README

**************************
*  zita-convolver 4.0.0  *
*  Released 2018-06-06   *
**************************

API changes between 3.x.x and  4.x.x
------------------------------------

1. Version 4 now uses int types from <stdint.h>
   internally and for the arguments of all member
   funcions.

2. The set_density() function has been removed, and the
   matrix density hint is now an additional argument to
   configure().

If your application does not use impdata_update(),
then (1) and (2) are the only relevant changes.

3. The way impdata_update() works has changed.

This function is used to modify IR data while the convolver
is actually running. It does not use any memory allocation
nor modify internal data structures, and only data in already
existing partitions can be modified this way.
In versions <= 3, this function would *overwrite* any existing
data. From version 4, impdata_update() *adds* to existing IR
data, just as impdata_create() does. So in order to replace an
existing IR, you first need to clear it using the new function
impdata_clear(). This will clear (but not delete) all IR data
for a given input, output pair.


Version test macro and function
-------------------------------

If your application depends on this version of zita-convolver,
insert the following two code fragments, normally in your main
program source file:

This will test for zita-convolver-4.x.x at compile time.
-----
#include <zita-convolver.h>

#if ZITA_CONVOLVER_MAJOR_VERSION != 4
#error "This program requires zita-convolver 4.x.x"
#endif
-----

This will check that the compile time and run time libraries
are compatible.
-----
if (zita_convolver_major_version () != ZITA_CONVOLVER_MAJOR_VERSION)
{
    fprintf (stderr, "Zita-convolver version does not match.\n");
    return 1;
}
-----