/******************************************************************************
 * Copyright (C) Ultraleap, Inc. 2011-2021.                                   *
 *                                                                            *
 * Use subject to the terms of the Apache License 2.0 available at            *
 * http://www.apache.org/licenses/LICENSE-2.0, or another agreement           *
 * between Ultraleap and you, your company or other organization.             *
 ******************************************************************************/

using Leap.Unity.Drawing;
using Leap.Unity.Infix;
using UnityEngine;

namespace Leap.Unity.Geometry
{

    public static class GeometryUtils
    {

        /// <summary> Converts a sample point from the unit square (XY [-1, 1]) to
        /// a point in the unit circle.
        /// See: https://www.shadertoy.com/view/3dsSWs </summary>
        public static Vector2 Square2Circle(this Vector2 unitSquarePoint)
        {
            var v = unitSquarePoint;
            return v.Abs().CompMax() *
              (v.CompMul(Vector2.one * 2.0f + v.Abs())).normalized;
        }

        #region Runtime Gizmos

        private static Drawer s_drawer;

        #region Render Sphere

        /// <summary>
        /// Renders this Sphere in world space.
        /// </summary>
        public static void Render(this Sphere sphere)
        {
            Drawer drawer;
            if (TryGetDrawer(out drawer))
            {
                drawer.Sphere(sphere.center, sphere.radius);
            }
        }

        public static void Render(this Sphere sphere, Color color)
        {
            Drawer drawer;
            if (TryGetDrawer(out drawer))
            {
                drawer.color = color;
                drawer.Sphere(sphere.center, sphere.radius);
            }
        }

        #endregion

        #region Render Point

        /// <summary>
        /// Renders the point with world-aligned axis lines one centimeter outward from the
        /// point's position. Optionally pass a scale multliplier for the scale of the
        /// render.
        /// </summary>
        public static void Render(this Point point, Color? color, float scale = 1f)
        {
            Drawer drawer;
            if (TryGetDrawer(out drawer))
            {

                float finalScale = 0.01f * scale;
                var pos = point.position;

                if (color.HasValue)
                {
                    drawer.color = color.GetValueOrDefault();
                }

                if (!color.HasValue)
                {
                    drawer.color = Color.red;
                }
                drawer.Line(pos - Vector3.right * finalScale,
                            pos + Vector3.right * finalScale);

                if (!color.HasValue)
                {
                    drawer.color = Color.green;
                }
                drawer.Line(pos - Vector3.up * finalScale,
                            pos + Vector3.up * finalScale);

                if (!color.HasValue)
                {
                    drawer.color = Color.blue;
                }
                drawer.Line(pos - Vector3.forward * finalScale,
                            pos + Vector3.forward * finalScale);
            }
        }
        /// <summary>
        /// Renders the point with a sphere of one centimeter radius. Optionally pass a
        /// color and scale multiplier.
        /// </summary>
        public static void RenderSphere(this Point point, Color? color, float scale = 1f)
        {
            Drawer drawer;
            if (TryGetDrawer(out drawer))
            {

                float finalScale = 0.01f * scale;
                var pos = point.position;

                if (color.HasValue)
                {
                    drawer.color = color.GetValueOrDefault();
                }

                drawer.Sphere(pos, finalScale);
            }
        }

        #endregion

        #endregion

        #region Internal

        private static bool TryGetDrawer(out Drawer drawer)
        {
            drawer = Drawer.UnityDebugDrawer;
            return true;
        }

        #endregion

    }

}