Using Skills

Understanding skill usage.

Using a Skill

When a skill should be used, SkillTree.TryUseSkill should be called. This will attempt to use a skill if possible. It goes through basic checks to see if a skill can be used. If not, nothing will happen. You wouldn't want a skill to be used while it's winding up or it's on cooldown, right?

This method requires a SkillNode and UnitStatsProvider reference. A skill node is required to know which skill was attempted. A stats provider is useful because it will make the skill user's stats easily accessible—more on that later.

// Where skill is a SkillNode and stats is a UnitStatsProvider object
UsedSkill usedSkill = SkillTree.TryUseSkill(skill, stats);

This is called automatically with the Default Prefabs. TryUseSkill returns a UsedSkill object.

Completing Skill Use

After a skill is used with TryUseSkill, you need to look to call SkillTree.CompleteSkillUse. This will tell Skill Tree when a skill's usage has been completed. This does not refer to the entire duration of the skill, but rather just the duration of the skill's animation because you wouldn't want another skill to be used while the previous skill's animation is currently running—unless you do, which is why you're free to call it whenever you'd like.

// Where skill is a SkillNode and stats is a UnitStatsProvider object
SkillTree.CompleteSkillUse(skill, stats);

Used Skill

A UsedSkill object is, as it sounds—a skill that was used. It handles a skill's windup and cooldown behind the scenes. You can use UsedSkill.skill to get the SkillNode and UsedSkill.user to get the UnitStatsProvider.

Custom Functions

With the Skill Interpreter component, you can run your own functions when a certain skill is used. Each event in the interpreter accepts a UsedSkill object. Your custom function can use this to get the stats.

Example

For example, let's say you want to damage an enemy when the "Attack" skill is used. Here's how you could write a function for this:

public void OnAttackSkillUsed(UsedSkill usedSkill)
{
    // Combine user and skill damage
    var skillDmg = usedSkill.skill.GetStat("DMG");
    var userDmg = usedSkill.user.GetStat("DMG");
    var totalDmg = skillDmg.baseValue + userDmg.currentValue;
    
    // target is an enemy with HP
    // ApplyDamage is a method that will decrease the taget's HP by an amount
    target.ApplyDamage(totalDmg);
}

In the Skill Interpreter component, add an interpreter and give it the key "Attack" (the key of the skill), and then add this function to the On Skill Used event.

This is just an example. The code will greatly depend on your game. Check out the demo scene in the Assets > StylishEsper > SkillTree > Example folder for better examples.