rj-action-library/Runtime/Procedural/MeshGeometry.cs

using System.Collections;
using System.Collections.Generic;
using Godot;
using System;



namespace Rokojori
{
  public class MeshGeometry
  {
    public List<Vector3> vertices;
    public List<int> indices;

    public List<Vector3> normals;
    public List<Vector2> uvs;
    public List<Vector2> uv2s;
    public List<Color> colors;
  

    public void Initialize( bool normals = true, bool uvs = true, bool colors = false, bool uvs2 = false)
    {
      this.vertices = new List<Vector3>();
      this.indices = new List<int>();
      
      this.normals = normals ? new List<Vector3>() : null;
      this.uvs = uvs ? new List<Vector2>() : null;
      this.uv2s = uvs2 ? new List<Vector2>() : null;
      this.colors = colors ? new List<Color>() : null;      
    }

    public void AddTriangle( 
      Vector3 va, Vector3 vb, Vector3 vc, 
      Vector3 na, Vector3 nb, Vector3 nc,
      Vector2 uva, Vector2 uvb, Vector2 uvc
    )
    {
      var index = vertices.Count;
      Lists.Add( vertices, va, vb, vc );
      Lists.Add( normals, na, nb, nc );
      Lists.Add( uvs, uva, uvb, uvc );
      Lists.Add( indices, index, index + 1, index + 2 );
    }

    public void AddQuad(
      Vector3 va, Vector3 vb, Vector3 vc, Vector3 vd,
      Vector3 na, Vector3 nb, Vector3 nc, Vector3 nd, 
      Vector2 uva, Vector2 uvb, Vector2 uvc, Vector2 uvd
    )
    {
      AddTriangle( va, vb, vc,  na, nb, nc,  uva, uvb, uvc );
      AddTriangle( vc, vd, va,  nc, nd, na,  uvc, uvd, uva );
    }

    public void AddTriangle( 
      Vector3 va, Vector3 vb, Vector3 vc, 
      Vector2 uva, Vector2 uvb, Vector2 uvc
    )
    {
      var n = Vector3.Up;

      AddTriangle( va, vb, vc, 
                   n, n, n,
                   uva, uvb, uvc );
    }

    public void AddQuad(
      Vector3 va, Vector3 vb, Vector3 vc, Vector3 vd,
      Vector2 uva, Vector2 uvb, Vector2 uvc, Vector2 uvd
    )
    {

      AddTriangle( va, vb, vc, uva, uvb, uvc );
      AddTriangle( vc, vd, va, uvc, uvd, uva );
    }

    public void AddTriangle( Vector3 va, Vector3 vb, Vector3 vc )    
    {
      var n  = Vector3.Up;
      var uv = Vector2.Zero;

      AddTriangle( va, vb, vc,  n, n, n, uv, uv, uv );
    }

    public void AddQuad(  Vector3 va, Vector3 vb, Vector3 vc, Vector3 vd  )
    {
      AddTriangle( va, vb, vc );
      AddTriangle( vc, vd, va );
    }


    public ArrayMesh Generate( Mesh.PrimitiveType type = Mesh.PrimitiveType.Triangles, ArrayMesh arrayMesh = null )
    {
      if ( arrayMesh == null )
      {
        arrayMesh = new ArrayMesh();
      }

      var surfaceArray = new Godot.Collections.Array();
      surfaceArray.Resize( (int) Mesh.ArrayType.Max );

      if ( vertices != null )
      {
        surfaceArray[ (int) Mesh.ArrayType.Vertex ] = vertices.ToArray();
      }

      if ( normals != null )
      {
        surfaceArray[ (int) Mesh.ArrayType.Normal ] = normals.ToArray();
      }

      if ( uvs != null )
      {
        surfaceArray[ (int) Mesh.ArrayType.TexUV ] = uvs.ToArray();
      }

      if ( uv2s != null )
      {
        surfaceArray[ (int) Mesh.ArrayType.TexUV2 ] = uv2s.ToArray();
      }

      if ( colors != null )
      {
        surfaceArray[ (int) Mesh.ArrayType.Color ] = colors.ToArray();
      }

      if ( indices != null )
      {
        surfaceArray[ (int) Mesh.ArrayType.Index ] = indices.ToArray();
      }

      arrayMesh.AddSurfaceFromArrays( Mesh.PrimitiveType.Triangles, surfaceArray );

      return arrayMesh;
    }

  }
}