2.8 branch: This change brings the PNG plugin up to sync with trunk head. It adds the OSG_CPP_EXCEPTIONS_AVAILABLE CMake option and adds PNG plugin compatibility with multiple versions of libPNG. Merged from trunk: 10763 and 11121.

src/osgPlugins/CMakeLists.txt

@@ -168,7 +168,6 @@ ADD_SUBDIRECTORY(lwo)
 ADD_SUBDIRECTORY(bvh)
 ADD_SUBDIRECTORY(x)
 ADD_SUBDIRECTORY(dw)
-ADD_SUBDIRECTORY(ply)
 ADD_SUBDIRECTORY(dxf)
 ADD_SUBDIRECTORY(OpenFlight)
 # ADD_SUBDIRECTORY(flt)
@@ -190,13 +189,17 @@ ADD_SUBDIRECTORY(md2)
 ADD_SUBDIRECTORY(osgtgz)
 ADD_SUBDIRECTORY(tgz)
 
-ADD_SUBDIRECTORY(txp)
 ADD_SUBDIRECTORY(shp)
 ADD_SUBDIRECTORY(txf)
 
 ADD_SUBDIRECTORY(bsp)
 ADD_SUBDIRECTORY(mdl)
 
+IF(OSG_CPP_EXCEPTIONS_AVAILABLE)
+    ADD_SUBDIRECTORY(ply)
+    ADD_SUBDIRECTORY(txp)
+ENDIF()
+
 IF(XINE_FOUND)
     ADD_SUBDIRECTORY(xine)
 ENDIF(XINE_FOUND)

src/osgPlugins/png/CMakeLists.txt

@@ -3,9 +3,14 @@
 
 INCLUDE_DIRECTORIES( ${PNG_INCLUDE_DIR} ${ZLIB_INCLUDE_DIR} )
 
+IF(OSG_CPP_EXCEPTIONS_AVAILABLE)
+    ADD_DEFINITIONS(-DOSG_CPP_EXCEPTIONS_AVAILABLE)
+ENDIF()
 
 SET(TARGET_SRC ReaderWriterPNG.cpp )
 SET(TARGET_LIBRARIES_VARS PNG_LIBRARY ZLIB_LIBRARY )
+
+
 #### end var setup  ###
 SETUP_PLUGIN(png)
 

src/osgPlugins/png/ReaderWriterPNG.cpp

@@ -51,7 +51,11 @@ private:
 
 void user_error_fn(png_structp png_ptr, png_const_charp error_msg)
 {
+#ifdef OSG_CPP_EXCEPTIONS_AVAILABLE
     throw PNGError(error_msg);
+#else
+    osg::notify(osg::WARN) << "PNG lib warning : " << error_msg << std::endl;
+#endif
 }
 
 void user_warning_fn(png_structp png_ptr, png_const_charp warning_msg)
@@ -166,14 +170,15 @@ class ReaderWriterPNG : public osgDB::ReaderWriter
             // Set custom error handlers
             png_set_error_fn(png, png_get_error_ptr(png), user_error_fn, user_warning_fn);
 
+            #ifdef OSG_CPP_EXCEPTIONS_AVAILABLE
             try
+            #endif
             {
-
                 info = png_create_info_struct(png);
                 endinfo = png_create_info_struct(png);
 
                 fin.read((char*)header,8);
-                if (fin.gcount() == 8 && png_check_sig(header, 8))
+                if (fin.gcount() == 8 && png_sig_cmp(header, 0, 8) == 0)
                     png_set_read_fn(png,&fin,png_read_istream); //Use custom read function that will get data from istream
                 else
                 {
@@ -224,7 +229,14 @@ class ReaderWriterPNG : public osgDB::ReaderWriter
                 if (color == PNG_COLOR_TYPE_PALETTE)
                     png_set_palette_to_rgb(png);
                 if (color == PNG_COLOR_TYPE_GRAY && depth < 8)
+                {
+                #if PNG_LIBPNG_VER >= 10209
+                    png_set_expand_gray_1_2_4_to_8(png);
+                #else
+                    // use older now deprecated but identical call
                     png_set_gray_1_2_4_to_8(png);
+                #endif
+                }
                 if (png_get_valid(png, info, PNG_INFO_tRNS))
                     png_set_tRNS_to_alpha(png);
 
@@ -300,13 +312,16 @@ class ReaderWriterPNG : public osgDB::ReaderWriter
                     osg::Image::USE_NEW_DELETE);
 
                 return pOsgImage;
+
             }
+            #ifdef OSG_CPP_EXCEPTIONS_AVAILABLE
             catch (PNGError& err)
             {
                 osg::notify(osg::WARN) << err << std::endl;
                 png_destroy_read_struct(&png, &info, &endinfo);
                 return ReadResult::ERROR_IN_READING_FILE;
             }
+            #endif
         }
 
         int getCompressionLevel(const osgDB::ReaderWriter::Options *options) const