function.cpp

void in_round_turn(){
	if(!inAuto) return;
	if(!in_round) {
		if(center[1]>40 && center[2]>40) setServoDegree(-30), in_round = 1; // turn right if top center line is on the right side
		else setServoDegree(30), in_round = 2; // else turn left
	} else{ // if in round && center line points to black img
		switch(in_round){
		case 1:
			setServoDegree(-30);
			break;
		case 2:
			setServoDegree(30);
			break;
		}
		in_round = 0;
	}
}

void about_centerline(const Byte* camPtr){
	for(int line=0,x=0;line<60;line++){
		sideL[line] = 0; sideR[line] = 60; maybe_black_img_in_track = 0; black_img_in_trackL[line]=0; black_img_in_trackR[line]=0;
		if(!image[line][0]) find_sideL = 1;
		for(int i=0; i<10; i++){
			for(int j=7; j>=0; j--){
				if(((*(camPtr+line*10+i))>>j)&1==1) image[line][x++] = 1;
				else image[line][x++] = 0;

				if(x>1){
					if(image[line][x-2] && !image[line][x-1] && !image[line][x]){ // BWW
						if(maybe_black_img_in_track){
							maybe_black_img_in_track=0;
							black_img_in_trackR[line] = x-1;
						} else{
							if(!find_sideL){
								sideL[line] = x-1;
								find_sideL = 1;
							} else { // if left edge exists
								if(!image[line][x-2] && image[line][x-1] && image[line][x]){ // WBB
									maybe_black_img_in_track = 1;
									black_img_in_trackL[line] = x-1;
									sideR[line] = x-1; // find the right most edge
								}
							}
						}
					}
				}
			}
		}
		if(black_img_in_trackR[line]){ // if black img in track
			// roundabout or obstacles detected
			if(sideR[line]-sideL[line] > track_size){ // roundabout
				in_round_turn();
			} else{ //obstacle
				if(black_img_in_trackL[line]-sideL[line] > sideR[line]-black_img_in_trackR[line]){ // left road width > right
					sideR[line] = black_img_in_trackL[line];
				} else{
					sideL[line] = black_img_in_trackR[line];
				}
			}
		}
		center[line] = (sideL[line]+sideR[line])/2;
	}
	track_size = sideR[58]-sideL[58];
}