1# Rust PNG decoder 2 3This directory contains experimental code for 4 5* Providing `SkCodec` API for decoding PNG images using Rust `png` crate. 6* Providing `SkEncoder` API for encoding PNG images using Rust `png` crate. 7 8See the following document for more details: 9https://docs.google.com/document/d/1glx5ue5JDlCld5WzWgTOGK3wsMErQFnkY5N5Dsbi91Y/edit?usp=sharing 10 11## Chromium build instructions 12 13To build and test the code from this directory from Chromium: 14 151. `gn args out/...` and set `enable_rust_png = true` 161. `autoninja -C out/... gfx_unittests blink_platform_unittests chrome` 171. `out/.../gfx_unittests --gtest_filter=RustEnabled*` 181. `out/.../blink_platform_unittests --gtest_filter=RustEnabled*` 191. `out/.../chrome --enable-features=RustyPng` 20 21## Skia build instructions 22 23### Bazel 24 25To build the code from this directory from Skia (testing via Bazel is not 26supported yet): 27 28``` 29$ cd skia-repo-root 30$ bazelisk build experimental/rust_png/... 31``` 32 33### gn / ninja 34 35To build the code from this directory from Skia: 36 371. `gn args out/RustPng` and set `skia_use_rust_png_decode = true` 38 as well as `skia_use_rust_png_encode = true` 391. `gn gen out/RustPng` 401. `autoninja -C out/RustPng dm` 41``` 42 43To test the code (via `tests/SkPngRustDecoderTest.cpp` and 44`tests/SkPngRustEncoderTest.cpp`): 45 46``` 47$ out/RustPng/dm --src tests --nogpu \ 48 --match RustPngCodec \ 49 RustEncodePng 50``` 51 52TODO(https://crbug.com/356875275): Add support for running older tests 53(e.g. ones from `tests/CodecTest.cpp`) against `SkPngRustCodec`. 54 55## Differences between `SkPngCodec` and `SkRustPngCodec` 56 57* `SkPngCodec`: 58 - No APNG support. 59 - No CICP support. 60* `SkPngRustCodec` differences - see 61 https://issues.chromium.org/issues?q=parentid:362829876%2B 62 63## Differences between `SkPngEncoder` and `SkPngRustEncoder` 64 65* `SkPngRustEncoder` differences - see 66 https://issues.chromium.org/issues?q=parentid:381140294%2B 67