PDF contrast: incorrect set by a gesture (#10798)

frontend/apps/reader/modules/readerkoptlistener.lua

@@ -21,10 +21,7 @@ function ReaderKoptListener:onReadSettings(config)
     normal_zoom_mode = ReaderZooming.zoom_mode_label[normal_zoom_mode] and normal_zoom_mode or ReaderZooming.DEFAULT_ZOOM_MODE
     self.normal_zoom_mode = normal_zoom_mode
     self:setZoomMode(normal_zoom_mode)
-    self.document.configurable.contrast = config:readSetting("kopt_contrast")
-                                       or G_reader_settings:readSetting("kopt_contrast")
-                                       or 1.0
-    self.ui:handleEvent(Event:new("GammaUpdate", 1/self.document.configurable.contrast))
+    self.ui:handleEvent(Event:new("GammaUpdate", self.document.configurable.contrast))
     -- since K2pdfopt v2.21 negative value of word spacing is also used, for config
     -- compatability we should manually change previous -1 to a more reasonable -0.2
     if self.document.configurable.word_spacing == -1 then

frontend/apps/reader/modules/readerview.lua

@@ -862,7 +862,10 @@ function ReaderView:onReadSettings(config)
     if self.ui.paging then
         self.document:setTileCacheValidity(config:readSetting("tile_cache_validity_ts"))
         self.render_mode = config:readSetting("render_mode") or 0
-        self.state.gamma = config:readSetting("gamma") or 1.0
+        if config:has("gamma") then -- old doc contrast setting
+            config:saveSetting("kopt_contrast", config:readSetting("gamma"))
+            config:delSetting("gamma")
+        end
     end
     local rotation_mode = nil
     local locked = G_reader_settings:isTrue("lock_rotation")
@@ -996,7 +999,7 @@ function ReaderView:onGammaUpdate(gamma)
     if self.page_scroll then
         self.ui:handleEvent(Event:new("UpdateScrollPageGamma", gamma))
     end
-    Notification:notify(T(_("Font gamma set to: %1."), gamma))
+    Notification:notify(T(_("Contrast set to: %1."), gamma))
 end
 
 -- For ReaderKOptListener
@@ -1073,7 +1076,6 @@ function ReaderView:onSaveSettings()
         end
         self.ui.doc_settings:saveSetting("tile_cache_validity_ts", self.document:getTileCacheValidity())
         self.ui.doc_settings:saveSetting("render_mode", self.render_mode)
-        self.ui.doc_settings:saveSetting("gamma", self.state.gamma)
     end
     -- Don't etch the current rotation in stone when sticky rotation is enabled
     local locked = G_reader_settings:isTrue("lock_rotation")

frontend/dispatcher.lua

@@ -226,7 +226,7 @@ local settingsList = {
     kopt_font_fine_tune = {category="string", paging=true},
     kopt_word_spacing = {category="configurable", paging=true},
     kopt_text_wrap = {category="string", paging=true},
-    kopt_contrast = {category="absolutenumber", paging=true},
+    kopt_contrast = {category="string", paging=true},
     kopt_page_opt = {category="configurable", paging=true},
     kopt_hw_dithering = {category="configurable", paging=true, condition=Device:hasEinkScreen() and Device:canHWDither()},
     kopt_sw_dithering = {category="configurable", paging=true, condition=Device:hasEinkScreen() and not Device:canHWDither() and Device.screen.fb_bpp == 8},

frontend/document/koptinterface.lua

@@ -144,7 +144,8 @@ function KoptInterface:createContext(doc, pageno, bbox)
     kc:setZoom(doc.configurable.font_size)
     kc:setMargin(doc.configurable.page_margin)
     kc:setQuality(doc.configurable.quality)
-    kc:setContrast(doc.configurable.contrast)
+    -- k2pdfopt (for reflowing) and mupdf use different algorithms to apply gamma when rendering
+    kc:setContrast(1 / doc.configurable.contrast)
     kc:setDefectSize(doc.configurable.defect_size)
     kc:setLineSpacing(doc.configurable.line_spacing)
     kc:setWordSpacing(doc.configurable.word_spacing)

frontend/ui/data/koptoptions.lua

@@ -483,7 +483,7 @@ Some of the other settings are only available when reflow mode is enabled.]]),
                 buttonprogress = true,
                 -- See https://github.com/koreader/koreader/issues/1299#issuecomment-65183895
                 -- For pdf reflowing mode (kopt_contrast):
-                values = {1/0.8, 1/1.0, 1/1.5, 1/2.0, 1/4.0, 1/6.0, 1/10.0, 1/50.0},
+                values = {0.8, 1.0, 1.5, 2.0, 4.0, 6.0, 10.0, 50.0},
                 default_pos = 2,
                 default_value = G_defaults:readSetting("DKOPTREADER_CONFIG_CONTRAST"),
                 event = "GammaUpdate",
@@ -491,6 +491,12 @@ Some of the other settings are only available when reflow mode is enabled.]]),
                 args =   {0.8, 1.0, 1.5, 2.0, 4.0, 6.0, 10.0, 50.0},
                 labels = {0.8, 1.0, 1.5, 2.0, 4.0, 6.0, 10.0, 50.0},
                 name_text_hold_callback = optionsutil.showValues,
+                more_options = true,
+                more_options_param = {
+                    value_step = 0.1, value_hold_step = 1,
+                    value_min = 0.8, value_max = 50,
+                    precision = "%.1f",
+                },
             },
             {
                 name = "page_opt",

frontend/ui/data/onetime_migration.lua

@@ -10,7 +10,7 @@ local util = require("util")
 local _ = require("gettext")
 
 -- Date at which the last migration snippet was added
-local CURRENT_MIGRATION_DATE = 20230802
+local CURRENT_MIGRATION_DATE = 20230901
 
 -- Retrieve the date of the previous migration, if any
 local last_migration_date = G_reader_settings:readSetting("last_migration_date", 0)
@@ -622,5 +622,15 @@ if last_migration_date < 20230802 then
     end
 end
 
+-- 20230901, new handling of the pdf contrast ("gamma") setting
+if last_migration_date < 20230901 then
+    logger.info("Performing one-time migration for 20230901")
+
+    local contrast = G_reader_settings:readSetting("kopt_contrast")
+    if contrast then
+        G_reader_settings:saveSetting("kopt_contrast", 1 / contrast)
+    end
+end
+
 -- We're done, store the current migration date
 G_reader_settings:saveSetting("last_migration_date", CURRENT_MIGRATION_DATE)