negative x panning if writing direction is set right to left

so that in right to left writing/drawing system the right part
of the page is drawn first

frontend/apps/reader/modules/readerpaging.lua

@@ -644,7 +644,9 @@ function ReaderPaging:onGotoPageRel(diff)
     elseif self.zoom_mode:find("width") then
         y_pan_off = self.visible_area.h * diff
     elseif self.zoom_mode:find("height") then
-        x_pan_off = self.visible_area.w * diff
+        -- negative x panning if writing direction is right to left
+        local direction = self.ui.document.configurable.writing_direction
+        x_pan_off = self.visible_area.w * diff * (direction == 1 and -1 or 1)
     else
         -- must be fit content or page zoom mode
         if self.visible_area.w == self.page_area.w then

frontend/apps/reader/modules/readerview.lua

@@ -459,11 +459,17 @@ function ReaderView:recalculate()
             self.state.page,
             self.state.zoom,
             self.state.rotation)
-        -- starts from left top of page_area
-        self.visible_area.x = self.page_area.x
-        self.visible_area.y = self.page_area.y
         -- reset our size
         self.visible_area:setSizeTo(self.dimen)
+        if self.ui.document.configurable.writing_direction == 0 then
+            -- starts from left top of page_area
+            self.visible_area.x = self.page_area.x
+            self.visible_area.y = self.page_area.y
+        else
+            -- start from right top of page_area
+            self.visible_area.x = self.page_area.x + self.page_area.w - self.visible_area.w
+            self.visible_area.y = self.page_area.y
+        end
         -- and recalculate it according to page size
         self.visible_area:offsetWithin(self.page_area, 0, 0)
         -- clear dim area

frontend/ui/data/koptoptions.lua

@@ -195,7 +195,6 @@ local KoptOptions = {
                 toggle = {S.LTR, S.RTL, S.TBRTL},
                 values = {0, 1, 2},
                 default_value = 0,
-                advanced = true,
             },
             {
                 name = "quality",