Question

Say each pixel in this picture(fig 1) is an element in an array. How would I rotate it 90 degress counter-clockwise(fig 2) and invert it vertically(fig 3)?

figure 1:

figure 2:

figure 3:

My current codes are:

private static Color[][] invert(Color[][] chunk){ //same as rotate
    Color[] temp;
    for(int i=0;i<chunk.length/2;i++){ //reverse the data
        temp=chunk[i];
        chunk[i]=chunk[chunk.length-i-1];
        chunk[chunk.length-i-1]=temp;
    }
    return chunk;
}

private static Color[][] rotate(Color[][] chunk){
    int cx = chunk.length;
    int cz = chunk[0].length;
    Color[][] rotated = new Color[cz][cx];
    for(int x=0;x<cx;++x){
        for(int z=0;z<cz;++z){
            rotated[z][x]=chunk[cz-z-1][x];
        }
    }
    return rotated;
}

The invert does the same function as the rotate though. Any help?

Answer 1

seems like you are trying to transpose the array (fig3 = transpose(fig1)).

use a double for loop and save in the entry [i][j] the value of [j][i].

see LINK for more information on the matrix transpose…

so all in all, you can use transpose to get fig3 and afterwards invert to get fig2.