feat(epub): complete wxread parity scope

Sources/RDReaderView/EPUBUI/RDEPUBReaderConfiguration.swift

@@ -21,6 +21,10 @@ public struct RDEPUBReaderConfiguration: Equatable {
     public var fontSize: CGFloat
     /// 行距倍数，默认 1.6（即行距为字号的 1.6 倍）
     public var lineHeightMultiple: CGFloat
+    /// 栏数，默认单栏
+    public var numberOfColumns: Int
+    /// 栏间距，默认 20pt
+    public var columnGap: CGFloat
     /// 翻页显示模式：.pageCurl（仿真翻页）或 .scroll（滚动阅读）
     public var displayType: RDReaderView.DisplayType
     /// 横屏时是否启用双页显示，默认开启
@@ -73,6 +77,8 @@ public struct RDEPUBReaderConfiguration: Equatable {
     public init(
         fontSize: CGFloat = 15,
         lineHeightMultiple: CGFloat = 1.6,
+        numberOfColumns: Int = 1,
+        columnGap: CGFloat = 20,
         displayType: RDReaderView.DisplayType = .pageCurl,
         landscapeDualPageEnabled: Bool = true,
         showsTableOfContents: Bool = true,
@@ -87,6 +93,8 @@ public struct RDEPUBReaderConfiguration: Equatable {
     ) {
         self.fontSize = fontSize
         self.lineHeightMultiple = lineHeightMultiple
+        self.numberOfColumns = max(1, numberOfColumns)
+        self.columnGap = max(0, columnGap)
         self.displayType = displayType
         self.landscapeDualPageEnabled = landscapeDualPageEnabled
         self.showsTableOfContents = showsTableOfContents
@@ -115,6 +123,8 @@ extension RDEPUBReaderConfiguration {
             lineHeightMultiple: lineHeightMultiple,
             reflowableContentInsets: reflowableContentInsets,
             fixedContentInset: fixedContentInset,
+            numberOfColumns: numberOfColumns,
+            columnGap: columnGap,
             themeBackgroundColor: theme.themeBackgroundColorCSS,
             themeTextColor: theme.themeTextColorCSS,
             fixedBackgroundColor: theme.themeBackgroundColorCSS,
@@ -122,4 +132,4 @@ extension RDEPUBReaderConfiguration {
             fixedLayoutSpreadMode: fixedLayoutSpreadMode
         )
     }
-}
+}