Move most game logic into its own file

public/map.svg

@@ -53,21 +53,21 @@
       <g class="start-locations">
         <g>
           <!-- <use data-x="13" href="#t-1" data-allegiance="liao" data-number="1"/> -->
-          <use data-x="14" href="#t-2" data-allegiance="liao" data-number="2"/>
+          <use data-x="14" class="counter" href="#t-2" data-allegiance="liao" data-number="2"/>
-          <use data-x="15" href="#t-3" data-allegiance="liao" data-number="3"/>
+          <use data-x="15" class="counter" href="#t-3" data-allegiance="liao" data-number="3"/>
-          <use data-x="16" href="#t-4" data-allegiance="liao" data-number="4"/>
+          <use data-x="16" class="counter" href="#t-4" data-allegiance="liao" data-number="4"/>
-          <use data-x="17" href="#t-5" data-allegiance="liao" data-number="5"/>
+          <use data-x="17" class="counter" href="#t-5" data-allegiance="liao" data-number="5"/>
-          <use data-x="18" href="#t-6" data-allegiance="liao" data-number="6"/>
+          <use data-x="18" class="counter" href="#t-6" data-allegiance="liao" data-number="6"/>
-          <use data-x="19" href="#t-7" data-allegiance="liao" data-number="7"/>
+          <use data-x="19" class="counter" href="#t-7" data-allegiance="liao" data-number="7"/>
         </g>
         <g>
-          <use data-x="13" href="#t-1" data-allegiance="davion" data-number="1"/>
+          <use data-x="13" class="counter" href="#t-1" data-allegiance="davion" data-number="1"/>
-          <use data-x="14" href="#t-2" data-allegiance="davion" data-number="2"/>
+          <use data-x="14" class="counter" href="#t-2" data-allegiance="davion" data-number="2"/>
-          <use data-x="15" href="#t-3" data-allegiance="davion" data-number="3"/>
+          <use data-x="15" class="counter" href="#t-3" data-allegiance="davion" data-number="3"/>
-          <use data-x="16" href="#t-4" data-allegiance="davion" data-number="4"/>
+          <use data-x="16" class="counter" href="#t-4" data-allegiance="davion" data-number="4"/>
-          <use data-x="17" href="#t-5" data-allegiance="davion" data-number="5"/>
+          <use data-x="17" class="counter" href="#t-5" data-allegiance="davion" data-number="5"/>
-          <use data-x="18" href="#t-6" data-allegiance="davion" data-number="6"/>
+          <use data-x="18" class="counter" href="#t-6" data-allegiance="davion" data-number="6"/>
-          <use data-x="19" href="#t-7" data-allegiance="davion" data-number="7"/>
+          <use data-x="19" class="counter" href="#t-7" data-allegiance="davion" data-number="7"/>
         </g>
       </g>
       <g data-y="0">

src/modules/game.js

@@ -0,0 +1,906 @@
+function isEven(n) {
+  return n % 2 === 0;
+}
+
+function radToDeg(radians) {
+  return radians * 180 / Math.PI;
+}
+
+function calculateAngle(xDiff, yDiff) {
+  yDiff = -yDiff;
+  let angle = Math.abs(Math.atan(yDiff / xDiff));
+
+  if (xDiff < 0 && yDiff > 0) {
+    angle = Math.PI - angle;
+  } else if (xDiff < 0 && yDiff < 0) {
+    angle = Math.PI + angle;
+  } else if (xDiff > 0 && yDiff < 0) {
+    angle = 2 * Math.PI - angle;
+  }
+
+  return angle;
+}
+
+function edgePoint(x1, y1, x2, y2, maxX, maxY) {
+  let pointCoords,
+    xDiff = x2 - x1,
+    yDiff = y2 - y1,
+    xIntercept = y => (y - y1) * xDiff / yDiff + x1,
+    yIntercept = x => (x - x1) * yDiff / xDiff + y1;
+
+  if (xDiff > 0 && yDiff > 0) {
+    let x = xIntercept(maxY);
+
+    pointCoords = x <= maxX ? [x, maxY] : [maxX, yIntercept(maxX)];
+  } else if (xDiff > 0 && yDiff < 0) {
+    let y = yIntercept(maxX);
+
+    pointCoords = y >= 0 ? [maxX, y] : [xIntercept(0), 0];
+  } else if (xDiff < 0 && yDiff < 0) {
+    let x = xIntercept(0);
+
+    pointCoords = x >= 0 ? [x, 0] : [0, yIntercept(0)];
+  } else {
+    let y = yIntercept(0);
+
+    pointCoords = y <= maxY ? [0, y] : [xIntercept(maxY), maxY];
+  }
+
+  return pointCoords;
+}
+
+function evenr_to_axial(x, y) {
+  return { q: x - (y + (y & 1)) / 2, r: y };
+}
+
+function axial_to_evenr(q, r) {
+  return { x: q + (r + (r & 1)) / 2, y: r };
+}
+
