/*
 * The MIT License
 *
 * Copyright (c) 2007 MIT 6.270 Robotics Competition
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 */ 

#include <joyos.h>
#include <math.h>

#define GYRO_PORT 11

#define MOTOR_LEFT 0 
#define MOTOR_RIGHT 1
#define VELOCITY 150
#define MOTOR_MAX_VEL 220
#define MOTOR_MIN_VEL 80

int16_t motor_left_vel, motor_right_vel;

int sign(float number) {

	if(number > 0)
		return 1;
	else if(number < 0)
		return -1;
	else 
		return 0;

}

//bound velocity by MAX_VEL and MIN_VEL
int16_t limitVelocity(int16_t velocity) {

	int16_t speed = abs(velocity);
	
	if(speed > MOTOR_MAX_VEL) 
		return velocity * sign(velocity);
	else if (speed < MOTOR_MIN_VEL)
		return -velocity * sign(velocity);
	else
		return velocity;

}

void setVelocity(int left, int right) {

	motor_set_vel(MOTOR_LEFT, limitVelocity(left));
	motor_set_vel(MOTOR_RIGHT, limitVelocity(right));

}

float testFactor() {

	return 100.0 / frob_read_range(1, 1000);

}

void moveStraight(float desired_heading) {

	motor_left_vel = VELOCITY;
	motor_right_vel = VELOCITY;
	
	while(1) {	
		float delta_heading = desired_heading - gyro_get_degrees();
		
		motor_left_vel = VELOCITY - delta_heading * testFactor();
		motor_right_vel = VELOCITY + delta_heading * testFactor();
		setVelocity(motor_left_vel, motor_right_vel);		
	}

}


int umain (void) {

	moveStraight(gyro_get_degrees());		
	
	return 0;	
}

void usetup (void) {
	
	printf("\n Place robot. Press go to calibrate.");
	go_click();
	pause(500);
	gyro_init(GYRO_PORT, 1400000 , 800L);
	
}