cre highlights: draw segments instead of word boxes

It gives a cleaner drawing of multi-lines selected text.
Bump base and crengine.

base

@@ -1 +1 @@
-Subproject commit 0e7a6dcfb58aa706f6fa231930c7ef58d8e9b3cb
+Subproject commit 79574a5a40ab4648af9e4bba733ad6ef5eddf299

frontend/apps/reader/modules/readerhighlight.lua

@@ -192,6 +192,10 @@ function ReaderHighlight:onTapPageSavedHighlight(ges)
 end
 
 function ReaderHighlight:onTapXPointerSavedHighlight(ges)
+    -- Getting screen boxes is done for each tap on screen (changing pages,
+    -- showing menu...). We might want to cache these boxes per page (and
+    -- clear that cache when page layout change or highlights are added
+    -- or removed).
     local cur_page
     -- In scroll mode, we'll need to check for highlights in previous or next
     -- page too as some parts of them may be displayed

frontend/apps/reader/modules/readerview.lua

@@ -473,6 +473,10 @@ function ReaderView:drawPageSavedHighlight(bb, x, y)
 end
 
 function ReaderView:drawXPointerSavedHighlight(bb, x, y)
+    -- Getting screen boxes is done for each tap on screen (changing pages,
+    -- showing menu...). We might want to cache these boxes per page (and
+    -- clear that cache when page layout change or highlights are added
+    -- or removed).
     local cur_page
     -- In scroll mode, we'll need to check for highlights in previous or next
     -- page too as some parts of them may be displayed
@@ -499,7 +503,7 @@ function ReaderView:drawXPointerSavedHighlight(bb, x, y)
             -- (A highlight starting on cur_page-17 and ending on cur_page+13 is
             -- a highlight to consider)
             if start_page <= cur_page + neighbour_pages and end_page >= cur_page - neighbour_pages then
-                local boxes = self.ui.document:getScreenBoxesFromPositions(pos0, pos1)
+                local boxes = self.ui.document:getScreenBoxesFromPositions(pos0, pos1, true) -- get_segments=true
                 if boxes then
                     for _, box in pairs(boxes) do
                         local rect = self:pageToScreenTransform(page, box)

frontend/document/credocument.lua

@@ -274,10 +274,10 @@ function CreDocument:getTextFromPositions(pos0, pos1)
     end
 end
 
-function CreDocument:getScreenBoxesFromPositions(pos0, pos1)
+function CreDocument:getScreenBoxesFromPositions(pos0, pos1, get_segments)
     local line_boxes = {}
     if pos0 and pos1 then
-        local word_boxes = self._document:getWordBoxesFromPositions(pos0, pos1)
+        local word_boxes = self._document:getWordBoxesFromPositions(pos0, pos1, get_segments)
         for i = 1, #word_boxes do
             local line_box = word_boxes[i]
             table.insert(line_boxes, Geom:new{
@@ -303,6 +303,10 @@ function CreDocument:drawCurrentView(target, x, y, rect, pos)
         -- But it is all fine if we use TYPE_BBRGB16.
         self.buffer = Blitbuffer.new(rect.w, rect.h, self.render_color and Blitbuffer.TYPE_BBRGB16 or nil)
     end
+    -- TODO: self.buffer could be re-used when no page/layout/highlights
+    -- change has been made, to avoid having crengine redraw the exact
+    -- same buffer.
+    -- And it could only change when some other methods from here are called
     self._document:drawCurrentPage(self.buffer, self.render_color)
     target:blitFrom(self.buffer, x, y, 0, 0, rect.w, rect.h)
 end