibrary;
@@ -624,6 +643,34 @@ class RegisterReaderWriterProxy
 };
 
 
+/** Proxy class for automatic registration of reader/writers with the Registry.*/
+template<class T>
+class RegisterImageProcessorProxy
+{
+    public:
+        RegisterImageProcessorProxy()
+        {
+            if (Registry::instance())
+            {
+                _rw = new T;
+                Registry::instance()->addImageProcessor(_rw.get());
+            }
+        }
+
+        ~RegisterImageProcessorProxy()
+        {
+            if (Registry::instance())
+            {
+                Registry::instance()->removeImageProcessor(_rw.get());
+            }
+        }
+
+        T* get() { return _rw.get(); }
+
+    protected:
+        osg::ref_ptr<T> _rw;
+};
+
 struct PluginFunctionProxy
 {
     PluginFunctionProxy(CPluginFunction function) { (function)(); }
@@ -657,6 +704,9 @@ struct PluginFunctionProxy
     extern "C" void osgdb_##ext(void) {} \
     static osgDB::RegisterReaderWriterProxy<classname> g_proxy_##classname;
 
+#define REGISTER_OSGIMAGEPROCESSOR(ext, classname) \
+    extern "C" void osgdb_##ext(void) {} \
+    static osgDB::RegisterImageProcessorProxy<classname> g_proxy_##classname;
 
 }