The data source implementation of a ma_pcm_rb could possibly return a
frame count of 0 which would in turn result in
ma_data_source_read_pcm_frames() returning MA_AT_END which does not
make sense for a ring buffer since it has no notion of an end.
This is useful because MA_ASSERT is only defined in the implementation
section of miniaudio.h which can cause issues when people copy/paste
the code and use it in a file that does not have visibility of the
implementation.
Note that there are still more references to implementation-defined
macros, but these have been moved to the public section in the dev-0.12
branch so I'm not bothering to change those just yet.
Public issue https://github.com/mackron/miniaudio/issues/787
With this commit, custom backends can now be implemented as
self-contained modules that can easily be plugged in and mixed and
matched depending on a programs requirements. The order in which
custom backends are specified in the context config determine their
priority.
This commit updates the custom_backend example by moving the SDL
code out into its own file in "extras/backends/sdl". The example will
now just include the SDL code files like normal. This represents a more
realistic scenario.
Custom backends must now use the `ma_device_backend_vtable` object to
define their callbacks. All of these functions are largely the same,
except they all now take a `void*` as their first parameter which
represents the user data pointer.
The ma_backend_callbacks parameter has been removed from onContextInit
which means you must now statically define your callbacks in the
ma_device_backend_vtable object that you pass into the context config.
The `custom` member of the context config has been replaced with a new
set of members to support the ability to plug in multiple vtables.
This example captures data from the microphone using the low-level API
and then plays back the data through the engine. The intermediary data
source is a ring buffer.
This is the new default. The size of the buffer will be based on the
periodSizeInFrames and periodSizeInMilliseconds config variable. To go
back to the previous system, where the data callback could specify any
number of frames, set the noFixedSizedCallback config variable to true.
David Reid
RainRat
cdigit