private void AddLetter(VectorPath chr, ParticleEmitterConfig cfg, float px, float py, float scale, float animOffset, float animLen)
 {
     if (UseCPUParticles)
     {
         var emt = new AnimatedPathCPUParticleEmitter(_screen, new FPoint(px, py), chr.AsScaled(scale), cfg, animOffset, animLen, _order);
         _childEmitter.Add(emt);
         _screen.Entities.AddEntity(emt);
     }
     else
     {
         var emt = new AnimatedPathGPUParticleEmitter(_screen, new FPoint(px, py), chr.AsScaled(scale), cfg, animOffset, animLen, _order);
         _childEmitter.Add(emt);
         _screen.Entities.AddEntity(emt);
     }
 }