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/**
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 * Copyright (c) 2011 Colony Project
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 * 
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 * Permission is hereby granted, free of charge, to any person
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 * obtaining a copy of this software and associated documentation
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 * files (the "Software"), to deal in the Software without
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 * restriction, including without limitation the rights to use,
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 * copy, modify, merge, publish, distribute, sublicense, and/or sell
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 * copies of the Software, and to permit persons to whom the
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 * Software is furnished to do so, subject to the following
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 * conditions:
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 * 
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 * The above copyright notice and this permission notice shall be
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 * included in all copies or substantial portions of the Software.
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 * 
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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 * OTHER DEALINGS IN THE SOFTWARE.
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 */
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#include "smart_runaround.h"
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using namespace std;
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// want to have a minimal working thing, use a big enough 
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// static array and start in the middle
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// we assume we are facing right, that affects where we store
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// wall information
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// -1 for wall, 0 for unseen, 1 for traveled, 2 for critical
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#define WALL -1
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#define UNSEEN 0
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#define SEEN 1
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#define CRITICAL 2
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// facings on map, NOT on robot
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#define UP 0
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#define RIGHT 1
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#define DOWN 2
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#define LEFT 3
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// number of pixels on one row/column of map block
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#define BLOCK_LENGTH 13
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// robot control variables
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#define BASESPEED 50
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// robots row and column on map, starting at center
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int row = MAP_LENGTH/2+1; // add 1 because we know MAP_LENGTH is odd
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int col = MAP_LENGTH/2+1;
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// utility functions
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// pixels to meters
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float pix_to_m(int pixels)
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{
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    return pixels/200.0;
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}
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// meters to pixels
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int m_to_idx(float meters)
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{
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    float pixels = meters*200.0;
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    float idx = pixels/BLOCK_LENGTH;
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    return floor(idx+0.5);
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}
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/* return a direction (if any) where adjacent block
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 * is labeled "info" on map. Searches clockwise
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 * starting at up. Returns -1 if no direction valid.
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 */
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int smart_runaround::choose_direc(int row, int col, int info)
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{
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    if (map[row-1][col] == info)
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        return UP;
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    else if (map[row][col+1] == info)
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        return RIGHT;
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    else if (map[row+1][col] == info)
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        return DOWN;
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    else if (map[row][col-1] == info)
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        return LEFT;
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    return -1;
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}
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// TODO This is bad! It's defined globally across all behaviors. Please fix this. -Alex
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Duration sonar_update_time2(1.5);
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// THIS VERSION MODIFIED BY ZANE
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void smart_runaround::run(){
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    ROS_INFO("Starting to solve the maze");
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    // Go up to the first line.
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    //follow_line();
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    // Turn the sonar on.
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    sonar->set_on();
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    sonar->set_range(0, 23);
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    // initialize map to all UNSEEN
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    for(int r = 0; r < MAP_LENGTH; r++) {
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        for(int c = 0; c < MAP_LENGTH; c++)
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            map[r][c] = UNSEEN;
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    }
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    // Wait for the sonar to initialize.
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    while(!look_around(25, 25, RIGHT) && ok())
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    {
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      spinOnce();
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    }
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    /* Assumptions:
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     * Grid has a fixed size
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     * Start location unknown
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     * When robot moves forward, it moves to exact center
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     * of the block in front.
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     */
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    int dir = RIGHT; // current direction
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    int new_dir = RIGHT; // direction in which to turn after a scan
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    bool success = false; // true when maze solved
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    while(ok())
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    {
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        // Look left, right, and forward
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        look_around(row, col, dir);
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        // Try moving in each direction
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        new_dir = choose_direc(row, col, UNSEEN);
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        if(new_dir < 0)
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            new_dir = choose_direc(row, col, SEEN);
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        if(new_dir >= 0) {
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            turn_from_to(dir, new_dir);
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            dir = new_dir;
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        }
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    }
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    // Check and report final condition.
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    if (success)
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        ROS_INFO("YAY! I have solved the maze");
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    else
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        ROS_INFO("NO! The maze is unsolvable");
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}
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// NOT CURRENTLY USED!!!
