scancode-miro/node_modules/marchingsquares/src/isobands.js

/* eslint no-console: ["error", { allow: ["log"] }] */
/* eslint-env browser,node */

import {isoBandOptions} from './options.js';
import {cell2Polygons, traceBandPaths} from './polygons.js';
import {QuadTree} from './quadtree.js';


/*
 * lookup table to generate polygon paths or edges required to
 * trace the full polygon(s)
 */
var shapeCoordinates = {
  square:       function(cell, x0, x1, x2, x3, opt) {
    if (opt.polygons)
      cell.polygons.push([ [0,0], [0, 1], [1, 1], [1, 0] ]);
  },

  triangle_bl:  function(cell, x0, x1, x2, x3, opt) {
    var bottomleft = opt.interpolate(x0, x1, opt.minV, opt.maxV);
    var leftbottom = opt.interpolate(x0, x3, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.lb = {
        path: [ [0, leftbottom], [bottomleft, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tl'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, leftbottom], [bottomleft, 0], [0, 0] ]);
  },

  triangle_br:  function(cell, x0, x1, x2, x3, opt) {
    var bottomright = opt.interpolate(x0, x1, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.br = {
        path: [ [bottomright, 0], [1, rightbottom] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lb'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [bottomright, 0], [1, rightbottom], [1, 0] ]);
  },

  triangle_tr:  function(cell, x0, x1, x2, x3, opt) {
    var righttop = opt.interpolate(x1, x2, opt.minV, opt.maxV);
    var topright = opt.interpolate(x3, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.rt = {
        path: [ [1, righttop], [topright, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'br'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [1, righttop], [topright, 1], [1, 1] ]);
  },

  triangle_tl:  function(cell, x0, x1, x2, x3, opt) {
    var topleft = opt.interpolate(x3, x2, opt.minV, opt.maxV);
    var lefttop = opt.interpolate(x0, x3, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.tl = {
        path: [ [topleft, 1], [0, lefttop] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rt'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, lefttop], [0, 1], [topleft, 1] ]);
  },

  tetragon_t:   function(cell, x0, x1, x2, x3, opt) {
    var righttop  = opt.interpolate(x1, x2, opt.minV, opt.maxV);
    var lefttop   = opt.interpolate(x0, x3, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.rt = {
        path: [ [1, righttop], [0, lefttop] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rt'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, lefttop], [0, 1], [1, 1], [1, righttop] ]);
  },

  tetragon_r:   function(cell, x0, x1, x2, x3, opt) {
    var bottomright = opt.interpolate(x0, x1, opt.minV, opt.maxV);
    var topright    = opt.interpolate(x3, x2, opt.minV, opt.maxV);
    if (opt.polygons_full) {
      cell.edges.br = {
        path: [ [bottomright, 0], [topright, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'br'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [bottomright, 0], [topright, 1], [1, 1], [1, 0] ]);
  },

  tetragon_b:   function(cell, x0, x1, x2, x3, opt) {
    var leftbottom  = opt.interpolate(x0, x3, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.lb = {
        path: [ [0, leftbottom], [1, rightbottom] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lb'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, 0], [0, leftbottom], [1, rightbottom], [1, 0] ]);
  },

  tetragon_l:   function(cell, x0, x1, x2, x3, opt) {
    var topleft     = opt.interpolate(x3, x2, opt.minV, opt.maxV);
    var bottomleft  = opt.interpolate(x0, x1, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.tl = {
        path: [ [topleft, 1], [bottomleft, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tl'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, 0], [0, 1], [topleft, 1], [bottomleft, 0] ]);
  },

  tetragon_bl:  function(cell, x0, x1, x2, x3, opt) {
    var bottomleft  = opt.interpolate_a(x0, x1, opt.minV, opt.maxV);
    var bottomright = opt.interpolate_b(x0, x1, opt.minV, opt.maxV);
    var leftbottom  = opt.interpolate_a(x0, x3, opt.minV, opt.maxV);
    var lefttop     = opt.interpolate_b(x0, x3, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.bl = {
        path: [ [bottomleft, 0], [0, leftbottom] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rb'
        }
      };
      cell.edges.lt = {
        path: [ [0, lefttop], [bottomright, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tr'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [bottomleft, 0], [0, leftbottom], [0, lefttop], [bottomright, 0] ]);
  },

  tetragon_br:  function(cell, x0, x1, x2, x3, opt) {
    var bottomleft  = opt.interpolate_a(x0, x1, opt.minV, opt.maxV);
    var bottomright = opt.interpolate_b(x0, x1, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate_a(x1, x2, opt.minV, opt.maxV);
    var righttop    = opt.interpolate_b(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.bl = {
        path: [ [bottomleft, 0], [1, righttop] ],
        move: {
          x: 1,
          y: 0,
          enter: 'lt'
        }
      };
      cell.edges.rb = {
        path: [ [1, rightbottom], [bottomright, 0] ],
        move: {
          x: 0,
          y: -1,
          enter: 'tr'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [bottomleft, 0], [1, righttop], [1, rightbottom], [bottomright, 0] ]);
  },

  tetragon_tr:  function(cell, x0, x1, x2, x3, opt) {
    var topleft     = opt.interpolate_a(x3, x2, opt.minV, opt.maxV);
    var topright    = opt.interpolate_b(x3, x2, opt.minV, opt.maxV);
    var righttop    = opt.interpolate_b(x1, x2, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate_a(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.rb = {
        path: [ [1, rightbottom], [topleft, 1] ],
        move: {
          x: 0,
          y: 1,
          enter: 'bl'
        }
      };
      cell.edges.tr = {
        path: [ [topright, 1], [1, righttop] ],
        move: {
          x: 1,
          y: 0,
          enter: 'lt'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [1, rightbottom], [topleft, 1], [topright, 1], [1, righttop] ]);
  },

