Simple and fast Entity-Component-System (ECS) library written in Dart

void update(double deltatime, setentity entities) {
    for (var i = 0; i < entities.size; i++) {
      entity entity = entities[i];
      transformcomponent transform = transformcomponents[entity] as transformcomponent;
      velocitycomponent rotation = velocitycomponents[entity] as velocitycomponent;
      transform.rotation += rotation.velocity * deltatime;
      transform.dirty = true;
    }
  }

void updatesprite(transformcomponent transform, spritecomponent sprite) {
    var textureregion = sprite.textureregion;
    if (transform.dirty && textureregion != null) {
      var scos = cos(transform.rotation) * transform.scale;
      var ssin = sin(transform.rotation) * transform.scale;
      var tx = -scos * textureregion.anchorx + ssin * textureregion.anchory;
      var ty = -ssin * textureregion.anchorx - scos * textureregion.anchory;
      sprite.transformdata.set(scos, ssin, tx, ty);
      transform.dirty = false;
    }
  }