ANGLE Orientation

A basic guide to get up and running fixing bugs and performance issues in ANGLE.

First ANGLE Compile

Download and install Visual Studio Community. Installing takes some time.
Take the time to register a Microsoft account, otherwise you'll get nagged to death.
Download and install Chromium's depot_tools for building ANGLE.
Add the depot_tools dir to your system path. Open start menu, type "edit environment variables", add it to PATH.
(recommended) Download and install Git for Windows.
Open Git bash, head to C:/src and follow the steps on the ANGLE wiki to set up the ANGLE solution for the first time.
If you follow the ANGLE wiki VS solution building and debugging guide, the VS solution will be in c:/src/angle/out/Debug/angle-debug.sln. Open and let the installation finish. Important: set indent style to spaces, not tabs!
Building should work at this point!
Try running angle_end2end_tests, angle_unittests or a sample program.
Useful VS extensions:

Cherry is the UI for viewing test results. ANGLE checks out a copy in <angledir>/third_party/cherry.
Follow the instructions in the installation README to get it running. On Windows, use 64-bit.
Read up on testing with dEQP on the ANGLE Wiki.
Try running angle_deqp_gles2_tests_no_gtest with the flag --deqp-case=dEQP-GLES2.functional.negative_api.* and load a test report in Cherry.
To use Cherry, browse to http://localhost:8080/#/results and click 'Import existing batch', loading TestResults.qpa. Look for the qpa file in the current working directory, or <angledir>/src/tests if you ran the tests from Visual Studio.
Note: we only use Cherry for viewing test output, not running the tests. On start, you may see some runtime messages about unable to load case lists. These are safe to ignore. If you didn't load the results URL directly, click the "Results" tab to find the Import button.

You can use scripts/perf_test_runner.py to run any target of ./angle_perftests (see script source for details).

In Visual Studio 2017, look under Debug/Profiler/Performance Explorer/New Performance Session. Right-click "Targets" and add angle_perftests as a Target Project.
Run angle_perftests with the flag --gtest_filter=DrawCallPerfBenchmark.Run/d3d11_null for D3D11, .../d3d9_null for D3D9, .../gl_null for OpenGL and .../vulkan_null for Vulkan.
Make sure you close all open instances of Chrome, they use a lot of background CPU and GPU. In fact, close every process and application you can.

Install Chrome Canary.
Canary's install dir is usually %APPDATA%/Local/Google/Chrome SxS/Application
Build ANGLE x64, Release, and run 'python scripts/update_chrome_angle.py' to replace Canary's ANGLE with your custom ANGLE. (Note: Canary must be closed)
Start Canary with --gpu-startup-dialog --disable-gpu-sandbox, wait for the dialog.
In Visual Studio, under Debug/Profiler, choose attach to process.
Attach to the Chrome GPU process, then immediately pause profiling.
IMPORTANT: Verify ANGLE details are correct in about:gpu.
In Canary, start your benchmark, then resume profiling, and exit when done. The report will load automatically.

These specs can be found in the OpenGL Registry and the Vulkan Docs repositories as well.