void CDibView::OnL6Chaincode()
{
	BYTE dir;
	int currentI = 0;
	int currentJ = 0;
	vector<int> contourI;
	vector<int> contourJ;
	vector<int> directions;

	BEGIN_PROCESSING();
	bool first = false;
	for (int i = dwHeight - 1; i >= 0; i--) {
		for (int j = 0; j < dwWidth; j++) {
			if (lpSrc[i*w + j] == 0) {
				currentI = i;
				currentJ = j;
				contourI.push_back(currentI);
				contourJ.push_back(currentJ);
				first = true;
				dir = 7;
				break;
			}
		}
		if (first) break;
	}

	int di[8] = { 0, -1, -1, -1, 0, 1, 1, 1 };
	int dj[8] = { 1, 1, 0, -1, -1, -1, 0, 1 };

	bool stop = false;
	while (!stop) {
		if (dir % 2 == 0) {
			dir = (dir + 7) % 8;
		}
		else {
			dir = (dir + 6) % 8;
		}

		for (int i = 0; i < 8; i++) {
			int newDir = (dir + i) % 8;
			if (lpSrc[(currentI + di[newDir])*w + currentJ + dj[newDir]] == 0) {
				directions.push_back(newDir);
				if (contourI.size() > 2
					&& currentI == contourI.front() && currentJ == contourJ.front()
					&& currentI + di[newDir] == contourI[1] && currentJ + dj[newDir] == contourJ[1]) {
					stop = true;
					break;
				}
				currentI += di[newDir];
				currentJ += dj[newDir];
				contourI.push_back(currentI);
				contourJ.push_back(currentJ);
				dir = newDir;
				break;
			}
		}
	}

	int initialI = contourI[0];
	int initialJ = contourJ[0];
	for (int direction : directions) {
		initialI += di[direction];
		initialJ += dj[direction];
		lpDst[initialI*w + initialJ] = 1;
	}

	bmiColorsDst[1].rgbBlue = rand() % 256;
	bmiColorsDst[1].rgbGreen = rand() % 256;
	bmiColorsDst[1].rgbRed = rand() % 256;
	END_PROCESSING("Border trancing");
}