add helper for layout blank

internal/epub/epub.go

@@ -261,6 +261,10 @@ func (e *ePub) Write() error {
 				"PageWidth":  e.Image.View.Width,
 				"PageHeight": e.Image.View.Height,
 			})},
+			{"OEBPS/Text/space_title.xhtml", e.render(epubtemplates.Blank, map[string]any{
+				"Title":    "Blank Page Title",
+				"ViewPort": fmt.Sprintf("width=%d,height=%d", e.Image.View.Width, e.Image.View.Height),
+			})},
 			{"OEBPS/Text/title.xhtml", e.render(epubtemplates.Text, map[string]any{
 				"Title":      title,
 				"ViewPort":   fmt.Sprintf("width=%d,height=%d", e.Image.View.Width, e.Image.View.Height),

internal/epub/templates/epub_templates_content.go

@@ -142,6 +142,7 @@ func getManifest(o *ContentOptions) []tag {
 	items := []tag{
 		{"item", tagAttrs{"id": "toc", "href": "toc.xhtml", "properties": "nav", "media-type": "application/xhtml+xml"}, ""},
 		{"item", tagAttrs{"id": "css", "href": "Text/style.css", "media-type": "text/css"}, ""},
+		{"item", tagAttrs{"id": "space_title", "href": "Text/space_title.xhtml", "media-type": "application/xhtml+xml"}, ""},
 		{"item", tagAttrs{"id": "page_title", "href": "Text/title.xhtml", "media-type": "application/xhtml+xml"}, ""},
 		{"item", tagAttrs{"id": "img_title", "href": "Images/title.jpg", "media-type": "image/jpeg"}, ""},
 	}
@@ -165,9 +166,9 @@ func getManifest(o *ContentOptions) []tag {
 // spine part of the content
 func getSpine(o *ContentOptions) []tag {
 	isOnTheRight := !o.ImageOptions.Manga
-	getSpread := func(doublePageNoBlank bool) string {
+	getSpread := func(isDoublePage bool) string {
 		isOnTheRight = !isOnTheRight
-		if doublePageNoBlank {
+		if isDoublePage {
 			// Center the double page then start back to comic mode (mange/normal)
 			isOnTheRight = !o.ImageOptions.Manga
 			return "rendition:page-spread-center"
@@ -178,15 +179,19 @@ func getSpine(o *ContentOptions) []tag {
 			return "rendition:page-spread-left"
 		}
 	}
+	getSpreadBlank := func() string {
+		return fmt.Sprintf("%s layout-blank", getSpread(false))
+	}
 
 	spine := []tag{
-		{"itemref", tagAttrs{"idref": "page_title", "properties": getSpread(true)}, ""},
+		{"itemref", tagAttrs{"idref": "space_title", "properties": getSpreadBlank()}, ""},
+		{"itemref", tagAttrs{"idref": "page_title", "properties": getSpread(false)}, ""},
 	}
 	for _, img := range o.Images {
-		if img.DoublePage && isOnTheRight {
+		if img.DoublePage && o.ImageOptions.Manga == isOnTheRight {
 			spine = append(spine, tag{
 				"itemref",
-				tagAttrs{"idref": img.SpaceKey(), "properties": getSpread(false) + " layout-blank"},
+				tagAttrs{"idref": img.SpaceKey(), "properties": getSpreadBlank()},
 				"",
 			})
 		}