The spine docummentation shows how to scale the skeleton when loading. Is it a must to reload the skeleton to scale the animation while playing it?
This is done by manipulating the bone directly, as in this documentation: http://esotericsoftware.com/spine-using-runtimes#Manipulating-bones
The key here is that you have to perform the operation after calling AnimationState_update/apply but before calling Skeleton_updateWorldTransform:
Skeleton_update(spine->_Skeleton, dt); AnimationState_update(spine->_AnimationState, dt); AnimationState_apply(spine->_AnimationState, spine->_Skeleton); // Now that the animation has applied any changes, provide our own manipulations: spine->_Skeleton->x = transform->position.x; spine->_Skeleton->y = transform->position.y; spine->_Skeleton->root->scaleX = 0.5f; spine->_Skeleton->root->scaleY = 0.5f; spine->_Skeleton->root->rotation = 45.0f; Skeleton_updateWorldTransform(spine->_Skeleton);