simplify content opf, revamp needspace

internal/epub/core.go

@@ -60,27 +60,10 @@ func NewEpub(options *EpubOptions) *ePub {
 		panic(err)
 	}
 
-	var spreadRight = options.Manga
-
 	tmpl := template.New("parser")
 	tmpl.Funcs(template.FuncMap{
 		"mod":  func(i, j int) bool { return i%j == 0 },
 		"zoom": func(s int, z float32) int { return int(float32(s) * z) },
-		"spread": func() (spread string) {
-			if spreadRight {
-				spread = "right"
-			} else {
-				spread = "left"
-			}
-			spreadRight = !spreadRight
-			return
-		},
-		"spread_blank": func(part int) bool {
-			if !options.NoBlankPage && part == 1 && spreadRight == options.Manga {
-				return true
-			}
-			return false
-		},
 	})
 
 	return &ePub{
@@ -118,14 +101,6 @@ func (e *ePub) getParts() ([]*epubPart, error) {
 	if e.HasCover {
 		images = images[1:]
 	}
-	if e.LimitMb == 0 {
-		parts = append(parts, &epubPart{
-			Cover:  cover,
-			Images: images,
-		})
-		return parts, nil
-	}
-
 	maxSize := uint64(e.LimitMb * 1024 * 1024)
 
 	xhtmlSize := uint64(1024)
@@ -135,20 +110,24 @@ func (e *ePub) getParts() ([]*epubPart, error) {
 	currentSize := baseSize
 	currentImages := make([]*Image, 0)
 	part := 1
+	imgIsOnRightSide := false
 
 	for _, img := range images {
 		imgSize := img.Data.CompressedSize() + xhtmlSize
-		if len(currentImages) > 0 && currentSize+imgSize > maxSize {
+		if maxSize > 0 && len(currentImages) > 0 && currentSize+imgSize > maxSize {
 			parts = append(parts, &epubPart{
 				Cover:  cover,
 				Images: currentImages,
 			})
 			part += 1
+			imgIsOnRightSide = false
 			currentSize = baseSize
 			currentImages = make([]*Image, 0)
 		}
 		currentSize += imgSize
+		img.NeedSpace = img.Part == 1 && imgIsOnRightSide
 		currentImages = append(currentImages, img)
+		imgIsOnRightSide = !imgIsOnRightSide
 	}
 	if len(currentImages) > 0 {
 		parts = append(parts, &epubPart{
@@ -235,7 +214,7 @@ func (e *ePub) Write() error {
 				return err
 			}
 
-			if !e.NoBlankPage && img.Part == 1 {
+			if img.NeedSpace {
 				if err := wz.WriteFile(
 					fmt.Sprintf("OEBPS/Text/%d_sp.xhtml", img.Id),
 					e.render(blankTmpl, map[string]any{

internal/epub/image_processing.go

@@ -28,6 +28,7 @@ type Image struct {
 	Width     int
 	Height    int
 	IsCover   bool
+	NeedSpace bool
 }
 
 type imageTask struct {
@@ -154,6 +155,7 @@ func LoadImages(path string, options *ImageOptions) ([]*Image, error) {
 					dst.Bounds().Dx(),
 					dst.Bounds().Dy(),
 					img.Id == 0,
+					false,
 				}
 
 				// Auto split double page
@@ -176,6 +178,7 @@ func LoadImages(path string, options *ImageOptions) ([]*Image, error) {
 							dst.Bounds().Dx(),
 							dst.Bounds().Dy(),
 							false,
+							false, // NeedSpace reajust during parts computation
 						}
 					}
 				}

internal/epub/templates/content.opf.tmpl

@@ -8,46 +8,44 @@
     <dc:contributor id="contributor">GO Comic Converter</dc:contributor>
     <dc:creator>GO Comic Converter</dc:creator>
     <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="book-type" content="comic"/>
     <meta name="primary-writing-mode" content="horizontal-{{ if $info.Manga }}rl{{ else }}lr{{ end }}"/>
-<meta name="zero-gutter" content="true"/>
+    <meta property="rendition:orientation">portrait</meta>
-<meta name="zero-margin" content="true"/>
-<meta name="ke-border-color" content="#FFFFFF"/>
-<meta name="ke-border-width" content="0"/>
     <meta name="orientation-lock" content="portrait"/>
+{{ if eq $info.AddPanelView true }}
     <meta name="region-mag" content="true"/>
+{{ end }}
   </metadata>
   <manifest>
     <item id="ncx" href="toc.ncx" media-type="application/x-dtbncx+xml"/>
     <item id="nav" href="nav.xhtml" properties="nav" media-type="application/xhtml+xml"/>
-<item id="cover" href="Images/{{ .Cover.Id }}_p{{ .Cover.Part }}.jpg" media-type="image/jpeg" properties="cover-image"/>
     <item id="style_css" href="Text/style.css" media-type="text/css"/>
 {{ if eq $info.AddPanelView true }}
     <item id="panelview_css" href="Text/panelview.css" media-type="text/css"/>
 {{ end }}
-<item id="page_part" href="Text/part.xhtml" media-type="application/xhtml+xml"/>
+    <item id="cover" href="Images/{{ .Cover.Id }}_p{{ .Cover.Part }}.jpg" media-type="image/jpeg" properties="cover-image"/>
 {{ range .Images }}
-<item id="page_{{ .Id }}_p{{ .Part}}" href="Text/{{ .Id }}_p{{ .Part}}.xhtml" media-type="application/xhtml+xml"/>
 {{ if eq .IsCover false }}
     <item id="img_{{ .Id }}_p{{ .Part}}" href="Images/{{ .Id }}_p{{ .Part}}.jpg" media-type="image/jpeg"/>
 {{ end }}
-{{ if eq $info.NoBlankPage false }}
+{{ end }}
-{{ if eq .Part 1 }}
+    <item id="page_part" href="Text/part.xhtml" media-type="application/xhtml+xml"/>
+{{ range .Images }}
+    <item id="page_{{ .Id }}_p{{ .Part}}" href="Text/{{ .Id }}_p{{ .Part}}.xhtml" media-type="application/xhtml+xml"/>
+{{ if eq .NeedSpace true }}
     <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 toc="ncx" page-progression-direction="{{ if $info.Manga }}rtl{{ else }}ltr{{ end }}">
-<itemref idref="page_part" linear="yes" properties="page-spread-{{ spread }}"/>
+    <itemref idref="page_part" linear="yes"/>
 {{ range .Images }}
-{{ if spread_blank .Part }}
+{{ if eq .NeedSpace true }}
-<itemref idref="page_{{ .Id }}_sp" linear="yes" properties="page-spread-{{ spread }}"/>
+    <itemref idref="page_{{ .Id }}_sp" linear="yes"/>
 {{ end }}
-<itemref idref="page_{{ .Id }}_p{{ .Part }}" linear="yes" properties="page-spread-{{ spread }}"/>
+    <itemref idref="page_{{ .Id }}_p{{ .Part }}" linear="yes"/>
 {{ end }}
   </spine>
 </package>