  tetragon_tl:  function(cell, x0, x1, x2, x3, opt) {
    var topleft     = opt.interpolate_a(x3, x2, opt.minV, opt.maxV);
    var topright    = opt.interpolate_b(x3, x2, opt.minV, opt.maxV);
    var lefttop     = opt.interpolate_b(x0, x3, opt.minV, opt.maxV);
    var leftbottom  = opt.interpolate_a(x0, x3, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.tr = {
        path: [ [topright, 1], [0, leftbottom] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rb'
        }
      };
      cell.edges.lt = {
        path: [ [0, lefttop], [topleft, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'bl'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [topright, 1], [0, leftbottom], [0, lefttop], [topleft, 1] ]);
  },

  tetragon_lr:  function(cell, x0, x1, x2, x3, opt) {
    var leftbottom  = opt.interpolate_a(x0, x3, opt.minV, opt.maxV);
    var lefttop     = opt.interpolate_b(x0, x3, opt.minV, opt.maxV);
    var righttop    = opt.interpolate_b(x1, x2, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate_a(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.lt = {
        path: [ [0, lefttop], [1, righttop] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lt'
        }
      };
      cell.edges.rb = {
        path: [ [1, rightbottom], [0, leftbottom] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rb'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, leftbottom], [0, lefttop], [1, righttop], [1, rightbottom] ]);
  },

  tetragon_tb:  function(cell, x0, x1, x2, x3, opt) {
    var topleft     = opt.interpolate_a(x3, x2, opt.minV, opt.maxV);
    var topright    = opt.interpolate_b(x3, x2, opt.minV, opt.maxV);
    var bottomright = opt.interpolate_b(x0, x1, opt.minV, opt.maxV);
    var bottomleft  = opt.interpolate_a(x0, x1, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.tr =  {
        path: [ [topright, 1], [bottomright, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tr'
        }
      };
      cell.edges.bl = {
        path: [ [bottomleft, 0], [topleft, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'bl'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [bottomleft, 0], [topleft, 1], [topright, 1], [bottomright, 0] ]);
  },

  pentagon_tr:  function(cell, x0, x1, x2, x3, opt) {
    var topleft     = opt.interpolate(x3, x2, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.tl = {
        path: [[topleft, 1], [1, rightbottom]],
        move: {
          x:      1,
          y:      0,
          enter:  'lb'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, 0], [0, 1], [topleft, 1], [1, rightbottom], [1, 0] ]);
  },

  pentagon_tl:  function(cell, x0, x1, x2, x3, opt) {
    var leftbottom  = opt.interpolate(x0, x3, opt.minV, opt.maxV);
    var topright    = opt.interpolate(x3, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.lb = {
        path: [ [0, leftbottom], [topright, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'br'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, 0], [0, leftbottom], [topright, 1], [1, 1], [1, 0] ]);
  },

  pentagon_br:  function(cell, x0, x1, x2, x3, opt) {
    var bottomleft  = opt.interpolate(x0, x1, opt.minV, opt.maxV);
    var righttop    = opt.interpolate(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.rt = {
        path: [ [1, righttop], [bottomleft, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tl'
        }
      };
    }
    if (opt.polygons)
      cell.polygons.push([ [0, 0], [0, 1], [1, 1], [1, righttop], [bottomleft, 0] ]);
  },

  pentagon_bl:  function(cell, x0, x1, x2, x3, opt) {
    var lefttop     = opt.interpolate(x0, x3, opt.minV, opt.maxV);
    var bottomright = opt.interpolate(x0, x1, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.br = {
        path: [ [bottomright, 0], [0, lefttop] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rt'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, lefttop], [0, 1], [1, 1], [1, 0], [bottomright, 0] ]);
  },

  pentagon_tr_rl: function(cell, x0, x1, x2, x3, opt) {
    var lefttop     = opt.interpolate(x0, x3, opt.minV, opt.maxV);
    var topleft     = opt.interpolate(x3, x2, opt.minV, opt.maxV);
    var righttop    = opt.interpolate_b(x1, x2, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate_a(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.tl = {
        path: [ [topleft, 1], [1, righttop] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lt'
        }
      };
      cell.edges.rb = {
        path: [ [1, rightbottom], [0, lefttop] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rt'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, lefttop], [0, 1], [topleft, 1], [1, righttop], [1, rightbottom] ]);
  },

  pentagon_rb_bt: function(cell, x0, x1, x2, x3, opt) {
    var righttop    = opt.interpolate(x1, x2, opt.minV, opt.maxV);
    var bottomright = opt.interpolate_b(x0, x1, opt.minV, opt.maxV);
    var bottomleft  = opt.interpolate_a(x0, x1, opt.minV, opt.maxV);
    var topright    = opt.interpolate(x3, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.rt = {
        path: [ [1, righttop], [bottomright, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tr'
        }
      };
      cell.edges.bl = {
        path: [ [bottomleft, 0], [topright, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'br'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [topright, 1], [1, 1], [1, righttop], [bottomright, 0], [bottomleft, 0] ]);
  },

  pentagon_bl_lr: function(cell, x0, x1, x2, x3, opt) {
    var bottomright = opt.interpolate(x0, x1, opt.minV, opt.maxV);
    var leftbottom  = opt.interpolate_a(x0, x3, opt.minV, opt.maxV);
    var lefttop     = opt.interpolate_b(x0, x3, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.br = {
        path: [ [bottomright, 0], [0, leftbottom] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rb'
        }
      };
      cell.edges.lt = {
        path: [ [0, lefttop], [1, rightbottom] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lb'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [bottomright, 0], [0, leftbottom], [0, lefttop], [1, rightbottom], [1, 0] ]);
  },

  pentagon_lt_tb: function(cell, x0, x1, x2, x3, opt) {
    var leftbottom  = opt.interpolate(x0, x3, opt.minV, opt.maxV);
    var topleft     = opt.interpolate_a(x3, x2, opt.minV, opt.maxV);
    var topright    = opt.interpolate_b(x3, x2, opt.minV, opt.maxV);
    var bottomleft  = opt.interpolate(x0, x1, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.lb = {
        path: [ [0, leftbottom], [topleft, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'bl'
        }
      };
      cell.edges.tr = {
        path: [ [topright, 1], [bottomleft, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tl'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, 0], [0, leftbottom], [topleft, 1], [topright, 1], [bottomleft, 0] ]);
  },

