From d0fefdf04ed1334b1ca268584b9ed03f2cf08606 Mon Sep 17 00:00:00 2001
From: braks <78412429+bcakmakoglu@users.noreply.github.com>
Date: Wed, 1 Feb 2023 20:55:34 +0100
Subject: [PATCH] feat(core): add auto pan utils

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>
---
 packages/core/src/utils/autopan.ts | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 packages/core/src/utils/autopan.ts

diff --git a/packages/core/src/utils/autopan.ts b/packages/core/src/utils/autopan.ts
new file mode 100644
index 00000000..feb60c35
--- /dev/null
+++ b/packages/core/src/utils/autopan.ts
@@ -0,0 +1,20 @@
+import type { Dimensions, XYPosition } from '~/types'
+
+// returns a number between 0 and 1 that represents the velocity of the movement
+// when the mouse is close to the edge of the canvas
+const calcAutoPanVelocity = (value: number, min: number, max: number) => {
+  if (value < min) {
+    return clamp(Math.abs(value - min), 1, 50) / 50
+  } else if (value > max) {
+    return -clamp(Math.abs(value - max), 1, 50) / 50
+  }
+
+  return 0
+}
+
+export const calcAutoPan = (pos: XYPosition, bounds: Dimensions) => {
+  const xMovement = calcAutoPanVelocity(pos.x, 35, bounds.width - 35) * 20
+  const yMovement = calcAutoPanVelocity(pos.y, 35, bounds.height - 35) * 20
+
+  return [xMovement, yMovement]
+}