mirror of
https://github.com/koreader/koreader
synced 2024-10-31 21:20:20 +00:00
01f045e7f9
I found it will be especially helpful to cache glyph separately so that glyph caches won't be washed out by a single page cache.
118 lines
3.5 KiB
Lua
118 lines
3.5 KiB
Lua
require "cache"
|
|
|
|
--[[
|
|
TODO: all these functions should probably be methods on Face objects
|
|
]]--
|
|
|
|
GlyphCache = Cache:new{
|
|
max_memsize = 512*1024,
|
|
current_memsize = 0,
|
|
cache = {},
|
|
-- this will hold the LRU order of the cache
|
|
cache_order = {}
|
|
}
|
|
|
|
function getGlyph(face, charcode, bgcolor, fgcolor)
|
|
if bgcolor == nil then bgcolor = 0.0 end
|
|
if fgcolor == nil then fgcolor = 1.0 end
|
|
local hash = "glyph|"..face.hash.."|"..charcode.."|"..bgcolor.."|"..fgcolor
|
|
local glyph = GlyphCache:check(hash)
|
|
if glyph then
|
|
-- cache hit
|
|
return glyph[1]
|
|
end
|
|
local rendered_glyph = face.ftface:renderGlyph(charcode, bgcolor, fgcolor)
|
|
if not rendered_glyph then
|
|
DEBUG("error rendering glyph (charcode=", charcode, ") for face", face)
|
|
return
|
|
end
|
|
glyph = CacheItem:new{rendered_glyph}
|
|
glyph.size = glyph[1].bb:getWidth() * glyph[1].bb:getHeight() / 2 + 32
|
|
GlyphCache:insert(hash, glyph)
|
|
return rendered_glyph
|
|
end
|
|
|
|
function getSubTextByWidth(text, face, width, kerning)
|
|
local pen_x = 0
|
|
local prevcharcode = 0
|
|
local char_list = {}
|
|
for uchar in string.gfind(text, "([%z\1-\127\194-\244][\128-\191]*)") do
|
|
if pen_x < width then
|
|
local charcode = util.utf8charcode(uchar)
|
|
local glyph = getGlyph(face, charcode)
|
|
if kerning and prevcharcode then
|
|
local kern = face.ftface:getKerning(prevcharcode, charcode)
|
|
pen_x = pen_x + kern
|
|
end
|
|
pen_x = pen_x + glyph.ax
|
|
if pen_x <= width then
|
|
prevcharcode = charcode
|
|
table.insert(char_list, uchar)
|
|
else
|
|
break
|
|
end
|
|
end
|
|
end
|
|
return table.concat(char_list)
|
|
end
|
|
|
|
function sizeUtf8Text(x, width, face, text, kerning)
|
|
if not text then
|
|
DEBUG("sizeUtf8Text called without text");
|
|
return
|
|
end
|
|
|
|
-- may still need more adaptive pen placement when kerning,
|
|
-- see: http://freetype.org/freetype2/docs/glyphs/glyphs-4.html
|
|
local pen_x = 0
|
|
local pen_y_top = 0
|
|
local pen_y_bottom = 0
|
|
local prevcharcode = 0
|
|
for uchar in string.gfind(text, "([%z\1-\127\194-\244][\128-\191]*)") do
|
|
if pen_x < (width - x) then
|
|
local charcode = util.utf8charcode(uchar)
|
|
local glyph = getGlyph(face, charcode)
|
|
if kerning and (prevcharcode ~= 0) then
|
|
pen_x = pen_x + face.ftface:getKerning(prevcharcode, charcode)
|
|
end
|
|
pen_x = pen_x + glyph.ax
|
|
pen_y_top = math.max(pen_y_top, glyph.t)
|
|
pen_y_bottom = math.max(pen_y_bottom, glyph.bb:getHeight() - glyph.t)
|
|
--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)
|
|
prevcharcode = charcode
|
|
end -- if pen_x < (width - x)
|
|
end -- for uchar
|
|
return { x = pen_x, y_top = pen_y_top, y_bottom = pen_y_bottom}
|
|
end
|
|
|
|
function renderUtf8Text(buffer, x, y, face, text, kerning, bgcolor, fgcolor)
|
|
if not text then
|
|
DEBUG("renderUtf8Text called without text");
|
|
return 0
|
|
end
|
|
|
|
-- may still need more adaptive pen placement when kerning,
|
|
-- see: http://freetype.org/freetype2/docs/glyphs/glyphs-4.html
|
|
local pen_x = 0
|
|
local prevcharcode = 0
|
|
local buffer_width = buffer:getWidth()
|
|
for uchar in string.gfind(text, "([%z\1-\127\194-\244][\128-\191]*)") do
|
|
if pen_x < buffer_width then
|
|
local charcode = util.utf8charcode(uchar)
|
|
local glyph = getGlyph(face, charcode, bgcolor, fgcolor)
|
|
if kerning and (prevcharcode ~= 0) then
|
|
pen_x = pen_x + face.ftface:getKerning(prevcharcode, charcode)
|
|
end
|
|
buffer:addblitFrom(
|
|
glyph.bb,
|
|
x + pen_x + glyph.l, y - glyph.t,
|
|
0, 0,
|
|
glyph.bb:getWidth(), glyph.bb:getHeight(), 1)
|
|
pen_x = pen_x + glyph.ax
|
|
prevcharcode = charcode
|
|
end -- if pen_x < buffer_width
|
|
end -- for uchar
|
|
|
|
return pen_x
|
|
end
|