+function axial_distance(q1, r1, q2, r2) {
+  return (Math.abs(q1 - q2) + Math.abs(q1 + r1 - q2 - r2) + Math.abs(r1 - r2)) / 2;
+}
+
+function offset_distance(x1, y1, x2, y2) {
+  let { q: q1, r: r1 } = evenr_to_axial(x1, y1),
+    { q: q2, r: r2 } = evenr_to_axial(x2, y2);
+
+  return axial_distance(q1, r1, q2, r2);
+}
+
+function cube_to_axial(q, r, s) {
+  return { q: q, r: r };
+}
+
+function axial_to_cube(q, r) {
+  return { q: q, r: r, s: -q - r };
+}
+
+function cube_round(q, r, s) {
+  rQ = Math.round(q);
+  rR = Math.round(r);
+  rS = Math.round(s);
+
+  let q_diff = Math.abs(rQ - q),
+    r_diff = Math.abs(rR - r),
+    s_diff = Math.abs(rS - s);
+
+  if (q_diff > r_diff && q_diff > s_diff) {
+    rQ = -rR - rS;
+  } else if (r_diff > s_diff) {
+    rR = -rQ - rS;
+  } else {
+    rS = -rQ - rR;
+  }
+
+  return { q: rQ, r: rR, s: rS };
+}
+
+function axial_round(q, r) {
+  let cube = axial_to_cube(q, r),
+    round = cube_round(cube.q, cube.r, cube.s),
+    axial = cube_to_axial(round.q, round.r, round.s);
+
+  return { q: axial.q, r: axial.r };
+}
+
+function lerp(a, b, t) {
+  return a + (b - a) * t;
+}
+
+function axial_lerp(q1, r1, q2, r2, t) {
+  return { q: lerp(q1, q2, t), r: lerp(r1, r2, t) };
+}
+
+function linedraw(x1, y1, x2, y2) {
+  let axial1 = evenr_to_axial(x1, y1),
+    axial2 = evenr_to_axial(x2, y2),
+    n = offset_distance(x1, y1, x2, y2),
+    results = [];
+
+  for (let i = 0; i <= n; i++) {
+    let lerp = axial_lerp(axial1.q, axial1.r, axial2.q, axial2.r, 1.0 / n * i),
+      round = axial_round(lerp.q, lerp.r),
+      { x, y } = axial_to_evenr(round.q, round.r);
+
+    results.push([x, y]);
+  }
+
+  return results;
+}
+
+export default class Game {
+  info;
+
+  #firingArcVisibility = {
+    davion: false,
+    liao: false
+  };
+
+  constructor(svg) {
+    this.svg = svg;
+
+    this.setUpSightLine(this);
+    this.setUpCounter(this);
+    // this.setUpRecordSheet();
+    this.setUpCells();
+  }
+
+  static HORZ_POINT_DISTANCE = 1.005;
+  static VERT_POINT_DISTANCE = Math.sqrt(3) * Game.HORZ_POINT_DISTANCE / 2;
+
+  static FIRING_ARC_SIZE = {
+    'small': Math.atan(Game.HORZ_POINT_DISTANCE / (6 * Game.VERT_POINT_DISTANCE)),
+    'medium': Math.atan((Game.HORZ_POINT_DISTANCE / 2) / Game.VERT_POINT_DISTANCE),
+    'large': Math.atan((21 * Game.HORZ_POINT_DISTANCE) / (6 * Game.VERT_POINT_DISTANCE))
+  };
+
+  #positionFiringArc(e) {
+    let activeFiringArc = this.querySelector('polygon.firing-arc.active');
+
+    // TODO: handle exactly horizontal and vertical lines
+
+    if (activeFiringArc) {
+      let activeFiringArcOutline = this.querySelector(`#lines polygon[data-troop-number="${activeFiringArc.dataset.troopNumber}"][data-troop-allegiance="${activeFiringArc.dataset.troopAllegiance}"]`),
+        board = this.querySelector('#image-maps'),
+        { width, height } = board.getBBox(),
+        pt = new DOMPoint(e.clientX, e.clientY),
+        { x: pointerX, y: pointerY } = pt.matrixTransform(board.getScreenCTM().inverse()),
+        [maxXpx, maxYpx] = [width, height],
+        { x: x1px, y: y1px } = activeFiringArc.points[0];
+
+      let [x2px, y2px] = [
+        pointerX / width * maxXpx,
+        pointerY / height * maxYpx
+      ];
+
+      let xDiff = x2px - x1px;
+      let yDiff = y2px - y1px;
+      let angle = calculateAngle(xDiff, yDiff);
+
+      let arcAngle = Game.FIRING_ARC_SIZE[activeFiringArc.dataset.size];
+      let distance = Math.sqrt((x2px - x1px) ** 2 + (y2px - y1px) ** 2);
+      let yDelta = distance * Math.cos(angle) * Math.tan(arcAngle);
+      let xDelta = distance * Math.sin(angle) * Math.tan(arcAngle);
+
+      let [newY1, newX1] = [y2px + yDelta, x2px + xDelta];
+      let [newY2, newX2] = [y2px - yDelta, x2px - xDelta];
+
+      [newX1, newY1] = edgePoint(x1px, y1px, newX1, newY1, maxXpx, maxYpx);
+      [newX2, newY2] = edgePoint(x1px, y1px, newX2, newY2, maxXpx, maxYpx);
+
+      let oppositeEdgeConditions = [
+        newX1 == 0 && newX2 == maxXpx,
+        newX2 == 0 && newX1 == maxXpx,
+        newY1 == 0 && newY2 == maxYpx,
+        newY2 == 0 && newY1 == maxYpx
