private void button3_Click(object sender, EventArgs e)
{
//convert button
Bitmap border = (Bitmap)Bitmap.FromFile(textBox2.Text);
Bitmap main = (Bitmap)Bitmap.FromFile(textBox1.Text);
int u = (int)numericUpDown1.Value;
border = border.ClearCenter(u);
pictureBox1.Image = main;
pictureBox2.Image = border;
Bitmap s0 = main;
Bitmap s1 = main.AddToTop(border);
//missing one side border
Bitmap s2 = main.AddToTop(border.RemoveBorder(u)); // missing bot
Bitmap s3 = s2.rotate(); // missing left
Bitmap s4 = s3.rotate(); // missing top
Bitmap s5 = s4.rotate(); // missing right
//missing two adjacent sides
Bitmap s6 = main.AddToTop(border.RemoveBorder(u).rotate().RemoveBorder(u));
Bitmap s7 = s6.rotate();
Bitmap s8 = s7.rotate();
Bitmap s9 = s8.rotate();
//missing two adjacent sides and a corner
Bitmap s17 = main.AddToTop(border.RemoveBorder(u).rotate().RemoveBorder(u).RemoveCorner(u));
Bitmap s18 = s17.rotate();
Bitmap s19 = s18.rotate();
Bitmap s20 = s19.rotate();
//missing two opposite sides
Bitmap s10 = main.AddToTop(border.RemoveBorder(u).rotate().rotate().RemoveBorder(u));
Bitmap s11 = s10.rotate();
//missing three adjacent sides
Bitmap s12 = main.AddToTop(border.RemoveBorder(u).rotate().RemoveBorder(u).rotate().RemoveBorder(u));
Bitmap s13 = s12.rotate();
Bitmap s14 = s13.rotate();
Bitmap s15 = s14.rotate();
//missing three adjacent sides and a corner
Bitmap s21 = main.AddToTop(border.RemoveBorder(u).rotate().RemoveBorder(u).rotate().RemoveBorder(u).RemoveCorner(u));
Bitmap s22 = s21.rotate();
Bitmap s23 = s22.rotate();
Bitmap s24 = s23.rotate();
//missing three adjacent sides and the other corner
Bitmap s25 = main.AddToTop(border.RemoveBorder(u).rotate().RemoveBorder(u).rotate().RemoveBorder(u).rotate().rotate().rotate().RemoveCorner(u).rotate());
Bitmap s26 = s25.rotate();
Bitmap s27 = s26.rotate();
Bitmap s28 = s27.rotate();
//missing three adjacent sides and both corners
Bitmap s29 = main.AddToTop(border.RemoveBorder(u).rotate().RemoveBorder(u).rotate().RemoveBorder(u).RemoveCorner(u).rotate().rotate().rotate().RemoveCorner(u).rotate());
Bitmap s30 = s29.rotate();
Bitmap s31 = s30.rotate();
Bitmap s32 = s31.rotate();
//missing all sides
Bitmap s16 = main.AddToTop(border.RemoveBorder(u).rotate().RemoveBorder(u).rotate().RemoveBorder(u).rotate().RemoveBorder(u));
//missing all sides and a corner
Bitmap s33 = main.AddToTop(border.RemoveBorder(u).rotate().RemoveBorder(u).rotate().RemoveBorder(u).rotate().RemoveBorder(u).RemoveCorner(u));
Bitmap s34 = s33.rotate();
Bitmap s35 = s34.rotate();
Bitmap s36 = s35.rotate();
//missing all sides and two corners
Bitmap s37 = main.AddToTop(border.RemoveBorder(u).rotate().RemoveBorder(u).rotate().RemoveBorder(u).rotate().RemoveBorder(u).RemoveCorner(u).rotate().RemoveCorner(u).rotate().rotate().rotate());
Bitmap s38 = s37.rotate();
Bitmap s39 = s38.rotate();
Bitmap s40 = s39.rotate();
//missing all sides and three corners
Bitmap s41 = main.AddToTop(border.RemoveBorder(u).rotate().RemoveBorder(u).rotate().RemoveBorder(u).rotate().RemoveBorder(u).RemoveCorner(u).rotate().RemoveCorner(u).rotate().RemoveCorner(u).rotate().rotate());
Bitmap s42 = s41.rotate();
Bitmap s43 = s42.rotate();
Bitmap s44 = s43.rotate();
//saving
string name = textBox3.Text;
save(s0, $"{name}_0");
save(s1, $"{name}_1");
save(s2, $"{name}_2");
save(s3, $"{name}_3");
save(s4, $"{name}_4");
save(s5, $"{name}_5");
save(s6, $"{name}_6");
save(s7, $"{name}_7");
save(s8, $"{name}_8");
save(s9, $"{name}_9");
save(s10, $"{name}_10");
save(s11, $"{name}_11");
save(s12, $"{name}_12");
save(s13, $"{name}_13");
save(s14, $"{name}_14");
save(s15, $"{name}_15");
save(s16, $"{name}_16");
save(s17, $"{name}_17");
save(s18, $"{name}_18");
save(s19, $"{name}_19");
save(s20, $"{name}_20");
save(s21, $"{name}_21");
save(s22, $"{name}_22");
save(s23, $"{name}_23");
save(s24, $"{name}_24");
save(s25, $"{name}_25");
save(s26, $"{name}_26");
save(s27, $"{name}_27");
save(s28, $"{name}_28");
save(s29, $"{name}_29");
save(s30, $"{name}_30");
save(s31, $"{name}_31");
save(s32, $"{name}_32");
save(s33, $"{name}_33");
save(s34, $"{name}_34");
save(s35, $"{name}_35");
save(s36, $"{name}_36");
save(s37, $"{name}_37");
save(s38, $"{name}_38");
save(s39, $"{name}_39");
save(s40, $"{name}_40");
save(s41, $"{name}_41");
save(s42, $"{name}_42");
save(s43, $"{name}_43");
save(s44, $"{name}_44");
}