Fix issue with model parsing

Sometimes we don't get the data elements in order.  Use the stream name
to ensure we have the correct model.

Also give the parser a bit more memory to work with, avoiding unneeded
resizes

pcbnew/pcb_io/altium/altium_pcb.cpp

@@ -1345,20 +1345,33 @@ void ALTIUM_PCB::ConvertComponentBody6ToFootprintItem( const ALTIUM_PCB_COMPOUND
 
     EMBEDDED_FILES::EMBEDDED_FILE* file = new EMBEDDED_FILES::EMBEDDED_FILE();
     file->name = aElem.modelName;
-    // Decompress the model data before assigning
-    std::vector<char> decompressedData;
-    wxMemoryInputStream compressedStream(model->second.data(), model->second.size());
-    wxZlibInputStream zlibStream(compressedStream);
 
-    decompressedData.reserve(model->second.size() * 2); // Reserve some space, assuming decompressed data is larger
-    while (!zlibStream.Eof()) {
-        size_t currentSize = decompressedData.size();
-        decompressedData.resize(currentSize + 4096); // Increase buffer size
-        zlibStream.Read(decompressedData.data() + currentSize, 4096);
+    // Decompress the model data before assigning
+    std::vector<char>   decompressedData;
+    wxMemoryInputStream compressedStream( model->second.data(), model->second.size() );
+    wxZlibInputStream   zlibStream( compressedStream );
+
+    // Reserve some space, assuming decompressed data is larger -- STEP file
+    // compression is typically 5:1 using zlib like Altium does
+    decompressedData.resize( model->second.size() * 6 );
+    size_t offset = 0;
+
+    while( !zlibStream.Eof() )
+    {
+        zlibStream.Read( decompressedData.data() + offset, decompressedData.size() - offset );
         size_t bytesRead = zlibStream.LastRead();
-        decompressedData.resize(currentSize + bytesRead); // Resize to actual read size
+
+        if( !bytesRead )
+            break;
+
+        offset += bytesRead;
+
+        if( offset >= decompressedData.size() )
+            decompressedData.resize( 2 * decompressedData.size() ); // Resizing is expensive, avoid if we can
     }
 
+    decompressedData.resize( offset );
+
     file->decompressedData = std::move( decompressedData );
     file->type = EMBEDDED_FILES::EMBEDDED_FILE::FILE_TYPE::MODEL;
 
@@ -1369,8 +1382,8 @@ void ALTIUM_PCB::ConvertComponentBody6ToFootprintItem( const ALTIUM_PCB_COMPOUND
 
     modelSettings.m_Filename = aFootprint->GetEmbeddedFiles()->GetEmbeddedFileLink( *file );
 
-    modelSettings.m_Offset.x = pcbIUScale.IUTomm((int) aElem.modelPosition.x - fpPosition.x );
-    modelSettings.m_Offset.y = -pcbIUScale.IUTomm((int) aElem.modelPosition.y - fpPosition.y );
+    modelSettings.m_Offset.x = pcbIUScale.IUTomm( (int) aElem.modelPosition.x - fpPosition.x );
+    modelSettings.m_Offset.y = -pcbIUScale.IUTomm( (int) aElem.modelPosition.y - fpPosition.y );
     modelSettings.m_Offset.z = pcbIUScale.IUTomm( (int) aElem.modelPosition.z + model->first.z_offset );
 
     EDA_ANGLE orientation = aFootprint->GetOrientation();

pcbnew/pcb_io/altium/altium_pcb_compound_file.cpp

@@ -155,33 +155,37 @@ bool ALTIUM_PCB_COMPOUND_FILE::CacheLibModels()
     if( !models_root )
         return false;
 
-    int      idx = 0;
+    m_reader->EnumFiles(
+        models_root, 1,
+        [&]( const CFB::COMPOUND_FILE_ENTRY* stepEntry, const CFB::utf16string&, int ) -> int
+        {
+            long     fileNumber;
+            wxString fileName = UTF16ToUTF8( stepEntry->name, stepEntry->nameLen );
 
-    m_reader->EnumFiles( models_root, 1, [&]( const CFB::COMPOUND_FILE_ENTRY* stepEntry, const CFB::utf16string&, int ) -> int
-    {
-        wxString fileName = UTF16ToUTF8( stepEntry->name, stepEntry->nameLen );
+            if( !fileName.ToLong( &fileNumber ) )
+                return 0;
 
-        if( !m_reader->IsStream( stepEntry ) || idx >= models.size() )
+
+            if( !m_reader->IsStream( stepEntry ) || fileNumber >= long( models.size() ) )
+                return 0;
+
+            size_t            stepSize = static_cast<size_t>( stepEntry->size );
+            std::vector<char> stepContent( stepSize );
+
+            // read file into buffer
+            m_reader->ReadFile( stepEntry, 0, stepContent.data(), stepSize );
+
+            if( stepContent.empty() )
+                return 0;
+
+            // We store the models in their original compressed form so as to speed the caching process
+            // When we parse an individual footprint, we decompress and recompress the model data into
+            // our format
+            m_libModelsCache.emplace( models[fileNumber].id,
+                                      std::make_pair( std::move( models[fileNumber] ),
+                                                      std::move( stepContent ) ) );
             return 0;
-
-        size_t            stepSize = static_cast<size_t>( stepEntry->size );
-        std::vector<char> stepContent( stepSize );
-
-        // read file into buffer
-        m_reader->ReadFile( stepEntry, 0, stepContent.data(), stepSize );
-
-        if( stepContent.empty() )
-            return 0;
-
-        // We store the models in their original compressed form so as to speed the caching process
-        // When we parse an individual footprint, we decompress and recompress the model data into
-        // our format
-        m_libModelsCache.emplace( models[idx].id, std::make_pair( std::move( models[idx] ),
-                                                                  std::move( stepContent ) ) );
-        idx++;
-
-        return 0;
-    } );
+        } );
 
     return true;
 }