/**
* @brief Changes the direction of the movement vector, keeping the same speed.
*
* x_speed and y_speed are recomputed so that the total speed is unchanged.
* Warning: if x_speed and y_speed are both equal to zero, this function
* stops the program on an error message.
*
* @param angle the new movement direction in radians
*/
void StraightMovement::set_angle(double angle) {
if (!is_stopped()) {
double speed = get_speed();
set_x_speed(speed * std::cos(angle));
set_y_speed(-speed * std::sin(angle));
}
this->angle = angle;
notify_movement_changed();
}
/**
* @brief Sets the speed to zero.
*/
void StraightMovement::stop() {
double old_angle = this->angle;
set_x_speed(0);
set_y_speed(0);
x_move = 0;
y_move = 0;
this->angle = old_angle;
notify_movement_changed();
}
/**
* @brief Sets the speed to zero.
*/
void StraightMovement::stop() {
double old_angle = this->angle;
set_x_speed(0);
set_y_speed(0);
x_move = 0;
y_move = 0;
this->angle = old_angle;
if (get_entity() != NULL) {
get_entity()->notify_movement_changed();
}
}
/**
* @brief Changes the speed, keeping the same direction of the movement.
*
* x_speed and y_speed are recomputed so that the movement direction is unchanged.
*
* @param speed the new speed
*/
void StraightMovement::set_speed(double speed) {
if (x_speed == 0 && y_speed == 0) {
x_speed = 1;
}
// compute the new speed vector
double old_angle = this->angle;
set_x_speed(speed * std::cos(old_angle));
set_y_speed(-speed * std::sin(old_angle));
this->angle = old_angle;
notify_movement_changed();
}
