Merge pull request #787 from chrox/background_hint

add background hinting in koptinterface

frontend/document/djvudocument.lua

@@ -80,6 +80,14 @@ function DjvuDocument:renderPage(pageno, rect, zoom, rotation, gamma, render_mod
 	end
 end
 
+function DjvuDocument:hintPage(pageno, zoom, rotation, gamma, render_mode)
+	if self.configurable.text_wrap == 1 then
+		self.koptinterface:hintPage(self, pageno, zoom, rotation, gamma, render_mode)
+	else
+		Document.hintPage(self, pageno, zoom, rotation, gamma, render_mode)
+	end
+end
+
 function DjvuDocument:drawPage(target, x, y, rect, pageno, zoom, rotation, gamma, render_mode)
 	if self.configurable.text_wrap == 1 then
 		self.koptinterface:drawPage(self, target, x, y, rect, pageno, zoom, rotation, render_mode)

frontend/document/koptinterface.lua

@@ -195,10 +195,38 @@ KoptOptions = {
 	},
 }
 
-KoptInterface = {}
+KoptInterface = {
+	bg_context = {
+		contex = nil,
+		pageno = nil,
+		hash = nil,
+		cached = false,
+	},
+}
+
+function KoptInterface:waitForContext(kc)
+	-- if koptcontext is being processed in background thread 
+	-- the isPreCache will return 1.
+	while kc and kc:isPreCache() == 1 do
+		DEBUG("waiting for background rendering")
+		util.usleep(100000)
+	end
+end
+
+function KoptInterface:consumeBgContext(doc)
+	-- clear up background context
+	self:waitForContext(self.bg_context.context)
+	if self.bg_context.context and not self.bg_context.cached then
+		self:makeCache(doc, self.bg_context.pageno, self.bg_context.hash)
+		self.bg_context.cached = true
+	end
+end
 
 -- get reflow context
 function KoptInterface:getKOPTContext(doc, pageno, bbox)
+	-- since libk2pdfopt only has one bitmap buffer that holds reflowed page
+	-- we should consume background production before allocating new context.
+	self:consumeBgContext(doc)
 	local kc = KOPTContext.new()
 	local screen_size = Screen:getSize()
 	kc:setTrim(doc.configurable.trim_page)
@@ -222,6 +250,7 @@ function KoptInterface:getKOPTContext(doc, pageno, bbox)
 end
 
 function KoptInterface:setTrimPage(doc, pageno)
+	if doc.configurable.trim_page == 0 then return end
 	local page_dimens = doc:getNativePageDimensions(pageno)
 	--DEBUG("original page dimens", page_dimens)
 	local orig_bbox = doc:getUsedBBox(pageno)
@@ -251,6 +280,11 @@ function KoptInterface:logReflowDuration(pageno, dur)
 	end
 end
 
+function KoptInterface:getReflowedDim(kc)
+	self:waitForContext(kc)
+	return kc:getPageDim()
+end
+
 -- calculates page dimensions
 function KoptInterface:getPageDimensions(doc, pageno, zoom, rotation)
 	self:setTrimPage(doc, pageno)
@@ -277,11 +311,37 @@ function KoptInterface:getPageDimensions(doc, pageno, zoom, rotation)
 		return page_size
 	end
 	--DEBUG("Found cached koptcontex on page", pageno, cached)
-	local fullwidth, fullheight = cached.kctx:getPageDim()
+	local fullwidth, fullheight = self:getReflowedDim(cached.kctx)
 	local page_size = Geom:new{ w = fullwidth, h = fullheight }
 	return page_size
 end
 
