/// <summary>
/// Counts the bounding box corners of the given RectTransform that are visible from the given Camera in screen space.
/// </summary>
/// <returns>The amount of bounding box corners that are visible from the Camera.</returns>
/// <param name="rectTransform">Rect transform.</param>
/// <param name="camera">Camera.</param>
private static int CountCornersVisibleFrom(this RectTransform rectTransform, Camera camera, CanvasScaler cs)
{
Vector2 scaled = cs.Scale((new Vector2(Screen.width, Screen.height)));
Rect screenBounds = new Rect(0f, 0f, scaled.x, scaled.y); // Screen space bounds (assumes camera renders across the entire screen)
Vector3[] objectCorners = new Vector3[4];
rectTransform.GetWorldCorners(objectCorners);
int visibleCorners = 0;
Vector3 tempScreenSpaceCorner; // Cached
for (var i = 0; i < objectCorners.Length; i++) // For each corner in rectTransform
{
tempScreenSpaceCorner = objectCorners[i]; // Transform world space position of corner to screen space
if (screenBounds.Contains(tempScreenSpaceCorner)) // If the corner is inside the screen
{
visibleCorners++;
}
}
return(visibleCorners);
}