From 9c1bc02fe9635f689c130f2eb4edf29b7c83ab7a Mon Sep 17 00:00:00 2001
From: Cocoa <momijizukamori@gmail.com>
Date: Tue, 12 Mar 2024 17:11:42 -0400
Subject: [PATCH] Fixed folio duplexrotate - but at what cost...

---
 src/book.js         |  8 +++++++-
 src/utils/layout.js | 17 +++++++++++++----
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/src/book.js b/src/book.js
index af666c1..fd2008f 100644
--- a/src/book.js
+++ b/src/book.js
@@ -94,6 +94,11 @@ export class Book {
     const pageLayout = PAGE_LAYOUTS[configuration.pageLayout];
 
     this.page_layout = pageLayout;
+    // Slightly messy hack because folio with duplex rotation is the only layout where different sides have different rotations
+    this.alt_layout =
+      configuration.rotatePage && configuration.pageLayout === 'folio'
+        ? PAGE_LAYOUTS.folio_alt
+        : null;
     this.per_sheet = pageLayout.per_sheet;
     this.pack_pages = configuration.wackySpacing === 'wacky_pack';
     this.fore_edge_padding_pt = configuration.foreEdgePaddingPt;
@@ -477,7 +482,8 @@ export class Book {
 
     // const alt_folio = this.per_sheet == 4 && back;
 
-    const positions = calculateLayout(this);
+    const positions =
+      this.alt_layout && !back ? calculateLayout(this) : calculateLayout(this, true);
 
     let side2flag = back;
 
diff --git a/src/utils/layout.js b/src/utils/layout.js
index a040371..98e928d 100644
--- a/src/utils/layout.js
+++ b/src/utils/layout.js
@@ -4,7 +4,7 @@
  *
  * @return {import("../book.js").Position[]}
  */
-export function calculateLayout(book) {
+export function calculateLayout(book, alt) {
   const l = calculateDimensions(book);
   const {
     layoutCell,
@@ -16,8 +16,8 @@ export function calculateLayout(book) {
   } = l;
   const [cellWidth, cellHeight] = layoutCell;
   const positions = [];
-
-  l.layout.rotations.forEach((row, i) => {
+  const rotations = alt && l.alt_layout ? l.alt_layout.rotations : l.layout.rotations;
+  rotations.forEach((row, i) => {
     row.forEach((col, j) => {
       const xForeEdgeShift = xForeEdgeShiftFunc();
       const xBindingShift = xBindingShiftFunc();
@@ -94,7 +94,15 @@ export function calculateLayout(book) {
  * }
  */
 export function calculateDimensions(book) {
-  const { cropbox, padding_pt, papersize, page_layout, page_positioning, page_scaling } = book;
+  const {
+    cropbox,
+    padding_pt,
+    papersize,
+    page_layout,
+    alt_layout,
+    page_positioning,
+    page_scaling,
+  } = book;
 
   const { width, height } = cropbox;
   const pageX = width + Math.max(padding_pt.binding, 0) + Math.max(padding_pt.fore_edge, 0);
@@ -160,6 +168,7 @@ export function calculateDimensions(book) {
   };
   return {
     layout: page_layout,
+    alt_layout: alt_layout,
     rawPdfSize: [width, height],
     pdfScale: [sx, sy],
     pdfSize: [pageX, pageY],