commit | 36e258b475702bdb1a95a88fcebd78b51069c532 | [log] [tgz] |
---|---|---|
author | caryclark <caryclark@google.com> | Thu Jun 02 08:59:20 2016 -0700 |
committer | Commit bot <commit-bot@chromium.org> | Thu Jun 02 08:59:20 2016 -0700 |
tree | 6752f85aa4944cbc59b7e05decfd1e891ad22ed1 | |
parent | 2235b7b52e2cedea9b5d4822de9548994362ca96 [diff] |
The PDFium source in core/fxge/dib implements a bit-blitting backend. This code has several disadvantages over a more modern graphics engine: - no SIMD support - no GPU support - limited quality Further, calling this code locks in the perceived resolution, so that the output cannot be scaled without additional loss. By directing all bitmap drawing through CFX_SkiaDeviceDriver::StartDIBits, Skia can handle all appropriate bitmap optimizations. To that end, SetDIBits and StretchDIBits now call StartDIBits. Other changes: Skia's bitmaps are premultiplied. PDF contains bitmaps that are unpremultiplied. PDFium appears to use premultiplied bitmaps sometimes, and unpremultiplied bitmaps elsewhere. Add a debug check for unpremultiplied bits in Skia's driver, and add a utility to premultiply PDFium's bitmaps' bits. PDFium supports a 24 bit RGB bitmap padded to a 32 bit word. Set the high byte so that Skia can treat this as an ARGB bitmap. Defer the application of the alpha value to the draw call rather than calling MultiplyAlpha where possible. Allow the destination bitmap to be alpha 8 or argb 32. Review-Url: https://codereview.chromium.org/2025043002
As of 2016-05-04, GN is used to generate build files replacing GYP. GYP support will remain until it is disabled in Chromium and then will be removed from PDFium.
As of 2016-04-28, the Visual Studio toolchain from depot_tools is used as the default Windows toolchain for Googlers. Please set DEPOT_TOOLS_WIN_TOOLCHAIN=0 if you need to use the system toolchain. See Windows development subsection for details.
Get the chromium depot tools via the instructions at http://www.chromium.org/developers/how-tos/install-depot-tools (this provides the gclient utility needed below).
Also install Python, Subversion, and Git and make sure they're in your path.
PDFium uses a similar Windows toolchain as Chromium:
Visual Studio 2015 Update 2 or later is highly recommended.
Run set DEPOT_TOOLS_WIN_TOOLCHAIN=0
, or set that variable in your global environment.
Compilation is done through ninja, not Visual Studio.
Run: download_from_google_storage --config
and follow the authentication instructions. Note that you must authenticate with your @google.com credentials. Enter "0" if asked for a project-id.
Once you've done this, the toolchain will be installed automatically for you in the step below.
The toolchain will be in depot_tools\win_toolchain\vs_files\<hash>
, and windbg can be found in depot_tools\win_toolchain\vs_files\<hash>\win_sdk\Debuggers
.
If you want the IDE for debugging and editing, you will need to install it separately, but this is optional and not needed for building PDFium.
The name of the top-level directory does not matter. In our examples, we use "repo". This directory must not have been used before by gclient config
as each directory can only house a single gclient configuration.
mkdir repo cd repo gclient config --unmanaged https://pdfium.googlesource.com/pdfium.git gclient sync cd pdfium
We use GN to generate the build files and Ninja (also included with the depot_tools checkout) to execute the build files.
gn gen <directory>
If you want to set to out/Debug
or out/Release
you'll need to export GYP_PDFIUM_NO_ACTION=1
to stop gclient sync
from executing GYP and overwriting your build files.
### Selecting build configuration
PDFium may be built either with or without JavaScript support, and with or without XFA forms support. Both of these features are enabled by default. Also note that the XFA feature requires JavaScript.
Configuration is done by executing gn args <directory>
to configure the build. This will launch an editor in which you can set the following arguments.
use_goma = true # Googlers only. is_debug = true # Enable debugging features. pdf_use_skia = false # Set true to enable experimental skia backend. pdf_enable_xfa = true # Set false to remove XFA support (implies JS support). pdf_enable_v8 = true # Set false to remove Javascript support. pdf_is_standalone = true # Set for a non-embedded build. clang_use_chrome_plugins = false # Currently must be false.
Note, you must set pdf_is_standalone = true
if you want the sample applications like pdfium_test
to build.
When complete the arguments will be stored in <directory>/args.gn
.
If you used Ninja, you can build the sample program by: ninja -C <directory>/pdfium_test
You can build the entire product (which includes a few unit tests) by: ninja -C <directory>
.
The pdfium_test program supports reading, parsing, and rasterizing the pages of a .pdf file to .ppm or .png output image files (windows supports two other formats). For example: <directory>/pdfium_test --ppm path/to/myfile.pdf
. Note that this will write output images to path/to/myfile.pdf.<n>.ppm
.
There are currently several test suites that can be run:
It is possible the tests in the testing
directory can fail due to font differences on the various platforms. These tests are reliable on the bots. If you see failures, it can be a good idea to run the tests on the tip-of-tree checkout to see if the same failures appear.
The current health of the source tree can be found at http://build.chromium.org/p/client.pdfium/console
There are several mailing lists that are setup:
Note, the Reviews and Bugs lists are typically read-only.
We use this bug tracker, but for security bugs, please use [Chromium's security bug template] (https://code.google.com/p/chromium/issues/entry?template=Security%20Bug) and add the "Cr-Internals-Plugins-PDF" label.
For contributing code, we will follow Chromium's process as much as possible. The main exceptions is: