//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//     file="CollisionTexture.cs"
//     Project: StgSharp
//     AuthorGroup: Nitload Space
//     Copyright (c) Nitload Space. 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.Data;
using StgSharp.Geometries;
using StgSharp.Graphics;
using StgSharp.Graphics.OpenGL;

using StgSharp.Math;
using StgSharp.MVVM;

using System;
using System.Buffers;
using System.Collections.Generic;
using System.Linq;
using System.Resources;
using System.Text;
using System.Threading.Tasks;

namespace StgSharp.Stg
{
    public interface IOneDimensionalCollisionTexture2D
    {

        public void Init(Radius angleStride, string name);

    }

    public sealed class OneDimensionalCollisionTexture2D_GL : glRender, IOneDimensionalCollisionTexture2D
    {

        float[] textureOutput;
        ElementBuffer ebo;
        private FrameBuffer fbo;
        RenderBuffer rbo;

        ShaderProgram generatingShader;

        TextureGL t;

        VertexArray vao;
        VertexBuffer vbo;

        public OneDimensionalCollisionTexture2D_GL()
        {

        }

        public override bool IsContextSharable => false;

        public void GenerateCollisionTexture(IEnumerable<IInstancingBuffer> bufferEnumeration)
        {
            fbo.Bind(0);
            GL.ClearColor(0, 0, 0, 1);
            GL.Clear(MaskBufferBit.DEPTH | MaskBufferBit.COLOR);
            generatingShader.Use();
            vao.Bind(0);

            foreach (IInstancingBuffer item in bufferEnumeration)
            {
                IGeometry g = item.TypicalShape;

                if (!(g is PlainGeometry))
                {
                    throw new InvalidOperationException("The current particle buffer contains non-planar geometry,");
                }

                ebo.Bind(0);
                ebo.SetValue<int>(0, g.VertexIndices, BufferUsage.StreamDraw);

                vbo.WriteVectorData<vec4d>(0, item.CoordAndRotationSpan, BufferUsage.StreamDraw);
                vao.SetVertexAttribute(1, 3, TypeCode.Single, false, 4 * sizeof(float), 0);
                vao.SetVertexAttribute(2, 1, TypeCode.Single, false, 4 * sizeof(float), 3 * sizeof(float));

                vbo.WriteScalerData<float>(2, item.ScalingSpan, BufferUsage.StreamDraw);
                vao.SetVertexAttribute(3, 1, TypeCode.Single, false, sizeof(float), 0);

                vbo.WriteVectorData(1, g.VertexStream, BufferUsage.StreamDraw);
                vao.SetVertexAttribute(0, 3, TypeCode.Single, false, 4 * sizeof(float), 0);

                GL.DrawElementsInstanced(GeometryType.TRIANGLES, ((uint)g.VertexIndices.Length) / 3,
                    TypeCode.UInt32, IntPtr.Zero, (uint)item.ScalingSpan.Length);
            }

            t.Bind2D(0);
            GL.GetTextureImage(Texture2DTarget.Texture2D, 0, ImageChannel.SingleColor, PixelChannelLayout.Float, textureOutput);
            VertexArray.BindNull();
        }

        public void Init(Radius angleStride, string name)
        {
            primeArgs = new ViewPort
            {
                Height = 1,
                Width = (int)((new Radius(Scaler.Pi)) / angleStride),
                Name = name,
            };

            _coordStretch = (1, 1, 1);

            PlatformSpecifiedInitialize();
            CustomizeInit();
        }

#pragma warning disable CS8618

        protected override void CustomizeDeinit()
        {
            throw new NotImplementedException();
        }

        protected override void CustomizeInit()
        {
            generatingShader = CreateShaderProgram();

            Shader vertexShader = CreateShaderSegment(ShaderType.Vertex, 1);
            Shader fragmentShader = CreateShaderSegment(ShaderType.Fragment, 1);

            vertexShader.Compile(0, InternalIO.CollisionTextureVertexShader);
            fragmentShader.Compile(0, InternalIO.CollisionTextureFragmentShader);
            vertexShader.AttachTo(0, generatingShader);
            fragmentShader.AttachTo(0, generatingShader);

            generatingShader.Link();
            generatingShader.Use();

            vbo = CreateVertexBuffer(3);
            vao = CreateVertexArray(1);
            ebo = CreateElementBuffer(1);


            fbo = CreateFrameBuffer(1);
            rbo = CreateRenderBuffer(1);
            GL.SetRenderBufferStorage(
                RenderBufferInternalFormat.Depth24_Stencil8, this.Size);


            t = CreateTexture(1);
            t.Bind2D(0);
            GL.TextureImage2d<byte>(Texture2DTarget.Texture2D, 0, (int)ImageChannel.WithAlphaChannel,
                (uint)Width, (uint)Height, (int)ImageChannel.WithAlphaChannel, PixelChannelLayout.Byte, Array.Empty<byte>());

            t.Set2dWrapProperty(0, TextureWrap.Repeat, TextureWrap.Repeat);
            t.Set2dFilterProperty(0, TextureFilter.Nearest, TextureFilter.Nearest);

            GL.FrameBufferTexture2d(FrameBufferTarget.All, glAttachment.Color(0),
        Texture2DTarget.Texture2D, t[0], 0);

            GL.CombineFrameBufferRenderBuffer(FrameBufferAttachment.Color, rbo[0]);

            textureOutput = new float[this.Width];
        }

        protected override void Main()
        {
            throw new NotSupportedException();
        }

    }
}