add hw2

node_modules/roughjs/bin/fillers/dashed-filler.js

@@ -0,0 +1,36 @@
+import { lineLength } from '../geometry';
+import { polygonHachureLines } from './scan-line-hachure';
+export class DashedFiller {
+    constructor(helper) {
+        this.helper = helper;
+    }
+    fillPolygons(polygonList, o) {
+        const lines = polygonHachureLines(polygonList, o);
+        return { type: 'fillSketch', ops: this.dashedLine(lines, o) };
+    }
+    dashedLine(lines, o) {
+        const offset = o.dashOffset < 0 ? (o.hachureGap < 0 ? (o.strokeWidth * 4) : o.hachureGap) : o.dashOffset;
+        const gap = o.dashGap < 0 ? (o.hachureGap < 0 ? (o.strokeWidth * 4) : o.hachureGap) : o.dashGap;
+        const ops = [];
+        lines.forEach((line) => {
+            const length = lineLength(line);
+            const count = Math.floor(length / (offset + gap));
+            const startOffset = (length + gap - (count * (offset + gap))) / 2;
+            let p1 = line[0];
+            let p2 = line[1];
+            if (p1[0] > p2[0]) {
+                p1 = line[1];
+                p2 = line[0];
+            }
+            const alpha = Math.atan((p2[1] - p1[1]) / (p2[0] - p1[0]));
+            for (let i = 0; i < count; i++) {
+                const lstart = i * (offset + gap);
+                const lend = lstart + offset;
+                const start = [p1[0] + (lstart * Math.cos(alpha)) + (startOffset * Math.cos(alpha)), p1[1] + lstart * Math.sin(alpha) + (startOffset * Math.sin(alpha))];
+                const end = [p1[0] + (lend * Math.cos(alpha)) + (startOffset * Math.cos(alpha)), p1[1] + (lend * Math.sin(alpha)) + (startOffset * Math.sin(alpha))];
+                ops.push(...this.helper.doubleLineOps(start[0], start[1], end[0], end[1], o));
+            }
+        });
+        return ops;
+    }
+}