make overlap pixels configurable

defaults.lua

@@ -53,6 +53,9 @@ DSHOWFILESIZE = false
 -- default to true, set to false for counterclockwise rotation
 DLANDSCAPE_CLOCKWISE_ROTATION = true
 
+-- page overlap pixels
+DOVERLAPPIXELS = 30
+
 -- customizable tap zones(rectangles)
 -- x: x coordinate of top left corner in proportion of screen width
 -- y: y coordinate of top left corner in proportion of screen height

frontend/ui/reader/readerpaging.lua

@@ -17,7 +17,7 @@ local ReaderPaging = InputContainer:new{
 	visible_area = nil,
 	page_area = nil,
 	show_overlap_enable = nil,
-	overlap = Screen:scaleByDPI(30),
+	overlap = Screen:scaleByDPI(DOVERLAPPIXELS),
 	
 	page_flipping_mode = false,
 	bookmark_flipping_mode = false,