I'm writing a tetris clone, and I have sprites (of every possible piece and rotation) loaded through the XNA content pipeline. For example, I have assets "i", "i2", "i3", and "i4" for each rotation of the 4-block-long I-tetrimino. For the O-tetrimino, I only have asset "o", because the O-tetrimino doesn't require any rotations.
I want to load each of these assets into a 2D array of Texture2Ds. Here's my attempt:
1 Texture2D[,] tetriminoTextures = new Texture2D[7, 4];
2 char[] tetriminos = { 'o', 'i', 'l', 'j', 'z', 's', 't' };
3 string t;
4
5 for (int i = 0; i < 7; i++)
6 {
7 for (int j = 1; i <= 4; i++)
8 {
9 if (i == 0 || j == 1) // If char[i] == 'o', then don't consider rotations.
10 // The square piece doesn't have rotations.
11 // If j == 1, then leave the asset name as is.
12 t = letters[i].ToString();
13 else // (i != 0 && j <= 2 && j <= 4)
14 t = letters[i].ToString() + j;
15 tetriminoTextures[i, j-1] = Content.Load<Texture2D>(t);
16 }
17 }
However, when I attempt to
spriteBatch.Draw(tetriminoTextures[x, y], /* some position vector */, Color.White);
I get an ArgumentNullException. Apparently tetriminoTextures[x, y] is null when y >= 1 && y <= 3.
I have no idea what's going on. I think it may have something to do with my concatenating a string and an int together in line 14. But I'm getting an ArgumentNullException even when i == 0 && j >= 2 && j <= 4 (i.e. for each rotation of the O-tetrimino excluding the first one), though the if statement in line 9 should have caught these cases. Any help would be appreciated!
