btroops/index.js

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 troopSelector(number, allegiance) {
  return `[data-troop-number="${number}"][data-troop-allegiance="${allegiance}"]`;
}

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'),
    hex = document.getElementById('point');

const { x: VIEWBOX_X, y: VIEWBOX_Y, width: VIEWBOX_WIDTH, height: VIEWBOX_HEIGHT } =
  svg.viewBox.baseVal;

const COLUMN_COUNT = 33,
      ROW_COUNT = 51,
      HORZ_POINT_DISTANCE = 1.005,
      VERT_POINT_DISTANCE = Math.sqrt(3) * HORZ_POINT_DISTANCE / 2,
      ALTERNATING_OFFSET = HORZ_POINT_DISTANCE / 2,
      CIRCUMRADIUS = Math.max(...[...new Set(Object.values(hex.points).flatMap(({x, y}) => [x, y]))]),
      INRADIUS = CIRCUMRADIUS * Math.sqrt(3) / 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))
      }

const settingsPanel = document.getElementById('panel');

Object.values(settingsPanel.querySelectorAll('fieldset')).forEach(fieldset => {
  const target = document.getElementById(fieldset.name);
  const transform = window.getComputedStyle(target).transform.match(/-?\d+\.?\d*/g);
  const inputs = fieldset.querySelectorAll('input');

  if (transform) {
    const [scaleX, skewX, skewY, scaleY, translateX, translateY] =
      transform.map(n => parseFloat(n));

      const cosScale = Math.sqrt(scaleX**2 + skewY**2);
      const sinScale = Math.sqrt(scaleY**2 + skewX**2);

      let values = {
        scale: Math.round((sinScale + cosScale) / 2 * 10) / 10,
        translateX: translateX,
        translateY: translateY,
        rotate: Math.round(radToDeg((Math.acos(scaleX / cosScale) + Math.asin(skewX / sinScale)) / 2) * 10) / 10
      }

      inputs.forEach(input => input.value = values[input.name]);
  }

  inputs.forEach(input => {
    input.addEventListener('pointerenter', e => e.target.focus());

    input.addEventListener('input', e => {
      let { scale, translateX, translateY, rotate} = Object.values(inputs).reduce((acc, input) => {
        acc[input.name] = input.value;
        return acc;
      }, {});

      let transform = `translate(${translateX}px, ${translateY}px) rotate(${rotate}deg) scale(${scale}) `
      target.style.transform = transform;
    });

    input.addEventListener('pointerleave', () => document.activeElement.blur());
  });
});

const pointsGroup = document.getElementById('points');

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,
  // var cx = x * Math.sqrt(3) + X_OFFSET + (isEven(index) ? INRADIUS : 0),
  var cx = x * INRADIUS * 2 + (isEven(index) ? INRADIUS : 0),
      cy = y * 3 / 2 * CIRCUMRADIUS,
      point = document.createElementNS(svgns, 'use');

  point.setAttributeNS(null, 'href', `#point`);
  point.setAttributeNS(null, 'x', `${toFixed(cx)}`);
  point.setAttributeNS(null, 'y', `${toFixed(cy)}`);
  // point.setAttributeNS(null, 'x', `${cx}`);
  // point.setAttributeNS(null, 'y', `${cy}`);
  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'),
          text = document.createElementNS(svgns, 'text'),
          {troopNumber, troopAllegiance} = selectedSoldier.dataset,
          selector = troopSelector(troopNumber, troopAllegiance);

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

      document.querySelectorAll(`.counter${selector}`).forEach(el => el.remove());

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

        if (selectedSoldier) {
          let {troopNumber, troopAllegiance} = selectedSoldier.dataset,
              selector = troopSelector(troopNumber, troopAllegiance),
              targetIsSelectedSoldier = [
                e.target.dataset.troopNumber == troopNumber,
                e.target.dataset.troopAllegiance == troopAllegiance
              ].every(el => el);

          if (targetIsSelectedSoldier) {
            document.querySelectorAll(`.counter${selector}`).forEach(el => el.remove());
            document.querySelectorAll(`.firing-arc${selector}`).forEach(el => el.remove());
          }
        }
      });

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

        if (selectedSoldier) {
          let {troopNumber, troopAllegiance} = selectedSoldier.dataset,
              selector = troopSelector(troopNumber, troopAllegiance),
              source = document.querySelector(`circle.counter${selector}`),

