From feb1572ab1f196c7c7f60209c53dbf65c8d67142 Mon Sep 17 00:00:00 2001
From: Shivang Dwivedi <83856109+studentshivang@users.noreply.github.com>
Date: Thu, 18 May 2023 23:06:53 +0530
Subject: [PATCH] Fix horizontal flip functionality for Hi-C display (#3667)

This commit intends to add functionality to the "Horizontally Flip" Feature in the Hamburger Menu.
Detailed discussion can be found in issue #3460 (https://github.com/GMOD/jbrowse-components/issues/3460)
---
 plugins/hic/src/HicRenderer/HicRenderer.tsx | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/plugins/hic/src/HicRenderer/HicRenderer.tsx b/plugins/hic/src/HicRenderer/HicRenderer.tsx
index c8c9d9a15c..aa7b88306b 100644
--- a/plugins/hic/src/HicRenderer/HicRenderer.tsx
+++ b/plugins/hic/src/HicRenderer/HicRenderer.tsx
@@ -61,7 +61,9 @@ export default class HicRenderer extends ServerSideRendererType {
       resolution,
       sessionId,
       adapterConfig,
+      regions,
     } = props
+    const [region] = regions
     const { dataAdapter } = await getAdapter(
       this.pluginManager,
       sessionId,
@@ -87,6 +89,14 @@ export default class HicRenderer extends ServerSideRendererType {
         maxBin = Math.max(Math.max(bin1, bin2), maxBin)
       }
       await abortBreakPoint(signal)
+      function horizontallyFlip() {
+        ctx.scale(-1, 1)
+        const width = (region.end - region.start) / bpPerPx
+        ctx.translate(-width, 0)
+      }
+      if (region.reversed === true) {
+        horizontallyFlip()
+      }
       ctx.rotate(-Math.PI / 4)
       let start = Date.now()
       for (let i = 0; i < features.length; i++) {