Merge pull request #108 from leviat-tech/feat-annotation-arrow

feat: annotations - arrow

docs/src/guide/api.md

@@ -301,6 +301,25 @@ Places an angle dimension given a center point, a point along a line, and an ang
 // Construction: center, point, angle
 const result = sketch.angle_dim([0, 0], [100, 0], 30);
 // Will result in an angle dimension indicating 30 degrees.
+
+```
+
+
+### arrow( { startPoint, endPoint, neckWidth, arrowHeadLength, arrowHeadWidth, } )_
+
+Places a basic arrow using the params object structure example below:.
+params = {
+      startPoint: [0, 0],
+      endPoint: [0, 20],
+      neckWidth: 2,
+      arrowHeadLength: 7.5,
+      arrowHeadWidth: 6,
+    }
+
+```js
+const result = sketch.arrow({ startPoint: [0, 0], endPoint: [0, 20], neckWidth: 2, arrowHeadLength: 7.5, arrowHeadWidth: 6 });
+// Will result in an arrow pointing vertically upwards.
+
 ```
 
 ## Operations

src/features/annotation/arrow.js

@@ -0,0 +1,38 @@
+module.exports = function arrow(sketch, params) {
+  // start points = start points, x, y
+  // end points = end points, x, y
+  // width = width or thickness of neck of arrow, required parameter
+  // arrowHeadLength = Arrow Head Length, required parameter
+  // arrowHeadWidth = Arrow Head Width, required parameter
+
+  const { startPoint, endPoint, neckWidth, arrowHeadLength, arrowHeadWidth } = params;
+  const radsToDegrees = (rads) => (rads / Math.PI) * 180.0;
+  const relativeX = endPoint[0] - startPoint[0];
+  const relativeY = endPoint[1] - startPoint[1];
+  const arrowLength = Math.sqrt(relativeX ** 2 + relativeY ** 2);
+  const rotationRads = Math.atan2(relativeY, relativeX);
+  const rotationDegrees = radsToDegrees(rotationRads) - 90;
+  const neckWidthHalf = neckWidth / 2;
+  const arrowHeadWidthHalf = arrowHeadWidth / 2;
+  const neckLength = arrowLength - arrowHeadLength;
+
+  const pointsHead = [
+    [-arrowHeadWidthHalf, neckLength],
+    [0, arrowLength],
+    [arrowHeadWidthHalf, neckLength],
+    [0, neckLength],
+  ];
+  const pointsNeck = [
+    [-neckWidthHalf, neckLength],
+    [neckWidthHalf, neckLength],
+    [neckWidthHalf, 0],
+    [-neckWidthHalf, 0],
+    [-neckWidthHalf, neckLength],
+  ];
+
+  const arrowHead = sketch.polyface(...pointsHead);
+  const arrowNeck = sketch.polyface(...pointsNeck);
+  const arrowSketch = arrowNeck.union(arrowHead);
+
+  return sketch.new.add(arrowSketch.rotate(rotationDegrees).translate(startPoint[0], startPoint[1]));
+};

src/features/index.js

@@ -7,6 +7,7 @@ const style_all = require('./style/style_all.js');
 
 const aligned_dim = require('./annotation/aligned-dim.js');
 const angle_dim = require('./annotation/angle-dim.js');
+const arrow = require('./annotation/arrow.js');
 const diameter_dim = require('./annotation/diameter-dim.js');
 const dim_string = require('./annotation/dim-string.js');
 const leader = require('./annotation/leader.js');
@@ -67,6 +68,7 @@ module.exports = {
 
   aligned_dim,
   angle_dim,
+  arrow,
   diameter_dim,
   dim_string,
   leader,