Phase singularity analysis provides a quantitative description of spiral wave patterns observed in chemical or biological excitable media, for instance in a cardiac tissue during an arrhythmia. The configuration of phase singularities (locations and directions of rotation) is easily derived from phase maps in two-dimensional manifolds. The question arises whether one can construct a phase map with a given configuration of phase singularities. We will present a constructive mathematical approach to numerically solve this problem in geometries relevant to atrial anatomy. This tool can notably be used to create initial conditions with controllable spiral wave configuration for cardiac propagation models and thus help in the design of computer experiments in atrial electrophysiology.