//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="TextureProvider"
// 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.Graphics;

using System;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.CompilerServices;

namespace StgSharp.Graphics
{
    public class TextureProvider : IImageProvider
    {

        private Vec2[] _texCoord;
        private Image _tex;

        public TextureProvider(
               Image image,
               Vec2[] coord
        )
        {
            _tex = image;
            _texCoord = coord;
        }

        public ref Vec2 this[
                        int index
        ]
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get => ref _texCoord[index];
        }

        public Span<Vec2> TextureCoordinate
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get => new Span<Vec2>(_texCoord);
        }

        public Image ProvideImage()
        {
            return _tex;
        }

        public void ReadImage(
                    IImageProvider provider
        )
        {
            _tex = provider.ProvideImage();
        }

        public void UpdateFromImage(
                    [NotNull]Image i
        )
        {
            if (i == _tex) {
                return;
            }
            if (i.Size == _tex.Size)
            {
                _tex = i;
            } else
            {
                throw new ArgumentException(
                    $"Size of {nameof(i)} does not equals to current image.");
            }
        }

    }
}