+function KoptInterface:makeCache(doc, pageno, context_hash)
+	-- draw to blitbuffer
+	local kc_hash = "kctx|"..context_hash
+	local tile_hash = "renderpg|"..context_hash
+	local page = doc._document:openPage(pageno)
+	local cached = Cache:check(kc_hash)
+	if cached then
+		local fullwidth, fullheight = self:getReflowedDim(cached.kctx)
+		-- prepare cache item with contained blitbuffer	
+		local tile = CacheItem:new{
+			size = fullwidth * fullheight / 2 + 64, -- estimation
+			excerpt = Geom:new{ w = fullwidth, h = fullheight },
+			pageno = pageno,
+			bb = Blitbuffer.new(fullwidth, fullheight)
+		}
+		page:rfdraw(cached.kctx, tile.bb)
+		page:close()
+		--DEBUG("cached hash", hash)
+		if not Cache:check(tile_hash) then
+			Cache:insert(tile_hash, tile)
+		end
+		return tile
+	end
+	DEBUG("Error: cannot render page before reflowing.")
+end
+
 function KoptInterface:renderPage(doc, pageno, rect, zoom, rotation, render_mode)
 	self:setTrimPage(doc, pageno)
 	doc.render_mode = render_mode
@@ -307,30 +367,33 @@ function KoptInterface:renderPage(doc, pageno, rect, zoom, rotation, render_mode
 	end
 	
 	local cached = Cache:check(hash)
-	if cached then return cached end
-
-	-- prepare cache item with contained blitbuffer	
-	local tile = CacheItem:new{
-		size = size.w * size.h / 2 + 64, -- estimation
-		excerpt = size,
-		pageno = pageno,
-		bb = Blitbuffer.new(size.w, size.h)
-	}
-
-	-- draw to blitbuffer
-	local kc_hash = "kctx|"..context_hash
-	local page = doc._document:openPage(pageno)
-	local cached = Cache:check(kc_hash)
 	if cached then
-		page:rfdraw(cached.kctx, tile.bb)
-		page:close()
-		--DEBUG("cached hash", hash)
-		if not Cache:check(hash) then
-			Cache:insert(hash, tile)
-		end
-		return tile
+		return cached
+	else
+		return self:makeCache(doc, pageno, context_hash)
+	end
+end
+
+function KoptInterface:hintPage(doc, pageno, zoom, rotation, gamma, render_mode)
+	self:setTrimPage(doc, pageno)
+	local bbox = doc:getPageBBox(pageno)
+	local context_hash = self:getContextHash(doc, pageno, bbox)
+	local hash = "kctx|"..context_hash
+	local cached = Cache:check(hash)
+	if not cached then
+		local kc = self:getKOPTContext(doc, pageno, bbox)
+		local page = doc._document:openPage(pageno)
+		kc:setPreCache()
+		self.bg_context.context = kc
+		self.bg_context.pageno = pageno
+		self.bg_context.hash = context_hash
+		self.bg_context.cached = false
+		DEBUG("hinting page", pageno, "in background")
+		-- will return immediately
+		page:reflow(kc, 0)
+		page:close()
+		Cache:insert(hash, CacheItem:new{ kctx = kc })
 	end
-	DEBUG("Error: cannot render page before reflowing.")
 end
 
 function KoptInterface:drawPage(doc, target, x, y, rect, pageno, zoom, rotation, render_mode)

frontend/document/pdfdocument.lua

@@ -82,6 +82,14 @@ function PdfDocument:renderPage(pageno, rect, zoom, rotation, gamma, render_mode
 	end
 end
 
+function PdfDocument:hintPage(pageno, zoom, rotation, gamma, render_mode)
+	if self.configurable.text_wrap == 1 then
+		self.koptinterface:hintPage(self, pageno, zoom, rotation, gamma, render_mode)
+	else
+		Document.hintPage(self, pageno, zoom, rotation, gamma, render_mode)
+	end
+end
+
 function PdfDocument:drawPage(target, x, y, rect, pageno, zoom, rotation, gamma, render_mode)
 	if self.configurable.text_wrap == 1 then
 		self.koptinterface:drawPage(self, target, x, y, rect, pageno, zoom, rotation, render_mode)

frontend/ui/reader/readerconfig.lua

@@ -82,8 +82,11 @@ function ReaderConfig:onShowConfigMenu()
 		ui = self.ui,
 		configurable = self.configurable,
 		config_options = self.options,
+		close_callback = function() 
+			self.ui:handleEvent(Event:new("RestoreHinting"))
+		end,
 	}
-
+	self.ui:handleEvent(Event:new("DisableHinting"))
 	UIManager:show(self.config_dialog)
 
