btroops/index.js

class SoldierRecordBlock extends HTMLDivElement {
  constructor() {
    super();

    let template = document.getElementById('soldier-record-block');
    let templateContent = template.content;

    const shadowRoot = this.attachShadow({ mode: "open" });
    shadowRoot.appendChild(templateContent.cloneNode(true));

    this.shadowRoot
      .querySelectorAll('p:has(input[type="number"]), .physical-status-track')
      .forEach(el => el.addEventListener('click', e => e.stopPropagation()))
      ;
  }
}

customElements.define(
  'damage-block',
  class extends HTMLSpanElement {
    constructor() {
      super();

      let template = document.getElementById('damage-block');
      let templateContent = template.content;

      const shadowRoot = this.attachShadow({ mode: "open" });
      shadowRoot.appendChild(templateContent.cloneNode(true));
    }
  },
  { extends: 'span' }
);

customElements.define(
  'soldier-record-block',
  SoldierRecordBlock,
  { extends: 'div'}
);

function isEven(n) {
  return n % 2 === 0;
}

function toFixed(n) {
  return Number.parseFloat(n).toFixed(2);
}

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;
}

let getPointCoords = (x, y) => {
  let point = document.querySelector(`[data-x="${x}"][data-y="${y}"]`);

  return [point.x.baseVal.value, point.y.baseVal.value]
};

let svgns = "http://www.w3.org/2000/svg",
    svg = document.querySelector('svg'),
    map = document.querySelector('rect#map');

const COLUMN_COUNT = 33,
      ROW_COUNT = 25,
      HORZ_POINT_DISTANCE = 1.005,
      VERT_POINT_DISTANCE = Math.sqrt(3) * HORZ_POINT_DISTANCE / 2,
      ALTERNATING_OFFSET = HORZ_POINT_DISTANCE / 2,
      [X_OFFSET, Y_OFFSET] = [0.25, 0.45],
      [COLUMNS, ROWS] = [COLUMN_COUNT, ROW_COUNT].map(n => [...Array(n).keys()]),
      POINTS = ROWS.map(y => COLUMNS.map(x => [x, y]));

const FIRING_ARC_SIZE = {
        'small': Math.atan(HORZ_POINT_DISTANCE / (6 * VERT_POINT_DISTANCE)),
        'medium': Math.atan((HORZ_POINT_DISTANCE / 2) / VERT_POINT_DISTANCE),
        'large': Math.atan((21 * HORZ_POINT_DISTANCE) / (6 * VERT_POINT_DISTANCE))
      }

POINTS.forEach((row, index) => row.forEach(([x, y]) => {
  var cx = x * HORZ_POINT_DISTANCE + X_OFFSET + (isEven(index) ? ALTERNATING_OFFSET : 0),
      cy = y * HORZ_POINT_DISTANCE * VERT_POINT_DISTANCE + Y_OFFSET,
      point = document.createElementNS(svgns, 'use');

  point.setAttributeNS(null, 'href', `#point`);
  point.setAttributeNS(null, 'x', `${cx}in`);
  point.setAttributeNS(null, 'y', `${cy}in`);
  point.dataset.x = x;
  point.dataset.y = y;

  point.addEventListener('click', e => {
    let selectedSoldier = document.querySelector('.soldier-record.selected');

    if (selectedSoldier) {
      let counter = document.createElementNS(svgns, 'circle');
      let text = document.createElementNS(svgns, 'text');

      counter.setAttributeNS(null, 'cx', `${cx}in`);
      counter.setAttributeNS(null, 'cy', `${cy}in`);
      counter.setAttributeNS(null, 'r', '0.25in');
      counter.dataset.troopNumber = selectedSoldier.dataset.troopNumber;
      counter.dataset.troopAllegiance = selectedSoldier.dataset.troopAllegiance;
      counter.classList.add('counter');

      text.setAttributeNS(null, 'text-anchor', 'middle');
      text.setAttributeNS(null, 'x', `${cx}in`);
      text.setAttributeNS(null, 'y', `${cy + 0.25}in`);
      text.dataset.troopNumber = selectedSoldier.dataset.troopNumber;
      text.dataset.troopAllegiance = selectedSoldier.dataset.troopAllegiance;
      text.textContent = `${selectedSoldier.dataset.troopNumber}`;
      text.classList.add('counter');

      document.querySelectorAll(
        `.counter[data-troop-number="${selectedSoldier.dataset.troopNumber}"][data-troop-allegiance="${selectedSoldier.dataset.troopAllegiance}"]`
      ).forEach(el => el.remove());

