From f0673b8f585e2963b542998aba16671a4ffa1caa Mon Sep 17 00:00:00 2001
From: celogeek <65178+celogeek@users.noreply.github.com>
Date: Mon, 16 Jan 2023 08:46:32 +0100
Subject: [PATCH] remove blank page for double page rendering

---
 README.md                                |  2 ++
 internal/epub/core.go                    |  5 +++--
 internal/epub/templates/content.opf.tmpl | 15 +++++++++------
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/README.md b/README.md
index 57a11bb..672647e 100644
--- a/README.md
+++ b/README.md
@@ -94,6 +94,8 @@ Usage of go-comic-converter:
     	Limit size of the ePub: Default nolimit (0), Minimum 20
   -manga
     	Manga mode (right to left)
+  -noblankpage
+    	Remove blank pages
   -nocrop
     	Disable cropping
   -output string
diff --git a/internal/epub/core.go b/internal/epub/core.go
index 41a3cf5..5cf21fe 100644
--- a/internal/epub/core.go
+++ b/internal/epub/core.go
@@ -23,6 +23,7 @@ type ImageOptions struct {
 	Contrast            int
 	AutoRotate          bool
 	AutoSplitDoublePage bool
+	NoBlankPage         bool
 	Manga               bool
 	Workers             int
 }
@@ -73,7 +74,7 @@ func NewEpub(options *EpubOptions) *ePub {
 			return
 		},
 		"spread_blank": func(part int) bool {
-			if part == 1 && spreadRight == options.Manga {
+			if !options.NoBlankPage && part == 1 && spreadRight == options.Manga {
 				return true
 			}
 			return false
@@ -216,7 +217,7 @@ func (e *ePub) Write() error {
 				return err
 			}
 
-			if img.Part == 1 {
+			if !e.NoBlankPage && img.Part == 1 {
 				if err := wz.WriteFile(
 					fmt.Sprintf("OEBPS/Text/%d_sp.xhtml", img.Id),
 					e.render(blankTmpl, map[string]any{
diff --git a/internal/epub/templates/content.opf.tmpl b/internal/epub/templates/content.opf.tmpl
index a1855cb..6a59158 100644
--- a/internal/epub/templates/content.opf.tmpl
+++ b/internal/epub/templates/content.opf.tmpl
@@ -1,17 +1,18 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <package version="3.0" unique-identifier="BookID" xmlns="http://www.idpf.org/2007/opf">
+{{ $info := .Info }}
 <metadata xmlns:opf="http://www.idpf.org/2007/opf" xmlns:dc="http://purl.org/dc/elements/1.1/">
-<dc:title>{{ .Info.Title }}</dc:title>
+<dc:title>{{ $info.Title }}</dc:title>
 <dc:language>en-US</dc:language>
-<dc:identifier id="BookID">urn:uuid:{{ .Info.UID }}</dc:identifier>
+<dc:identifier id="BookID">urn:uuid:{{ $info.UID }}</dc:identifier>
 <dc:contributor id="contributor">GO Comic Converter</dc:contributor>
 <dc:creator>GO Comic Converter</dc:creator>
-<meta property="dcterms:modified">{{ .Info.UpdatedAt }}</meta>
+<meta property="dcterms:modified">{{ $info.UpdatedAt }}</meta>
 <meta name="cover" content="cover"/>
 <meta name="fixed-layout" content="true"/>
-<meta name="original-resolution" content="{{ .Info.ViewWidth }}x{{ .Info.ViewHeight }}"/>
+<meta name="original-resolution" content="{{ $info.ViewWidth }}x{{ $info.ViewHeight }}"/>
 <meta name="book-type" content="comic"/>
-<meta name="primary-writing-mode" content="horizontal-{{ if .Info.Manga }}rl{{ else }}lr{{ end }}"/>
+<meta name="primary-writing-mode" content="horizontal-{{ if $info.Manga }}rl{{ else }}lr{{ end }}"/>
 <meta name="zero-gutter" content="true"/>
 <meta name="zero-margin" content="true"/>
 <meta name="ke-border-color" content="#FFFFFF"/>
@@ -28,12 +29,14 @@
 {{ range .Images }}
 <item id="page_{{ .Id }}_p{{ .Part}}" href="Text/{{ .Id }}_p{{ .Part}}.xhtml" media-type="application/xhtml+xml"/>
 <item id="img_{{ .Id }}_p{{ .Part}}" href="Images/{{ .Id }}_p{{ .Part}}.jpg" media-type="image/jpeg"/>
+{{ if eq $info.NoBlankPage false }}
 {{ if eq .Part 1 }}
 <item id="page_{{ .Id }}_sp" href="Text/{{ .Id }}_sp.xhtml" media-type="application/xhtml+xml"/>
 {{ end }}
 {{ end }}
+{{ end }}
 </manifest>
-<spine page-progression-direction="{{ if .Info.Manga }}rtl{{ else }}ltr{{ end }}" toc="ncx">
+<spine page-progression-direction="{{ if $info.Manga }}rtl{{ else }}ltr{{ end }}" toc="ncx">
 <itemref idref="page_part" linear="yes" properties="page-spread-{{ spread }}"/>
 {{ range .Images }}
 {{ if spread_blank .Part }}