Add zooming in both directions

src/main/js/Main.ts

@@ -53,6 +53,16 @@ class LineSegment {
     }
 
 
+    /**
+     * Returns the angle formed by this `LineSegment` in radians.
+     *
+     * @return the angle formed by this `LineSegment` in radians
+     */
+    angle(): number {
+        return Math.atan2(this.y, this.x);
+    }
+
+
     /**
      * Returns `true` if and only if this `LineSegment` is exactly the same as `other`.
      *
@@ -117,6 +127,7 @@ const settings = {
     fillGoal: 0.3,
     stepTime: 250,
     stepsPerLevel: 5,
+    zoomSpeed: 1 / 30,
 };
 
 
@@ -131,41 +142,37 @@ doAfterLoad(() => {
 
 
     // Model
+    // TODO: Dynamic thickness calculation
     const lines: Line[] = [new Line(1), new Line(5)];
-
     let step = 0;
-    let lastStepTime = Date.now();
     setInterval(() => {
-        const stepLine = Math.floor(step / (settings.stepsPerLevel ** 2));
-        const inductionLine = stepLine + 1;
-        const superInductionLine = stepLine + 2;
+        const currentLevel = lines.findIndex(it => it.segments.length !== 25);
 
-        // Add new low-level segment
-        const length = settings.stepsPerLevel ** (2 + stepLine);
-        // TODO: Accumulate angles
-        const angle = (random_normal() - 0.5) * Math.PI * 2;
-        lines[stepLine].segments.push(new LineSegment(Math.cos(angle) * length, Math.sin(angle) * length));
+        // Add low-level segment
+        const length = settings.stepsPerLevel ** (2 + currentLevel);
+        let angle: number;
+        if (lines[currentLevel].segments.length > 0)
+            angle = lines[currentLevel].segments.slice(-1)[0].angle() + (random_normal() - 0.5) * Math.PI * 2;
+        else
+            angle = Math.random() * Math.PI * 2;
+        lines[currentLevel].segments.push(new LineSegment(Math.cos(angle) * length, Math.sin(angle) * length));
 
-        // Add first-level induction line
-        if ((step + 1) % settings.stepsPerLevel === 0) {
-            if (lines.length <= inductionLine) {
-                lines[inductionLine] = new Line(5 ** inductionLine);
+        // Add induction segments
+        for (const level of [1, 2]) {
+            const inductionLevel = currentLevel + level;
+            const lowerLines = lines[inductionLevel - 1];
+
+            if (lowerLines.segments.length !== 0 && lowerLines.segments.length % 5 === 0) {
+                if (lines.length <= inductionLevel) {
+                    lines[inductionLevel] = new Line(5 ** inductionLevel);
+                }
+
+                lines[inductionLevel].segments.push(lowerLines.sumSegmentsSlice(-settings.stepsPerLevel));
             }
-
-            lines[inductionLine].segments.push(lines[stepLine].sumSegmentsSlice(-settings.stepsPerLevel));
-        }
-
-        // Add second-level induction line
-        if ((step + 1) % (settings.stepsPerLevel ** 2) === 0) {
-            if (lines.length <= superInductionLine) {
-                lines[superInductionLine] = new Line(5 ** superInductionLine);
-            }
-
-            lines[superInductionLine].segments.push(lines[inductionLine].sumSegmentsSlice(-settings.stepsPerLevel));
         }
 
+        // Update shared info
         step++;
-        lastStepTime = Date.now();
     }, settings.stepTime);
 
 
@@ -179,8 +186,7 @@ doAfterLoad(() => {
 
 
     // Draw
-    const startTime = Date.now();
-    let maxX = 0;
+    let maxPoint = new Point(0, 0);
     let zoomFactor = 1;
     const draw = () => {
         ctx.restore();
@@ -201,8 +207,12 @@ doAfterLoad(() => {
         ctx.stroke();
 
         // Zoom
-        if ((1 / zoomFactor) * maxX > canvas.width * settings.fillGoal) {
-            zoomFactor *= (((1 / zoomFactor) * maxX) / (canvas.width * settings.fillGoal)) ** (1 / 60);
+        const excessFactor = Math.max(
+            ((1 / zoomFactor) * maxPoint.x) / (canvas.width * settings.fillGoal),
+            ((1 / zoomFactor) * maxPoint.y) / (canvas.height * settings.fillGoal)
+        );
+        if (excessFactor > 1) {
+            zoomFactor *= excessFactor ** settings.zoomSpeed;
         }
         ctx.scale(1 / zoomFactor, 1 / zoomFactor);
 
@@ -218,7 +228,10 @@ doAfterLoad(() => {
                 lastPos = new Point(lastPos.x + segment.x, lastPos.y + segment.y);
                 ctx.lineTo(lastPos.x, lastPos.y);
 
-                maxX = Math.max(maxX, lastPos.x);
+                maxPoint = new Point(
+                    Math.max(maxPoint.x, Math.abs(lastPos.x)),
+                    Math.max(maxPoint.y, Math.abs(lastPos.y))
+                );
             }
 
             ctx.stroke();