Web Dev Solutions

+const HORZ_POINT_DISTANCE = 1.005,

+ VERT_POINT_DISTANCE = Math.sqrt(3) * HORZ_POINT_DISTANCE / 2,

+

+ 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))

+};

+

+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 position(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 = 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);

+ }

+}

+

+export default class FiringArc {

+ constructor(svg) {

+ this.svg = svg;

+ }

+

+ set(size, troopAllegiance, troopNumber, { x, y }) {

+ const svgns = "http://www.w3.org/2000/svg";

+

+ 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 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', position);

+ 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', position);

+ };

+

+ grid.style.pointerEvents = 'none';

+ this.svg.addEventListener('mousemove', position);

+ firingArc.addEventListener('click', firingArcPlacementListener);

+ firingArc.addEventListener('contextmenu', cancelFiringArcPlacement);

+ }

+}