  pentagon_bl_tb: function(cell, x0, x1, x2, x3, opt) {
    var lefttop     = opt.interpolate(x0, x3, opt.minV, opt.maxV);
    var topleft     = opt.interpolate(x3, x2, opt.minV, opt.maxV);
    var bottomright = opt.interpolate_b(x0, x1, opt.minV, opt.maxV);
    var bottomleft  = opt.interpolate_a(x0, x1, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.bl = {
        path: [ [bottomleft, 0], [0, lefttop] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rt'
        }
      };
      cell.edges.tl = {
        path: [ [ topleft, 1], [bottomright, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tr'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, lefttop], [0, 1], [topleft, 1], [bottomright, 0], [bottomleft, 0] ]);
  },

  pentagon_lt_rl: function(cell, x0, x1, x2, x3, opt) {
    var leftbottom  = opt.interpolate_a(x0, x3, opt.minV, opt.maxV);
    var lefttop     = opt.interpolate_b(x0, x3, opt.minV, opt.maxV);
    var topright    = opt.interpolate(x3, x2, opt.minV, opt.maxV);
    var righttop    = opt.interpolate(x1, x3, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.lt = {
        path: [ [0, lefttop], [topright, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'br'
        }
      };
      cell.edges.rt = {
        path: [ [1, righttop], [0, leftbottom] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rb'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, leftbottom], [0, lefttop], [topright, 1], [1, 1], [1, righttop] ]);
  },

  pentagon_tr_bt: function(cell, x0, x1, x2, x3, opt) {
    var topleft     = opt.interpolate_a(x3, x2, opt.minV, opt.maxV);
    var topright    = opt.interpolate_b(x3, x2, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate(x1, x2, opt.minV, opt.maxV);
    var bottomright = opt.interpolate(x0, x1, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.br = {
        path: [ [bottomright, 0], [topleft, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'bl'
        }
      };
      cell.edges.tr = {
        path: [ [topright, 1], [1, rightbottom] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lb'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [topleft, 1], [topright, 1], [1, rightbottom], [1, 0], [bottomright, 0] ]);
  },

  pentagon_rb_lr: function(cell, x0, x1, x2, x3, opt) {
    var leftbottom  = opt.interpolate(x0, x3, opt.minV, opt.maxV);
    var righttop    = opt.interpolate_b(x1, x2, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate_a(x1, x2, opt.minV, opt.maxV);
    var bottomleft  = opt.interpolate(x0, x1, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.lb = {
        path: [ [0, leftbottom], [1, righttop] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lt'
        }
      };
      cell.edges.rb = {
        path: [ [1, rightbottom], [bottomleft, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tl'
        }
      };
    }
    if (opt.polygons)
      cell.polygons.push([ [0, 0], [0, leftbottom], [1, righttop], [1, rightbottom], [bottomleft, 0] ]);
  },

  hexagon_lt_tr:  function(cell, x0, x1, x2, x3, opt) {
    var leftbottom  = opt.interpolate(x0, x3, opt.minV, opt.maxV);
    var topleft     = opt.interpolate_a(x3, x2, opt.minV, opt.maxV);
    var topright    = opt.interpolate_b(x3, x2, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.lb = {
        path: [ [0, leftbottom], [topleft, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'bl'
        }
      };
      cell.edges.tr = {
        path: [ [topright, 1], [1, rightbottom] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lb'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, 0], [0, leftbottom], [topleft, 1], [topright, 1], [1, rightbottom], [1, 0] ]);
  },

  hexagon_bl_lt:  function(cell, x0, x1, x2, x3, opt) {
    var bottomright = opt.interpolate(x0, x1, opt.minV, opt.maxV);
    var leftbottom  = opt.interpolate_a(x0, x3, opt.minV, opt.maxV);
    var lefttop     = opt.interpolate_b(x0, x3, opt.minV, opt.maxV);
    var topright    = opt.interpolate(x3, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.br = {
        path: [ [bottomright, 0], [0, leftbottom] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rb'
        }
      };
      cell.edges.lt = {
        path: [ [0, lefttop], [topright, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'br'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [bottomright, 0], [0, leftbottom], [0, lefttop], [topright, 1], [1, 1], [1, 0] ]);
  },

  hexagon_bl_rb:  function(cell, x0, x1, x2, x3, opt) {
    var bottomleft  = opt.interpolate_a(x0, x1, opt.minV, opt.maxV);
    var bottomright = opt.interpolate_b(x0, x1, opt.minV, opt.maxV);
    var lefttop     = opt.interpolate(x0, x3, opt.minV, opt.maxV);
    var righttop    = opt.interpolate(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.bl = {
        path: [ [bottomleft, 0], [0, lefttop] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rt'
        }
      };
      cell.edges.rt = {
        path: [ [1, righttop], [bottomright, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tr'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [bottomleft, 0], [0, lefttop], [0, 1], [1, 1], [1, righttop], [bottomright, 0] ]);
  },

  hexagon_tr_rb:  function(cell, x0, x1, x2, x3, opt) {
    var bottomleft  = opt.interpolate(x0, x1, opt.minV, opt.maxV);
    var topleft     = opt.interpolate(x3, x2, opt.minV, opt.maxV);
    var righttop    = opt.interpolate_b(x1, x2, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate_a(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.tl = {
        path: [ [topleft, 1], [1, righttop] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lt'
        }
      };
      cell.edges.rb = {
        path: [ [1, rightbottom], [bottomleft, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tl'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, 0], [0, 1], [topleft, 1], [1, righttop], [1, rightbottom], [bottomleft, 0] ]);
  },

  hexagon_lt_rb:  function(cell, x0, x1, x2, x3, opt) {
    var leftbottom  = opt.interpolate(x0, x3, opt.minV, opt.maxV);
    var topright    = opt.interpolate(x3, x2, opt.minV, opt.maxV);
    var righttop    = opt.interpolate(x1, x2, opt.minV, opt.maxV);
    var bottomleft  = opt.interpolate(x0, x1, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.lb = {
        path: [ [0, leftbottom], [topright, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'br'
        }
      };
      cell.edges.rt = {
        path: [ [1, righttop], [bottomleft, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tl'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, 0], [0, leftbottom], [topright, 1], [1, 1], [1, righttop], [bottomleft, 0] ]);
  },

