DataTypes

As you may know, many SOFA C++ classes are templated. Examples of templates can be found in the MechanicalObject page, in the templates section. In the code, the use of templates implies the many types in the C++ variable, that are not always easy to understand. This page provides a short introduction to all these types.

All following types are defined from the DataTypes class, and can therefore be used by writing: DataTypes::MyType.

Real: corresponds to a double or float value, depending on the DataTypes used: a class templated in Vec3d will return a double, whereas a a class templated in Vec3f will return a float

Coord: standing for “coordinate”, corresponds to a vector of Real with a size given by the number of degrees of freedom: a class templated in Vec6d will return a vector of 6 doubles. This vector is homogeneous to your degrees of freedom.

Deriv standing for “derivative”, corresponds to a vector of Real with a size given by the number of degrees of freedom: a class templated in Vec6d will return a vector of 6 doubles

VecCoord or VecDeriv: corresponds to a vector of respectively Coord or Deriv

DataVecCoord or DataVecDeriv: corresponds to a Data containing a vector of respectively Coord or Deriv. As noted in the assocaited article, the Data are variable of the class exposed to the user and other components in the scene

MatrixCoord or MatrixDeriv: corresponds to a matrix of respectively Coord or Deriv, this is more especially used by solvers and constraint algorithms

VecCoordId, VecDerivId, MatrixCoordId or MatrixDerivId: corresponds to an identifiant value (int) pointing to a vector or matrix of respectively Coord or Deriv. This is very useful to access specific vectors or matrix in the simulation. State vectors for instance are managed with specific protected Ids by the solvers.