Method resamplePrimitiveVariable

src/IECoreScene/MeshAlgoResample.cpp:287–385

} // namespace

void IECoreScene::MeshAlgo::resamplePrimitiveVariable( const MeshPrimitive *mesh, PrimitiveVariable& primitiveVariable, PrimitiveVariable::Interpolation interpolation, const Canceller *canceller )
{
	PrimitiveVariable::Interpolation srcInterpolation = primitiveVariable.interpolation;
	if ( srcInterpolation == interpolation )
	{
		return;
	}

	DataPtr dstData = nullptr;
	DataPtr srcData = nullptr;

	if( primitiveVariable.indices )
	{
		if( srcInterpolation < interpolation )
		{
			// upsampling can be a resampling of indices
			srcData = primitiveVariable.indices;
		}
		else
		{
			// downsampling forces index expansion to
			// simplify the algorithms.
			// \todo: allow indices to be maintained.
			Canceller::check( canceller );
			srcData = primitiveVariable.expandedData();
			primitiveVariable.indices = nullptr;
		}
	}
	else
	{
		// with no indices we can just resample the data
		srcData = primitiveVariable.data;
	}

	// average array to single value
	if ( interpolation == PrimitiveVariable::Constant )
	{
		IECoreScene::Detail::AverageValueFromVector fn;
		dstData = dispatch( srcData.get(), fn );
		primitiveVariable = PrimitiveVariable( interpolation, dstData );
		return;
	}

	if ( primitiveVariable.interpolation == PrimitiveVariable::Constant )
	{
		IECoreScene::Detail::FillVectorFromValue fn( mesh->variableSize( interpolation ) );
		DataPtr arrayData = dispatch( srcData.get(), fn );
		if (arrayData)
		{
			primitiveVariable = PrimitiveVariable(interpolation, arrayData);
		}
		return;
	}

	if( interpolation == PrimitiveVariable::Uniform )
	{
		if( srcInterpolation == PrimitiveVariable::Varying || srcInterpolation == PrimitiveVariable::Vertex )
		{