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mirror of https://github.com/koreader/koreader synced 2024-11-04 12:00:25 +00:00
koreader/frontend/ui/renderimage.lua
NiLuJe 62059f8d68
Misc: Get rid of the legacy defaults.lua globals (#9546)
* This removes support for the following deprecated constants: `DTAP_ZONE_FLIPPING`, `DTAP_ZONE_BOOKMARK`, `DCREREADER_CONFIG_DEFAULT_FONT_GAMMA`
* The "Advanced settings" panel now highlights modified values in bold (think about:config in Firefox ;)).
* LuaData: Isolate global table lookup shenanigans, and fix a few issues in unused-in-prod codepaths.
* CodeStyle: Require module locals for Lua/C modules, too.
* ScreenSaver: Actually garbage collect our widget on close (ScreenSaver itself is not an instantiated object).
* DateTimeWidget: Code cleanups to ensure child widgets can be GC'ed.
2022-09-28 01:10:50 +02:00

456 lines
17 KiB
Lua

--[[--
Image rendering module.
All the render* functions should return a BlitBuffer object on success, nil otherwise.
]]
local Blitbuffer = require("ffi/blitbuffer")
local Math = require("optmath")
local ffi = require("ffi")
local logger = require("logger")
-- Backends are lazy-loaded
local Mupdf = nil
local Pic = nil
local NnSVG = nil
local WebP = nil
local RenderImage = {}
--- Renders image file as a BlitBuffer with the best renderer
--
-- @string filename image file path
-- @bool[opt=false] want_frames whether to return a list of animated GIF frames
-- @int width requested width
-- @int height requested height
-- @treturn BlitBuffer or list of frames (each a function returning a Blitbuffer)
function RenderImage:renderImageFile(filename, want_frames, width, height)
local file = io.open(filename, "rb")
if not file then
logger.warn("could not open image file:", filename)
return
end
local data = file:read("*a")
file:close()
return RenderImage:renderImageData(data, #data, want_frames, width, height)
end
--- Renders image data as a BlitBuffer with the best renderer
--
-- @tparam data string or userdata (pointer) with image bytes
-- @int size size of data
-- @bool[opt=false] want_frames whether to return a list of animated GIF frames
-- @int width requested width
-- @int height requested height
-- @treturn BlitBuffer or list of frames (each a function returning a Blitbuffer)
function RenderImage:renderImageData(data, size, want_frames, width, height)
if not data or not size or size == 0 then
return
end
-- Guess if it is a GIF or a WebP image: the dedicated methods are able to handle
-- animated GIF or WebP images, which MuPDF don't handle.
local buffer = ffi.cast("unsigned char*", data)
local header = ffi.string(buffer, math.min(4, size))
if header == "GIF8" then
logger.dbg("GIF file provided, renderImageData: using GifLib")
local image = self:renderGifImageDataWithGifLib(data, size, want_frames, width, height)
if image then
return image
end
-- fallback to rendering with MuPDF
elseif header == "RIFF" then
-- (The header should be "RIFFxxxxWEBPVP8", but we let libwebp check for what's after "RIFF".)