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bool smart_runaround::solve(int row, int col, int dir)
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{
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    int initial_dir = dir;
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    ROS_INFO("I am at direction %d", dir);
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    // use backtracking to solve the maze
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    if (at_destination())
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        return true;
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    // Wait for sonar to update.
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    sonar_update_time2.sleep();
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    // this function should fill the adjacent cells around me with
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    // wall's or paths
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    while(!look_around(row, col, dir) && ok())
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    {
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        spinOnce();
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    }
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    /* try go up */
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    if (map[row-1][col] != WALL && initial_dir != UP)
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    {
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    ROS_INFO("GOING UP!");
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        // Turn up.
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        turn_from_to(dir, UP);
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        follow_line();
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        // Solve recursively.
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        bool solved = solve(row-1, col, DOWN);
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        if (solved)
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        {
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            return solved;
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        }
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        else
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        {
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            //Update where we are.
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            dir = UP;
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        }
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    }
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    /* try right */
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    if (map[row][col+1] != WALL && initial_dir != RIGHT)
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    {
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    ROS_INFO("GOING RIGHT!");
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        // Turn right.
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        turn_from_to(dir, RIGHT);
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        follow_line();
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        // Solve recursively.
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        bool solved = solve(row, col+1, LEFT);
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        if (solved)
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        {
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            return solved;
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        }
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        else
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        {
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            //Update where we are.
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            dir = RIGHT;
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        }
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    }
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    /* try down */
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    if (map[row+1][col] != WALL && initial_dir != DOWN)
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    {
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    ROS_INFO("GOING DOWN!");
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        // Turn down.
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        turn_from_to(dir, DOWN);
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        follow_line();
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        // Solve recursively.
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        bool solved = solve(row+1, col, UP);
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        if (solved)
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        {
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            return solved;
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        }
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        else
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        {
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            //Update where we are.
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            dir = DOWN;
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        }
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    }
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    /* try left */
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    if (map[row][col-1] != WALL && initial_dir != LEFT)
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    {
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    ROS_INFO("GOING LEFT!");
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        // Turn down.
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        turn_from_to(dir, LEFT);
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        follow_line();
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        // Solve recursively.
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        bool solved = solve(row, col-1, RIGHT);
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        if (solved)
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        {
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            return solved;
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        }
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        else
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        {
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            //Update where we are.
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            dir = LEFT;
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        }
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    }
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    ROS_INFO("DEAD END FOUND, TURNING BACK.");
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    // we have exhausted all the options. This path is clearly a
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    // dead end. go back to where we come from and return false.
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    turn_from_to(dir, initial_dir);
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    follow_line();
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    return false;
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}
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/* this function takes in the current direction,
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 * and turns the scout to the intended direction
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 */
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void smart_runaround::turn_from_to(int current_dir, int intended_dir) {
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    switch ((4 + intended_dir - current_dir) % 4) // TODO: Try without "4 +" at start
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    {
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        case 0:
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            turn_straight(intended_dir);
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            break;
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        case 1:
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            turn_right();
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            break;
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        case 2:
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            spot_turn();
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            break;
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        case 3:
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            turn_left();
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            break;
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    }
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}
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bool smart_runaround::look_around(int row, int col, int dir)
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{
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    // look around current place using sonar
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    // store whether or not
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    // there is a wall into the map
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    // stores at row col 2 if point is critical, 1 otherwise
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    int* readings = sonar->get_sonar_readings();
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    spinOnce();
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    // Assumption: readings are given in millimeters - Zane
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    // distances with respect to robot, NOT map
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    // Look to the left.
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    float left_distance = readings[0]/1000.0;
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    int left_idx = m_to_idx(left_distance);
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    // Look to the front.
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    float front_distance = readings[36]/1000.0;
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    int front_idx = m_to_idx(front_distance);
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    // Look to the right.
