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Diffstat (limited to 'src')
| -rw-r--r-- | src/lib.rs | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/src/lib.rs b/src/lib.rs new file mode 100644 index 0000000..436bcbe --- /dev/null +++ b/src/lib.rs @@ -0,0 +1,220 @@ +// Copyright (C) 2018 Jakob L. Kreuze, All Rights Reserved. +// +// This file is part of wildmidi. +// +// wildmidi is free software: you can redistribute it and/or modify it under the +// terms of the GNU Lesser General Public License as published by the Free +// Software Foundation, either version 3 of the License, or (at your option) any +// later version. +// +// wildmidi is distributed in the hope that it will be useful, but WITHOUT ANY +// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR +// A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more +// details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with wildmidi. If not, see <http://www.gnu.org/licenses/>. + +#[macro_use] +extern crate simple_error; + +use std::error::Error; +use std::ffi::CString; +use std::os::raw::{c_char, c_uchar, c_ushort, c_int, c_ulong, c_void}; +use std::path::Path; + +extern "C" { + // "Methods" of the Midi player. + fn WildMidi_Init(cfg: *const c_char, rate: c_ushort, flags: c_ushort) -> c_int; + fn WildMidi_Open(path: *const c_char) -> *const c_void; + fn WildMidi_OpenBuffer(data: *const c_uchar, size: c_ulong) -> *const c_void; + // fn WildMidi_SetOption(); + fn WildMidi_MasterVolume(volume: c_uchar) -> c_int; + fn WildMidi_Shutdown(); + + // "Methods" of the individual Midi handles. + fn WildMidi_Close(ptr: *const c_void) -> c_int; + fn WildMidi_FastSeek(ptr: *const c_void, pos: c_ushort) -> c_int; + fn WildMidi_GetOutput(ptr: *const c_void, buf: *mut c_uchar, len: c_ulong) -> c_int; +} + +/// Loader for the Midi format. +pub struct Player; + +impl Player { + fn locate_cfg() -> Option<&'static str> { + let paths = vec![ + "/etc/wildmidi/wildmidi.cfg", + "/etc/wildmidi.cfg" + ]; + + for path in paths.iter() { + if Path::new(path).exists() { + return Some(path); + } + } + + None + } + + /// Create a new Player with the given sample rate, using the default + /// configuration file. + /// + /// # Errors + /// + /// Will fail if 'rate' is not on the interval [11025,65535], or if neither + /// of the default configuration files exist ('/etc/wildmidi/wildmidi.cfg', + /// '/etc/wildmidi.cfg'). + pub fn new(rate: u16) -> Result<Player, Box<Error>> { + let cfg = match Player::locate_cfg() { + Some(cfg) => cfg, + None => bail!("No valid configuration file found"), + }; + + Player::with_cfg(cfg, rate) + } + + /// Create a new Player with the given config path and sample rate. + /// + /// # Errors + /// + /// Will fail if 'rate' is not on the interval [11025,65535]. + pub fn with_cfg(cfg: &str, rate: u16) -> Result<Player, Box<Error>> { + let cfg = CString::new(cfg)?; + + unsafe { + // WildMidi_Shutdown(); + if WildMidi_Init(cfg.as_ptr(), rate, 0) != 0 { + bail!("Couldn't initialize WildMidi."); + } + } + + Ok(Player { }) + } + + // TODO: Document this. + pub fn volume(&mut self, volume: u8) -> Result<(), Box<Error>> { + unsafe { + if WildMidi_MasterVolume(volume) != 0 { + bail!("Couldn't set volume."); + } + } + + Ok(()) + } + + /// Loads a Midi file from memory. + /// + /// # Errors + /// + /// Will fail if an internal error occurs in WildMidi (such as a parse + /// error). + pub fn load(&self, data: &[u8]) -> Result<Midi, Box<Error>> { + unsafe { + let len = data.len() as c_ulong; + let ptr = WildMidi_OpenBuffer(data.as_ptr(), len); + + if !ptr.is_null() { + return Ok(Midi::new(ptr)); + } + } + + bail!("Failed to open Midi file.") + } + + /// Loads a Midi file from disk. + /// + /// # Errors + /// + /// Will fail if the file does not exist, or if an internal error occurs in + /// WildMidi (such as a parse error). + pub fn load_file(&self, path: &str) -> Result<Midi, Box<Error>> { + if !Path::new(path).exists() { + bail!("File does not exist"); + } + + let path = CString::new(path)?; + + unsafe { + let ptr = WildMidi_Open(path.as_ptr()); + + if !ptr.is_null() { + return Ok(Midi::new(ptr)); + } + } + + bail!("Failed to open Midi file.") + } +} + +impl Drop for Player { + fn drop(&mut self) { + unsafe { + WildMidi_Shutdown(); + } + } +} + +/// An actual Midi file, capable of producing a PCM output. +pub struct Midi { + ptr: *const c_void, +} + +impl Midi { + fn new(ptr: *const c_void) -> Midi { + Midi { ptr } + } + + /// Returns a Vec<u8> containing 'len' bytes of PCM data. + pub fn play(&mut self, len: usize) -> Vec<u8> { + let mut vec = vec![0;len]; + + unsafe { + let buf = vec.as_mut_ptr(); + let handle = self.ptr; + let read = WildMidi_GetOutput(handle, buf, len as c_ulong) as usize; + + if read < len { + vec.resize(read, 0); + } + } + + vec + } + + // TODO: Document this. + pub fn seek(&mut self, pos: u32) { + unsafe { + // FIXME: Doesn't check return value. + WildMidi_FastSeek(self.ptr, pos as c_ushort); + } + } +} + +impl Drop for Midi { + fn drop(&mut self) { + unsafe { + // There isn't much of a point in handling errors here. + WildMidi_Close(self.ptr); + } + } +} + +#[cfg(test)] +mod player_tests { + use ::*; + + #[test] + fn create() { + if let Err(e) = Player::new(44100) { + panic!("{}", e); + } + } + + #[test] + fn invalid_rate() { + if let Ok(_) = Player::new(0) { + panic!("Allowed player to be created with invalid rate."); + } + } +} |