+      ]
+
+      let orthogonalEdgeConditions = [
+        (newX1 == 0 || newX1 == maxXpx) && (newY2 == 0 || newY2 == maxYpx),
+        (newX2 == 0 || newX2 == maxXpx) && (newY1 == 0 || newY1 == maxYpx),
+      ]
+
+      let points;
+
+      if (oppositeEdgeConditions.some(e => e)) {
+        let cornerPoints;
+
+        if (xDiff > 0 && yDiff > 0) {
+          if ((newY1 == 0 && newY2 == maxYpx) || (newY1 == maxYpx && newY2 == 0)) {
+            cornerPoints = [[maxXpx, 0], [maxXpx, maxYpx]];
+          } else {
+            cornerPoints = [[maxXpx, maxYpx], [0, maxYpx]];
+          }
+        } else if (xDiff > 0 && yDiff < 0) {
+          if ((newY1 == 0 && newY2 == maxYpx) || (newY1 == maxYpx && newY2 == 0)) {
+            cornerPoints = [[maxXpx, 0], [maxXpx, maxYpx]];
+          } else {
+            cornerPoints = [[0, 0], [maxXpx, 0]];
+          }
+
+        } else if (xDiff < 0 && yDiff > 0) {
+          if ((newY1 == 0 && newY2 == maxYpx) || (newY1 == maxYpx && newY2 == 0)) {
+            cornerPoints = [[0, maxYpx], [0, 0]];
+          } else {
+            cornerPoints = [[maxXpx, maxYpx], [0, maxYpx]];
+          }
+
+        } else {
+          if ((newY1 == 0 && newY2 == maxYpx) || (newY1 == maxYpx && newY2 == 0)) {
+            cornerPoints = [[0, maxYpx], [0, 0]];
+          } else {
+            cornerPoints = [[0, 0], [maxXpx, 0]];
+          }
+
+        }
+        points = `${x1px},${y1px} ${newX1},${newY1} ${cornerPoints[1]} ${cornerPoints[0]} ${newX2},${newY2}`;
+      } else if (orthogonalEdgeConditions.some(e => e)) {
+        let cornerPoints = [];
+        let cp1, cp2;
+
+        if (newX1 == 0 || newX1 == maxXpx) {
+          cp1 = [newX1, yDiff > 0 ? maxYpx : 0];
+        } else {
+          cp1 = [xDiff > 0 ? maxXpx : 0, newY1];
+        }
+
+        if (newX2 == 0 || newX2 == maxXpx) {
+          cp2 = [newX2, yDiff > 0 ? maxYpx : 0];
+        } else {
+          cp2 = [xDiff > 0 ? maxXpx : 0, newY2];
+        }
+
+        if (cp1[0] == cp2[0] && cp1[1] == cp2[1]) {
+          cornerPoints.push(cp1);
+        } else {
+          cornerPoints.push(cp1);
+          cornerPoints.push([xDiff > 0 ? maxXpx : 0, yDiff > 0 ? maxYpx : 0])
+          cornerPoints.push(cp2);
+        }
+
+        points = `${x1px},${y1px} ${newX1},${newY1} ${cornerPoints.join(' ')} ${newX2},${newY2}`;
+      } else {
+        points = `${x1px},${y1px} ${newX1},${newY1} ${newX2},${newY2}`;
+      }
+
+      activeFiringArcOutline.setAttributeNS(null, 'points', points);
+      activeFiringArc.setAttributeNS(null, 'points', points);
+    }
+  }
+
+  getCells() {
+    return this.svg.querySelectorAll('g[data-x]');
+  }
+
+  getCell(x, y) {
+    return this.svg.querySelector(`g[data-y="${y}"] g[data-x="${x}"]`);
+  }
+
+  getHex(cell) {
+    return cell.querySelector('use[href="#hex"]');
+  }
+
+  getCounters() {
+    return this.svg.querySelectorAll(`use[data-allegiance][data-number]:not(.clone)`);
+  }
+
+  getCounter(al, n) {
+    return this.svg.querySelector(`use[data-allegiance="${al}"][data-number="${n}"]:not(.clone)`);
+  }
+
+  getCounterAndClones(al, n) {
+    return this.svg.querySelectorAll(`use[data-allegiance="${al}"][data-number="${n}"]`);
+  }
+
+  getClones(al, n) {
+    return this.svg.querySelectorAll(`use[data-allegiance="${al}"][data-number="${n}"].clone`);
+  }
+
+  getSelected() {
+    return this.svg.querySelector(`use[data-allegiance][data-number].selected`);
+  }
+
+  getSightLine() {
+    return this.svg.querySelector('line.sight-line');
+  }
+
+  getExistingArcs(al, n) {
+    return this.svg.querySelectorAll(`#firing-arcs polygon[data-troop-number="${n}"][data-troop-allegiance="${al}"]`);
+  }
+
+  getUnclippedFiringArcs() {
+    return this.svg.querySelectorAll('#firing-arcs polygon:not([clip-path])');
+  }
+
+  getGridIndex({ parentElement }) {
+    return { x: parentElement.dataset.x, y: parentElement.parentElement.dataset.y };
+  }
+
+  getBoard() {
+    return this.svg.querySelector('.board');
+  }
+
+  getActiveHexes() {
+    return this.svg.querySelectorAll('use[href="#hex"].active');
