private static ContentSizeComponent ProcessParticleEmitter(ParticleEmitter emitter)
{
if (emitter.ParticlesLinkage != ParticlesLinkage.Parent)
{
return(null);
}
const float EmulationDuration = 15f;
const float EmulationStep = (float)AnimationUtils.SecondsPerFrame;
var parent = emitter.ParentWidget;
var modifiers = new List <ParticleModifier>();
for (var i = 0; i < emitter.Nodes.Count; i++)
{
var modifier = emitter.Nodes[i] as ParticleModifier;
if (modifier != null)
{
modifiers.Add(modifier);
}
}
var corners = new[] {
Vector2.Zero,
Vector2.Right,
Vector2.One,
Vector2.Down
};
// Particles pivot == (0.5, 0.5)
for (var i = 0; i < corners.Length; i++)
{
corners[i] = corners[i] - Vector2.Half;
}
var aabb = new Rectangle(float.MaxValue, float.MaxValue, float.MinValue, float.MinValue);
var isEmpty = true;
var animatedFrames = new SortedSet <int>();
foreach (var animator in emitter.Animators)
{
for (var i = 0; i < animator.ReadonlyKeys.Count; i++)
{
animatedFrames.Add(animator.ReadonlyKeys[i].Frame);
}
}
if (animatedFrames.Count == 0)
{
animatedFrames.Add(parent.DefaultAnimation.Frame);
}
var grandParent = parent.Parent;
var parentIndex = grandParent?.Nodes.IndexOf(parent) ?? 0;
parent.Unlink();
var animationFrame = parent.DefaultAnimation.Frame;
var parentVisibility = parent.Visible;
parent.Visible = true;
foreach (var frame in animatedFrames)
{
parent.DefaultAnimation.Frame = frame;
var parentToLocalTransform = emitter.CalcLocalToParentTransform().CalcInversed();
for (var time = 0f; time < EmulationDuration; time += EmulationStep)
{
foreach (var particle in emitter.particles)
{
if (particle.ColorCurrent.A <= 0)
{
continue;
}
isEmpty = false;
var transform = particle.Transform * parentToLocalTransform;
for (var i = 0; i < corners.Length; i++)
{
var corner = transform.TransformVector(corners[i]);
aabb = aabb.IncludingPoint(corner);
}
}
emitter.Update(EmulationStep);
}
emitter.DeleteAllParticles();
}
grandParent?.Nodes.Insert(parentIndex, parent);
parent.DefaultAnimation.Frame = animationFrame;
parent.Visible = parentVisibility;
if (isEmpty)
{
return(ProcessEmptyNode(emitter));
}
var safeHV = aabb.Size * 0.1f;
aabb = aabb.ExpandedBy(new Thickness(safeHV.X, safeHV.Y));
var selfSize = emitter.Components.GetOrAdd <ContentSizeComponent>();
selfSize.Size = new ContentRectangle(aabb, Vector2.One / emitter.Size);
return(selfSize);
}