  hexagon_bl_tr:  function(cell, x0, x1, x2, x3, opt) {
    var bottomright = opt.interpolate(x0, x1, opt.minV, opt.maxV);
    var lefttop     = opt.interpolate(x0, x3, opt.minV, opt.maxV);
    var topleft     = opt.interpolate(x3, x2, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.br = {
        path: [ [bottomright, 0], [0, lefttop] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rt'
        }
      };
      cell.edges.tl = {
        path: [ [topleft, 1], [1, rightbottom] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lb'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [bottomright, 0], [0, lefttop], [0, 1], [topleft, 1], [1, rightbottom], [1, 0] ]);
  },

  heptagon_tr:    function(cell, x0, x1, x2, x3, opt) {
    var bottomleft  = opt.interpolate_a(x0, x1, opt.minV, opt.maxV);
    var bottomright = opt.interpolate_b(x0, x1, opt.minV, opt.maxV);
    var leftbottom  = opt.interpolate_a(x0, x3, opt.minV, opt.maxV);
    var lefttop     = opt.interpolate_b(x0, x3, opt.minV, opt.maxV);
    var topright    = opt.interpolate(x3, x2, opt.minV, opt.maxV);
    var righttop    = opt.interpolate(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.bl = {
        path: [ [bottomleft, 0], [0, leftbottom] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rb'
        }
      };
      cell.edges.lt = {
        path: [ [0, lefttop], [topright, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'br'
        }
      };
      cell.edges.rt = {
        path: [ [1, righttop], [bottomright, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tr'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [bottomleft, 0], [0, leftbottom], [0, lefttop], [topright, 1], [1, 1], [1, righttop], [bottomright, 0] ]);
  },

  heptagon_bl:    function(cell, x0, x1, x2, x3, opt) {
    var bottomleft  = opt.interpolate(x0, x1, opt.minV, opt.maxV);
    var leftbottom  = opt.interpolate(x0, x3, opt.minV, opt.maxV);
    var topleft     = opt.interpolate_a(x3, x2, opt.minV, opt.maxV);
    var topright    = opt.interpolate_b(x3, x2, opt.minV, opt.maxV);
    var righttop    = opt.interpolate_b(x1, x2, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate_a(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.lb = {
        path: [ [0, leftbottom], [topleft, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'bl'
        }
      };
      cell.edges.tr = {
        path: [ [topright, 1], [1, righttop] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lt'
        }
      };
      cell.edges.rb = {
        path: [ [1, rightbottom], [bottomleft, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tl'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [0, 0], [0, leftbottom], [topleft, 1], [topright, 1], [1, righttop], [1, rightbottom], [bottomleft, 0] ]);
  },

  heptagon_tl:    function(cell, x0, x1, x2, x3, opt) {
    var bottomleft  = opt.interpolate_a(x0, x1, opt.minV, opt.maxV);
    var bottomright = opt.interpolate_b(x0, x1, opt.minV, opt.maxV);
    var lefttop     = opt.interpolate(x0, x3, opt.minV, opt.maxV);
    var topleft     = opt.interpolate(x3, x2, opt.minV, opt.maxV);
    var righttop    = opt.interpolate_b(x1, x2, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate_a(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.bl = {
        path: [ [bottomleft, 0], [0, lefttop] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rt'
        }
      };
      cell.edges.tl = {
        path: [ [topleft, 1], [1, righttop] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lt'
        }
      };
      cell.edges.rb = {
        path: [ [1, rightbottom], [bottomright, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tr'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [bottomleft, 0], [0, lefttop], [0, 1], [topleft, 1], [1, righttop], [1, rightbottom], [bottomright, 0] ]);
  },

  heptagon_br:    function(cell, x0, x1, x2, x3, opt) {
    var bottomright = opt.interpolate(x0, x1, opt.minV, opt.maxV);
    var leftbottom  = opt.interpolate_a(x0, x3, opt.minV, opt.maxV);
    var lefttop     = opt.interpolate_b(x0, x3, opt.minV, opt.maxV);
    var topleft     = opt.interpolate_a(x3, x2, opt.minV, opt.maxV);
    var topright    = opt.interpolate_b(x3, x2, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.br = {
        path: [ [bottomright, 0], [0, leftbottom] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rb'
        }
      };
      cell.edges.lt = {
        path: [ [0, lefttop], [topleft, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'bl'
        }
      };
      cell.edges.tr = {
        path: [ [topright, 1], [1, rightbottom] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lb'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [bottomright,0], [0, leftbottom], [0, lefttop], [topleft, 1], [topright, 1], [1, rightbottom], [1, 0] ]);
  },

  octagon:        function(cell, x0, x1, x2, x3, opt) {
    var bottomleft  = opt.interpolate_a(x0, x1, opt.minV, opt.maxV);
    var bottomright = opt.interpolate_b(x0, x1, opt.minV, opt.maxV);
    var leftbottom  = opt.interpolate_a(x0, x3, opt.minV, opt.maxV);
    var lefttop     = opt.interpolate_b(x0, x3, opt.minV, opt.maxV);
    var topleft     = opt.interpolate_a(x3, x2, opt.minV, opt.maxV);
    var topright    = opt.interpolate_b(x3, x2, opt.minV, opt.maxV);
    var righttop    = opt.interpolate_b(x1, x2, opt.minV, opt.maxV);
    var rightbottom = opt.interpolate_a(x1, x2, opt.minV, opt.maxV);

    if (opt.polygons_full) {
      cell.edges.bl = {
        path: [ [bottomleft, 0], [0, leftbottom] ],
        move: {
          x:      -1,
          y:      0,
          enter:  'rb'
        }
      };
      cell.edges.lt = {
        path: [ [0, lefttop], [topleft, 1] ],
        move: {
          x:      0,
          y:      1,
          enter:  'bl'
        }
      };
      cell.edges.tr = {
        path: [ [topright, 1], [1, righttop] ],
        move: {
          x:      1,
          y:      0,
          enter:  'lt'
        }
      };
      cell.edges.rb = {
        path: [ [1, rightbottom], [bottomright, 0] ],
        move: {
          x:      0,
          y:      -1,
          enter:  'tr'
        }
      };
    }

    if (opt.polygons)
      cell.polygons.push([ [bottomleft, 0], [0, leftbottom], [0, lefttop], [topleft, 1], [topright, 1], [1, righttop], [1, rightbottom], [bottomright, 0] ]);
  }
};