+  }
+
+  getCellPosition(cell) {
+    let pt = new DOMPoint(0, 0),
+      transform = getComputedStyle(cell).transform.match(/-?\d+\.?\d*/g),
+      mtx = new DOMMatrix(transform);
+      pt = pt.matrixTransform(mtx);
+
+    transform = getComputedStyle(cell.parentElement).transform.match(/-?\d+\.?\d*/g);
+    mtx = new DOMMatrix(transform);
+    pt = pt.matrixTransform(mtx);
+
+    return pt;
+  }
+
+  endMove() {
+    const selected = this.getSelected();
+
+    if (selected) {
+      this.Counter.endMove(selected);
+      // this.RecordSheet.endMove();
+    }
+  }
+
+  toggleFiringArcVisibility(allegiance) {
+    const vis = this.#firingArcVisibility[allegiance],
+      clipPaths = this.svg.querySelectorAll(`clipPath[data-troop-allegiance="${allegiance}"]`);
+
+    clipPaths.forEach(cp => cp.style.display = !vis ? 'none' : '');
+    this.#firingArcVisibility[allegiance] = !vis;
+  }
+
+  clipFiringArcs() {
+    let unclipped = this.getUnclippedFiringArcs();
+
+    unclipped.forEach(el => {
+      const { troopNumber, troopAllegiance } = el.dataset,
+        clipPathId = `clip-path-${troopAllegiance}-${troopNumber}`,
+        isVisible = this.#firingArcVisibility[troopAllegiance];
+
+      if (isVisible) {
+        this.svg.querySelector(`#${clipPathId}`).style.display = 'none';
+      }
+
+      el.setAttributeNS(null, 'clip-path', `url(#${clipPathId})`);
+    });
+  }
+
+  setUpCells() {
+    this.getCells().forEach(cell => {
+      let group = cell,
+        point = this.getHex(cell);
+
+      point.addEventListener('click', e => {
+        // TODO
+        let existingOccupant =
+          this.svg.querySelector(`.counter[data-x="${point.dataset.x}"][data-y="${point.dataset.y}"]`);
+
+        if (this.getSelected() && !existingOccupant) {
+          let sl = this.svg.querySelector('.sight-line');
+
+          this.Counter.place(point);
+
+          if (sl) {
+            if (sl.classList.contains('active')) {
+              this.SightLine.clear();
+            } else {
+              this.SightLine.update(point);
+            }
+          }
+        }
+      });
+
+      group.addEventListener('contextmenu', e => {
+        e.preventDefault();
+        let sl = this.svg.querySelector('.sight-line');
+
+        if (sl) {
+          sl.classList.toggle('active');
+
+          if (sl.classList.contains('active')) {
+            this.SightLine.clear();
+          } else {
+            group.querySelector(`use[href="#hex"]`).classList.add('sight-line-target');
+          }
+
+          group.dispatchEvent(new MouseEvent('pointerover'));
+        }
+      });
+
+      group.addEventListener('pointerover', e => {
+        let selected = this.getSelected();
+
+        if (selected) {
+          let sl = this.svg.querySelector('.sight-line'),
+            isOnBoard = selected.parentElement.hasAttribute('data-x'),
+            sourceCell = selected.parentElement;
+
+          if (isOnBoard && (!sl || sl.classList.contains('active')) && sourceCell != group) {
+            this.SightLine.draw(sourceCell, group);
+          }
+        }
+      });
+
+      group.addEventListener('pointerout', e => {
+        let sl = this.svg.querySelector('.sight-line.active');
+
+        if (sl && sl.classList.contains('active')) {
+          this.SightLine.clear();
+        }
+      });
+    });
+  }
+
+  setUpCounter(container) {
+    this.Counter = new function () {
+      let selectedClass = 'selected',
+        svgns = "http://www.w3.org/2000/svg",
+
+        dataSelector = function (troopNumber, allegiance) {
+          return `[data-number="${troopNumber}"][data-allegiance="${allegiance}"]`;
+        },
+
+        selector = function (troopNumber, allegiance) {
+          return `use.counter${dataSelector(troopNumber, allegiance)}`;
+        },
+
+        position = function (x, y) {
+          return `g[data-x="${x}"][data-y="${y}"]`;
+        },
+
+        counterPosition = function (x, y) {
+          return `use.counter[data-x="${x}"][data-x="${y}"]`;
+        },
+
+        traceSelector = function (troopNumber, allegiance) {
