feat: routes rendering

modules/dynamic/auto-update.js

@@ -843,4 +843,12 @@ export function resolveVersionConflicts(version) {
       }
     });
   }
+
+  if (version < 1.98) {
+    // v1.98.00 changed routes generation algorithm and data format
+    // 1. cells.road => cells.route; 1 = MAIN; 2 = TRAIL; 3 = SEA;
+    // 2. cells.crossroad is removed
+    // 3. pack.routes is added
+    // 4. rendering is changed
+  }
 }

modules/routes-generator.js

@@ -134,15 +134,15 @@ window.Routes = (function () {
       const routes = [];
 
       for (const {feature, cells} of mainRoads) {
-        routes.push({i: routes.length, type: "road", feature, cells});
+        routes.push({i: routes.length, group: "roads", feature, cells});
       }
 
       for (const {feature, cells} of trails) {
-        routes.push({i: routes.length, type: "trail", feature, cells});
+        routes.push({i: routes.length, group: "trails", feature, cells});
       }
 
       for (const {feature, cells} of seaRoutes) {
-        routes.push({i: routes.length, type: "sea", feature, cells});
+        routes.push({i: routes.length, group: "searoutes", feature, cells});
       }
 
       return routes;

modules/ui/layers.js

@@ -169,6 +169,7 @@ function restoreLayers() {
   if (layerIsOn("toggleGrid")) drawGrid();
   if (layerIsOn("toggleCoordinates")) drawCoordinates();
   if (layerIsOn("toggleCompass")) compass.style("display", "block");
+  if (layerIsOn("toggleRoutes")) drawRoutes();
   if (layerIsOn("toggleTemp")) drawTemp();
   if (layerIsOn("togglePrec")) drawPrec();
   if (layerIsOn("togglePopulation")) drawPopulation();
@@ -1624,18 +1625,137 @@ function drawRivers() {
 function toggleRoutes(event) {
   if (!layerIsOn("toggleRoutes")) {
     turnButtonOn("toggleRoutes");
-    $("#routes").fadeIn();
+    drawRoutes();
     if (event && isCtrlClick(event)) editStyle("routes");
   } else {
-    if (event && isCtrlClick(event)) {
-      editStyle("routes");
-      return;
-    }
-    $("#routes").fadeOut();
+    if (event && isCtrlClick(event)) return editStyle("routes");
+    routes.selectAll("path").remove();
     turnButtonOff("toggleRoutes");
   }
 }
 
+function drawRoutes() {
+  TIME && console.time("drawRoutes");
+  const {cells, burgs} = pack;
+  const lineGen = d3.line();
+
+  const SHARP_ANGLE = 135;
+  const VERY_SHARP_ANGLE = 115;
+
+  const points = adjustBurgPoints(); // mutable array of points
+  const routePaths = {};
+
+  const lineGenMap = {
+    roads: d3.curveCatmullRom.alpha(0.1),
+    trails: d3.curveCatmullRom.alpha(0.1),
+    searoutes: d3.curveBasis,
+    default: d3.curveCatmullRom.alpha(0.1)
+  };
+
+  for (const {i, group, cells} of pack.routes) {
+    if (group !== "searoutes") straightenPathAngles(cells); // mutates points
+    const pathPoints = getPathPoints(cells);
+
+    lineGen.curve(lineGenMap[group] || lineGenMap.default);
+    const path = round(lineGen(pathPoints), 1);
+
+    if (!routePaths[group]) routePaths[group] = [];
+    routePaths[group].push(`<path id="route${i}" d="${path}"/>`);
+  }
+
+  routes.selectAll("path").remove();
+  for (const group in routePaths) {
+    routes.select("#" + group).html(routePaths[group].join(""));
+  }
+
+  TIME && console.timeEnd("drawRoutes");
+
+  function adjustBurgPoints() {
+    const points = Array.from(cells.p);
+
+    for (const burg of burgs) {
+      if (burg.i === 0) continue;
+      const {cell, x, y} = burg;
+      points[cell] = [x, y];
+    }
+
+    return points;
+  }
+
+  function straightenPathAngles(cellIds) {
+    for (let i = 1; i < cellIds.length - 1; i++) {
+      const cellId = cellIds[i];
+      if (cells.burg[cellId]) continue;
+
+      const prev = points[cellIds[i - 1]];
+      const that = points[cellId];
+      const next = points[cellIds[i + 1]];
+
+      const dAx = prev[0] - that[0];
+      const dAy = prev[1] - that[1];
+      const dBx = next[0] - that[0];
+      const dBy = next[1] - that[1];
+      const angle = (Math.atan2(dAx * dBy - dAy * dBx, dAx * dBx + dAy * dBy) * 180) / Math.PI;
+
+      if (Math.abs(angle) < SHARP_ANGLE) {
+        const middleX = (prev[0] + next[0]) / 2;
+        const middleY = (prev[1] + next[1]) / 2;
+
+        if (Math.abs(angle) < VERY_SHARP_ANGLE) {
+          const newX = (that[0] + middleX * 2) / 3;
+          const newY = (that[1] + middleY * 2) / 3;
+          points[cellId] = [newX, newY];
+          continue;
+        }
+
+        const newX = (that[0] + middleX) / 2;
+        const newY = (that[1] + middleY) / 2;
+        points[cellId] = [newX, newY];
+      }
+    }
+  }
+
+  function getPathPoints(cellIds) {
+    const pathPoints = cellIds.map(cellId => points[cellId]);
+
+    if (pathPoints.length === 2) {
+      // curve and shorten 2-points line
+      const [[x1, y1], [x2, y2]] = pathPoints;
+
+      const middleX = (x1 + x2) / 2;
+      const middleY = (y1 + y2) / 2;
+
+      // add shifted point at the middle to curve the line a bit
+      const NORMAL_LENGTH = 0.3;
+      const normal = getNormal([x1, y1], [x2, y2]);
+      const sign = cellIds[0] % 2 ? 1 : -1;
+      const normalX = middleX + NORMAL_LENGTH * Math.cos(normal) * sign;
+      const normalY = middleY + NORMAL_LENGTH * Math.sin(normal) * sign;
+
+      // make line shorter to avoid overlapping with other lines
+      const SHORT_LINE_LENGTH_MODIFIER = 0.8;
+      const distX = x2 - x1;
+      const distY = y2 - y1;
+      const nx1 = x1 + distX * SHORT_LINE_LENGTH_MODIFIER;
+      const ny1 = y1 + distY * SHORT_LINE_LENGTH_MODIFIER;
+      const nx2 = x2 - distX * SHORT_LINE_LENGTH_MODIFIER;
+      const ny2 = y2 - distY * SHORT_LINE_LENGTH_MODIFIER;
+
+      return [
+        [nx1, ny1],
+        [normalX, normalY],
+        [nx2, ny2]
+      ];
+    }
+
+    return pathPoints;
+  }
+
+  function getNormal([x1, y1], [x2, y2]) {
+    return Math.atan2(y1 - y2, x1 - x2) + Math.PI / 2;
+  }
+}
+
 function toggleMilitary() {
   if (!layerIsOn("toggleMilitary")) {
     turnButtonOn("toggleMilitary");