贴图处理

/************************************************************************
* @brief  ：TextureExtra.
*  
* @author  ：DYY
* @copyright :
* 
* @date  :
************************************************************************/
using UnityEngine;
using System.Collections;

public static class TextureExtra
{
    public static Texture2D toNormalMap(this Texture2D source, float strength = 1.0f)
    {
        strength = Mathf.Clamp(strength, 0.0f, 1.0f);

        Texture2D newTex = new Texture2D(source.width, source.height, TextureFormat.ARGB32, true);
        float xLeft;
        float xRight;
        float yUp;
        float yDown;
        float yDelta;
        float xDelta;

        for (int y = 0; y < source.height; ++y)
        {
            for (int x = 0; x < source.width; ++x)
            {
                xLeft = source.GetPixel(x - 1, y).grayscale * strength;
                xRight = source.GetPixel(x + 1, y).grayscale * strength;
                yUp = source.GetPixel(x, y - 1).grayscale * strength;
                yDown = source.GetPixel(x, y + 1).grayscale * strength;
                xDelta = ((xLeft - xRight) + 1) * 0.5f;
                yDelta = ((yUp - yDown) + 1) * 0.5f;
                newTex.SetPixel(x, y, new Color(xDelta, yDelta, 1.0f, yDelta));
            }
        }
        newTex.Apply();

        return newTex;
    }
}