+          return `polyline.move-trace${dataSelector(troopNumber, allegiance)}`;
+        },
+
+        clickClone = function (e) {
+          e.stopPropagation();
+
+          let { number: troopNumber, allegiance: troopAllegiance } = this.dataset,
+            pos = container.getCellPosition(this.parentElement);
+
+          if (container.Counter.isSelected(troopNumber, troopAllegiance)) {
+            let trace = container.svg.querySelector(traceSelector(troopNumber, troopAllegiance)),
+              points = trace.getAttribute('points').split(' ');
+
+            if (`${pos.x},${pos.y}` == points.at(0)) {
+              const counter = container.getCounter(troopAllegiance, troopNumber),
+                lockedSl = container.svg.querySelector('.sight-line:not(.active)');
+
+              counter.setAttributeNS(null, 'x', 0);
+              counter.setAttributeNS(null, 'y', 0);
+
+              if (!lockedSl) {
+                container.SightLine.clear();
+              } else {
+                container.SightLine.update(this);
+              }
+
+              this.parentElement.appendChild(counter);
+              container.Counter.removeClones(counter);
+              trace.remove();
+            } else {
+              points = points.filter(p => p != `${pos.x},${pos.y}`).join(' ');
+              trace.setAttributeNS(null, 'points', points);
+            }
+
+            this.remove();
+          }
+        },
+
+        pointerOver = function () {
+          let { number: troopNumber, allegiance: troopAllegiance } = this.dataset,
+            cp = container.svg.querySelector(`#clip-path-${troopAllegiance}-${troopNumber}`);
+
+          if (cp) {
+            cp.style.display = 'none';
+          }
+        },
+
+        pointerOut = function () {
+          let { number: troopNumber, allegiance: troopAllegiance } = this.dataset,
+            cp = container.svg.querySelector(`#clip-path-${troopAllegiance}-${troopNumber}`);
+
+          if (cp) {
+            let isVisible =
+              document
+                .getElementById('toggle-firing-arc-vis')
+                .querySelector(`input[data-allegiance="${troopAllegiance}"]`)
+                .checked;
+
+            cp.style.display = isVisible ? 'none' : '';
+          }
+        },
+
+        click = function (e) {
+          if (this.classList.contains(selectedClass)) {
+            e.stopPropagation();
+            let { number: troopNumber, allegiance: troopAllegiance } = this.dataset,
+              trace = container.svg.querySelector(traceSelector(troopNumber, troopAllegiance));
+
+            if (trace) {
+              let points = trace.getAttribute('points').split(' '),
+                [clonePosX, clonePosY] = points.at(-2).split(',').map(p => parseFloat(p)),
+
+                { clone } = Array
+                  .from(container.getClones(troopAllegiance, troopNumber))
+                  .map(c => { return { clone: c, pos: container.getCellPosition(c.parentElement) }})
+                  .find(({ pos: { x, y }}) => x == clonePosX && y == clonePosY);
+
+              points.pop();
+
+              if (points.length >= 2) {
+                trace.setAttributeNS(null, 'points', points.join(' '));
+              } else {
+                trace.remove();
+              }
+
+              let sl = container.svg.querySelector('.sight-line');
+
+              if (sl) {
+                container.SightLine.update(clone)
+              } else {
+                container.SightLine.draw(this.parentElement, clone.parentElement);
+              }
+
+              clone.parentElement.appendChild(this);
+              clone.remove();
+            }
+          } else {
+            e.stopPropagation();
+            // this.RecordSheet.select(e.target);
+            container.Counter.select(e.target);
+          }
+        },
+
+        dblClick = function () {
+          if (this.classList.contains(selectedClass)) {
+            let { troopNumber, troopAllegiance } = this.dataset,
+              trace = grid.querySelector(traceSelector(troopNumber, troopAllegiance));