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    float right_distance = readings[24]/1000.0;
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    int right_idx = m_to_idx(right_distance);
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    ROS_INFO("front: %d  left: %d  right: %d", front_distance, left_distance, right_distance);
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    if (right_distance == 0 || front_distance == 0 || left_distance == 0)
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      return false;
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    // determine relative distances on map, based on robot position
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    int up_d, right_d, down_d, left_d;
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    // determine upward distance
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    switch (dir)
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    {
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        case UP:
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            up_d = front_idx;
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            right_d = right_idx;
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            down_d = 0; // unknown
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            left_d = left_idx;
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            break;
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        case RIGHT:
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            up_d = left_idx;
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            right_d = front_idx;
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            down_d = right_idx;
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            left_d = 0; // unknown
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            break;
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        case DOWN:
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            up_d = 0; // unknown
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            right_d = left_idx;
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            down_d = front_idx;
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            left_d = right_idx;
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            break;
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        case LEFT:
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            up_d = right_idx;
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            right_d = 0; // unknown
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            down_d = left_idx;
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            left_d = front_idx;
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            break;
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    }
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    // change map until wall index, or until reading < 500
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    // reading < 500 <=> left_idx < 8 (approx.)
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    // map blocks above robot (on map)
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    for(int u = 0; u < 8; u++)
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    {
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        if(u = up_d) {
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            map[row-u][col] = (up_d)?WALL:SEEN;
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            break;
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        }
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        map[row-u][col] = SEEN;
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    }
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    // map blocks to right of robot
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    for(int r = 0; r < 8; r++)
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    {
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        if(r = right_d) {
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            map[row][col+r] = (right_d)?WALL:SEEN;
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            break;
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        }
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        map[row][col+r] = SEEN;
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    }
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    // map blocks under robot (on map)
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    for(int d = 0; d < 8; d++)
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    {
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        if(d = down_d) {
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            map[row+d][col] = (down_d)?WALL:SEEN;
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            break;
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        }
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        map[row+d][col] = SEEN;
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    }
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    // map blocks to left of robot
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    for(int l = 0; l < 8; l++)
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    {
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        if(l = left_d) {
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            map[row][col-l] = (left_d)?WALL:SEEN;
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            break;
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        }
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        map[row][col-l] = SEEN;
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    }
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    return true;
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}
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// TODO: test this function
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// return true iff the map has been completely explored
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// and only true if it "returned" to home destination after solving
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bool smart_runaround::at_destination() 
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{
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    // check whether there is a square portion with
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    // only SEEN or WALL blocks, of the size of the map.
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    int start_row = -1;
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    int start_col = -1;
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    int seen_width = 0;
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    int seen_height = 0;
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    for(int r = 0; r < MAP_LENGTH; r++) {
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        for(int c = 0; c < MAP_LENGTH; c++) {
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            if(map[r][c] == UNSEEN) {
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                start_row = -1;
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                start_col = -1;
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                seen_width = 0;
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                seen_height = 0;
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            }
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            else {
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                start_row = r;
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                start_col = c;
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                seen_width++;
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                seen_height++;
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            }
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            if(seen_width >= 15)
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                return true;
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        }
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    }
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    return false;
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}
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// TODO: test these functions to make sure robot moves well
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// move forward one block in direction "dir"
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void smart_runaround::turn_straight(int dir)
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{
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    // TODO: try to use motor encoder values to move forward enough
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    motors->set_sides(BASESPEED, BASESPEED, MOTOR_ABSOLUTE);
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    spinOnce();
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    Duration moveTime(1.0);
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    moveTime.sleep();
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    // update robot's position on map
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    switch(dir)
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    {
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        case UP:
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          row--;
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          break;
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        case RIGHT:
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          col++;
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          break;
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        case DOWN:
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          row++;
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          break;
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        case LEFT:
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          col--;
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          break;
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    }
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}
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// turn clockwise (right)
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void smart_runaround::turn_right()
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{
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    motors->set_sides(BASESPEED, -BASESPEED, MOTOR_ABSOLUTE);
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    spinOnce();
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    Duration moveTime(3.3);
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    moveTime.sleep();
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}
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// do a 180 deg turn, NOT a barrel roll
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void smart_runaround::spot_turn()
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{
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    motors->set_sides(BASESPEED, -BASESPEED, MOTOR_ABSOLUTE);
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    spinOnce();
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    Duration moveTime(6.6);
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    moveTime.sleep();
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}
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// turn counter-clockwise (left)
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void smart_runaround::turn_left()
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{
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    motors->set_sides(-BASESPEED, BASESPEED, MOTOR_ABSOLUTE);
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    spinOnce();
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    Duration moveTime(3.3);
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    moveTime.sleep();
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}