logger.dbg("possible WebP file provided, renderImageData: using libwebp")
local image = self:renderWebpImageDataWithLibwebp(data, size, want_frames, width, height)
if image then
return image
end
-- fallback to rendering with MuPDF
elseif header == "<svg" or header == "<?xm" then
logger.dbg("possible SVG file provided, renderImageData: using crengine")
local image = self:renderSVGImageDataWithCRengine(data, size, width, height)
if image then
return image
end
end
logger.dbg("renderImageData: using MuPDF")
return self:renderImageDataWithMupdf(data, size, width, height)
end
--- Renders image data as a BlitBuffer with MuPDF
--
-- @tparam data string or userdata (pointer) with image bytes
-- @int size size of data
-- @int width requested width
-- @int height requested height
-- @treturn BlitBuffer
function RenderImage:renderImageDataWithMupdf(data, size, width, height)
if not Mupdf then Mupdf = require("ffi/mupdf") end
local ok, image = pcall(Mupdf.renderImage, data, size, width, height)
logger.dbg("Mupdf.renderImage", ok, image)
if not ok then
logger.warn("failed rendering image (MuPDF):", image)
return
end
return image
end
--- Renders SVG image data as a BlitBuffer with CRengine (and extended LunaSVG)
--
-- @tparam data string or userdata (pointer) with image bytes
-- @int size size of data
-- @int width requested width
-- @int height requested height
-- @treturn BlitBuffer
function RenderImage:renderSVGImageDataWithCRengine(data, size, width, height)
local cre = require("document/credocument"):engineInit()
local image_data, image_w, image_h = cre.renderImageData(data, size, width, height)
if not image_data then
logger.warn("failed rendering image (SVG/CRengine)")
return
end
local image = Blitbuffer.new(image_w, image_h, Blitbuffer.TYPE_BBRGB32, image_data)
return image
end
--- Renders image data as a BlitBuffer with GifLib
--
-- @tparam data string or userdata (pointer) with image bytes
-- @int size size of data
-- @bool[opt=false] want_frames whether to also return a list with animated GIF frames
-- @int width requested width
-- @int height requested height
-- @treturn BlitBuffer or list of frames (each a function returning a Blitbuffer)
function RenderImage:renderGifImageDataWithGifLib(data, size, want_frames, width, height)
if not data or not size or size == 0 then
return
end
if not Pic then Pic = require("ffi/pic") end
local ok, gif = pcall(Pic.openGIFDocumentFromData, data, size)
logger.dbg("Pic.openGIFDocumentFromData", ok)
if not ok then
logger.warn("failed rendering image (GifLib):", gif)
return
end
local nb_frames = gif:getPages()
logger.dbg("GifDocument, nb frames:", nb_frames)
if want_frames and nb_frames > 1 then
-- Returns a regular table, with functions (returning the BlitBuffer)
-- as values. Users will have to check via type() and call them.
-- (The __len metamethod is a Lua 5.2 feature, otherwise we
-- could have used setmetatable to avoid creating all the functions)
local frames = {}
-- As we don't cache the bb we build on the fly, let caller know it
-- will have to free them
frames.image_disposable = true
for i=1, nb_frames do
table.insert(frames, function()
local page = gif:openPage(i)
-- we do not page.close(), so image_bb is not freed
if page and page.image_bb then
return self:scaleBlitBuffer(page.image_bb, width, height)
end
end)
end
-- We can't close our GifDocument as long as we may fetch some
-- frame: we need to delay it till 'frames' is no longer used.
frames.gif_close_needed = true
-- Since frames is a plain table, __gc won't work on Lua 5.1/LuaJIT,
-- not without a little help from the newproxy hack...
frames.gif = gif
local frames_mt = {}
function frames_mt:__gc()
logger.dbg("frames.gc() called, closing GifDocument", self.gif)
if self.gif_close_needed then
self.gif:close()
self.gif_close_needed = nil
end
end
-- Much like our other stuff, when we're puzzled about __gc, we do it manually!
-- So, also set this method, so that ImageViewer can explicitely call it onClose.
function frames:free()
logger.dbg("frames.free() called, closing GifDocument", self.gif)
if self.gif_close_needed then
self.gif:close()
self.gif_close_needed = nil
end
end
local setmetatable = require("ffi/__gc")
setmetatable(frames, frames_mt)
return frames
else
local page = gif:openPage(1)
-- we do not page.close(), so image_bb is not freed
if page and page.image_bb then
gif:close()
return self:scaleBlitBuffer(page.image_bb, width, height)
end
gif:close()
end
logger.warn("failed rendering image (GifLib)")
end
--- Renders image data as a BlitBuffer with libwebp
--
-- @tparam data string or userdata (pointer) with image bytes
-- @int size size of data
-- @bool[opt=false] want_frames whether to also return a list with animated WebP frames
-- @int width requested width
-- @int height requested height
-- @treturn BlitBuffer or list of frames (each a function returning a Blitbuffer)
function RenderImage:renderWebpImageDataWithLibwebp(data, size, want_frames, width, height)
if not data or not size or size == 0 then
return
end
if not WebP then WebP = require("ffi/webp") end
local valid, webp = pcall(WebP.fromData, data, size)
if not valid then
logger.warn("failed opening image (libwebp):", webp)
return
end
logger.dbg("WebP image, nb frames:", webp.nb_frames)
if want_frames and webp.nb_frames > 1 then
-- Returns a regular table, with functions (returning the BlitBuffer)
-- as values. Users will have to check via type() and call them.
