fn connect_contour_segments(mut segments: Vec<Deque2>) -> Vec<Deque2> {
  let mut contour_lines = vec![];

  'outer: loop {
    // grab random segment
    match segments.pop() {
      None => break 'outer,
      Some(mut line) => {
        'inner: loop {
          // find segments that join at the head of the line.
          // if we find a point that matches, we must take the other point from the segment, so
          // we continue to build a line moving forwards with no duplicate points.
          let cloned_segments = segments.clone();
          let mut head_segments: Vec<(usize, &Deque2)> = cloned_segments
            .iter()
            .enumerate()
            .filter(|(_i, seg)| {
              is_near(line.back().unwrap(), &seg[0]) || is_near(line.back().unwrap(), &seg[1])
            })
            .collect();
          let no_head_segments = head_segments.is_empty();
          match head_segments.pop() {
            None => (),
            Some((index, new_seg)) => {
              if is_near(&new_seg[0], line.back().unwrap()) {
                line.push_back(new_seg[1]);
              } else {
                line.push_back(new_seg[0]);
              }
              segments.remove(index);
            }
          }

          // find segments that join at the tail of the line
          // if we find a point that matches, we must take the other point from the segment
          // and insert it at the beginning of the line
          let cloned_segments = segments.clone();
          let mut tail_segments: Vec<(usize, &Deque2)> = cloned_segments
            .iter()
            .enumerate()
            .filter(|(_i, seg)| is_near(&line[0], &seg[0]) || is_near(&line[0], &seg[1]))
            .collect();
          let no_tail_segments = tail_segments.is_empty();
          match tail_segments.pop() {
            None => (),
            Some((index, new_seg)) => {
              if is_near(&new_seg[0], &line[0]) {
                line.push_front(new_seg[1]);
              } else {
                line.push_front(new_seg[0]);
              }
              segments.remove(index);
            }
          }

          // when no matching segments were found, push the line and start again!
          // Otherwise, iterate
          if no_head_segments && no_tail_segments {
            contour_lines.push(line);
            break 'inner;
          }
        }
      }
    }
  }