/*
 * Compute isobands(s) for a scalar 2D field given a certain
 * threshold and a bandwidth by applying the Marching Squares
 * Algorithm. The function returns a list of path coordinates
 * either for individual polygons within each grid cell, or the
 * outline of connected polygons.
 */
function isoBands(input, minV, bandWidth, options) {
  var i,
    j,
    settings,
    useQuadTree   = false,
    tree          = null,
    root          = null,
    data          = null,
    cellGrid      = null,
    multiBand     = false,
    bw            = [],
    bandPolygons  = [],
    ret           = [];

  /* basic input validation */
  if (!input) throw new Error('data is required');
  if (minV === undefined || minV === null) throw new Error('lowerBound is required');
  if (bandWidth === undefined || bandWidth === null) throw new Error('bandWidth is required');
  if ((!!options) && (typeof options !== 'object')) throw new Error('options must be an object');

  settings = isoBandOptions(options);

  /* check for input data */
  if (input instanceof QuadTree) {
    tree = input;
    root = input.root;
    data = input.data;
    if (!settings.noQuadTree)
      useQuadTree = true;
  } else if (Array.isArray(input) && Array.isArray(input[0])) {
    data = input;
  } else {
    throw new Error('input is neither array of arrays nor object retrieved from \'QuadTree()\'');
  }

  /* check and prepare input thresholds */
  if (Array.isArray(minV)) {
    multiBand = true;

    /* activate QuadTree optimization if not explicitly forbidden by user settings */
    if (!settings.noQuadTree)
      useQuadTree = true;

    /* check if all minV are numbers */
    for (i = 0; i < minV.length; i++)
      if (isNaN(+minV[i]))
        throw new Error('lowerBound[' + i + '] is not a number');

    if (Array.isArray(bandWidth)) {
      if (minV.length !== bandWidth.length)
        throw new Error('lowerBound and bandWidth have unequal lengths');

      /* check bandwidth values */
      for (i = 0; i < bandWidth.length; i++)
        if (isNaN(+bandWidth[i]))
          throw new Error('bandWidth[' + i + '] is not a number');
    } else {
      if (isNaN(+bandWidth))
        throw new Error('bandWidth must be a number');

      bw = [];
      for (i = 0; i < minV.length; i++) {
        bw.push(bandWidth);
      }
      bandWidth = bw;
    }
  } else {
    if (isNaN(+minV))
      throw new Error('lowerBound must be a number');

    minV = [ minV ];

    if (isNaN(+bandWidth))
      throw new Error('bandWidth must be a number');

    bandWidth = [ bandWidth ];
  }

  /* create QuadTree root node if not already present */
  if ((useQuadTree) && (!root)) {
    tree = new QuadTree(data);
    root = tree.root;
    data = tree.data;
  }

  if (settings.verbose) {
    if(settings.polygons)
      console.log('MarchingSquaresJS-isoBands: returning single polygons for each grid cell');
    else
      console.log('MarchingSquaresJS-isoBands: returning polygon paths for entire data grid');

    if (multiBand)
      console.log('MarchingSquaresJS-isoBands: multiple bands requested, returning array of band polygons instead of polygons for a single band');
  }

  /* Done with all input validation, now let's start computing stuff */

  /* loop over all minV values */
  minV.forEach(function(lowerBound, b) {
    bandPolygons = [];

    /* store bounds for current computation in settings object */
    settings.minV = lowerBound;
    settings.maxV = lowerBound + bandWidth[b];

    if(settings.verbose)
      console.log('MarchingSquaresJS-isoBands: computing isobands for [' + lowerBound + ':' + (lowerBound + bandWidth[b]) + ']');

    if (settings.polygons) {
      /* compose list of polygons for each single cell */
      if (useQuadTree) {
        /* go through list of cells retrieved from QuadTree */
        root
          .cellsInBand(settings.minV, settings.maxV, true)
          .forEach(function(c) {
            bandPolygons  = bandPolygons.concat(
              cell2Polygons(
                prepareCell(data,
                  c.x,
                  c.y,
                  settings),
                c.x,
                c.y,
                settings
              ));
          });
      } else {
        /* go through entire array of input data */
        for (j = 0; j < data.length - 1; ++j) {
          for (i = 0; i < data[0].length - 1; ++i)
            bandPolygons  = bandPolygons.concat(
              cell2Polygons(
                prepareCell(data,
                  i,
                  j,
                  settings),
                i,
                j,
                settings
              ));
        }
      }
    } else {
      /* sparse grid of input data cells */
      cellGrid = [];
      for (i = 0; i < data[0].length - 1; ++i)
        cellGrid[i] = [];

      /* compose list of polygons for entire input grid */
      if (useQuadTree) {
        /* collect the cells */
        root
          .cellsInBand(settings.minV, settings.maxV, false)
          .forEach(function(c) {
            cellGrid[c.x][c.y] = prepareCell(data,
              c.x,
              c.y,
              settings);
          });
      } else {
        /* prepare cells */
        for (i = 0; i < data[0].length - 1; ++i) {
          for (j = 0; j < data.length - 1; ++j) {
            cellGrid[i][j]  = prepareCell(data,
              i,
              j,
              settings);
          }
        }
      }

      bandPolygons = traceBandPaths(data, cellGrid, settings);
    }

    /* finally, add polygons to output array */
    if (multiBand)
      ret.push(bandPolygons);
    else
      ret = bandPolygons;

    if(typeof settings.successCallback === 'function')
      settings.successCallback(ret, lowerBound, bandWidth[b]);
  });

  return ret;
}

/*
 * Thats all for the public interface, below follows the actual
 * implementation
 */

