using System.Runtime.InteropServices;

namespace Raylib_cs;

/// <summary>
/// Vertex data definning a mesh<br/>
/// NOTE: Data stored in CPU memory (and GPU)
/// </summary>
[StructLayout(LayoutKind.Sequential)]
public unsafe partial struct Mesh
{
    /// <summary>
    ///  Creates a mesh ready for default vertex data allocation
    /// </summary>
    public Mesh(int vertexCount, int triangleCount)
    {
        VertexCount = vertexCount;
        TriangleCount = triangleCount;
    }

    /// <summary>
    ///  Number of vertices stored in arrays
    /// </summary>
    public int VertexCount;

    /// <summary>
    /// Number of triangles stored (indexed or not)
    /// </summary>
    public int TriangleCount;

    #region Default vertex data

    /// <summary>
    /// Vertex position (XYZ - 3 components per vertex) (shader-location = 0)
    /// </summary>
    public float* Vertices = default;

    /// <summary>
    /// Vertex texture coordinates (UV - 2 components per vertex) (shader-location = 1)
    /// </summary>
    public float* TexCoords = default;

    /// <summary>
    /// Vertex second texture coordinates (useful for lightmaps) (shader-location = 5)
    /// </summary>
    public float* TexCoords2 = default;

    /// <summary>
    /// Vertex normals (XYZ - 3 components per vertex) (shader-location = 2)
    /// </summary>
    public float* Normals = default;

    /// <summary>
    /// Vertex tangents (XYZW - 4 components per vertex) (shader-location = 4)
    /// </summary>
    public float* Tangents = default;

    /// <summary>
    /// Vertex colors (RGBA - 4 components per vertex) (shader-location = 3)
    /// </summary>
    public byte* Colors = default;

    /// <summary>
    /// Vertex indices (in case vertex data comes indexed)
    /// </summary>
    public ushort* Indices = default;

    #endregion

    #region Animation vertex data

    /// <summary>
    /// Animated vertex positions (after bones transformations)
    /// </summary>
    public float* AnimVertices = default;

    /// <summary>
    /// Animated normals (after bones transformations)
    /// </summary>
    public float* AnimNormals = default;

    /// <summary>
    /// Vertex bone ids, up to 4 bones influence by vertex (skinning)
    /// </summary>
    public byte* BoneIds = default;

    /// <summary>
    /// Vertex bone weight, up to 4 bones influence by vertex (skinning)
    /// </summary>
    public float* BoneWeights = default;

    #endregion

    #region OpenGL identifiers

    /// <summary>
    /// OpenGL Vertex Array Object id
    /// </summary>
    public uint VaoId = default;

    /// <summary>
    /// OpenGL Vertex Buffer Objects id (default vertex data, uint[])
    /// </summary>
    public uint* VboId = default;

    #endregion
}