-- (The __len metamethod is a Lua 5.2 feature, otherwise we
-- could have used setmetatable to avoid creating all the functions)
local frames = {}
-- As we don't cache the bb we build on the fly, let caller know it
-- will have to free them
frames.image_disposable = true
for i=1, webp.nb_frames do
table.insert(frames, function()
-- As we may be rescaling the bb we'll get, we can provide no_copy=true
-- to avoid the copy done by default, and do it ourselves if needed.
local ok, webp_bb = pcall(webp.getFrameImage, webp, i, true)
if ok and webp_bb then
local image_bb = self:scaleBlitBuffer(webp_bb, width, height)
if image_bb == webp_bb then -- no scaling was done
image_bb = webp_bb:copy()
end
return image_bb
else
logger.warn("failed rendering image frame (libwebp)", i)
end
end)
end
-- We can't close our webp object as long as we may fetch some
-- frame: we need to delay it till 'frames' is no longer used.
frames.webp_close_needed = true
-- Since frames is a plain table, __gc won't work on Lua 5.1/LuaJIT,
-- not without a little help from the newproxy hack...
frames.webp = webp
local frames_mt = {}
function frames_mt:__gc()
logger.dbg("frames.gc() called, closing webp object", self.webp)
if self.webp_close_needed then
self.webp:close()
self.webp_close_needed = nil
end
end
-- Much like our other stuff, when we're puzzled about __gc, we do it manually!
-- So, also set this method, so that ImageViewer can explicitely call it onClose.
function frames:free()
logger.dbg("frames.free() called, closing webp object", self.webp)
if self.webp_close_needed then
self.webp:close()
self.webp_close_needed = nil
end
end
local setmetatable = require("ffi/__gc")
setmetatable(frames, frames_mt)
return frames
else
local ok, image_bb = pcall(webp.getFrameImage, webp, 1)
if ok and image_bb then
image_bb = self:scaleBlitBuffer(image_bb, width, height)
else
logger.warn("failed rendering image (libwebp)")
image_bb = nil
end
webp:close()
return image_bb
end
end
--- Rescales a BlitBuffer to the requested size if needed
--
-- @tparam bb BlitBuffer
-- @int width
-- @int height
-- @bool[opt=true] free_orig_bb free() original bb if scaled
-- @treturn BlitBuffer
function RenderImage:scaleBlitBuffer(bb, width, height, free_orig_bb)
if not width or not height then
logger.dbg("RenderImage:scaleBlitBuffer: no need")
return bb
end
-- Ensure we give integer width and height to MuPDF, to
-- avoid a black 1-pixel line at right and bottom of image
width, height = math.floor(width), math.floor(height)
if bb:getWidth() == width and bb:getHeight() == height then
logger.dbg("RenderImage:scaleBlitBuffer: no need")
return bb
end
logger.dbg("RenderImage:scaleBlitBuffer: scaling")
local scaled_bb
if G_reader_settings:isTrue("legacy_image_scaling") then
-- Uses "simple nearest neighbour scaling"
scaled_bb = bb:scale(width, height)
else
-- Better quality scaling with MuPDF
if not Mupdf then Mupdf = require("ffi/mupdf") end
scaled_bb = Mupdf.scaleBlitBuffer(bb, width, height)
end
if free_orig_bb ~= false then
bb:free()
end
return scaled_bb
end
--- Renders SVG image file as a BlitBuffer with the best renderer
--
-- @string filename image file path
-- @int width requested width
-- @int height requested height
-- @number zoom requested zoom
-- @treturn BlitBuffer
function RenderImage:renderSVGImageFile(filename, width, height, zoom)
if self.RENDER_SVG_WITH_NANOSVG then
return self:renderSVGImageFileWithNanoSVG(filename, width, height, zoom)
else
return self:renderSVGImageFileWithMupdf(filename, width, height, zoom)
end
end
-- For now (with our old MuPDF 1.13), NanoSVG is the best renderer
-- Note that both renderers currently enforce keeping the image's
-- original aspect ratio.