/*
 *  For isoBands, each square is defined by the three states
 * of its corner points. However, since computers use power-2
 * values, we use 2bits per trit, i.e.:
 *
 * 00 ... below minV
 * 01 ... between minV and maxV
 * 10 ... above maxV
 *
 * Hence we map the 4-trit configurations as follows:
 *
 * 0000 => 0
 * 0001 => 1
 * 0002 => 2
 * 0010 => 4
 * 0011 => 5
 * 0012 => 6
 * 0020 => 8
 * 0021 => 9
 * 0022 => 10
 * 0100 => 16
 * 0101 => 17
 * 0102 => 18
 * 0110 => 20
 * 0111 => 21
 * 0112 => 22
 * 0120 => 24
 * 0121 => 25
 * 0122 => 26
 * 0200 => 32
 * 0201 => 33
 * 0202 => 34
 * 0210 => 36
 * 0211 => 37
 * 0212 => 38
 * 0220 => 40
 * 0221 => 41
 * 0222 => 42
 * 1000 => 64
 * 1001 => 65
 * 1002 => 66
 * 1010 => 68
 * 1011 => 69
 * 1012 => 70
 * 1020 => 72
 * 1021 => 73
 * 1022 => 74
 * 1100 => 80
 * 1101 => 81
 * 1102 => 82
 * 1110 => 84
 * 1111 => 85
 * 1112 => 86
 * 1120 => 88
 * 1121 => 89
 * 1122 => 90
 * 1200 => 96
 * 1201 => 97
 * 1202 => 98
 * 1210 => 100
 * 1211 => 101
 * 1212 => 102
 * 1220 => 104
 * 1221 => 105
 * 1222 => 106
 * 2000 => 128
 * 2001 => 129
 * 2002 => 130
 * 2010 => 132
 * 2011 => 133
 * 2012 => 134
 * 2020 => 136
 * 2021 => 137
 * 2022 => 138
 * 2100 => 144
 * 2101 => 145
 * 2102 => 146
 * 2110 => 148
 * 2111 => 149
 * 2112 => 150
 * 2120 => 152
 * 2121 => 153
 * 2122 => 154
 * 2200 => 160
 * 2201 => 161
 * 2202 => 162
 * 2210 => 164
 * 2211 => 165
 * 2212 => 166
 * 2220 => 168
 * 2221 => 169
 * 2222 => 170
 */

/*
 * ####################################
 * Some small helper functions
 * ####################################
 */

function computeCenterAverage(bl, br, tr, tl, minV, maxV) {
  var average = (tl + tr + br + bl) / 4;

  if (average > maxV)
    return 2; /* above isoband limits */

  if (average < minV)
    return 0; /* below isoband limits */

  return 1; /* within isoband limits */
}


function prepareCell(grid, x, y, opt) {
  var cell,
    center_avg;

  /*  compose the 4-trit corner representation */
  var cval = 0;
  var x3 = grid[y + 1][x];
  var x2 = grid[y + 1][x + 1];
  var x1 = grid[y][x + 1];
  var x0 = grid[y][x];
  var minV  = opt.minV;
  var maxV  = opt.maxV;

  /*
   * Note that missing data within the grid will result
   * in horribly failing to trace full polygon paths
   */
  if(isNaN(x0) || isNaN(x1) || isNaN(x2) || isNaN(x3)) {
    return;
  }

  /*
   * Here we detect the type of the cell
   *
   * x3 ---- x2
   * |      |
   * |      |
   * x0 ---- x1
   *
   * with edge points
   *
   * x0 = (x,y),
   * x1 = (x + 1, y),
   * x2 = (x + 1, y + 1), and
   * x3 = (x, y + 1)
   *
   * and compute the polygon intersections with the edges
   * of the cell. Each edge value may be (i) below, (ii) within,
   * or (iii) above the values of the isoband limits. We
   * encode this property using 2 bits of information, where
   *
   * 00 ... below,
   * 01 ... within, and
   * 10 ... above
   *
   * Then we store the cells value as vector
   *
   * cval = (x0, x1, x2, x3)
   *
   * where x0 are the two least significant bits (0th, 1st),
   * x1 the 2nd and 3rd bit, and so on. This essentially
   * enables us to work with a single integer number
   */

  cval |= (x3 < minV) ? 0 : (x3 > maxV) ? 128 : 64;
  cval |= (x2 < minV) ? 0 : (x2 > maxV) ? 32 : 16;
  cval |= (x1 < minV) ? 0 : (x1 > maxV) ? 8 : 4;
  cval |= (x0 < minV) ? 0 : (x0 > maxV) ? 2 : 1;

  /* make sure cval is a number */
  cval = +cval;

  /*
   * cell center average trit for ambiguous cases, where
   * 0 ... below iso band
   * 1 ... within iso band
   * 2 ... above isoband
   */
  center_avg = 0;

  cell = {
    cval:         cval,
    polygons:     [],
    edges:        {},
    x0:           x0,
    x1:           x1,
    x2:           x2,
    x3:           x3,
    x:            x,
    y:            y
  };

  /*
   * Compute interpolated intersections of the polygon(s)
   * with the cell borders and (i) add edges for polygon
   * trace-back, or (ii) a list of small closed polygons
   * according to look-up table
   */
  switch (cval) {
  case 85:  /* 1111 */
    shapeCoordinates.square(cell, x0, x1, x2, x3, opt);
    /* fall through */
  case 0:   /* 0000 */
    /* fall through */
  case 170: /* 2222 */
    break;

    /* single triangle cases */

  case 169: /* 2221 */
    shapeCoordinates.triangle_bl(cell, x0, x1, x2, x3, opt);
    break;

  case 166: /* 2212 */
    shapeCoordinates.triangle_br(cell, x0, x1, x2, x3, opt);
    break;

  case 154: /* 2122 */
    shapeCoordinates.triangle_tr(cell, x0, x1, x2, x3, opt);
    break;

  case 106: /* 1222 */
    shapeCoordinates.triangle_tl(cell, x0, x1, x2, x3, opt);
    break;

  case 1: /* 0001 */
    shapeCoordinates.triangle_bl(cell, x0, x1, x2, x3, opt);
    break;

  case 4: /* 0010 */
    shapeCoordinates.triangle_br(cell, x0, x1, x2, x3, opt);
    break;

  case 16: /* 0100 */
    shapeCoordinates.triangle_tr(cell, x0, x1, x2, x3, opt);
    break;

  case 64: /* 1000 */
    shapeCoordinates.triangle_tl(cell, x0, x1, x2, x3, opt);
    break;