+
+            if (!trace) {
+              container.Counter.remove(this);
+              container.svg.querySelectorAll(`#firing-arcs ${dataSelector(troopNumber, troopAllegiance)}`).forEach(el => el.remove());
+            }
+          }
+        };
+
+      this.get = function (troopNumber, allegiance) {
+        return container.getCounter(allegiance, troopNumber);
+      };
+
+      this.getAt = function (x, y) {
+        return container.querySelector(`${counterPosition(x, y)}:not(.clone)`);
+      };
+
+      this.select = function ({ dataset: { allegiance, number }}) {
+        this.unSelect();
+
+        let counter = container.getCounter(allegiance, number);
+
+        if (counter) {
+          counter.classList.add(selectedClass);
+          let existingArcs = container.getExistingArcs(allegiance, number);
+          existingArcs.forEach(el => el.removeAttribute('clip-path'));
+        }
+      };
+
+      this.unSelect = function () {
+        let selected = container.getSelected();
+
+        if (selected) {
+          let { troopNumber, troopAllegiance } = selected.dataset;
+
+          selected.classList.remove(selectedClass);
+          selected.removeAttribute('style');
+          container.SightLine.clear();
+
+          container
+            .svg
+            .querySelectorAll(`${selector(troopNumber, troopAllegiance)}.clone`)
+            .forEach(el => el.removeAttribute('style'));
+        }
+
+        container.clipFiringArcs();
+      };
+
+      this.isSelected = function (troopNumber, allegiance) {
+        return container.svg.querySelector(`${selector(troopNumber, allegiance)}.${selectedClass}`) !== null;
+      };
+
+      this.place = function (point) {
+        const selected = container.getSelected(),
+          troopAllegiance = selected.dataset.allegiance,
+          troopNumber = selected.dataset.number;
+
+        let counter, points,
+          counterNodeList = container.getCounterAndClones(troopAllegiance, troopNumber);
+
+        if (counterNodeList.length > 0 && selected.parentElement.hasAttribute('data-x')) {
+          let counters = Array.from(counterNodeList),
+            original = counters.find(el => !el.classList.contains('clone')),
+            trace = container.svg.querySelector(traceSelector(troopNumber, troopAllegiance));
+
+          counter = original.cloneNode();
+          counter.setAttributeNS(null, 'x', 0);
+          counter.setAttributeNS(null, 'y', 0);
+          counter.classList.remove(selectedClass);
+          counter.classList.add('clone');
+
+          original.setAttributeNS(null, 'x', 0);
+          original.setAttributeNS(null, 'y', 0);
+
+          original.parentElement.appendChild(counter);
+          point.parentElement.appendChild(original);
+
+          let previous = container.getCellPosition(counter.parentElement),
+            current = container.getCellPosition(original.parentElement);
+
+          if (!trace) {
+            trace = document.createElementNS(svgns, 'polyline');
+
+            points = `${previous.x},${previous.y} ${current.x},${current.y}`;
+
+            trace.dataset.number = troopNumber;
+            trace.dataset.allegiance = troopAllegiance;
+            trace.classList.add('move-trace');
+
+            container.getBoard().prepend(trace);
+          } else {
+            points = `${trace.getAttribute('points')} ${current.x},${current.y}`;
+          }
+
+          trace.setAttributeNS(null, 'points', points);
+          counter.addEventListener('click', clickClone);
+        } else {
+          selected.removeAttribute('data-x');
+          point.parentElement.appendChild(selected);
+        }
+      };
+
+      this.remove = function ({ dataset: { troopNumber, troopAllegiance }}) {
+        container
+          .querySelectorAll(dataSelector(troopNumber, troopAllegiance))
+          .forEach(el => el.remove());
+      };
+
+      this.removeClones = function ({ dataset: { allegiance, number }}) {
+        container.getClones(allegiance, number).forEach(el => el.remove());
