Piglit
------
1. About
2. Setup
3. How to run tests
4. How to write tests
5. Todo


1. About
--------

Piglit is a collection of automated tests for OpenGL implementations.

The goal of Piglit is to help improve the quality of open source
OpenGL drivers by providing developers with a simple means to
perform regression tests.

The original tests have been taken from
- Glean ( http://glean.sf.net/ ) and
- Mesa ( http://www.mesa3d.org/ )


2. Setup
--------

First of all, you need to make sure that the following are installed:

  - Python 2.4 or greater
  - cmake (http://www.cmake.org)
  - GL, glu and glut libraries and development packages (i.e. headers)
  - X11 libraries and development packages (i.e. headers)
  - libtiff

Now configure the build system:

  $ ccmake .

This will start cmake's configuration tool, just follow the onscreen
instructions. The default settings should be fine, but I recommend you:
 - Press 'c' once (this will also check for dependencies) and then
 - Set "CMAKE_BUILD_TYPE" to "Debug"
Now you can press 'c' again and then 'g' to generate the build system.
Now build everything:

  $ make



3. How to run tests
-------------------

Make sure that everything is set up correctly:

  $ ./piglit-run.py tests/sanity.tests results/sanity.results

This will run some minimal tests. Use

  $ ./piglit-run.py

to learn more about the command's syntax. Have a look into the tests/
directory to see what test profiles are available:

  $ cd tests
  $ ls *.tests
     ...
  $ cd ..

To create some nice formatted test summaries, run

  $ ./piglit-summary-html.py summary/sanity results/sanity.results

Hint: You can combine multiple test results into a single summary.
      During development, you can use this to watch for regressions:

  $ ./piglit-summary-html.py summary/compare results/baseline.results results/current.results

      You can combine as many testruns as you want this way(in theory;
      the HTML layout becomes awkward when the number of testruns increases)

Have a look at the results with a browser:

  $ xdg-open summary/sanity/index.html

The summary shows the 'status' of a test:

 pass  This test has completed successfully.

 warn  The test completed successfully, but something unexpected happened.
       Look at the details for more information.

 fail  The test failed.

 skip  The test was skipped.

[Note: Once performance tests are implemented, 'fail' will mean that the test
       rendered incorrectly or didn't complete, while 'warn' will indicate a
       performance regression]
[Note: For performance tests, result and status will be different concepts.
       While status is always restricted to one of the four values above,
       the result can contain a performance number like frames per second]


4. How to write tests
---------------------

Every test is run as a separate process. This minimizes the impact that
severe bugs like memory corruption have on the testing process.

Therefore, tests can be implemented in an arbitrary standalone language.
I recommend C, C++ and Python, as these are the languages that are already
used in Piglit.

All new tests must be added to the all.tests profile. The test profiles
are simply Python scripts. There are currently two supported test types:

 PlainExecTest
   This test starts a new process and watches the process output (stdout and
   stderr). Lines that start with "PIGLIT:" are collected and interpreted as
   a Python dictionary that contains test result details.

 GleanTest
   This is a test that is only used to integrate Glean tests

Additional test types (e.g. for automatic image comparison) would have to
be added to core.py.

Rules of thumb:
  Test process that exit with a nonzero returncode are considered to have
  failed.

  Output on stderr causes a warning.


5. Todo
-------

 Get automated tests into widespread use ;)

 Automate and integrate tests and demos from Mesa
   Add code that automatically tests whether the test has rendered correctly

 Performance regression tests
   Ideally, this should be done by summarizing / comparing a history of
   test results