      counter.addEventListener('click', e => {
        document.querySelectorAll(
          `.counter[data-troop-number="${selectedSoldier.dataset.troopNumber}"][data-troop-allegiance="${selectedSoldier.dataset.troopAllegiance}"]`
        ).forEach(el => el.remove());

        document.querySelectorAll(
          `.firing-arc[data-troop-number="${selectedSoldier.dataset.troopNumber}"][data-troop-allegiance="${selectedSoldier.dataset.troopAllegiance}"]`
        ).forEach(el => el.remove());
      });

      svg.appendChild(counter);
      svg.appendChild(text);
    }
  });

  point.addEventListener('mouseover', e => {
    let selectedSoldier = document.querySelector('.soldier-record.selected');

    if (selectedSoldier) {
      e.target.classList.add('active');
    }
  });

  point.addEventListener('mouseout', e => e.target.removeAttribute('class'));

  svg.appendChild(point);
}));

map.addEventListener('mousemove', e => {
  let boundingRect = e.target.getBoundingClientRect();
  let pointerX = e.clientX - boundingRect.left;
  let pointerY = e.clientY - boundingRect.top;
  let [maxXpx, maxYpx] = [e.target.width, e.target.height].map(v => v.baseVal.value);

  // console.log('x', `${toFixed(x / boundingRect.width * maxX)}"`, 'y', `${toFixed(y / boundingRect.height * maxY)}"`);

  let activeFiringArc = document.querySelector('polygon.firing-arc.active');

  // TODO: handle exactly horizontal and vertical lines

  if (activeFiringArc) {
    let {x: x1px, y: y1px} = activeFiringArc.points[0];

    let [x2px, y2px] = [
      pointerX / boundingRect.width * maxXpx,
      pointerY / boundingRect.height * maxYpx
    ];

    let xDiff = x2px - x1px;
    let yDiff = y2px - y1px;
    let angle = calculateAngle(xDiff, yDiff);

    console.log('angle:', `${toFixed(radToDeg(angle))}\u00B0`, `${angle}rad`);

    let arcAngle = 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}`;
    }

    activeFiringArc.setAttributeNS(null, 'points', points);
  }
});

document.querySelectorAll('.soldier-record').forEach(el =>
  el.addEventListener('click', e => {
    if (el.classList.contains('selected')) {
      el.classList.remove('selected');
    } else {
      document.querySelectorAll('.soldier-record.selected').forEach(el =>
        el.classList.remove('selected')
      );
      el.classList.add('selected');
    }
  })
);

document.querySelectorAll('.set-firing-arc').forEach(el => el.addEventListener('click', e => {
  let selectedSoldier = document.querySelector('.soldier-record.selected');

  if (selectedSoldier) {
    let {troopNumber, troopAllegiance} = selectedSoldier.dataset;

    let existingArcs = document.querySelectorAll(
      `.firing-arc[data-troop-number="${troopNumber}"][data-troop-allegiance="${troopAllegiance}"]`
    );

    existingArcs.forEach(el => el.remove());

    let counter = document.querySelector(
      `circle.counter[data-troop-number="${troopNumber}"][data-troop-allegiance="${troopAllegiance}"]`
    );

    if (counter) {
      let arcLayer = document.getElementById('firing-arcs');

      let firingArcPlacementListener = e => {
        document.querySelectorAll('.firing-arc.active').forEach(el => el.classList.remove('active'));
        document.querySelector('circle#point').style.display = '';
        map.removeEventListener('click', firingArcPlacementListener);
      };

      map.addEventListener('click', firingArcPlacementListener);

      let pivotPoint = [counter.cx.baseVal.value, counter.cy.baseVal.value];
      let firingArc = document.createElementNS(svgns, 'polygon');

      firingArc.classList.add('firing-arc', 'active');
      firingArc.dataset.troopNumber = troopNumber;
      firingArc.dataset.troopAllegiance = troopAllegiance;
      firingArc.dataset.size = e.target.dataset.size;
      firingArc.setAttributeNS(null, 'points', `${pivotPoint} ${pivotPoint} ${pivotPoint}`);

      arcLayer.prepend(firingArc);

      document.querySelector('circle#point').style.display = 'none';
    }
  }
}));

document.querySelectorAll('.clear-firing-arcs').forEach(el =>
  el.addEventListener('click', ({target: {dataset: {allegiance}}}) =>
    document
      .querySelectorAll(`.firing-arc[data-troop-allegiance="${allegiance}"]`)
      .forEach(el => el.remove())
  )
);