DynamicMesh.cs

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

namespace SkyVoxels.Engine.Utilities
{
    /// <summary>
    /// This class serves as an advanced "wrapper" of sorts to the default Unity
    /// Mesh class to generate visual or physics meshes dynamically. This class
    /// is specially tailored for this project.
    /// </summary>
    public class DynamicMesh
    {
        public List<Vector3> RenderingVertices { get; set; }
        public List<int> RenderingTriangles { get; set; }
        public List<Vector2> RenderingUVs { get; set; }
        public List<Color> RenderingColors { get; set; }
        public List<Vector3> ColliderVertices { get; set; }
        public List<int> ColliderTriangles { get; set; }

        /// <summary>
        /// Constructor for the DynamicMesh class.
        /// </summary>
        /// <param name="overallAllocationSize">The base allocation size for all collections in the DynamicMesh.</param>
        public DynamicMesh(int overallAllocationSize)
        {
            this.RenderingVertices = new List<Vector3>(overallAllocationSize) { };
            this.RenderingTriangles = new List<int>(overallAllocationSize) { };
            this.RenderingUVs = new List<Vector2>(overallAllocationSize) { };
            this.RenderingColors = new List<Color>(overallAllocationSize) { };
            this.ColliderVertices = new List<Vector3>(overallAllocationSize) { };
            this.ColliderTriangles = new List<int>(overallAllocationSize) { };
        }

        /// <summary>
        /// Add a "quad" into the lists of triangle indices.
        /// </summary>
        /// <param name="isFlipped">Whether or not the rendering quad is flipped.</param>
        /// <param name="generateColliderData"></param>
        public void AddQuad(bool isFlipped, bool generateColliderData = true)
        {
            if(this.RenderingVertices.Count >= 4)
            {
                if(isFlipped)
                {
                    this.RenderingTriangles.Add(this.RenderingVertices.Count - 4);
                    this.RenderingTriangles.Add(this.RenderingVertices.Count - 3);
                    this.RenderingTriangles.Add(this.RenderingVertices.Count - 2);

                    this.RenderingTriangles.Add(this.RenderingVertices.Count - 4);
                    this.RenderingTriangles.Add(this.RenderingVertices.Count - 2);
                    this.RenderingTriangles.Add(this.RenderingVertices.Count - 1);
                }
                else
                {
                    this.RenderingTriangles.Add(this.RenderingVertices.Count - 4);
                    this.RenderingTriangles.Add(this.RenderingVertices.Count - 3);
                    this.RenderingTriangles.Add(this.RenderingVertices.Count - 1);

                    this.RenderingTriangles.Add(this.RenderingVertices.Count - 3);
                    this.RenderingTriangles.Add(this.RenderingVertices.Count - 2);
                    this.RenderingTriangles.Add(this.RenderingVertices.Count - 1);
                }
            }
            else
            {
                throw new System.Exception("At least 4 vertices are required to add a rendering quad.");
            }

            if(generateColliderData && this.ColliderVertices.Count >= 4)
            {
                this.ColliderTriangles.Add(this.ColliderVertices.Count - 4);
                this.ColliderTriangles.Add(this.ColliderVertices.Count - 3);
                this.ColliderTriangles.Add(this.ColliderVertices.Count - 1);

                this.ColliderTriangles.Add(this.ColliderVertices.Count - 3);
                this.ColliderTriangles.Add(this.ColliderVertices.Count - 2);
                this.ColliderTriangles.Add(this.ColliderVertices.Count - 1);
            }
            else
            {
                throw new System.Exception("At least 4 vertices are required to add a collider. quad.");
            }
        }

        /// <summary>
        /// Add a "triangle" into the lists of triangle indices.
        /// </summary>
        /// <param name="generateColliderData">Whether or not collider triangles should be generated.</param>
        public void AddTriangle(bool generateColliderData = true)
        {
            if(this.RenderingVertices.Count >= 3)
            {
                this.RenderingTriangles.Add(this.RenderingVertices.Count - 3);
                this.RenderingTriangles.Add(this.RenderingVertices.Count - 2);
                this.RenderingTriangles.Add(this.RenderingVertices.Count - 1);
            }
            else
            {
                throw new System.Exception("At least 3 vertices are required to add a rendering triangle.");
            }

            if(generateColliderData && this.ColliderVertices.Count >= 3)
            {
                this.ColliderTriangles.Add(this.ColliderVertices.Count - 3);
                this.ColliderTriangles.Add(this.ColliderVertices.Count - 2);
                this.ColliderTriangles.Add(this.ColliderVertices.Count - 1);
            }
            else
            {
                throw new System.Exception("At least 3 vertices are required to add a collider triangle.");
            }
        }

        /// <summary>
        /// Add an array of UVs to the list of UV coordinates.
        /// </summary>
        /// <param name="uvCoordinates">The list of UV coordinates to add.</param>
        public void AddUVs(Vector2[] uvCoordinates)
        {
            this.RenderingUVs.AddRange(uvCoordinates);
        }

        /// <summary>
        /// Add a UV to the list of UV coordinates.
        /// </summary>
        /// <param name="uvCoordinate">The UV coordinate to add.</param>
        public void AddUV(Vector2 uvCoordinate)
        {
            this.RenderingUVs.Add(uvCoordinate);
        }

        /// <summary>
        /// Add an array of vertices into the lists of vertices.
        /// </summary>
        /// <param name="vertexPositions">The array of vertex positions.</param>
        /// <param name="colors">The array of vertex colors.</param>
        /// <param name="generateColliderData">Whether or not collider data should be generated.</param>
        public void AddVertices(Vector3[] vertexPositions, Color[] colors, bool generateColliderData = true)
        {
            this.RenderingVertices.AddRange(vertexPositions);
            this.RenderingColors.AddRange(colors);

            if(generateColliderData)
            {
                this.ColliderVertices.AddRange(vertexPositions);
            }
        }

        /// <summary>
        /// Add a singular vertex into the lists of vertices.
        /// </summary>
        /// <param name="vertexPosition">The position of the vertex.</param>
        /// <param name="color">The color of the vertex.</param>
        /// <param name="generateColliderData">Whether or not the vertex should be added to the collider data.</param>
        public void AddVertex(Vector3 vertexPosition, Color32 color, bool generateColliderData = true)
        {
            this.RenderingVertices.Add(vertexPosition);
            this.RenderingColors.Add(color);

            if(generateColliderData)
            {
                this.ColliderVertices.Add(vertexPosition);
            }
        }
    }
}