skia2/third_party/libpng/README.google

URL: http://www.libpng.org/pub/png/libpng.html
Version: 1.6.16
License: libpng license
License File: LICENSE, pulled out of png.h
Description: png compression/decompression library
Local Modifications: (1) Created pnglibconf.h from pnglibconf.h.prebuilt (a
    rename with a few additional settings enabled). (2) Copied LICENSE into
    this directory. (Originally it was pulled from png.h, but libpng has
    now provided a separate LICENSE file for convenience, which we use
    directly.)

FAQ:
Q: Why does this directory exist?
A: libpng is pulled in through DEPS, but in order to build it using ninja, we
   need to create pnglibconf.h.  We originally tried creating
   the file as an action in https://codereview.chromium.org/930283002/, but this
   apparently led to a race condition on Windows, where some builds failed to
   create the file in time for other files to include it. By checking these
   files directly into Skia, we eliminate the race condition.
Add SkCodec, including PNG implementation. DM: Add a flag to use SkCodec instead of SkImageDecoder. SkCodec: Base class for codecs, allowing creation from an SkStream or an SkData. An SkCodec, on creation, knows properties of the data like its width and height. Further calls can be used to generate the image. TODO: Add scanline iterator SkPngCodec: New decoder for png. Wraps libpng. The code has been repurposed from SkImageDecoder_libpng. TODO: Handle other destination colortypes TODO: Substitute the transpose color TODO: Allow silencing warnings TODO: Use RGB instead of filler? TODO: sRGB SkSwizzler: Simplified version of SkScaledSampler. Unlike the sampler, this object does no sampling. TODO: Implement other swizzles. Requires a gclient sync to pull down libpng. BUG=skia:3257 Committed: https://skia.googlesource.com/skia/+/ca358852b4fed656d11107b2aaf28318a4518b49 (and then reverted) Review URL: https://codereview.chromium.org/930283002 2015-03-03 16:59:20 +00:00			`URL: http://www.libpng.org/pub/png/libpng.html`
			`Version: 1.6.16`
			`License: libpng license`
			`License File: LICENSE, pulled out of png.h`
			`Description: png compression/decompression library`
Enable both static and dynamically linked libpng All platforms except android are configured to use the statically linked copy of libpng. Android uses the system provided dynamic copy for SkImageDecoder and the static copy for SkCodec. The exception being android framework builds that currently use the dynamic copy everywhere. This CL also enables NEON optimizations for libpng. Review URL: https://codereview.chromium.org/1058823002 2015-04-03 19:35:27 +00:00			`Local Modifications: (1) Created pnglibconf.h from pnglibconf.h.prebuilt (a`
Update the version of libpng used by Skia tests The version of libpng we were using has some security vulnerabilities. Update to a newer version - 1.6.20 (http://sourceforge.net/p/libpng/code/ci/047737496a77eeb97f9991919dac08ca3c149711/). Update pnglibconf.h. The new version is a copy of the newer version of the file, with our /* custom settings */ tacked onto the end. (The custom settings are unchanged from the last version.) Update the LICENSE. The new version is a copy of the LICENSE that libpng now includes as a separate file. Update the README file to reflect the change in source of the LICENSE file. BUG=skia:4573 GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1453373003 Review URL: https://codereview.chromium.org/1453373003 2016-02-19 14:33:07 +00:00			`rename with a few additional settings enabled). (2) Copied LICENSE into`
			`this directory. (Originally it was pulled from png.h, but libpng has`
			`now provided a separate LICENSE file for convenience, which we use`
			`directly.)`
Add SkCodec, including PNG implementation. DM: Add a flag to use SkCodec instead of SkImageDecoder. SkCodec: Base class for codecs, allowing creation from an SkStream or an SkData. An SkCodec, on creation, knows properties of the data like its width and height. Further calls can be used to generate the image. TODO: Add scanline iterator SkPngCodec: New decoder for png. Wraps libpng. The code has been repurposed from SkImageDecoder_libpng. TODO: Handle other destination colortypes TODO: Substitute the transpose color TODO: Allow silencing warnings TODO: Use RGB instead of filler? TODO: sRGB SkSwizzler: Simplified version of SkScaledSampler. Unlike the sampler, this object does no sampling. TODO: Implement other swizzles. Requires a gclient sync to pull down libpng. BUG=skia:3257 Committed: https://skia.googlesource.com/skia/+/ca358852b4fed656d11107b2aaf28318a4518b49 (and then reverted) Review URL: https://codereview.chromium.org/930283002 2015-03-03 16:59:20 +00:00
			`FAQ:`
			`Q: Why does this directory exist?`
			`A: libpng is pulled in through DEPS, but in order to build it using ninja, we`
Fix the build on Android devices 2015-11-06 19:59:01 +00:00			`need to create pnglibconf.h. We originally tried creating`
Enable both static and dynamically linked libpng All platforms except android are configured to use the statically linked copy of libpng. Android uses the system provided dynamic copy for SkImageDecoder and the static copy for SkCodec. The exception being android framework builds that currently use the dynamic copy everywhere. This CL also enables NEON optimizations for libpng. Review URL: https://codereview.chromium.org/1058823002 2015-04-03 19:35:27 +00:00			`the file as an action in https://codereview.chromium.org/930283002/, but this`
			`apparently led to a race condition on Windows, where some builds failed to`
			`create the file in time for other files to include it. By checking these`
			`files directly into Skia, we eliminate the race condition.`