mirror of
https://github.com/koreader/koreader
synced 2024-11-13 19:11:25 +00:00
f3e0d44cc4
to make koreader on Android more stable
and with these opt params:
```
require("jit.opt").start("sizemcode=64","maxmcode=64", "hotloop=10000")
```
The strategy here is that we only use precious mcode memory (jitting)
on deep loops like the several blitting methods in blitbuffer.lua and
the pixel-copying methods in mupdf.lua. So that a small amount of mcode
memory (64KB) allocated when koreader is launched in the android.lua
is enough for the program and it won't need to jit other parts of lua
code and thus won't allocate mcode memory any more which by our
observation will be harder and harder as we run koreader.
237 lines
8.5 KiB
Lua
237 lines
8.5 KiB
Lua
--[[--
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Text rendering module.
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]]
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local Font = require("ui/font")
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local Cache = require("cache")
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local CacheItem = require("cacheitem")
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local BlitBuffer = require("ffi/blitbuffer")
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local DEBUG = require("dbg")
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if require("device"):isAndroid() then
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require("jit").off(true, true)
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end
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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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local RenderText = {}
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local GlyphCache = Cache:new{
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max_memsize = 512*1024,
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current_memsize = 0,
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cache = {},
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-- this will hold the LRU order of the cache
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cache_order = {}
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}
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-- iterator over UTF8 encoded characters in a string
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local function utf8Chars(input_text)
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local function read_next_glyph(input, pos)
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if string.len(input) < pos then return nil end
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local value = string.byte(input, pos)
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if bit.band(value, 0x80) == 0 then
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-- TODO: check valid ranges
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return pos+1, value, string.sub(input, pos, pos)
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elseif bit.band(value, 0xC0) == 0x80 -- invalid, continuation
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or bit.band(value, 0xF8) == 0xF8 -- 5-or-more byte sequence, illegal due to RFC3629
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then
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return pos+1, 0xFFFD, "\xFF\xFD"
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else
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local glyph, bytes_left
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if bit.band(value, 0xE0) == 0xC0 then
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glyph = bit.band(value, 0x1F)
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bytes_left = 1
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elseif bit.band(value, 0xF0) == 0xE0 then
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glyph = bit.band(value, 0x0F)
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bytes_left = 2
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elseif bit.band(value, 0xF8) == 0xF0 then
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glyph = bit.band(value, 0x07)
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bytes_left = 3
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else
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return pos+1, 0xFFFD, "\xFF\xFD"
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end
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if string.len(input) < (pos + bytes_left) then
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return pos+1, 0xFFFD, "\xFF\xFD"
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end
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for i = pos+1, pos + bytes_left do
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value = string.byte(input, i)
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if bit.band(value, 0xC0) == 0x80 then
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glyph = bit.bor(bit.lshift(glyph, 6), bit.band(value, 0x3F))
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else
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-- invalid UTF8 continuation - don't be greedy, just skip
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-- the initial char of the sequence.
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return pos+1, 0xFFFD, "\xFF\xFD"
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end
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end
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-- TODO: check for valid ranges here!
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return pos+bytes_left+1, glyph, string.sub(input, pos, pos+bytes_left)
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end
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end
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return read_next_glyph, input_text, 1
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end
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function RenderText:getGlyph(face, charcode, bold)
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local hash = "glyph|"..face.hash.."|"..charcode.."|"..(bold and 1 or 0)
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local glyph = GlyphCache: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, bold)
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if face.ftface:checkGlyph(charcode) == 0 then
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for index, font in pairs(Font.fallbacks) do
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-- use original size before scaling by screen DPI
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local fb_face = Font:getFace(font, face.orig_size)
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if fb_face ~= nil then
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-- for some characters it cannot find in Fallbacks, it will crash here
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if fb_face.ftface:checkGlyph(charcode) ~= 0 then
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rendered_glyph = fb_face.ftface:renderGlyph(charcode, bold)
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--DEBUG("fallback to font", font)
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break
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end
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end
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end
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end
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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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GlyphCache:insert(hash, glyph)
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return rendered_glyph
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end
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--- Return a substring of a given text that meets the maximum width (in pixels)
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-- restriction.
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--
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-- @string text text to truncate
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-- @tparam ui.font.FontFaceObj face font face for the text
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-- @int width maximum width in pixels
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-- @bool[opt=false] kerning whether the text should be measured with kerning
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-- @bool[opt=false] bold whether the text should be measured as bold
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-- @treturn string
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function RenderText:getSubTextByWidth(text, face, width, kerning, bold)
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local pen_x = 0
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local prevcharcode
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local char_list = {}
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for _, charcode, uchar in utf8Chars(text) do
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if pen_x < width then
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local glyph = self:getGlyph(face, charcode, bold)
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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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--- Measure rendered size for a given text.
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--
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-- Note this function does not render the text into a bitmap. Use it if you
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-- only need the estimated size information.
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--
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-- @int x start position for a given text (within maximum width)
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-- @int width maximum rendering width in pixels (think of it as size of the bitmap)
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-- @tparam ui.font.FontFaceObj face font face that will be used for rendering
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-- @string text text to measure
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-- @bool[opt=false] kerning whether the text should be measured with kerning
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-- @bool[opt=false] bold whether the text should be measured as bold
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-- @treturn RenderTextSize
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function RenderText:sizeUtf8Text(x, width, face, text, kerning, bold)
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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 _, charcode, uchar in utf8Chars(text) do
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if pen_x < (width - x) then
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local glyph = self:getGlyph(face, charcode, bold)
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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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prevcharcode = charcode
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end -- if pen_x < (width - x)
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end
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--- RenderText size information
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-- @table RenderTextSize
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-- @field x length of the text on x coordinate
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-- @field y_top distance between top-most pixel (scanline) and baseline
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-- (bearingY)
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-- @field y_bottom distance between bottom-most pixel (scanline) and
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-- baseline (height - y_top)
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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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--- Render a given text into a given BlitBuffer
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--
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-- @tparam BlitBuffer dest_bb Buffer to blit into
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-- @int x starting x coordinate position within dest_bb
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-- @int baseline y coordinate for baseline, within dest_bb
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-- @tparam ui.font.FontFaceObj face font face that will be used for rendering
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-- @string text text to render
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-- @bool[opt=false] kerning whether the text should be measured with kerning
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-- @bool[opt=false] bold whether the text should be measured as bold
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-- @tparam[opt=BlitBuffer.COLOR_BLACK] BlitBuffer.COLOR fgcolor foreground color
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-- @int[opt=nil] width maximum rendering width
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-- @return int width of rendered bitmap
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function RenderText:renderUtf8Text(dest_bb, x, baseline, face, text, kerning, bold, fgcolor, width)
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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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if not fgcolor then
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fgcolor = BlitBuffer.COLOR_BLACK
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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 text_width = dest_bb:getWidth() - x
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if width and width < text_width then
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text_width = width
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end
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for _, charcode, uchar in utf8Chars(text) do
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if pen_x < text_width then
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local glyph = self:getGlyph(face, charcode, bold)
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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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dest_bb:colorblitFrom(
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glyph.bb,
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x + pen_x + glyph.l,
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baseline - glyph.t,
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0, 0,
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glyph.bb:getWidth(), glyph.bb:getHeight(),
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fgcolor)
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pen_x = pen_x + glyph.ax
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prevcharcode = charcode
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end -- if pen_x < text_width
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end
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return pen_x
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end
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return RenderText
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