The idea is that all filenames we deal with are encoded as UTF-8, but the
Windows functions that take a char string interpret it using the ANSI codepage.
So instead, we convert the UTF-8 string to a wchar string, and then use the
wchar functions for proper extended character filename support.
They are still there for auxiliary sends. However, they should go away soon
enough too, and then we won't have to mess around with calculating extra
"predictive" samples in the mixer.
This is for unpacking (reading, e.g. alBufferData) and packing (writing, e.g.
alGetBufferSamplesSOFT) operations. The alignments are specified in sample
frames, with 0 meaning the default (65 for IMA4, 1 otherwise). IMA4 alignment
must be a multiple of 8, plus 1 (e.g. alignment = n*8 + 1), otherwise an error
will occur during (un)packing. Chenging the block alignment does not affect
already-loaded sample data, only future unpack/pack operations... so for
example, this is perfectly valid:
// Load mono IMA4 data with a block alignment of 1024 bytes, or 2041 sample
// frames.
alBufferi(buffer, AL_UNPACK_BLOCK_ALIGNMENT_SOFT, 2041);
alBufferData(buffer, AL_FORMAT_MONO_IMA4, data, data_len, srate);
alBufferi(buffer, AL_UNPACK_BLOCK_ALIGNMENT_SOFT, 0);
Some hefty caveats:
This function is not thread-safe. In particular, the current context affecting
the thread must not be changed, and the provided soundfont must not be
altered while the function is executing. Ideally, this will be fixed.
Error handling is poor. Some RIFF structure errors may not be caught (e.g. sub-
chunks with sizes greater than the parent chunk allows for), and generated AL
errors are ignored, possibly leading to resource leaks in certain situations.
These should be fixed in time.
There is minimal error checking on the provided soundfont ID. It does not
ensure a valid ID has been provided, nor does it ensure the provided soundfont
can be modified. These short-comings should be fixed eventually.
Proper cleanup is the responsibility of the caller. The caller must get the
preset objects from the soundfont before deleting it, and the fontsound objects
from each preset before deleting them, to make sure all resources are properly
deleted.
