PCK-Studio/PckStudio.Rendering/CubeMesh.cs

/* Copyright (c) 2024-present miku-666
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 * 
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 * 
 * 1.The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
**/
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using OpenTK;
using PckStudio.Core;
using PckStudio.Core.Extensions;

namespace PckStudio.Rendering
{
    public class CubeMesh : GenericMesh<TextureVertex>
    {
        private Cube _cube;

        public Vector3 Center => _cube.Center;

        internal static int[] IndicesData { get; } = [
                    // Face 1 (Back)
                     0,  1,  2,
                     2,  3,  0,
                    // Face 2 (Front)
                     4,  5,  6,
                     6,  7,  4,
                    // Face 3 (Top)
                     8,  9, 10,
                    10, 11,  8,
                    // Face 4 (Bottom)
                    12, 13, 14,
                    14, 15, 12,
                    // Face 5 (Left)
                    16, 17, 18,
                    18, 19, 16,
                    // Face 6 (Right)
                    20, 21, 22,
                    22, 23, 20
            ];

        internal static VertexBufferLayout VertexBufferLayout { get; } = new VertexBufferLayout().Add(ShaderDataType.Float3).Add(ShaderDataType.Float2);

        public CubeMesh(Cube cube) : this(nameof(CubeMesh), cube)
        {
        }

        public CubeMesh(string name, Cube cube) : this(name, cube, true)
        {
        }
        
        private CubeMesh(string name, Cube cube, bool visible)
            : base(name, visible, OpenTK.Graphics.OpenGL.PrimitiveType.Triangles, VertexBufferLayout)
        {
            _cube = cube;
        }

        public CubeMesh SetCube(Cube cube)
        {
            _ = cube ?? throw new ArgumentNullException(nameof(cube));
            return new CubeMesh(Name, cube, Visible);
        }
        
        public override GenericMesh<TextureVertex> SetVisible(bool visible) => new CubeMesh(Name, _cube, visible);

        public Cube GetCube() => _cube;

        public override Matrix4 GetTransform() => _cube.GetBoundingBox().GetTransform();

        public override BoundingBox GetBounds(Matrix4 transform)
        {
            return _cube.GetBoundingBox(transform);
        }

        public override IEnumerable<TextureVertex> GetVertices()
        {
            int mirror = Convert.ToInt32(_cube.MirrorTexture);

            Vector2 uv = _cube.Uv;

            Vector3 size = _cube.Size;

            // Back
            yield return new TextureVertex(new Vector3(0f, 1f, 1f), new Vector2(uv.X + size.Z * 2 + size.X + size.X * (1 - mirror), uv.Y + size.Z + size.Y));
            yield return new TextureVertex(new Vector3(1f, 1f, 1f), new Vector2(uv.X + size.Z * 2 + size.X + size.X * mirror, uv.Y + size.Z + size.Y));
            yield return new TextureVertex(new Vector3(1f, 0f, 1f), new Vector2(uv.X + size.Z * 2 + size.X + size.X * mirror, uv.Y + size.Z));
            yield return new TextureVertex(new Vector3(0f, 0f, 1f), new Vector2(uv.X + size.Z * 2 + size.X + size.X * (1 - mirror), uv.Y + size.Z));
            
            // Front
            yield return new TextureVertex(new Vector3(0f, 1f, 0f), new Vector2(uv.X + size.Z + size.X * mirror, uv.Y + size.Z + size.Y));
            yield return new TextureVertex(new Vector3(1f, 1f, 0f), new Vector2(uv.X + size.Z + size.X * (1 - mirror), uv.Y + size.Z + size.Y));
            yield return new TextureVertex(new Vector3(1f, 0f, 0f), new Vector2(uv.X + size.Z + size.X * (1 - mirror), uv.Y + size.Z));
            yield return new TextureVertex(new Vector3(0f, 0f, 0f), new Vector2(uv.X + size.Z + size.X * mirror, uv.Y + size.Z));
            
            // Top
            yield return new TextureVertex(new Vector3(0f, 0f, 0f), new Vector2(uv.X + size.Z + size.X * mirror, uv.Y + size.Z));
            yield return new TextureVertex(new Vector3(0f, 0f, 1f), new Vector2(uv.X + size.Z + size.X * mirror, uv.Y));
            yield return new TextureVertex(new Vector3(1f, 0f, 1f), new Vector2(uv.X + size.Z + size.X * (1 - mirror), uv.Y));
            yield return new TextureVertex(new Vector3(1f, 0f, 0f), new Vector2(uv.X + size.Z + size.X * (1 - mirror), uv.Y + size.Z));
            
            // Bottom
            yield return new TextureVertex(new Vector3(1f, 1f, 0f), new Vector2(uv.X + size.Z + size.X + size.X * (1 - mirror), uv.Y + (_cube.FlipZMapping ? size.Z : 0)));
            yield return new TextureVertex(new Vector3(1f, 1f, 1f), new Vector2(uv.X + size.Z + size.X + size.X * (1 - mirror), uv.Y + (!_cube.FlipZMapping ? size.Z : 0)));
            yield return new TextureVertex(new Vector3(0f, 1f, 1f), new Vector2(uv.X + size.Z + size.X + size.X * mirror, uv.Y + (!_cube.FlipZMapping ? size.Z : 0)));
            yield return new TextureVertex(new Vector3(0f, 1f, 0f), new Vector2(uv.X + size.Z + size.X + size.X * mirror, uv.Y + (_cube.FlipZMapping ? size.Z : 0)));
            
            // Left
            yield return new TextureVertex(new Vector3(_cube.MirrorTexture ? 0f : 1f, 0f, 0f), new Vector2(uv.X + size.X + size.Z, uv.Y + size.Z));
            yield return new TextureVertex(new Vector3(_cube.MirrorTexture ? 0f : 1f, 1f, 0f), new Vector2(uv.X + size.X + size.Z, uv.Y + size.Z + size.Y));
            yield return new TextureVertex(new Vector3(_cube.MirrorTexture ? 0f : 1f, 1f, 1f), new Vector2(uv.X + size.X + size.Z * 2, uv.Y + size.Z + size.Y));
            yield return new TextureVertex(new Vector3(_cube.MirrorTexture ? 0f : 1f, 0f, 1f), new Vector2(uv.X + size.X + size.Z * 2, uv.Y + size.Z));
            
            // Right
            yield return new TextureVertex(new Vector3(_cube.MirrorTexture ? 1f : 0f, 0f, 0f), new Vector2(uv.X + size.Z, uv.Y + size.Z));
            yield return new TextureVertex(new Vector3(_cube.MirrorTexture ? 1f : 0f, 1f, 0f), new Vector2(uv.X + size.Z, uv.Y + size.Z + size.Y));
            yield return new TextureVertex(new Vector3(_cube.MirrorTexture ? 1f : 0f, 1f, 1f), new Vector2(uv.X, uv.Y + size.Z + size.Y));
            yield return new TextureVertex(new Vector3(_cube.MirrorTexture ? 1f : 0f, 0f, 1f), new Vector2(uv.X, uv.Y + size.Z));
            yield break;
        }

        public override IEnumerable<int> GetIndices() => IndicesData;
    }
}