Unity 180 rotation for a Texture2D, or maybe flip both

Question

I could use just a little help. I am loading a png into a Texture2D, and have managed to flip it over the y axis using the following script I found. I need to flip it over the x axis now. I know a small modification should do it, but I have not managed to get the results I want.

    Texture2D FlipTexture(Texture2D original){
    Texture2D flipped = new Texture2D(original.width,original.height);

    int xN = original.width;
    int yN = original.height;

    for(int i=0;i<xN;i++){
        for(int j=0;j<yN;j++){
            flipped.SetPixel(xN-i-1, j, original.GetPixel(i,j));
        }
    }

    flipped.Apply();

    return flipped;
}

Metalloid

you mean mirror to the x-axis? – Winfredwinfrey

The image is upside down and I want it right side up. Yes mirror is another way to say it. – Metalloid

All I did was swap the xN-i-1 and j then swap i,j and it works. – Winfredwinfrey

Answer 1

say "pix" is a png,

Texture2D photo;
Color[] pix = photo.GetPixels(startAcross,0, 256,256);
// (256 is just an example size)

this ENTIRELY ROTATES a png 180 degrees

System.Array.Reverse(pix, 0, pix.Length);

this mirrors a PNG just around the upright axis

        for(int row=0;row<256;++row)
            System.Array.Reverse(pix, row*256, 256);

Ventilation

Thank you for the response. I want to flip it from upside down to right side up now. Shouldn't I be able to make a small change to the indexes of my current code to do that? – Metalloid

I do not want to turn it. It is the orientation I want, but the image is upside down. – Metalloid

Deleting my current code, and reversing the array ended up solving my problem. A 180 degree rotation was the equivalent of an x and y flip. – Metalloid

Answer 2

Texture2D FlipTexture(Texture2D original, bool upSideDown = true)
{

    Texture2D flipped = new Texture2D(original.width, original.height);

    int xN = original.width;
    int yN = original.height;


    for (int i = 0; i < xN; i++)
    {
        for (int j = 0; j < yN; j++)
        {
            if (upSideDown)
            {
                flipped.SetPixel(j, xN - i - 1, original.GetPixel(j, i));
            }
            else
            {
                flipped.SetPixel(xN - i - 1, j, original.GetPixel(i, j));
            }
        }
    }
    flipped.Apply();

    return flipped;
}

To call it:

FlipTexture(camTexture, true); //Upside down

FlipTexture(camTexture, false); //Sideways

Winfredwinfrey

That is what I did. The result was a rotation – Metalloid

Mine is not. It flips it. I tested it with an image and I know the difference between rotation and mirroring. Just copy this code and call it. Post a picture of before and after in your answer and I will show you that is is NOT rotation – Winfredwinfrey

So maybe this changes thing. I am doing this twice. Once over the x and once over the y. One seems to be undoing the other however. – Metalloid

Do it once like you should then you get an object mirrored in the y-axis. upside down. Also I did it twice. Doing it twice will only undo it and make the image look like the original image. You are probably modifying the image somewhere else. – Winfredwinfrey

Update. If you just want it to mirror upside down, use FlipTexture(camTexture, true);. If you want it to mirror sideways use FlipTexture(camTexture, false);. The reason you are seeing rotation is because you are doing FlipTexture(camTexture, true); followed by FlipTexture(camTexture, false); . So it flips the image up side down then flips it again to sideways. Just use FlipTexture(camTexture, true); for upside down and call FlipTexture(camTexture, true); again to go back to the original image. – Winfredwinfrey

Answer 3

This flips the texture upside down:

int width = texture.width;
int height = texture.height;
Texture2D snap = new Texture2D(width, height);
Color[] pixels = texture.GetPixels();
Color[] pixelsFlipped = new Color[pixels.Length];

for (int i = 0; i < height; i++)
{
    Array.Copy(pixels, i*width, pixelsFlipped, (height-i-1) * width , width);
}

snap.SetPixels(pixelsFlipped);
snap.Apply();

Armure