mirror of
https://github.com/koreader/koreader
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e3b567b2b1
refer to master pullrequest #386 and #383, related commits are (all in master(kpv) tree):cb25029dddc7b4cf71f8379cba7b68
108 lines
3.2 KiB
Lua
108 lines
3.2 KiB
Lua
require "cache"
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--[[
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TODO: all these functions should probably be methods on Face objects
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]]--
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function getGlyph(face, charcode)
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local hash = "glyph|"..face.hash.."|"..charcode
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local glyph = Cache:check(hash)
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if glyph then
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-- cache hit
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return glyph[1]
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end
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local rendered_glyph = face.ftface:renderGlyph(charcode)
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if not rendered_glyph then
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DEBUG("error rendering glyph (charcode=", charcode, ") for face", face)
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return
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end
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glyph = CacheItem:new{rendered_glyph}
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glyph.size = glyph[1].bb:getWidth() * glyph[1].bb:getHeight() / 2 + 32
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Cache:insert(hash, glyph)
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return glyph[1]
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end
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function getSubTextByWidth(text, face, width, kerning)
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local pen_x = 0
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local prevcharcode = 0
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local char_list = {}
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for uchar in string.gfind(text, "([%z\1-\127\194-\244][\128-\191]*)") do
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if pen_x < width then
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local charcode = util.utf8charcode(uchar)
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local glyph = getGlyph(face, charcode)
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if kerning and prevcharcode then
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local kern = face.ftface:getKerning(prevcharcode, charcode)
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pen_x = pen_x + kern
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end
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pen_x = pen_x + glyph.ax
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if pen_x <= width then
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prevcharcode = charcode
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table.insert(char_list, uchar)
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else
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break
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end
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end
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end
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return table.concat(char_list)
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end
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function sizeUtf8Text(x, width, face, text, kerning)
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if not text then
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DEBUG("sizeUtf8Text called without text");
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return
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end
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-- may still need more adaptive pen placement when kerning,
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-- see: http://freetype.org/freetype2/docs/glyphs/glyphs-4.html
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local pen_x = 0
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local pen_y_top = 0
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local pen_y_bottom = 0
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local prevcharcode = 0
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for uchar in string.gfind(text, "([%z\1-\127\194-\244][\128-\191]*)") do
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if pen_x < (width - x) then
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local charcode = util.utf8charcode(uchar)
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local glyph = getGlyph(face, charcode)
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if kerning and (prevcharcode ~= 0) then
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pen_x = pen_x + face.ftface:getKerning(prevcharcode, charcode)
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end
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pen_x = pen_x + glyph.ax
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pen_y_top = math.max(pen_y_top, glyph.t)
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pen_y_bottom = math.max(pen_y_bottom, glyph.bb:getHeight() - glyph.t)
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--DEBUG("ax:"..glyph.ax.." t:"..glyph.t.." r:"..glyph.r.." h:"..glyph.bb:getHeight().." w:"..glyph.bb:getWidth().." yt:"..pen_y_top.." yb:"..pen_y_bottom)
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prevcharcode = charcode
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end -- if pen_x < (width - x)
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end -- for uchar
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return { x = pen_x, y_top = pen_y_top, y_bottom = pen_y_bottom}
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end
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function renderUtf8Text(buffer, x, y, face, text, kerning)
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if not text then
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DEBUG("renderUtf8Text called without text");
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return 0
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end
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-- may still need more adaptive pen placement when kerning,
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-- see: http://freetype.org/freetype2/docs/glyphs/glyphs-4.html
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local pen_x = 0
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local prevcharcode = 0
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local buffer_width = buffer:getWidth()
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for uchar in string.gfind(text, "([%z\1-\127\194-\244][\128-\191]*)") do
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if pen_x < buffer_width then
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local charcode = util.utf8charcode(uchar)
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local glyph = getGlyph(face, charcode)
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if kerning and (prevcharcode ~= 0) then
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pen_x = pen_x + face.ftface:getKerning(prevcharcode, charcode)
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end
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buffer:addblitFrom(
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glyph.bb,
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x + pen_x + glyph.l, y - glyph.t,
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0, 0,
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glyph.bb:getWidth(), glyph.bb:getHeight())
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pen_x = pen_x + glyph.ax
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prevcharcode = charcode
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end -- if pen_x < buffer_width
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end -- for uchar
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return pen_x
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end
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