+      };
+
+      this.endMove = function (el) {
+        let { number: troopNumber, allegiance: troopAllegiance } = el.dataset;
+        let trace = container.svg.querySelector(traceSelector(troopNumber, troopAllegiance));
+
+        if (trace) {
+          trace.remove();
+        }
+
+        this.removeClones(el);
+        this.unSelect();
+      };
+
+      this.hasProne = function (troopNumber, troopAllegiance) {
+        let selector = `g#${troopAllegiance}-${troopNumber} use[href="#counter-prone"]`;
+
+        return !!container.svg.querySelector(selector);
+      };
+
+      this.addEventListeners = function (counter) {
+        counter.addEventListener('pointerover', pointerOver);
+        counter.addEventListener('pointerout', pointerOut);
+        counter.addEventListener('click', click);
+        // counter.addEventListener('dblclick', dblClick);
+      };
+    };
+
+    this.getCounters().forEach(c => this.Counter.addEventListeners(c));
+  }
+
+  setUpSightLine(ptGrp) {
+    const svgns = "http://www.w3.org/2000/svg",
+      grid = this.svg.querySelector('.board');
+
+    this.SightLine = new function() {
+      this.clear = function() {
+        let sl = grid.querySelector('line.sight-line');
+        let target = grid.querySelector(`use[href="#hex"].sight-line-target`);
+
+        if (sl) {
+          sl.remove();
+        }
+
+        if (target) {
+          target.classList.remove('sight-line-target');
+        }
+
+        this.clearHexes();
+      };
+
+      this.clearHexes = function() {
+        if (ptGrp.info) {
+          ptGrp.info.querySelector('#hex-count').textContent = '-';
+          ptGrp.info.style.display = 'none';
+        }
+
+        ptGrp.getActiveHexes().forEach(el => el.classList.remove('active'));
+      };
+
+      this.draw = function (source, target) {
+        ptGrp.SightLine.clear();
+
+        let pt = new DOMPoint(0, 0),
+          transform = getComputedStyle(source).transform.match(/-?\d+\.?\d*/g),
+          mtx = new DOMMatrix(transform);
+
+        pt = pt.matrixTransform(mtx);
+
+        transform = getComputedStyle(source.parentElement).transform.match(/-?\d+\.?\d*/g);
+        mtx = new DOMMatrix(transform);
+        pt = pt.matrixTransform(mtx);
+
+        let slX1 = pt.x,
+          slY1 = pt.y;
+
+        pt = new DOMPoint(0, 0);
+        transform = getComputedStyle(target).transform.match(/-?\d+\.?\d*/g);
+        mtx = new DOMMatrix(transform);
+
+        pt = pt.matrixTransform(mtx);
+
+        transform = getComputedStyle(target.parentElement).transform.match(/-?\d+\.?\d*/g);
+        mtx = new DOMMatrix(transform);
+        pt = pt.matrixTransform(mtx);
+
+        let slX2 = pt.x,
+          slY2 = pt.y;
+
+        let sightLine = document.createElementNS(svgns, 'line');
+
+        sightLine.classList.add('sight-line');
+        sightLine.classList.add('active');
+        sightLine.setAttributeNS(null, 'x1', slX1);
+        sightLine.setAttributeNS(null, 'y1', slY1);
+        sightLine.setAttributeNS(null, 'x2', slX2);
+        sightLine.setAttributeNS(null, 'y2', slY2);
+
+        ptGrp.getBoard().appendChild(sightLine);
+
+        let coords = [
+          source.dataset.x,
+          source.parentElement.dataset.y,
+          target.dataset.x,
+          target.parentElement.dataset.y
+        ].map(n => parseInt(n));
+
+        this.drawHexes(...coords);
+      };
+
+      this.update = function (cell) {
+        const sl = ptGrp.svg.querySelector('.sight-line'),
+          target = ptGrp.svg.querySelector('.sight-line-target').parentElement,
+          { x, y } = ptGrp.getCellPosition(cell.parentElement),
+          x1 = cell.parentElement.dataset.x,
+          y1 = cell.parentElement.parentElement.dataset.y,
+          x2 = target.dataset.x,
+          y2 = target.parentElement.dataset.y;
+
+        sl.setAttributeNS(null, 'x1', x);
+        sl.setAttributeNS(null, 'y1', y);
+
+        this.drawHexes(...[x1, y1, x2, y2].map(n => parseInt(n)));
+      }
+
+      this.drawHexes = function (...coords) {
+        this.clearHexes()
+
+        if (ptGrp.info) {
