// static
bool OBJLoader::parseOBJ( QString objFilename, std::shared_ptr< OBJData > pOBJData )
{
// attempt to read the file
QFile inputFile( objFilename );
if( !( inputFile.open( QIODevice::ReadOnly ) ) )
{
return false;
}
int lineNumber = 0;
QString line = "";
OBJGroup* pCurrentGroup = pOBJData->getGroupByName( "" ); // default group name is the empty string
QTextStream inputTextStream( &inputFile );
QString delim( " " );
line = inputTextStream.readLine();
while( !( line.isNull() ) )
{
if( line != "" )
{
QStringList tokens = line.split( delim, QString::SkipEmptyParts );
if( tokens.size() > 0 )
{
QString commandToken = tokens[ 0 ];
if( commandToken == "mtllib" )
{
QString mtlRelativeFilename = tokens[ 1 ];
QFileInfo objFileInfo( objFilename );
QDir objDir = objFileInfo.dir();
QString mtlAbsoluteFilename = objDir.absolutePath() + "/" + mtlRelativeFilename;
parseMTL( mtlAbsoluteFilename, pOBJData );
}
else if( commandToken == "g" )
{
QString newGroupName;
if( tokens.size() < 2 )
{
fprintf( stderr, "Warning: group has no name, defaulting to ""\nline: %d\n%s",
lineNumber, qPrintable( line ) );
newGroupName = "";
}
else
{
newGroupName = tokens[ 1 ];
}
if( newGroupName != pCurrentGroup->name() )
{
if( pOBJData->containsGroup( newGroupName ) )
{
pCurrentGroup = pOBJData->getGroupByName( newGroupName );
}
else
{
pCurrentGroup = pOBJData->addGroup( newGroupName );
}
}
}
else if( commandToken == "v" )
{
// TODO: error checking on all of these and tear down pOBJData
OBJLoader::parsePosition( lineNumber, line, tokens, pOBJData );
}
else if( commandToken == "vt" )
{
OBJLoader::parseTextureCoordinate( lineNumber, line, tokens, pOBJData );
}
else if( commandToken == "vn" )
{
OBJLoader::parseNormal( lineNumber, line, tokens, pOBJData );
}
else if( commandToken == "usemtl" )
{
pCurrentGroup->addMaterial( tokens[ 1 ] );
}
else if( commandToken == "f" || commandToken == "fo" )
{
OBJLoader::parseFace( lineNumber, line,
tokens, pCurrentGroup );
}
}
}
++lineNumber;
line = inputTextStream.readLine();
}
return true;
}
// static
bool OBJLoader::parseFace( int lineNumber, const std::string& line,
const std::vector< std::string >& tokens,
OBJGroup& currentGroup )
{
// TODO: support negative indices.
if( tokens.size() < 4 )
{
fprintf( stderr,
"Incorrect number of tokens at line number: %d\n, %s\n",
lineNumber, line.c_str() );
return false;
}
// first check line consistency - each vertex in the face
// should have the same number of attributes
bool faceIsValid;
bool faceHasTextureCoordinates;
bool faceHasNormals;
faceIsValid = OBJLoader::faceHasConsistentAttributes( tokens,
&faceHasTextureCoordinates, &faceHasNormals );
if( !faceIsValid )
{
fprintf( stderr, "Face attributes inconsistent at line number: %d\n%s\n",
lineNumber, line.c_str() );
return false;
}
// ensure that all faces in a group are consistent:
// they either all have texture coordinates or they don't
// they either all have normals or they don't
//
// check how many faces the current group has
// if the group has no faces, then the first face sets the group attributes
if( currentGroup.numFaces() == 0 )
{
currentGroup.setHasTextureCoordinates( faceHasTextureCoordinates );
currentGroup.setHasNormals( faceHasNormals );
}
bool faceIsConsistentWithGroup =
( currentGroup.hasTextureCoordinates() == faceHasTextureCoordinates )
&& ( currentGroup.hasNormals() == faceHasNormals );
if( !faceIsConsistentWithGroup )
{
// TODO: boolToString()
fprintf( stderr,
"Face attributes inconsistent with group: %s at line: %d\n%s\n",
currentGroup.name().c_str(), lineNumber, line.c_str() );
fprintf( stderr, "group.hasTextureCoordinates() = %d\n",
currentGroup.hasTextureCoordinates() );
fprintf( stderr, "face.hasTextureCoordinates() = %d\n",
faceHasTextureCoordinates );
fprintf( stderr, "group.hasNormals() = %d\n",
currentGroup.hasNormals() );
fprintf( stderr, "face.hasNormals() = %d\n", faceHasNormals );
return false;
}
OBJFace face( faceHasTextureCoordinates, faceHasNormals );
// Process each vertex.
for( int i = 1; i < tokens.size(); ++i )
{
int vertexPositionIndex;
int vertexTextureCoordinateIndex;
int vertexNormalIndex;
OBJLoader::getVertexAttributes( tokens[ i ],
&vertexPositionIndex, &vertexTextureCoordinateIndex,
&vertexNormalIndex );
face.positionIndices().push_back( vertexPositionIndex - 1 );
if( faceHasTextureCoordinates )
{
face.textureCoordinateIndices().push_back(
vertexTextureCoordinateIndex - 1 );
}
if( faceHasNormals )
{
face.normalIndices().push_back( vertexNormalIndex - 1 );
}
}
currentGroup.addFace( face );
return true;
}