2018年11月9日，星期五，晚上終於有時間玩switch了，不過在此之前，先搞一波Unity 目前，我已經添加了一些基本功能，亮度對比度飽和度，我都是用shader完成的，目前功能很少，這個shader也很簡單，和屏幕後處理用的一毛一樣

Shader "myshaders/BSC"
{
	Properties
	{
		_MainTex ("_MainTex", 2D) = "white" {}
		_Brightness("_Brightness",Float) = 1
		_Saturation("_Saturation",Float) = 1
		_Contrast("_Contrast",Float) = 1
	}
		SubShader
		{
			Pass
			{
				ZTest Always Cull Off ZWrite Off
				CGPROGRAM
				#pragma vertex vert
				#pragma fragment frag
				#include "UnityCG.cginc"
				sampler2D _MainTex;
				half _Brightness;
				half _Saturation;
				half _Contrast;
			struct v2a
			{
				float4 vertex : POSITION;
				float2 texcoord : TEXCOORD0;
			};

			struct v2f
			{
				float2 uv : TEXCOORD0;
				float4 pos : SV_POSITION;
			};
			v2f vert (v2a v)
			{
				v2f o;
				o.pos = UnityObjectToClipPos(v.vertex);
				o.uv = v.texcoord;
				return o;
			}
			
			fixed4 frag (v2f i) : SV_Target
			{
			fixed4 renderTex = tex2D(_MainTex,i.uv);
			fixed3 finalColor = renderTex.rgb*_Brightness;
			fixed luminance = 0.2125*renderTex.r + 0.7154*renderTex.g + 0.0721*renderTex.b;
			fixed3 luminanceColor = fixed3(luminance, luminance, luminance);
			finalColor = lerp(luminanceColor, finalColor, _Saturation);
			fixed3 avgColor = fixed3(0.5, 0.5, 0.5);//這是一個對比度為零的顏色
			finalColor = lerp(avgColor, finalColor, _Contrast);//對比度
			return fixed4(finalColor, renderTex.a);
			}
			ENDCG
		}
	}
			Fallback Off
}
 

這次真正的重點在於C#部分，目前已經有開啟檔案，更改亮度飽和度對比度，滑動滾落縮放，左鍵拖拽圖片這幾個功能 在通過OpenFileDialog得到檔案路徑之後，採用WWW方法拿到texture

	 WWW www = new WWW(path);
     yield return www;
     texture = www.texture;

通過Graphics.Blit把shader處理之後的texture輸出到RenderTexture，再衝RT中讀到texture物件中

			RenderTexture Disttexture = new RenderTexture(texture.
 
width, texture.height, 0);
			Graphics.Blit(texture, Disttexture, material);
			int width = Disttexture.width;
            int height = Disttexture.height;
            Viewtexture = new Texture2D(width, height, TextureFormat.ARGB32, false);
            RenderTexture.active = Disttexture;
            Viewtexture.
 
ReadPixels(new Rect(0, 0, width, height), 0, 0);
            Viewtexture.Apply();

需要特別注意的是，不要在Asset中提前建立RT，因為無法再程式碼中修改它的大小，還有一定要初始化程式碼建立的RT，萬物皆物件。 完整的檔案載入與影象處理C#程式碼如下

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using System.Windows.Forms;
public class transmit :PostEffectsBase 
{
    public Canvas uicanvas;
    public UnityEngine.UI.Image image;
    private Texture2D texture;
    public Shader processshader;
    private Material processmat;
    private Material material
    {
        get
        {
            processmat = CheckShaderAndCreateMaterial(processshader, processmat);
            return processmat;
        }
    }
    private Texture2D Viewtexture;
    private string path;
    [Range(0.0f, 3.0f)]
    public float brightness = 1.0f;
    [Range(0.0f, 3.0f)]
    public float saturation = 1.0f;
    [Range(0.0f, 3.0f)]
    public float contrast = 1.0f;
    public Slider slider1;
    public void BscChange1()
    {
        brightness = slider1.value;
        Updateimage();
    }
    public Slider slider2;
    public void BscChange2()
    {
        saturation = slider2.value;
        Updateimage();
    }
    public Slider slider3;
    public void BscChange3()
    {
        contrast = slider3.value;
        Updateimage();
    }
    public UnityEngine.UI.Button selectfile;
    public void Selectpic()
    {
        OpenFileDialog dialog = new OpenFileDialog();
        dialog.Multiselect = false;//只能選擇一個檔案
        dialog.Title = "請選擇圖片";
        dialog.Filter = "影象檔案(*bmp;*.jpg;*.jpeg;*.png)|*bmp;*.jpg;*.jpeg;*.png";
        if (dialog.ShowDialog() == DialogResult.OK)
        {
            path = dialog.FileName;
            selectfile.gameObject.SetActive(false);
            image.color = new Color32(255, 255, 255, 255);
            StartCoroutine(Load());
        }
    }
    IEnumerator Load()
    {
        WWW www = new WWW(path);
        yield return www;
        texture = www.texture;
        image.GetComponent<RectTransform>().sizeDelta = new Vector2(texture.width, texture.height);
        Sprite sprite = Sprite.Create(texture, new Rect(0, 0, texture.width, texture.height), new Vector2(0.5f, 0.5f));
        image.sprite = sprite;
        Gamevars.textureisable = true;
        Gamevars.imagewidth = texture.width;
        Gamevars.imageheight = texture.height;