    /* single trapezoid cases */

  case 168: /* 2220 */
    shapeCoordinates.tetragon_bl(cell, x0, x1, x2, x3, opt);
    break;

  case 162: /* 2202 */
    shapeCoordinates.tetragon_br(cell, x0, x1, x2, x3, opt);
    break;

  case 138: /* 2022 */
    shapeCoordinates.tetragon_tr(cell, x0, x1, x2, x3, opt);
    break;

  case 42: /* 0222 */
    shapeCoordinates.tetragon_tl(cell, x0, x1, x2, x3, opt);
    break;

  case 2: /* 0002 */
    shapeCoordinates.tetragon_bl(cell, x0, x1, x2, x3, opt);
    break;

  case 8: /* 0020 */
    shapeCoordinates.tetragon_br(cell, x0, x1, x2, x3, opt);
    break;

  case 32: /* 0200 */
    shapeCoordinates.tetragon_tr(cell, x0, x1, x2, x3, opt);
    break;

  case 128: /* 2000 */
    shapeCoordinates.tetragon_tl(cell, x0, x1, x2, x3, opt);
    break;


    /* single rectangle cases */

  case 5: /* 0011 */
    shapeCoordinates.tetragon_b(cell, x0, x1, x2, x3, opt);
    break;

  case 20: /* 0110 */
    shapeCoordinates.tetragon_r(cell, x0, x1, x2, x3, opt);
    break;

  case 80: /* 1100 */
    shapeCoordinates.tetragon_t(cell, x0, x1, x2, x3, opt);
    break;

  case 65: /* 1001 */
    shapeCoordinates.tetragon_l(cell, x0, x1, x2, x3, opt);
    break;

  case 165: /* 2211 */
    shapeCoordinates.tetragon_b(cell, x0, x1, x2, x3, opt);
    break;

  case 150: /* 2112 */
    shapeCoordinates.tetragon_r(cell, x0, x1, x2, x3, opt);
    break;

  case 90: /* 1122 */
    shapeCoordinates.tetragon_t(cell, x0, x1, x2, x3, opt);
    break;

  case 105: /* 1221 */
    shapeCoordinates.tetragon_l(cell, x0, x1, x2, x3, opt);
    break;

  case 160: /* 2200 */
    shapeCoordinates.tetragon_lr(cell, x0, x1, x2, x3, opt);
    break;

  case 130: /* 2002 */
    shapeCoordinates.tetragon_tb(cell, x0, x1, x2, x3, opt);
    break;

  case 10: /* 0022 */
    shapeCoordinates.tetragon_lr(cell, x0, x1, x2, x3, opt);
    break;

  case 40: /* 0220 */
    shapeCoordinates.tetragon_tb(cell, x0, x1, x2, x3, opt);
    break;


    /* single pentagon cases */

  case 101: /* 1211 */
    shapeCoordinates.pentagon_tr(cell, x0, x1, x2, x3, opt);
    break;

  case 149: /* 2111 */
    shapeCoordinates.pentagon_tl(cell, x0, x1, x2, x3, opt);
    break;

  case 86: /* 1112 */
    shapeCoordinates.pentagon_bl(cell, x0, x1, x2, x3, opt);
    break;

  case 89: /* 1121 */
    shapeCoordinates.pentagon_br(cell, x0, x1, x2, x3, opt);
    break;

  case 69: /* 1011 */
    shapeCoordinates.pentagon_tr(cell, x0, x1, x2, x3, opt);
    break;

  case 21: /* 0111 */
    shapeCoordinates.pentagon_tl(cell, x0, x1, x2, x3, opt);
    break;

  case 84: /* 1110 */
    shapeCoordinates.pentagon_bl(cell, x0, x1, x2, x3, opt);
    break;

  case 81: /* 1101 */
    shapeCoordinates.pentagon_br(cell, x0, x1, x2, x3, opt);
    break;

  case 96: /* 1200 */
    shapeCoordinates.pentagon_tr_rl(cell, x0, x1, x2, x3, opt);
    break;

  case 24: /* 0120 */
    shapeCoordinates.pentagon_rb_bt(cell, x0, x1, x2, x3, opt);
    break;

  case 6: /* 0012 */
    shapeCoordinates.pentagon_bl_lr(cell, x0, x1, x2, x3, opt);
    break;

  case 129: /* 2001 */
    shapeCoordinates.pentagon_lt_tb(cell, x0, x1, x2, x3, opt);
    break;

  case 74: /* 1022 */
    shapeCoordinates.pentagon_tr_rl(cell, x0, x1, x2, x3, opt);
    break;

  case 146: /* 2102 */
    shapeCoordinates.pentagon_rb_bt(cell, x0, x1, x2, x3, opt);
    break;

  case 164: /* 2210 */
    shapeCoordinates.pentagon_bl_lr(cell, x0, x1, x2, x3, opt);
    break;

  case 41: /* 0221 */
    shapeCoordinates.pentagon_lt_tb(cell, x0, x1, x2, x3, opt);
    break;

  case 66: /* 1002 */
    shapeCoordinates.pentagon_bl_tb(cell, x0, x1, x2, x3, opt);
    break;

  case 144: /* 2100 */
    shapeCoordinates.pentagon_lt_rl(cell, x0, x1, x2, x3, opt);
    break;

  case 36: /* 0210 */
    shapeCoordinates.pentagon_tr_bt(cell, x0, x1, x2, x3, opt);
    break;

  case 9: /* 0021 */
    shapeCoordinates.pentagon_rb_lr(cell, x0, x1, x2, x3, opt);
    break;

  case 104: /* 1220 */
    shapeCoordinates.pentagon_bl_tb(cell, x0, x1, x2, x3, opt);
    break;

  case 26: /* 0122 */
    shapeCoordinates.pentagon_lt_rl(cell, x0, x1, x2, x3, opt);
    break;

  case 134: /* 2012 */
    shapeCoordinates.pentagon_tr_bt(cell, x0, x1, x2, x3, opt);
    break;

  case 161: /* 2201 */
    shapeCoordinates.pentagon_rb_lr(cell, x0, x1, x2, x3, opt);
    break;


