add gamma correction for pdf/djvu reader

frontend/document/djvudocument.lua

@@ -72,19 +72,19 @@ function DjvuDocument:getPageDimensions(pageno, zoom, rotation)
 	end
 end
 
-function DjvuDocument:renderPage(pageno, rect, zoom, rotation, render_mode)
+function DjvuDocument:renderPage(pageno, rect, zoom, rotation, gamma, render_mode)
 	if self.configurable.text_wrap == 1 then
 		return self.koptinterface:renderPage(self, pageno, rect, zoom, rotation, render_mode)
 	else
-		return Document.renderPage(self, pageno, rect, zoom, rotation, render_mode)
+		return Document.renderPage(self, pageno, rect, zoom, rotation, gamma, render_mode)
 	end
 end
 
-function DjvuDocument:drawPage(target, x, y, rect, pageno, zoom, rotation, render_mode)
+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)
 	else
-		Document.drawPage(self, target, x, y, rect, pageno, zoom, rotation, render_mode)
+		Document.drawPage(self, target, x, y, rect, pageno, zoom, rotation, gamma, render_mode)
 	end
 end
 

frontend/document/document.lua

@@ -56,6 +56,8 @@ Document = {
 		date = ""
 	},
 	
+	GAMMA_NO_GAMMA = 1.0,
+	
 	-- override bbox from orignal page's getUsedBBox
 	bbox = {},
 		
@@ -182,8 +184,8 @@ function Document:getToc()
 	return self._document:getToc()
 end
 
-function Document:renderPage(pageno, rect, zoom, rotation, render_mode)
+function Document:renderPage(pageno, rect, zoom, rotation, gamma, render_mode)
-	local hash = "renderpg|"..self.file.."|"..pageno.."|"..zoom.."|"..rotation.."|"..render_mode
+	local hash = "renderpg|"..self.file.."|"..pageno.."|"..zoom.."|"..rotation.."|"..gamma.."|"..render_mode
 	local page_size = self:getPageDimensions(pageno, zoom, rotation)
 	-- this will be the size we actually render
 	local size = page_size
@@ -198,7 +200,7 @@ function Document:renderPage(pageno, rect, zoom, rotation, render_mode)
 			return
 		end
 		-- only render required part
-		hash = "renderpg|"..self.file.."|"..pageno.."|"..zoom.."|"..rotation.."|"..render_mode.."|"..tostring(rect)
+		hash = "renderpg|"..self.file.."|"..pageno.."|"..zoom.."|"..rotation.."|"..gamma.."|"..render_mode.."|"..tostring(rect)
 		size = rect
 	end
 
@@ -223,6 +225,11 @@ function Document:renderPage(pageno, rect, zoom, rotation, render_mode)
 		dc:setOffset(0, page_size.h)
 	end
 	dc:setZoom(zoom)
+	
+	if gamma ~= self.GAMMA_NO_GAMMA then
+		--DEBUG("gamma correction: ", gamma)
+		dc:setGamma(gamma)
+	end
 
 	-- render
 	local page = self._document:openPage(pageno)
@@ -235,10 +242,11 @@ end
 
 -- a hint for the cache engine to paint a full page to the cache
 -- TODO: this should trigger a background operation
-function Document:hintPage(pageno, zoom, rotation, render_mode)
+function Document:hintPage(pageno, zoom, rotation, gamma, render_mode)
-	local hash_full_page = "renderpg|"..self.file.."|"..pageno.."|"..zoom.."|"..rotation.."|"..render_mode
+	local hash_full_page = "renderpg|"..self.file.."|"..pageno.."|"..zoom.."|"..rotation.."|"..gamma.."|"..render_mode
 	if not Cache:check(hash_full_page) then
-		self:renderPage(pageno, nil, zoom, rotation, render_mode)
+		--DEBUG("hinting page", pageno)
+		self:renderPage(pageno, nil, zoom, rotation, gamma, render_mode)
 	end
 end
 
