[cairo] [PATCH] test: Fix coverage-intersecting-triangles reference

[Chris Wilson]

On Thu, Mar 26, 2015 at 05:55:37PM +0100, Andrea Canciani wrote:
> Commit 4e3ef57bc892b0b046c486390adc7164a1de64de added
> coverage-intersecting-triangles with an incorrect reference and
> generator. The test checks the rasterization of two overlapping
> triangles in the following position:
> 
>    .   .
>    |\ /|
>    | X |
>    |/ \|
>    .---.
> 
> Since the triangles have both vertical and horizontal sides of size
> x/WIDTH, the expected coverage is 3/4 (75%) of (x/WIDTH)^2. The
> original code, instead, was checking for a coverage of 0.75*x/WIDTH,
> as if one of the sides was always 1 unit long.
> 
> The image and xlib backends still suffer from some jitter, caused by
> the approximation of the actual coverage by means of sampling, but
> their result now looks consistent with the expected reference.
> ---
>  test/coverage.c                                         |   2 +-
>  .../coverage-intersecting-triangles.image.ref.png       | Bin 0 -> 14444 bytes
>  test/reference/coverage-intersecting-triangles.ref.png  | Bin 209 -> 262 bytes
>  .../reference/coverage-intersecting-triangles.xfail.png | Bin 14444 -> 0 bytes
>  .../coverage-intersecting-triangles.xlib.ref.png        | Bin 0 -> 16728 bytes
>  .../coverage-intersecting-triangles.xlib.xfail.png      | Bin 16728 -> 0 bytes
>  6 files changed, 1 insertion(+), 1 deletion(-)
>  create mode 100644 test/reference/coverage-intersecting-triangles.image.ref.png
>  delete mode 100644 test/reference/coverage-intersecting-triangles.xfail.png
>  create mode 100644 test/reference/coverage-intersecting-triangles.xlib.ref.png
>  delete mode 100644 test/reference/coverage-intersecting-triangles.xlib.xfail.png

Apart from they are still xfail since they are necessarily imperfect
approximations (xlib doubly so if backed by pixman due to the
intersections).
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre