A Component that creates and manages a blood decal animation. It initializes lifetime, randomized start time and size, increments a global decal count on spawn, updates decal size and alpha over time, and destroys the GameObject when expired.
using System;
using Sandbox;
public sealed class BloodDecal : Component
{
private TimeSince _timeSinceSpawn;
public float Lifetime { get; set; }
[Property] public Decal Decal { get; set; }
private float _personalStartTime;
private Vector2 _personalSize;
protected override void OnEnabled()
{
base.OnEnabled();
_timeSinceSpawn = 0f;
Lifetime = 10f;
_personalStartTime = Game.Random.Float( 0.025f, 0.15f );
var size = Game.Random.Float( 1f, 3f );
_personalSize = new Vector2( size * Game.Random.Float( 0.8f, 1.2f ), size * Game.Random.Float( 0.8f, 1.2f ) );
Manager.Instance.NumDecals++;
}
protected override void OnUpdate()
{
base.OnUpdate();
if ( _timeSinceSpawn > Lifetime )
{
Manager.Instance.NumDecals--;
GameObject.Destroy();
}
else
{
Decal.Size = Vector2.Lerp( Vector2.Zero, _personalSize, Utils.Map( _timeSinceSpawn, 0f, _personalStartTime, 0f, 1f, EasingType.ExpoOut ) );
Decal.ColorTint = Color.Red.WithAlpha( Utils.Map( _timeSinceSpawn, 0f, Lifetime, 1f, 0f, EasingType.QuadIn ) );
}
}
}