@@ -250,15 +258,15 @@ Draw page content to blitbuffer.
 @target: target blitbuffer
 @rect: visible_area inside document page
 --]]
-function Document:drawPage(target, x, y, rect, pageno, zoom, rotation, render_mode)
+function Document:drawPage(target, x, y, rect, pageno, zoom, rotation, gamma, render_mode)
-	local hash_full_page = "renderpg|"..self.file.."|"..pageno.."|"..zoom.."|"..rotation.."|"..render_mode
+	local hash_full_page = "renderpg|"..self.file.."|"..pageno.."|"..zoom.."|"..rotation.."|"..gamma.."|"..render_mode
 	local hash_excerpt = hash_full_page.."|"..tostring(rect)
 	local tile = Cache:check(hash_full_page)
 	if not tile then
 		tile = Cache:check(hash_excerpt)
 		if not tile then
 			DEBUG("rendering")
-			tile = self:renderPage(pageno, rect, zoom, rotation, render_mode)
+			tile = self:renderPage(pageno, rect, zoom, rotation, gamma, render_mode)
 		end
 	end
 	DEBUG("now painting", tile, rect)

frontend/document/koptinterface.lua

@@ -104,6 +104,8 @@ KoptOptions = {
 				item_align_center = 0.8,
 				values = {2.0, 1.5, 1.0, 0.5, 0.2},
 				default_value = 1.0,
+				event = "GammaUpdate",
+				args = {0.5, 0.8, 1.0, 2.0, 4.0},
 			}
 		}
 	},

frontend/document/pdfdocument.lua

@@ -68,19 +68,19 @@ function PdfDocument:getPageDimensions(pageno, zoom, rotation)
 	end
 end
 
-function PdfDocument:renderPage(pageno, rect, zoom, rotation, render_mode)
+function PdfDocument:renderPage(pageno, rect, zoom, rotation, gamma, render_mode)
 	if self.configurable.text_wrap == 1 then
 		return self.koptinterface:renderPage(self, pageno, rect, zoom, rotation, render_mode)
 	else
-		return Document.renderPage(self, pageno, rect, zoom, rotation, render_mode)
+		return Document.renderPage(self, pageno, rect, zoom, rotation, gamma, render_mode)
 	end
 end
 
-function PdfDocument:drawPage(target, x, y, rect, pageno, zoom, rotation, render_mode)
+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)
 	else
-		Document.drawPage(self, target, x, y, rect, pageno, zoom, rotation, render_mode)
+		Document.drawPage(self, target, x, y, rect, pageno, zoom, rotation, gamma, render_mode)
 	end
 end
 

frontend/ui/reader/readerview.lua

@@ -7,6 +7,7 @@ ReaderView = WidgetContainer:new{
 		pos = 0,
 		zoom = 1.0,
 		rotation = 0,
+		gamma = 1.0,
 		offset = {},
 		bbox = nil,
 	},
@@ -50,6 +51,7 @@ function ReaderView:paintTo(bb, x, y)
 			self.state.page,
 			self.state.zoom,
 			self.state.rotation,
+			self.state.gamma,
 			self.render_mode)
 		UIManager:scheduleIn(0, function() self.ui:handleEvent(Event:new("HintPage")) end)
 	else
@@ -160,6 +162,7 @@ function ReaderView:onReadSettings(config)
 	    table.insert(self.ui.postInitCallback, function()
 	        self:onSetScreenMode(screen_mode) end)
 	end
+	self.state.gamma = config:readSetting("gamma") or 1.0
 end
 
 function ReaderView:onPageUpdate(new_page_no)
@@ -186,12 +189,17 @@ function ReaderView:onRotationUpdate(rotation)
 	self:recalculate()
 end
 
+function ReaderView:onGammaUpdate(gamma)
+	self.state.gamma = gamma
+end
+
 function ReaderView:onHintPage()
 	if self.state.page < self.ui.document.info.number_of_pages then
 		self.ui.document:hintPage(
 			self.state.page+1, 
 			self.state.zoom, 
 			self.state.rotation, 
+			self.state.gamma, 
 			self.render_mode)
 	end
 	return true
@@ -207,4 +215,5 @@ end
 function ReaderView:onCloseDocument()
 	self.ui.doc_settings:saveSetting("render_mode", self.render_mode)
 	self.ui.doc_settings:saveSetting("screen_mode", self.screen_mode)
+	self.ui.doc_settings:saveSetting("gamma", self.state.gamma)
 end