    }
    //private RenderTexture Rt;
    private void Updateimage()
    {
        if (Gamevars.textureisable)
        {
            material.SetFloat("_Brightness", brightness);
            material.SetFloat("_Saturation", saturation);
            material.SetFloat("_Contrast", contrast);
            RenderTexture Disttexture = new RenderTexture(texture.width, texture.height, 0);
            Graphics.Blit(texture, Disttexture, material);
            //Debug.Log(Disttexture == null);
            int width = Disttexture.width;
            int height = Disttexture.height;
            Viewtexture = new Texture2D(width, height, TextureFormat.ARGB32, false);
            RenderTexture.active = Disttexture;
            Viewtexture.ReadPixels(new Rect(0, 0, width, height), 0, 0);
            Viewtexture.Apply();
            image.GetComponent<RectTransform>().sizeDelta = new Vector2(Viewtexture.width, Viewtexture.height);
            Sprite sprite = Sprite.Create(Viewtexture, new Rect(0, 0, Viewtexture.width, Viewtexture.height), new Vector2(0.5f, 0.5f));//因為居中顯示所以.5f
            image.sprite = sprite;
            Refresh();
        }
    }
    private void Refresh()
    {
        image.GetComponent<RectTransform>().sizeDelta = new Vector2(Gamevars.imagewidth, Gamevars.imageheight) * Gamevars.size;
    }
}

之後便是圖片縮放，拖拽程式碼，這兩個功能並沒有對圖片本身加工，而是為了方便使用者操作

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public struct Gamevars
{//方便兩個指令碼之間傳遞，控制整個程式
    public static bool textureisable=false;//當前打開了圖片
    public static int imagewidth = 0;
    public static int imageheight = 0;
    public static float size=1;
    public static Vector2 offect=new Vector2(0,0);
}
public class gamectrl : MonoBehaviour {
    private float xx = 0;
    private float yy = 0;
    public Text size1;
    public Camera ca;
    public Image image;
    [Range(.1f, 1f)]
    public float smooth=.1f;
    private Vector2 vectormtoo;
    private float fire = 0;
    // Use this for initialization
    void Start () {
	}
	
	// Update is called once per frame
	void Update () {
        
        if (Gamevars.textureisable)
        {

            if (Input.GetAxis("Mouse ScrollWheel") != 0)
            {//這個縮放真的搞得我。。。
                Vector2 mid = new Vector2(Gamevars.imagewidth, Gamevars.imageheight) * Gamevars.size;
                Gamevars.size += Input.GetAxis("Mouse ScrollWheel") * smooth;
                Vector2 sizedelta= new Vector2(Gamevars.imagewidth, Gamevars.imageheight) * Gamevars.size;
                mid = sizedelta - mid;//用來記錄縮放量
                Vector2 originpos = new Vector2(image.transform.position.x, image.transform.position.y - sizedelta.y);
                Vector2 mousepos = Input.mousePosition;
                Vector2 mouseposinimage = mousepos - originpos;
                xx = mouseposinimage.x / sizedelta.x;
                yy = mouseposinimage.y / sizedelta.y;
                image.GetComponent<RectTransform>().sizeDelta = sizedelta;
                size1.text = ((int)(Gamevars.size * 100)).ToString() + "%";
                if (!(xx < 0 || xx > 1 || yy < 0 ||yy > 1))
                {
                    //Debug.Log(xx);
                    //Debug.Log(yy);
                   image.GetComponent<RectTransform>().Translate(new Vector3(-xx * mid.x, (1-yy)* mid.y, 0));//因為錨點在左上角
                }
            }
            if (Input.GetAxis("Fire1") != 0&&Input.mousePosition.x<=900)
            {
                
                Vector2 mousepos = Input.mousePosition;
                if (fire == 0) {
                    vectormtoo = mousepos - (Vector2)image.transform.position;
                    fire = 1;
                }
                image.transform.position = mousepos - vectormtoo;
            }
            if (fire==1&&Input.GetAxis("Fire1") == 0)
            {
                fire = 0;
            }
        }

	}
}

縮放的主要思路是：獲取圖片左下角的座標originpos，通過這個座標獲取滑鼠在圖片上的座標mouseposinimage，然後，計算放大縮小的的增減，來位移image（因為我需要的是以滑鼠為原點進行縮放，至少看起來只這樣） 需要注意的是這裡

                xx = mouseposinimage.x / sizedelta.x;
                yy = mouseposinimage.y / sizedelta.y;

我為什麼不直接

	Vector2 xy=mouseposinimage/sizedelta;

這個多方便，然而，這個xx，yy是我用來檢查滑鼠在圖片上的位置的，如果直接用Vector2/Vector2，它的精度會降低到0.1，而xx，yy是一個[0,1]的值，這個精度實在滿足不了我，如果有大佬路過這裡，希望可以順手指點我一下。 正如各位大佬所見，這個軟體還是一個半成品 ，啊不，0.1成品，後續我會新增很多功能，都是通過RT來完成，後續的文章可能要偏向shader一點了。

題外話：我目前是計科大三學生，感覺高數，線代，物理都很重要，唯一讓我不解的地方時，我大二為什麼要上電氣工程學概論這門課，現在大三還有電工實驗，一週寫一篇預習報告，一篇試驗報告，還有網上測驗，還要在實驗室站一下午，做電工實驗，唯一有點聯絡的就是有幾個觸發器。唉，這週末有幾篇論文要寫，還要寫電工，大家大三都這麼滿的嗎？