const targetClassName = 'sight-line-target',
activeClassName = 'active';
function cubeDistance(a, b) {
return Math.max(Math.abs(a.q - b.q), Math.abs(a.r - b.r), Math.abs(a.s - b.s));
}
function cubeRound({ q, r, s }) {
let rQ = Math.round(q),
rR = Math.round(r),
rS = Math.round(s);
const 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 lerp(a, b, t) {
return a + (b - a) * t;
}
function cubeLerp(a, b, t) {
return { q: lerp(a.q, b.q, t), r: lerp(a.r, b.r, t), s: lerp(a.s, b.s, t) };
}
function lock(sightLine, cell) {
sightLine.classList.remove(activeClassName);
cell.classList.add(targetClassName);
return cell;
}
function unlock(sightLine, lockTarget) {
sightLine.classList.add(activeClassName);
lockTarget.classList.remove(targetClassName);
return null;
}
let sightLine, lockTarget,
activeHexes = [];
export function create({ x: x1, y: y1 }, { x: x2, y: y2 }) {
const line = document.createElementNS(svgns, 'line');
sightLine = line;
line.classList.add('sight-line');
line.classList.add(activeClassName);
line.setAttributeNS(null, 'x1', x1);
line.setAttributeNS(null, 'y1', y1);
line.setAttributeNS(null, 'x2', x2);
line.setAttributeNS(null, 'y2', y2);
return line;
}
export function calcIndexes(a, b) {
const N = cubeDistance(a, b);
const results = [];
for (let i = 0; i <= N; i++) {
results.push(cubeRound(cubeLerp(a, b, 1.0 / N * i)));
}
return results;
}
export function clear() {
sightLine && sightLine.remove();
sightLine = null;
lockTarget && lockTarget.classList.remove(targetClassName);
lockTarget = null;
}
export function update({ x, y }) {
sightLine.setAttributeNS(null, 'x1', x);
sightLine.setAttributeNS(null, 'y1', y);
}
export function toggleLock(cell) {
lockTarget = lockTarget ? unlock(sightLine, lockTarget) : lock(sightLine, cell);
}
export function getSightLine() {
return sightLine;
}
export function getLockTarget() {
return lockTarget;
}
export function setHexes(hexes) {
activeHexes.forEach(h => h.classList.remove(activeClassName));
hexes.forEach(h => h.classList.add(activeClassName));
activeHexes = hexes;
}