cre: use 'best' (Harfbuzz) as the default kerning method (#5553)

It might be slower, but is needed to properly display
books in arabic, indic...
Also bump crengine: use FreeType "light" hinting algorithm,
which hints on the y-axis only (and so avoid messing with
advances and kerning on the x-axis).

base

@@ -1 +1 @@
-Subproject commit db0f8e31feb02710a18352b97113fb49286fe2ae
+Subproject commit 8840d09cc8134bfa042f7b0ef5ce38ae592f2987

frontend/apps/reader/modules/readerfont.lua

@@ -127,7 +127,7 @@ function ReaderFont:onReadSettings(config)
     self.ui.document:setFontHinting(self.font_hinting)
 
     self.font_kerning = config:readSetting("font_kerning")
-            or G_reader_settings:readSetting("copt_font_kerning") or 1 -- freetype (default in cre.cpp)
+            or G_reader_settings:readSetting("copt_font_kerning") or 3 -- harfbuzz (slower, but needed for proper arabic)
     self.ui.document:setFontKerning(self.font_kerning)
 
     self.space_condensing = config:readSetting("space_condensing")

frontend/ui/data/creoptions.lua

@@ -385,7 +385,7 @@ Note that your selected font size is not affected by this setting.]]),
                 name_text = S.FONT_KERNING,
                 toggle = {S.OFF, S.FAST, S.GOOD, S.BEST},
                 values = {0, 1, 2, 3},
-                default_value = 1,
+                default_value = 3,
                 args = {0, 1, 2, 3},
                 event = "SetFontKerning",
                 name_text_hold_callback = optionsutil.showValues,
@@ -394,7 +394,7 @@ Note that your selected font size is not affected by this setting.]]),
 - off: no kerning.
 - fast: use FreeType's kerning implementation (no ligatures).
 - good: use HarfBuzz's light kerning implementation (faster than full but no ligatures and limited support for non-western scripts)
-- best: use HarfBuzz's full kerning implementation (slower, but may support ligatures with some fonts).
+- best: use HarfBuzz's full kerning implementation (slower, but may support ligatures with some fonts; also needed to properly display joined arabic glyphs and some other scripts).
 
 (Font Hinting may need to be adjusted for the best result with either kerning implementation.)]]),
             },

spec/unit/readerfooter_spec.lua

@@ -317,8 +317,8 @@ describe("Readerfooter module", function()
         assert.are.same(359, footer.text_width)
 
         footer:onPageUpdate(100)
-        assert.are.same(189, footer.progress_bar.width)
-        assert.are.same(391, footer.text_width)
+        assert.are.same(197, footer.progress_bar.width)
+        assert.are.same(383, footer.text_width)
     end)
 
     it("should support chapter markers", function()

spec/unit/readerhighlight_spec.lua

@@ -99,9 +99,9 @@ describe("Readerhighlight module", function()
         end)
         it("should response on tap gesture", function()
             tap_highlight_text(readerui,
-                               Geom:new{ x = 151, y = 115  },
-                               Geom:new{ x = 300, y = 285 },
-                               Geom:new{ x = 120, y = 240 })
+                               Geom:new{ x = 130, y = 100 },
+                               Geom:new{ x = 350, y = 395 },
+                               Geom:new{ x = 80, y = 265 })
             Screen:shot("screenshots/reader_tap_highlight_text_epub.png")
         end)
     end)

spec/unit/readerlink_spec.lua

@@ -18,7 +18,7 @@ describe("ReaderLink module", function()
             document = DocumentRegistry:openDocument(sample_epub),
         }
         readerui.rolling:onGotoPage(4)
-        readerui.link:onTap(nil, {pos = {x = 340, y = 110}})
+        readerui.link:onTap(nil, {pos = {x = 320, y = 120}})
         assert.is.same(36, readerui.rolling.current_page)
     end)
 
@@ -57,7 +57,7 @@ describe("ReaderLink module", function()
             document = DocumentRegistry:openDocument(sample_epub),
         }
         readerui.rolling:onGotoPage(4)
-        readerui.link:onTap(nil, {pos = {x = 340, y = 110}})
+        readerui.link:onTap(nil, {pos = {x = 320, y = 120}})
         assert.is.same(36, readerui.rolling.current_page)
         readerui.link:onGoBackLink()
         assert.is.same(4, readerui.rolling.current_page)

spec/unit/readerrolling_spec.lua

@@ -186,13 +186,13 @@ describe("Readerrolling module", function()
         it("should show pages for different word gap", function()
             readerui.document:setSpaceCondensing(100)
             readerui:handleEvent(Event:new("ChangeScreenMode", "portrait"))
-            assert.are.same(251, readerui.document:getPageCount())
+            assert.are.same(231, readerui.document:getPageCount())
             readerui.document:setSpaceCondensing(75)
             readerui:handleEvent(Event:new("ChangeScreenMode", "portrait"))
-            assert.are.same(242, readerui.document:getPageCount())
+            assert.are.same(229, readerui.document:getPageCount())
             readerui.document:setSpaceCondensing(50)
             readerui:handleEvent(Event:new("ChangeScreenMode", "portrait"))
-            assert.are.same(233, readerui.document:getPageCount())
+            assert.are.same(225, readerui.document:getPageCount())
         end)
     end)
 

spec/unit/readertoc_spec.lua

@@ -25,7 +25,7 @@ describe("Readertoc module", function()
         title = toc:getTocTitleByPage(60)
         DEBUG("toc", toc.toc)
         assert.is.equal("SCENE V. A hall in Capulet's house.", title)
-        title = toc:getTocTitleByPage(187)
+        title = toc:getTocTitleByPage(177)
         assert.is.equal("SCENE I. Friar Laurence's cell.", title)
     end)
     describe("getTocTicks API", function()
@@ -68,12 +68,12 @@ describe("Readertoc module", function()
     end)
     it("should get page left of chapter", function()
         assert.truthy(toc:getChapterPagesLeft(10, 0) > 10)
-        assert.truthy(toc:getChapterPagesLeft(97, 0) > 10)
+        assert.truthy(toc:getChapterPagesLeft(90, 0) > 10)
         assert.are.same(nil, toc:getChapterPagesLeft(290, 0))
     end)
     it("should get page done of chapter", function()
         assert.truthy(toc:getChapterPagesDone(11, 0) < 5)
-        assert.truthy(toc:getChapterPagesDone(95, 0) < 5)
+        assert.truthy(toc:getChapterPagesDone(83, 0) < 5)
         assert.truthy(toc:getChapterPagesDone(290, 0) > 10)
     end)
     describe("collasible TOC", function()