//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="GeometryOperation"
// Project: StgSharp
// AuthorGroup: Nitload
// Copyright (c) Nitload. All rights reserved.
//     
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//     
// -----------------------------------------------------------------------
// -----------------------------------------------------------------------
using StgSharp.Mathematics.Graphic;
using StgSharp.Timing;

using System;
using System.Runtime.InteropServices;

namespace StgSharp.Geometries
{
    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    public delegate Vec3 GeometryMotionDelegate(TimeSpanProvider timeSource, out float rotation);

    public class GeometryMotion
    {

        private bool isIncrementMode;
        private bool sourceIsStatic;
        private GeometryMotionDelegate movement;
        private IntPtr handle;
        private TimeSpanProvider time;

        public unsafe GeometryMotion(
                      bool isIncreament,
                      TimeSpanProvider timeSource,
                      GeometryMotionDelegate motionDelegate)
        {
            isIncrementMode = isIncreament;
            time = timeSource;
            if (motionDelegate == null)
            {
                handle = (IntPtr)(delegate*<TimeSpanProvider, out float, Vec3>)&defaultMotion;
                movement = defaultMotion;
            } else if (motionDelegate.Method.IsStatic)
            {
                sourceIsStatic = true;
                handle = Marshal.GetFunctionPointerForDelegate(motionDelegate);
                movement = motionDelegate;
            } else
            {
                movement = motionDelegate;
            }

            // sourceIsStatic = false;
        }

        public bool IsIncrement
        {
            get => isIncrementMode;
        }

        public static GeometryMotion DefaultMotion
        {
            get => new GeometryMotion(true, null, null);
        }

        public unsafe void RunMotion(ref Vec3 coord, ref float rotation)
        {
            float rot;
            Vec3 vec;
            if (sourceIsStatic)
            {
                vec = ((delegate* unmanaged[Cdecl]<TimeSpanProvider, out float, Vec3>)handle)(
                    time, out rot);
            } else
            {
                vec = movement(time, out rot);
            }

            if (isIncrementMode)
            {
                coord += vec;
                rotation += rot;
            } else
            {
                coord = vec;
                rotation = rot;
            }
        }

        private static Vec3 defaultMotion(TimeSpanProvider provider, out float rotation)
        {
            rotation = 0;
            return Vec3.Zero;
        }

    }//------------------------------- End of Class -------------------------------
}