RenderImage.RENDER_SVG_WITH_NANOSVG = true
function RenderImage:renderSVGImageFileWithNanoSVG(filename, width, height, zoom)
if not NnSVG then
NnSVG = require("libs/libkoreader-nnsvg")
end
local ok, svg_image = pcall(NnSVG.new, filename)
if not ok then
logger.warn("failed rendering SVG (NanoSVG):", svg_image)
return
end
local native_w, native_h = svg_image:getSize()
if not zoom then
if width and height then
-- Original aspect ratio will be kept, we might have
-- to center the SVG inside the target width/height
zoom = math.min(width/native_w, height/native_h)
elseif width then
zoom = width/native_w
elseif height then
zoom = height/native_h
else
zoom = 1
end
end
-- (Be sure we use integers; using floats can cause glitches)
local inner_w = math.ceil(zoom * native_w)
local inner_h = math.ceil(zoom * native_h)
local offset_x = 0
local offset_y = 0
if not width then
width = inner_w
elseif inner_w < width then
offset_x = Math.round((width - inner_w) / 2)
end
if not height then
height = inner_h
elseif inner_h < height then
offset_y = Math.round((height - inner_h) / 2)
end
logger.dbg("renderSVG", filename, zoom, native_w, native_h, ">", width, height, offset_x, offset_y)
local bb = Blitbuffer.new(width, height, Blitbuffer.TYPE_BBRGB32)
svg_image:drawTo(bb, zoom, offset_x, offset_y)
svg_image:free()
return bb, true -- is_straight_alpha=true
end
function RenderImage:renderSVGImageFileWithMupdf(filename, width, height, zoom)
local ok, document = pcall(Mupdf.openDocument, filename)
if not ok then
logger.warn("failed rendering SVG (MuPDF):", document)
return
end
-- document:layoutDocument(width, height, 20) -- does not change anything
if document:getPages() <= 0 then
return
end
local page = document:openPage(1)
local DrawContext = require("ffi/drawcontext")
local dc = DrawContext.new()
local native_w, native_h = page:getSize(dc)
if not zoom then
if width and height then
zoom = math.min(width/native_w, height/native_h)
elseif width then
zoom = width/native_w
elseif height then
zoom = height/native_h
else
zoom = 1
end
end
if not width or not height then
width = zoom * native_w
height = zoom * native_h
end
width = math.ceil(width)
height = math.ceil(height)
logger.dbg("renderSVG", filename, zoom, native_w, native_h, ">", width, height)
dc:setZoom(zoom)
-- local bb = page:draw_new(dc, width, height, 0, 0)
-- MuPDF or our FFI may fail on some icons (appbar.page.fit),
-- avoid a crash and return a blank and black image
local rendered, bb = pcall(page.draw_new, page, dc, width, height, 0, 0)
if not rendered then
logger.warn("MuPDF renderSVG error:", bb)
bb = nil
end
page:close()
document:close()
return bb -- pre-multiplied alpha: no is_straight_alpha=true
end
--- Renders a checkerboard pattern (useful as a fallback after a decoding failure)
function RenderImage:renderCheckerboard(width, height, bb_type)
width = width or 800
height = height or 800
local bb = Blitbuffer.new(width, height, bb_type or Blitbuffer.TYPE_BB8)
local checker_size = bit.rshift(math.min(width, height), 4)
local pen_color = Blitbuffer.COLOR_BLACK
local row_start
for y = 0, height - 1, checker_size do
row_start = pen_color
for x = 0, width - 1, checker_size do
-- BBs are zero-initialized (i.e., black)
if pen_color == Blitbuffer.COLOR_WHITE then
bb:paintRect(x, y, checker_size, checker_size, Blitbuffer.COLOR_WHITE)
-- Alternate pen color every "column"
pen_color = Blitbuffer.COLOR_BLACK
else
pen_color = Blitbuffer.COLOR_WHITE
end
end
-- Alternate initial pen color every "row"
if row_start == Blitbuffer.COLOR_WHITE then
pen_color = Blitbuffer.COLOR_BLACK
else
pen_color = Blitbuffer.COLOR_WHITE
end
end
return bb
end
return RenderImage