Thread: win checking in connect four

I am programming a game that is a rip of connect four for the GBA. The GBA isn't so fast. I'm not even done with my win-checking function and there is like a 1 sec slowdown when my program checks for a winner. If you don't know what connect four is read on, if you do, skip to the asterisks...anyway it's a game where you have a 7*6 board. There are two players, each with markers of different colors. You choose a column on the board and put your piece at the bottom of the column. If there is already a piece at the bottom you put your piece one space up from that piece. Whoever gets four of their pieces in a row horizontaly, vertically, or diagnaly first wins. I hope I did a good job of explaining...

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Anyway, my board is stored in a 1d array. Each spot has a number. Here is a picture of my board where each number is a space:

Code:

 5  6  7  8  9 10 11
12 13 14 17 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31 32
33 34 35 36 37 38 39
40 41 42 43 44 45 46

So I loop about the board checking to see if there are four of the same colored pieces in a row. This is very, very slow. I have nested loops that check for four in a row horizontaly and vertically. I have a bunch of loops that check diagonal ascending to the rightand diagonal ascending to the left. I have hit major problems checking diagonaly since every other row is a different length than any other row, so I need to have like 10 loops to check diagonaly.

Am I going about this the wrong way?

I would be very, very grateful if someone could help me.

here's my checkin function so far:

Code:

void CheckWin()
{
	//Try to find a way to avoid doing a lot of this checking as it seems slow
	
	u8 currentplayer;
	if (whosturn == 0)
		currentplayer = 32;
	if (whosturn == 1)
		currentplayer = 64;
	u16 loopy;
	u16 loopx;
	u8 inarow;
	
	//check hor wins
	inarow = 0;
	for (loopy = 0; loopy < 7; loopy++)
	{
		for (loopx = 0; loopx < 8; loopx++)
		{
			if (inarow == 4)
			{
				winner = whosturn + 1;
				break;
			}
			if (sprites[((loopy+1)*5)+loopy*2+loopx].attribute2 == currentplayer)
				inarow++;
			else
				inarow = 0;
		}
		inarow = 0;
		if (winner)
			break;
	}
	
	//check vert win
	inarow = 0;
	for (loopx = 0; loopx < 8; loopx++)
	{
		for (loopy = 0; loopy < 7; loopy++)
		{
			if (inarow == 4)
			{
				winner = whosturn + 1;
				break;
			}
			if (sprites[((loopy+1)*5)+loopy*2+loopx].attribute2 == currentplayer)
				inarow++;
			else
				inarow = 0;
		}
		inarow = 0;
		if (winner)
			break;
	}
	
	//check diag left up, right down
	//first do the diag rows 5 and 6 because they have the same lengths
	u8 current_spr;
	for (loopx = 5; loopx <= 6; loopx++)
	{
		current_spr = loopx;
		for (loopy = 1; loopy <= 6; loopy++)
		{
			if (inarow == 4)
			{
				winner = whosturn + 1;
				break;
			}
			if (sprites[current_spr].attribute2 == currentplayer)
				inarow++;
			else
				inarow = 0;
			current_spr += 8;
		}
		inarow = 0;
		if (winner)
			break;
	}
}

it only checks horizontal, vertical, and a little bit of diagonal wins.
With just this code I get a very noticable delay.