VRC_Avatar/Assets/04_Packages/RekornTools/Debug/DrawArrow.cs

using UnityEngine;

namespace RekornTools.Debug
{
    /// <summary>
    /// Based on  https://forum.unity3d.com/threads/debug-drawarrow.85980/
    /// </summary>
    public static class DrawArrow
    {
        public static void ForGizmo(
            Vector3 pos,
            Vector3 direction,
            float   arrowHeadLength = 0.25f,
            float   arrowHeadAngle  = 20.0f,
            float   arrowPosition   = 0.5f)
        {
            ForGizmo(pos, direction, Gizmos.color, arrowHeadLength, arrowHeadAngle, arrowPosition);
        }

        public static void ForGizmoTwoPoints(
            Vector3 from,
            Vector3 to,
            float   arrowHeadLength = 0.25f,
            float   arrowHeadAngle  = 20.0f,
            float   arrowPosition   = 0.5f)
        {
            ForGizmoTwoPoints(from, to, Gizmos.color, arrowHeadLength, arrowHeadAngle, arrowPosition);
        }

        public static void ForGizmo(
            Vector3 pos,
            Vector3 direction,
            Color   color,
            float   arrowHeadLength = 0.25f,
            float   arrowHeadAngle  = 20.0f,
            float   arrowPosition   = 0.5f)
        {
            Gizmos.color = color;
            Gizmos.DrawRay(pos, direction);
            DrawArrowEnd(true, pos, direction, color, arrowHeadLength, arrowHeadAngle, arrowPosition);
        }

        public static void ForGizmoTwoPoints(
            Vector3 from,
            Vector3 to,
            Color   color,
            float   arrowHeadLength = 0.25f,
            float   arrowHeadAngle  = 20.0f,
            float   arrowPosition   = 0.5f)
        {
            Gizmos.color = color;
            Gizmos.DrawLine(from, to);
            Vector3 direction = to - from;
            DrawArrowEnd(true, from, direction, color, arrowHeadLength, arrowHeadAngle, arrowPosition);
        }

        public static void ForDebug(
            Vector3 pos,
            Vector3 direction,
            float   arrowHeadLength = 0.25f,
            float   arrowHeadAngle  = 20.0f,
            float   arrowPosition   = 0.5f)
        {
            ForDebug(pos, direction, Color.white, arrowHeadLength, arrowHeadAngle, arrowPosition);
        }

        public static void ForDebug(
            Vector3 pos,
            Vector3 direction,
            Color   color,
            float   arrowHeadLength = 0.25f,
            float   arrowHeadAngle  = 20.0f,
            float   arrowPosition   = 0.5f)
        {
            UnityEngine.Debug.DrawRay(pos, direction, color);
            DrawArrowEnd(false, pos, direction, color, arrowHeadLength, arrowHeadAngle, arrowPosition);
        }

        private static void DrawArrowEnd(
            bool    gizmos,
            Vector3 pos,
            Vector3 direction,
            Color   color,
            float   arrowHeadLength = 0.25f,
            float   arrowHeadAngle  = 20.0f,
            float   arrowPosition   = 0.5f)
        {
            Vector3 right =
                (Quaternion.LookRotation(direction) * Quaternion.Euler(arrowHeadAngle, 0, 0) * Vector3.back) *
                arrowHeadLength;
            Vector3 left =
                (Quaternion.LookRotation(direction) * Quaternion.Euler(-arrowHeadAngle, 0, 0) * Vector3.back) *
                arrowHeadLength;
            Vector3 up = (Quaternion.LookRotation(direction) * Quaternion.Euler(0, arrowHeadAngle, 0) * Vector3.back) *
                         arrowHeadLength;
            Vector3 down =
                (Quaternion.LookRotation(direction) * Quaternion.Euler(0, -arrowHeadAngle, 0) * Vector3.back) *
                arrowHeadLength;

            Vector3 arrowTip = pos + (direction * arrowPosition);

            if (gizmos)
            {
                Gizmos.color = color;
                Gizmos.DrawRay(arrowTip, right);
                Gizmos.DrawRay(arrowTip, left);
                Gizmos.DrawRay(arrowTip, up);
                Gizmos.DrawRay(arrowTip, down);
            }
            else
            {
                UnityEngine.Debug.DrawRay(arrowTip, right, color);
                UnityEngine.Debug.DrawRay(arrowTip, left,  color);
                UnityEngine.Debug.DrawRay(arrowTip, up,    color);
                UnityEngine.Debug.DrawRay(arrowTip, down,  color);
            }
        }
    }
}