+          ptGrp.info.querySelector('#hex-count').textContent = offset_distance(...coords);
+          ptGrp.info.style.display = 'block';
+        }
+
+        let lineCoords = linedraw(...coords);
+
+        let s = lineCoords
+          .map(([x, y]) => `g[data-y="${y}"] g[data-x="${x}"] use[href="#hex"]`)
+          .join(', ');
+
+        ptGrp.svg.querySelectorAll(s).forEach(p => p.classList.add('active'));
+      };
+    }
+  }
+
+  setFiringArc(size) {
+    const svgns = "http://www.w3.org/2000/svg",
+      counter = this.getSelected();
+
+    if (counter) {
+      const { allegiance: troopAllegiance, number: troopNumber } = counter.dataset;
+
+      let existingArcs = this.svg.querySelectorAll(
+        `#firing-arcs [data-troop-number="${troopNumber}"][data-troop-allegiance="${troopAllegiance}"]`
+      );
+
+      existingArcs.forEach(el => el.remove());
+
+      let arcLayer = this.svg.querySelector('#shapes');
+      let outlineLayer = this.svg.querySelector('#lines');
+      let arcContainer = this.svg.querySelector('#firing-arcs');
+
+      let { x, y } = this.getCellPosition(counter.parentElement);
+
+      let grid = this.svg.querySelector('.board');
+      const transform = getComputedStyle(grid).transform.match(/-?\d+\.?\d*/g);
+      const pt = new DOMPoint(x, y);
+      const mtx = new DOMMatrix(transform);
+      let tPt = pt.matrixTransform(mtx);
+
+      let pivotPoint = [tPt.x, tPt.y];
+      let firingArc = document.createElementNS(svgns, 'polygon');
+      let firingArcOutline = document.createElementNS(svgns, 'polygon');
+
+      firingArc.classList.add('firing-arc', 'active');
+      firingArc.dataset.troopNumber = troopNumber;
+      firingArc.dataset.troopAllegiance = troopAllegiance;
+      firingArc.dataset.size = size;
+      firingArc.setAttributeNS(null, 'points', `${pivotPoint} ${pivotPoint} ${pivotPoint}`);
+
+      firingArcOutline.dataset.troopNumber = troopNumber;
+      firingArcOutline.dataset.troopAllegiance = troopAllegiance;
+      firingArcOutline.setAttributeNS(null, 'points', `${pivotPoint} ${pivotPoint} ${pivotPoint}`);
+
+      let clipShape = document.createElementNS(svgns, 'circle');
+      clipShape.setAttributeNS(null, 'cx', tPt.x);
+      clipShape.setAttributeNS(null, 'cy', tPt.y);
+      clipShape.setAttributeNS(null, 'r', 100);
+
+      let clipPath = document.createElementNS(svgns, 'clipPath');
+      clipPath.setAttributeNS(null, 'id', `clip-path-${troopAllegiance}-${troopNumber}`);
+      clipPath.dataset.troopNumber = troopNumber;
+      clipPath.dataset.troopAllegiance = troopAllegiance;
+      clipPath.appendChild(clipShape);
+
+      arcContainer.appendChild(clipPath);
+      arcLayer.appendChild(firingArc);
+      outlineLayer.appendChild(firingArcOutline);
+
+      let firingArcPlacementListener = e => {
+        this.svg.querySelectorAll('.firing-arc.active').forEach(el => el.classList.remove('active'));
+        grid.removeAttribute('style');
+        this.svg.removeEventListener('mousemove', this.#positionFiringArc);
+        firingArc.removeEventListener('click', firingArcPlacementListener);
+        firingArc.removeEventListener('contextmenu', cancelFiringArcPlacement);
+      };
+
+      let cancelFiringArcPlacement = e => {
+        e.preventDefault();
+
+        firingArc.removeEventListener('click', firingArcPlacementListener);
+        firingArc.removeEventListener('contextmenu', cancelFiringArcPlacement);
+
+        let existingArcs = this.svg.querySelectorAll(
+          `#firing-arcs [data-troop-number="${troopNumber}"][data-troop-allegiance="${troopAllegiance}"]`
+        );
+
+        existingArcs.forEach(el => el.remove());
+
+        grid.removeAttribute('style');
+        this.svg.removeEventListener('mousemove', this.#positionFiringArc);
+      };
+
+      grid.style.pointerEvents = 'none';
+      this.svg.addEventListener('mousemove', this.#positionFiringArc);
+      firingArc.addEventListener('click', firingArcPlacementListener);
+      firingArc.addEventListener('contextmenu', cancelFiringArcPlacement);
+    }
+  }
+}