feat: implement getLinePoints

Author: opatiny

src/utils/geometry/__tests__/getCirclePoints.test.ts

@@ -1,4 +1,9 @@
-import { getCirclePoints, getCompassPoints } from '../getCirclePoints';
+import {
+  getCirclePoints,
+  getCompassPoints,
+  getFilledCirclePoints,
+  getLinePoints,
+} from '../getCirclePoints';
 
 test('circle with radius 1', () => {
   expect(getCirclePoints(1)).toStrictEqual([
@@ -60,3 +65,22 @@ test('compass points, radius 1', () => {
     { row: -1, column: 0 },
   ]);
 });
+
+test('horizonal line', () => {
+  expect(
+    getLinePoints({ column: 0, row: 0 }, { column: 2, row: 0 }),
+  ).toStrictEqual([
+    { row: 0, column: 0 },
+    { row: 0, column: 1 },
+    { row: 0, column: 2 },
+  ]);
+});
+
+test('filled circle with radius 1', () => {
+  expect(getFilledCirclePoints(1, { column: 0, row: 0 })).toStrictEqual([
+    { row: 0, column: 1 },
+    { row: 1, column: 0 },
+    { row: 0, column: -1 },
+    { row: -1, column: 0 },
+  ]);
+});

src/utils/geometry/getCirclePoints.ts

@@ -1,9 +1,9 @@
-import { circle } from 'bresenham-zingl';
+import { circle, line } from 'bresenham-zingl';
 
 import { Point } from '../../geometry';
 
 /**
- * Get the coordinates of the points on a circle. The reference is the center of the circle.
+ * Get the coordinates of the points on a circle. The reference is the origin of the circle.
  * The first point is the right one and they are then sorted clockwise.
  *
  * @param radius - Radius of the circle.
@@ -31,7 +31,64 @@ export function getCirclePoints(radius: number): Point[] {
 }
 
 /**
- * Get the coordinates of the points that are on right, bottom, left and top at a given radius. The reference is the center of the circle.
+ * Get the coordinates of the points in a circle of given radius.
+ *
+ * @param radius - Radius of the circle.
+ * @param center - Center of the cirlce.
+ * @returns The coordinates of the points in a circle of given radius.
+ */
+export function getFilledCirclePoints(radius: number, center: Point): Point[] {
+  let circlePoints: Point[] = [];
+
+  if (radius === 1) {
+    circlePoints.push(center);
+  }
+  circle(center.column, center.row, radius, (column: number, row: number) => {
+    circlePoints.push({ row: row - radius, column: column - radius });
+
+    if (column - 1 > center.column) {
+      getLinePoints(
+        { row, column: column - 1 },
+        { row, column: center.column },
+      );
+    } else if (column + 1 < center.column) {
+      getLinePoints(
+        { row, column: column + 1 },
+        { row, column: center.column },
+      );
+    }
+  });
+
+  return circlePoints;
+}
+
+/**
+ * Get the coordinates of the points on a line.
+ *
+ * @param from - Starting point
+ * @param to - End point.
+ * @returns The coordinates of the points on the line.
+ */
+export function getLinePoints(from: Point, to: Point): Point[] {
+  let linePoints: Point[] = [];
+  line(
+    from.column,
+    from.row,
+    to.column,
+    to.row,
+    (column: number, row: number) => {
+      linePoints.push({
+        row,
+        column,
+      });
+    },
+  );
+
+  return linePoints;
+}
+
+/**
+ * Get the coordinates of the points that are on right, bottom, left and top at a given radius. The reference is the origin of the circle.
  * First point is the most on the right, then points are in clockwise order.
  *
  * @param radius - Radius of the circle.