求圆弧圆心坐标
double x1 = position1_x; double y1 = position1_y; double x2 = position2_x; double y2 = position2_y; double dy = y2 - y1; double dx = x2 - x1; double length = sqrt(pow(dx , 2) + pow(dy , 2)); if(length > 2 * radius) { ERROR("Radius is too little : %f , l: %f", radius, length); } double alpha = angles::normalize_angle(2 * asin((length/2.0)/radius)); double theta1 = (M_PI - alpha) / 2.0; double theta2 = atan2(dy, dx); double theta3 ; if(is_clock_wise == 1) { theta3 = theta2 - theta1; } else if(is_clock_wise == 2) { theta3 = theta2 + theta1; } else { ERROR("circle clock wise error!"); } double x_c = x1 + radius * cos(theta3); double y_c = y1 + radius * sin(theta3);
已知圆弧半径和方向(顺逆时针)