 	return true

frontend/ui/reader/readercropping.lua

@@ -63,6 +63,8 @@ function ReaderCropping:onPageCrop(mode)
 	-- backup original page scroll
 	self.orig_page_scroll = self.view.page_scroll
 	self.view.page_scroll = false
+	-- backup and disable original hinting state 
+	self.ui:handleEvent(Event:new("DisableHinting"))
 	-- backup original reflow mode as cropping use non-reflow mode
 	self.orig_reflow_mode = self.document.configurable.text_wrap
 	if self.orig_reflow_mode == 1 then
@@ -110,6 +112,8 @@ function ReaderCropping:onCancelPageCrop()
 end
 
 function ReaderCropping:exitPageCrop(confirmed)
+	-- restore hinting state
+	self.ui:handleEvent(Event:new("RestoreHinting"))
 	-- restore page scroll
 	self.view.page_scroll = self.orig_page_scroll
 	-- restore view bgcolor

frontend/ui/reader/readerhinting.lua

@@ -0,0 +1,19 @@
+
+ReaderHinting = EventListener:new{
+	hinting_states = {}
+}
+
+function ReaderHinting:onSetHinting(hinting)
+	self.view.hinting = hinting
+end
+
+function ReaderHinting:onDisableHinting()
+	table.insert(self.hinting_states, self.view.hinting)
+	self.view.hinting = false
+	return true
+end
+
+function ReaderHinting:onRestoreHinting()
+	self.view.hinting = table.remove(self.hinting_states)
+	return true
+end

frontend/ui/reader/readerpaging.lua

@@ -143,6 +143,7 @@ function ReaderPaging:onToggleFlipping()
 	if self.flipping_mode then
 		self:updateOriginalPage(self.current_page)
 	end
+	self.ui:handleEvent(Event:new("SetHinting", not self.flipping_mode))
 	UIManager:setDirty(self.view.dialog, "partial")
 end
 

frontend/ui/reader/readerview.lua

@@ -31,7 +31,8 @@ ReaderView = OverlapGroup:new{
 	render_mode = 0, -- default to COLOR
 	-- Crengine view mode
 	view_mode = "page", -- default to page mode
-
+	hinting = true,
+	
 	-- visible area within current viewing page
 	visible_area = Geom:new{x = 0, y = 0},
 	-- dimen for current viewing page
@@ -148,7 +149,9 @@ function ReaderView:drawScrollPages(bb, x, y)
 			pos.y = pos.y + self.page_gap.height
 		end
 	end
-	UIManager:scheduleIn(0, function() self.ui:handleEvent(Event:new("HintPage")) end)
+	UIManager:scheduleIn(0, function()
+		self.ui:handleEvent(Event:new("HintPage", self.hinting))
+	end)
 end
 
 function ReaderView:drawPageGap(bb, x, y)
@@ -170,7 +173,9 @@ function ReaderView:drawSinglePage(bb, x, y)
 		self.state.rotation,
 		self.state.gamma,
 		self.render_mode)
-	UIManager:scheduleIn(0, function() self.ui:handleEvent(Event:new("HintPage")) end)
+	UIManager:scheduleIn(0, function()
+		self.ui:handleEvent(Event:new("HintPage", self.hinting))
+	end)
 end
 
 function ReaderView:drawPageView(bb, x, y)

frontend/ui/reader/readerzooming.lua

@@ -110,6 +110,7 @@ function ReaderZooming:onPageUpdate(new_page_no)
 end
 
 function ReaderZooming:onHintPage()
+	if not self.view.hinting then return true end
 	if self.current_page < self.ui.document.info.number_of_pages then
 		self.ui.document:hintPage(
 			self.view.state.page + 1, 

frontend/ui/readerui.lua

@@ -15,6 +15,7 @@ require "ui/reader/readercropping"
 require "ui/reader/readerkopt"
 require "ui/reader/readercopt"
 require "ui/reader/readerscreenshot"
+require "ui/reader/readerhinting"
 
 --[[
 This is an abstraction for a reader interface
@@ -132,6 +133,14 @@ function ReaderUI:init()
 			document = self.document,
 		}
 		table.insert(self, cropper)
+		-- hinting controller
+		local hinter = ReaderHinting:new{
+			dialog = self.dialog,
+			view = self[1],
+			ui = self,
+			document = self.document,
+		}
+		table.insert(self, hinter)
 	else
 		-- make sure we load document first before calling any callback
 		table.insert(self.postInitCallback, function()