As already suggested by Thies this code won't compile anymore, because
php3_rqst has been removed in 1999[1]. Since apparently nobody
complained about that, we assume that EBCDIC support isn't required
here, and rid the respective code.
Furthermore, the code appears to be erroneous anyway, since at least
XBM isn't a binary file format.
[1] <3cd0af11ee (diff-1a9cfc6173e3a434387996e46086da56L258)>
We must not pass values to `gdImageScale()` which cannot be represented
by an `unsigned int`. Instead we return FALSE, according to what we
already did for negative integers.
We add PHP bindings for libgd's features to read and write BMP 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.
We expose the image resolution related GD functionality to userland
by introducing `imageresolution()` as getter/setter. Given only the
image argument, it returns the current resolution as indexed array.
Given only a second argument, it sets the horizontal and vertical
resolution to this value. Given three arguments, it sets the horizontal
and vertical resolution to the given arguments, respectively.
There's no need anymore to call an own error handler directly. Instead we
register our error handler and call libgd's error functions (which will
forward). We do this regardless of compiling with the bundled or an external
libgd.
gdImageOpenPolygon() has been introduced with líbgd 2.0.29, so we finally
add a PHP binding for it, and port the respective libgd functionality to
PHP's bundled libgd.
gdLayerMultiply() has been introduced in libgd 2.1.1, and as such would have
been already available for imagelayereffect() with a system libgd. We port
the respective code to the bundled libgd, and also make IMG_EFFECT_MULTIPLY
available to userland.
Instead of rolling our own in the bundled libgd, we use libgd's anti-aliased
drawing API. This way imageantialias() is also available, when built against
a system libgd.
We apply the law `(b**r)**s == b**(r*s)` which holds for all non-negative b
and positive r,s, so a single pow() suffices. Furthermore, we precompute the
gamma, so the refactored code is simpler and faster.
