立ち絵の透明部分をトリミングする

ImageTrimmer.cs

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

namespace TSKT
{
    public class ImageTrimmer : AssetPostprocessor
    {
        static bool IsTarget(string path)
        {
            if (path.StartsWith("Assets/Resources/Dialogs"))
            {
                return true;
            }
            return false;
        }

        void OnPostprocessTexture(Texture2D texture)
        {
            if (!IsTarget(assetPath))
            {
                return;
            }
            Trim(texture);
        }

        void Trim(Texture2D texture)
        {
            var originalWidth = texture.width;
            var pixels = texture.GetPixels();
            var trimmingSize = GetTrimmingSize(pixels, originalWidth, texture.height);

            if (trimmingSize > 0)
            {
                texture.Resize(originalWidth - trimmingSize * 2, texture.height);
                var newPixels = new Color[texture.width * texture.height];
                for (int y = 0; y < texture.height; ++y)
                {
                    System.Array.Copy(pixels, trimmingSize + y * originalWidth, newPixels, y * texture.width, texture.width);
                }
                texture.SetPixels(newPixels);
            }
        }

        int GetTrimmingSize(Color[] pixels, int textureWidth, int textureHeight)
        {
            for (int x = 0; x < textureWidth / 2; ++x)
            {
                for (int y = 0; y < textureHeight; ++y)
                {
                    {
                        var color = pixels[x + y * textureWidth];
                        if (color.a != 0f)
                        {
                            return x;
                        }
                    }
                    {
                        var color = pixels[textureWidth - x - 1 + y * textureWidth];
                        if (color.a != 0f)
                        {
                            return x;
                        }
                    }
                }
            }
            return textureWidth / 2;
        }
    }
}