Creating new Texture2D, size

I am creating a function that inverts black/white pictures pixels from either black to white, or white to black. In a slightly different piece of working code, I can convert white pixels to a color generated by perlin noise.

In this instance however, I am getting an error that the dimension of newTex is 0x0. I thought however, that I had created the texture with a width and height value. The line producing an error is line 27. mapPixels is declared on line 7, while newTex is defined on line 9.

The error report reads -
Texture '' is degenerate (dimensions 0x0)
UnityEngine.Texture2D:SetPixels(Color[])

Spoiler: InvertPixelColors()

Code (CSharp):

1.  public void InvertPixelColors()
2.     {
3.         int wid = pf.totalPixelsSquared;
4.         int hei = wid;
5.  
6.         Texture2D mapTex = (Texture2D)pixelMask.GetComponent<Renderer>().material.mainTexture;
7.         Texture2D newTex = new Texture2D(wid, hei);
8.  
9.         Color[] mapPixels = new Color[wid * hei];
10.  
11.         for (int h = 0; h < hei; h++)
12.         {
13.             for (int w = 0; w < wid; w++)
14.             {
15.                 Color pixColor = mapTex.GetPixel(w, h);
16.                 if (IsWhite(pixColor))
17.                 {
18.                     mapPixels[w * h] = new Color(0, 0, 0);
19.                 }
20.                 else
21.                 {
22.                     mapPixels[w * h] = new Color(1, 1, 1);
23.                 }
24.             }
25.         }
26.  
27.         newTex.SetPixels(mapPixels);
28.         mapTex = newTex;
29.         mapTex.Apply();
30.     }

I would appriciate any feedback, I can't see what's going wrong here. Thank you.

 

By changing Texture2D newTex = new Texture2D(wid, hei); to Texture2D newTex = mapTex; the error is resolved. However, now I have an issue, where the mapPixels array length is 0.

Could anyone enlighten me on why the mapPixels array has this length? I am trying to give it the length of wid * hei.

Thanks.

 

I have resolved the problem. I was calling the function at the wrong time. The function works when it is called at a particular point in the procedure I am making.

 

I met the same problem ，How did you solve it？mapTex mean what？

 

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