    /* single hexagon cases */

  case 37: /* 0211 */
    shapeCoordinates.hexagon_lt_tr(cell, x0, x1, x2, x3, opt);
    break;

  case 148: /* 2110 */
    shapeCoordinates.hexagon_bl_lt(cell, x0, x1, x2, x3, opt);
    break;

  case 82: /* 1102 */
    shapeCoordinates.hexagon_bl_rb(cell, x0, x1, x2, x3, opt);
    break;

  case 73: /* 1021 */
    shapeCoordinates.hexagon_tr_rb(cell, x0, x1, x2, x3, opt);
    break;

  case 133: /* 2011 */
    shapeCoordinates.hexagon_lt_tr(cell, x0, x1, x2, x3, opt);
    break;

  case 22: /* 0112 */
    shapeCoordinates.hexagon_bl_lt(cell, x0, x1, x2, x3, opt);
    break;

  case 88: /* 1120 */
    shapeCoordinates.hexagon_bl_rb(cell, x0, x1, x2, x3, opt);
    break;

  case 97: /* 1201 */
    shapeCoordinates.hexagon_tr_rb(cell, x0, x1, x2, x3, opt);
    break;

  case 145: /* 2101 */
    shapeCoordinates.hexagon_lt_rb(cell, x0, x1, x2, x3, opt);
    break;

  case 25: /* 0121 */
    shapeCoordinates.hexagon_lt_rb(cell, x0, x1, x2, x3, opt);
    break;

  case 70: /* 1012 */
    shapeCoordinates.hexagon_bl_tr(cell, x0, x1, x2, x3, opt);
    break;

  case 100: /* 1210 */
    shapeCoordinates.hexagon_bl_tr(cell, x0, x1, x2, x3, opt);
    break;


    /* 6-sided saddles */

  case 17: /* 0101 */
    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    /* should never be center_avg === 2 */
    if (center_avg === 0) {
      shapeCoordinates.triangle_bl(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.triangle_tr(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.hexagon_lt_rb(cell, x0, x1, x2, x3, opt);
    }
    break;

  case 68: /* 1010 */
    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    /* should never be center_avg === 2 */
    if (center_avg === 0) {
      shapeCoordinates.triangle_tl(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.triangle_br(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.hexagon_bl_tr(cell, x0, x1, x2, x3, opt);
    }
    break;

  case 153: /* 2121 */
    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    /* should never be center_avg === 0 */
    if (center_avg === 2) {
      shapeCoordinates.triangle_bl(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.triangle_tr(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.hexagon_lt_rb(cell, x0, x1, x2, x3, opt);
    }
    break;

  case 102: /* 1212 */
    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    /* should never be center_avg === 0 */
    if (center_avg === 2) {
      shapeCoordinates.triangle_tl(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.triangle_br(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.hexagon_bl_tr(cell, x0, x1, x2, x3, opt);
    }
    break;


    /* 7-sided saddles */

  case 152: /* 2120 */

    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    /* should never be center_avg === 0 */
    if (center_avg === 2) {
      shapeCoordinates.triangle_tr(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.tetragon_bl(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.heptagon_tr(cell, x0, x1, x2, x3, opt);
    }
    break;

  case 137: /* 2021 */
    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    /* should never be center_avg === 0 */
    if (center_avg === 2) {
      shapeCoordinates.triangle_bl(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.tetragon_tr(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.heptagon_bl(cell, x0, x1, x2, x3, opt);
    }
    break;

  case 98: /* 1202 */
    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    /* should never be center_avg === 0 */
    if (center_avg === 2) {
      shapeCoordinates.triangle_tl(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.tetragon_br(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.heptagon_tl(cell, x0, x1, x2, x3, opt);
    }
    break;

  case 38: /* 0212 */
    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    /* should never be center_avg === 0 */
    if (center_avg === 2) {
      shapeCoordinates.triangle_br(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.tetragon_tl(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.heptagon_br(cell, x0, x1, x2, x3, opt);
    }
    break;

  case 18: /* 0102 */
    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    /* should never be center_avg === 2 */
    if (center_avg === 0) {
      shapeCoordinates.triangle_tr(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.tetragon_bl(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.heptagon_tr(cell, x0, x1, x2, x3, opt);
    }
    break;

  case 33: /* 0201 */
    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    /* should never be center_avg === 2 */
    if (center_avg === 0) {
      shapeCoordinates.triangle_bl(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.tetragon_tr(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.heptagon_bl(cell, x0, x1, x2, x3, opt);
    }
    break;

  case 72: /* 1020 */
    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    /* should never be center_avg === 2 */
    if (center_avg === 0) {
      shapeCoordinates.triangle_tl(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.tetragon_br(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.heptagon_tl(cell, x0, x1, x2, x3, opt);
    }
    break;

  case 132: /* 2010 */
    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    /* should never be center_avg === 2 */
    if (center_avg === 0) {
      shapeCoordinates.triangle_br(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.tetragon_tl(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.heptagon_br(cell, x0, x1, x2, x3, opt);
    }
    break;


    /* 8-sided saddles */

  case 136: /* 2020 */
    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    if (center_avg === 0) {
      shapeCoordinates.tetragon_tl(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.tetragon_br(cell, x0, x1, x2, x3, opt);
    } else if (center_avg === 1) {
      shapeCoordinates.octagon(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.tetragon_bl(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.tetragon_tr(cell, x0, x1, x2, x3, opt);
    }
    break;

  case 34: /* 0202 */
    center_avg = computeCenterAverage(x0, x1, x2, x3, minV, maxV);
    if (center_avg === 0) {
      shapeCoordinates.tetragon_bl(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.tetragon_tr(cell, x0, x1, x2, x3, opt);
    } else if (center_avg === 1) {
      shapeCoordinates.octagon(cell, x0, x1, x2, x3, opt);
    } else {
      shapeCoordinates.tetragon_tl(cell, x0, x1, x2, x3, opt);
      shapeCoordinates.tetragon_br(cell, x0, x1, x2, x3, opt);
    }
    break;
  }

  return cell;
}


export {isoBands};