function doMarch()

in public/bubblesets.js [503:576]

• 73 lines of code
• 27 McCabe index (conditional complexity)

    function doMarch(xpos, ypos) {
      var x = xpos;
      var y = ypos;
      for(;;) { // iterative version of end recursion
        var p = new Point(x * step, y * step);
        // check if we're back where we started
        if(contour.contains(p)) {
          if(!contour.isFirst(p)) {
            // encountered a loop but haven't returned to start; will change
            // direction using conditionals and continue back to start
          } else {
            return true;
          }
        } else {
          contour.add(p);
        }
        var state = getState(x, y);
        // x, y are upper left of 2X2 marching square
        switch(state) {
          case -1:
            return true; // Marched out of bounds
          case 0:
          case 3:
          case 2:
          case 7:
            direction = MarchingSquares.E;
            break;
          case 12:
          case 14:
          case 4:
            direction = MarchingSquares.W;
            break;
          case 6:
            direction = (direction === MarchingSquares.N) ? MarchingSquares.W : MarchingSquares.E;
            break;
          case 1:
          case 13:
          case 5:
            direction = MarchingSquares.N;
            break;
          case 9:
            direction = (direction === MarchingSquares.E) ? MarchingSquares.N : MarchingSquares.S;
            break;
          case 10:
          case 8:
          case 11:
            direction = MarchingSquares.S;
            break;
          default:
            console.warn("Marching squares invalid state: " + state);
            return true;
        }

        switch(direction) {
          case MarchingSquares.N:
            y -= 1; // up
            break;
          case MarchingSquares.S:
            y += 1; // down
            break;
          case MarchingSquares.W:
            x -= 1; // left
            break;
          case MarchingSquares.E:
            x += 1; // right
            break;
          default:
            console.warn("Marching squares invalid state: " + state);
            return true;
        }
      }
      console.warn("should not be reachable...");
      return true;
    }