              // TODO: use isEqualNode() method instead
              sourceAndTargetAreNotTheSame = [
                troopNumber != e.target.dataset.troopNumber,
                troopAllegiance != e.target.dataset.troopAllegiance
              ].some(el => el);

          if (source && sourceAndTargetAreNotTheSame) {
            let sightLine = document.createElementNS(svgns, 'line');

            sightLine.classList.add('sight-line');
            sightLine.setAttributeNS(null, 'x1', source.getAttribute('cx'));
            sightLine.setAttributeNS(null, 'y1', source.getAttribute('cy'));
            sightLine.setAttributeNS(null, 'x2', e.target.getAttribute('cx'));
            sightLine.setAttributeNS(null, 'y2', e.target.getAttribute('cy'));

            svg.appendChild(sightLine);
          }
        }
      });

      counter.addEventListener('mouseleave', e => {
        document.querySelectorAll('.sight-line').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'));

  pointsGroup.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())
  )
);

svg.addEventListener('wheel', e => {
  e.preventDefault();

  // const pt = svg.createSVGPoint();
  const pt = new DOMPoint(e.clientX, e.clientY);

  // pt.x = e.clientX;
  // pt.y = e.clientY;

  const svgP = pt.matrixTransform(svg.getScreenCTM().inverse());

  let { x, y, width, height } = svg.viewBox.baseVal;

  let widthDelta = width * 0.25;
  let heightDelta = height * 0.25;

  let xChange = (svgP.x - x) / width * widthDelta;
  let yChange = (svgP.y - y) / height * heightDelta;

  let widthChange = (1 - ((svgP.x - x) / width)) * widthDelta;
  let heightChange = (1 - ((svgP.y - y) / height)) * heightDelta;

  let newX = parseInt(e.deltaY < 0 ? x + xChange : x - xChange);
  let newWidth = parseInt(e.deltaY < 0 ? width - xChange - widthChange : width + xChange + widthChange);

  let newY = parseInt(e.deltaY < 0 ? y + yChange : y - yChange);
  let newHeight = parseInt(e.deltaY < 0 ? height - yChange - heightChange : height + yChange + heightChange);

  // console.log('VIEWBOX_X', 'VIEWBOX_Y', VIEWBOX_X, VIEWBOX_Y);
  // console.log('VIEWBOX_WIDTH', 'VIEWBOX_HEIGHT', VIEWBOX_WIDTH, VIEWBOX_HEIGHT);

  // if (newWidth + newX > VIEWBOX_WIDTH + VIEWBOX_X && newX < VIEWBOX_X) {
  //   newWidth = VIEWBOX_WIDTH;
  //   newX = VIEWBOX_X;
  // } else if (newWidth + newX > VIEWBOX_WIDTH + VIEWBOX_X) {
  //   let diff = newWidth + newX - VIEWBOX_WIDTH - VIEWBOX_X;
  //   newX = newX - diff;
  // }

  // if (newHeight + newY > VIEWBOX_HEIGHT + VIEWBOX_Y && newY < VIEWBOX_Y) {
  //   newHeight = VIEWBOX_HEIGHT;
  //   newY = VIEWBOX_Y;
  // } else if (newHeight + newY > VIEWBOX_HEIGHT + VIEWBOX_Y) {
  //   let diff = newHeight + newY - VIEWBOX_HEIGHT - VIEWBOX_Y;
  //   newY = newY - diff;
  // }

  // newX = newX < VIEWBOX_X ? VIEWBOX_X : newX;
  // newY = newY < VIEWBOX_Y ? VIEWBOX_Y : newY;

  svg.setAttributeNS(null, 'viewBox', `${newX} ${newY} ${newWidth} ${newHeight}`);
});

svg.addEventListener('pointerdown', e => {
  const minPanDistanceThreshold = 5;

  let dist, ctm,
      pan = false,
      { x, y, width, height } = svg.viewBox.baseVal,
      startPt = new DOMPoint(e.clientX, e.clientY),
      movePt = new DOMPoint();

  function pointerMove(e) {
    movePt.x = e.clientX;
    movePt.y = e.clientY;
    dist = Math.sqrt((movePt.x - startPt.x)**2 + (movePt.y - startPt.y)**2);

    if (!pan && dist >= minPanDistanceThreshold) {
      pan = true;
      startPt.x = e.clientX;
      startPt.y = e.clientY;
    }

    if (pan) {
      svg.setPointerCapture(e.pointerId);
      ctm = svg.getScreenCTM().inverse();

      const [svgStartPt, svgMovePt] = [startPt, movePt].map(p => p.matrixTransform(ctm)),
            moveX = parseInt(svgStartPt.x - svgMovePt.x + x),
            moveY = parseInt(svgStartPt.y - svgMovePt.y + y);

      svg.setAttributeNS(null, 'viewBox', `${moveX} ${moveY} ${width} ${height}`);
    }
  }

  function pointerUp(e) {
    svg.releasePointerCapture(e.pointerId);
    svg.removeEventListener('pointermove', pointerMove);
    svg.removeEventListener('pointerup', pointerUp);
  }

  svg.addEventListener('pointermove', pointerMove);
  svg.addEventListener('pointerup', pointerUp);
});