  contour_lines
}
/// Kind of a tricky thing, building contiguous lines from a collection of segments!
/// This algorithm takes a mutable collection of segments, and iteratively builds
/// contiguous contour lines by
/// 1. popping a random segment from the stack
/// 2. finding all segments that could connect to the "head" of the line
/// 3. finding all segments that could connect to the "end" of the line
/// 4. concatenating the relevant points to the line
/// 5. breaking once no head or tail points are found.
Kind of a tricky thing, building contiguous lines from a collection of segments.
This algorithm takes a mutable collection of segments, and iteratively builds
contiguous contour lines by
1. popping a random segment from the stack
2. finding all segments that could connect to the "head" of the line
3. finding all segments that could connect to the "end" of the line
4. concatenating the relevant points to the line
5. breaking once no head or tail points are found.
Kind of a tricky thing building contiguous lines from a collection of segments . This algorithm takes a mutable collection of segments and iteratively builds contiguous contour lines by 1 . popping a random segment from the stack 2 . finding all segments that could connect to the " head " of the line 3 . finding all segments that could connect to the " end " of the line 4 . concatenating the relevant points to the line 5 . breaking once no head or tail points are found .
fn connect_contour_segments(mut segments: Vec<Deque2>) -> Vec<Deque2> {
  let mut contour_lines = vec![];
  'outer: loop {
    // grab random segment
    match segments.pop() {
      None => break 'outer,
      Some(mut line) => {
        'inner: loop {
          // find segments that join at the head of the line.
          // if we find a point that matches, we must take the other point from the segment, so
          // we continue to build a line moving forwards with no duplicate points.
          let cloned_segments = segments.clone();
          let mut head_segments: Vec<(usize, &Deque2)> = cloned_segments
            .iter()
            .enumerate()
            .filter(|(_i, seg)| {
              is_near(line.back().unwrap(), &seg[0]) || is_near(line.back().unwrap(), &seg[1])
            })
            .collect();
          let no_head_segments = head_segments.is_empty();
          match head_segments.pop() {
            None => (),
            Some((index, new_seg)) => {
              if is_near(&new_seg[0], line.back().unwrap()) {
                line.push_back(new_seg[1]);
              } else {
                line.push_back(new_seg[0]);
              }
              segments.remove(index);
            }
          }
          // find segments that join at the tail of the line
          // if we find a point that matches, we must take the other point from the segment
          // and insert it at the beginning of the line
          let cloned_segments = segments.clone();
          let mut tail_segments: Vec<(usize, &Deque2)> = cloned_segments
            .iter()
            .enumerate()
            .filter(|(_i, seg)| is_near(&line[0], &seg[0]) || is_near(&line[0], &seg[1]))
            .collect();
          let no_tail_segments = tail_segments.is_empty();
          match tail_segments.pop() {
            None => (),
            Some((index, new_seg)) => {
              if is_near(&new_seg[0], &line[0]) {
                line.push_front(new_seg[1]);
              } else {
                line.push_front(new_seg[0]);
              }
              segments.remove(index);
            }
          }
          // when no matching segments were found, push the line and start again!
          // Otherwise, iterate
          if no_head_segments && no_tail_segments {
            contour_lines.push(line);
            break 'inner;
          }
        }
      }
    }
  }
  contour_lines
}
fn connect_contour_segments ( mut segments : Vec < Deque2 > ) -> Vec < Deque2 > { let mut contour_lines = vec ! [ ] ; ' outer : loop { // grab random segment match segments . pop ( ) { None => break ' outer , Some ( mut line ) => { ' inner : loop { // find segments that join at the head of the line. // if we find a point that matches, we must take the other point from the segment, so // we continue to build a line moving forwards with no duplicate points. let cloned_segments = segments . clone ( ) ; let mut head_segments : Vec < ( usize , & Deque2 ) > = cloned_segments . iter ( ) . enumerate ( ) . filter ( | ( _i , seg ) | { is_near ( line . back ( ) . unwrap ( ) , & seg [ 0 ] ) || is_near ( line . back ( ) . unwrap ( ) , & seg [ 1 ] ) } ) . collect ( ) ; let no_head_segments = head_segments . is_empty ( ) ; match head_segments . pop ( ) { None => ( ) , Some ( ( index , new_seg ) ) => { if is_near ( & new_seg [ 0 ] , line . back ( ) . unwrap ( ) ) { line . push_back ( new_seg [ 1 ] ) ; } else { line . push_back ( new_seg [ 0 ] ) ; } segments . remove ( index ) ; } } // find segments that join at the tail of the line // if we find a point that matches, we must take the other point from the segment // and insert it at the beginning of the line let cloned_segments = segments . clone ( ) ; let mut tail_segments : Vec < ( usize , & Deque2 ) > = cloned_segments . iter ( ) . enumerate ( ) . filter ( | ( _i , seg ) | is_near ( & line [ 0 ] , & seg [ 0 ] ) || is_near ( & line [ 0 ] , & seg [ 1 ] ) ) . collect ( ) ; let no_tail_segments = tail_segments . is_empty ( ) ; match tail_segments . pop ( ) { None => ( ) , Some ( ( index , new_seg ) ) => { if is_near ( & new_seg [ 0 ] , & line [ 0 ] ) { line . push_front ( new_seg [ 1 ] ) ; } else { line . push_front ( new_seg [ 0 ] ) ; } segments . remove ( index ) ; } } // when no matching segments were found, push the line and start again! // Otherwise, iterate if no_head_segments && no_tail_segments { contour_lines . push ( line ) ; break ' inner ; } } } } } contour_lines }
Kind of a tricky thing, building contiguous lines from a collection of segments!
Kind of a tricky thing building contiguous lines from a collection of segments!
segments
Vec<Deque2>