While `imagesetinterpolation()` is available as of PHP 5.5.0,
there is no according getter function, so users would have to track the
current interpolation method manually.
To remedy this, we introduce `imagegetinterpolation()` as thin wrapper
for `gdImageGetInterpolationMethod()` (which has been introduced with
libgd 2.1.1), and use `im->interpolation_id` as fallback for older
libgd. Since our bundled libgd does not yet have this function, we add
it.
We also simplify the recently introduced bug79068.phpt, where it is
sufficient to check that the interpolation method has not been changed.
That parameter is mostly useless in practise, and likely has been
directly ported from the underlying `gdImagePolygon()` and friends,
which require that parameter since the number of elements of the point
array would otherwise be unknown. Typical usages of `imagepolygon()`,
`imageopenpolygon()` and `imagefilledpolygon()` pass `count($points)/2`
or hard-code this value as literal. Since explicitly specifying this
parameter is annoying and error-prone, we offer the possibility to omit
it, in which case the `$points` array must have an even number of
elements, and the number of points is calculated as `count($points)/2`.
We actually have to check `$num_points` instead of `2*count($points)`,
because the latter may be greater than the former, but not all elements
of `$points` are guaranteed to be used. This allowed to pass arrays
with excess elements to draw polygons with less than three vertices.
While the current implementation of `gdImagePolygon()` and friends
would allow us to draw monogons and digons, we don't allow that
anymore, because the respective drawing primitives work slightly
different (e.g. drawing lines support anti-aliasing, but drawing
general polygons does not).
To minimize the BC break, we do not fix this longstanding issue for PHP
7, but target PHP 8 only.
Raise a ValueError instead of a plain Error when calling imagecreate()
or imagecreatetruecolor() with too big or small values for the width or
height arguments.
We add PHP bindings for libgd's features to read TGA files, which are
available as of libgd 2.1.0.
As PHP's bundled libgd doesn't yet include the respective features of the
external libgd, we add these.
Since TGA has no easily recognizable file signature, we don't add TGA
support for imagecreatefromstring() or getimagesize() and friends.
For consistency with imagegd(), imagegd2() and imagexbm(), which throw
a TypeError if a path containing NUL bytes is given, we throw a
TypeError for the other image writer functions as well.
These tests actually check that no file with a name containing a NUL is
created by the GD image output functions. This is superfluous, since
it is sufficient to check that the function failed, and that an
appropriate warning has been raised.
We also add missing nullbyte injection tests.
