/// <summary>
/// Sorts the available Raycasts in to a priority order for query.
/// </summary>
/// <param name="priority">The layer mask priority.</param>
/// <returns><see cref="RaycastResult"/></returns>
private static RaycastResult PrioritizeRaycastResult(LayerMask[] priority, RaycastResultComparer raycastResultComparer)
{
// If not specified, default to the in-box RaycastResultComparer.
if (raycastResultComparer == null)
{
raycastResultComparer = RaycastResultComparer;
}
ComparableRaycastResult maxResult = default(ComparableRaycastResult);
for (var i = 0; i < RaycastResults.Count; i++)
{
if (RaycastResults[i].gameObject == null)
{
continue;
}
var layerMaskIndex = RaycastResults[i].gameObject.layer.FindLayerListIndex(priority);
if (layerMaskIndex == -1)
{
continue;
}
var result = new ComparableRaycastResult(RaycastResults[i], layerMaskIndex);
if (maxResult.RaycastResult.module == null || raycastResultComparer.Compare(maxResult, result) < 0)
{
maxResult = result;
}
}
return(maxResult.RaycastResult);
}
/// <summary>
/// Executes a raycast all and returns the closest element.
/// Fixes the current issue with Unity's raycast sorting which does not consider separate canvases.
/// </summary>
/// <remarks>
/// Takes an optional RaycastResultComparer, which will be used to select the highest priority
/// raycast result.
/// </remarks>
/// <returns>RaycastResult if hit, or an empty RaycastResult if nothing was hit</returns>
public static RaycastResult Raycast(this EventSystem eventSystem, PointerEventData pointerEventData, LayerMask[] layerMasks, RaycastResultComparer raycastResultComparer = null)
{
using (RaycastPerfMarker.Auto())
{
eventSystem.RaycastAll(pointerEventData, RaycastResults);
return(PrioritizeRaycastResult(layerMasks, raycastResultComparer));
}
}
