/*	wildmidi_lib.c 	Midi Wavetable Processing library  	Copyright (C)2001-2004 Chris Ison 	This library 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 2.1 of the License, or (at your option) any later version.	This library 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 this library; if not, write to the Free Software	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA	Email: cisos@bigpond.net.au		 wildcode@users.sourceforge.net  	$Id: wildmidi_lib.c,v 1.18 2004/01/28 05:45:09 wildcode Exp $	========================================	Changelog	----------------------------------------	Aug 3, 2003		- changed kill envelope from 6th to 5th		- changed data_length, loop_start, loop_end to 22:10 fixed point		- added fractional position to loop_start and loop_end		- added fake reverb			Aug 4, 2003		- added MIDI_EVENT_DEBUG to midi event functions		- fixed hold release killing off notes that hadn't been turned off		  by note off		- sped up fake reverb by doing it outside the channel mixing loop		Aug 5, 2003		- removed note_table init from ParseNewMidi, entries are now fully reset 		  in do_note_on		- moved fast kill envelope setting to sample loading		- removed envelopes from notes, use ones from sample instead		- optimized do_amp_setup functions		- do_control_volume, do_control_expression, do_channel_pressure,		  changed from setting note_table[] to note[] for performance.		- optimizations of sample conversion,			Aug 6, 2003		- removed changing sample volumes, the amp setting is now apart of 		  the midi volume maths.		- re-write conversion functions to make them more clearer and less bug prone			Aug 7, 2003		- fixed volume, expression and preasure changes effecting all notes.		Aug 8, 2003		- spead up midi processing by using an event index			Aug 9, 2003		- spead up sampling and mixing by using a seperate function depending on fixed		  modes		- fixed data lock where it would sleep reguardless of lock state		- fixed memory leak ... oops, forgot a free		- removed track data storge, isn't required by the core functions			Aug 10, 2003		- created error function and changed all error messages to use it		- malloc, calloc, realloc audit ensuring all are error checked.		- fixed potential reading beyond end of midi bug			Aug 11, 2003		- fixed expensive interpolation over-running the sample buffer		- changed stereo option so that changing it worked right away			Aug 14, 2003		- optimizations for and to the frequency calc code		- removal of wide stereo (it sucked anyway)	Aug 15, 2003		- fixed volume levels for panning when non-linear volumes are used		- removed fake reberb, it sucked on better sound systems.			Aug 17, 2003		- fixed autoamp		- added env_time#= and env_level#= to timiidty.cfg parser.		- fixed bug where last event in the midi before the last eot would		  have a large delta. This is a bug in the midi file itself.		- fixed some midi's having no sound cause they don't supply patch information.		  Now defaulting all channels to bank 0, patch 0.		Aug 18, 2003		- preload samples		- optimized envelope checking and controler code		- fixed bug where some samples have an envelope rate setting that doesn't 		  actually mean anything .. ie: 0x00 0x40 0x80 0xC0		- fixed amp bug where initial left/right levels were set to 0		- added timidity's keep=[loop|env] support for drum patches, 		  now ignores loops and env settings for drum patches unless keep=[loop|env]		  is in the patch line in the config.		Aug 21, 2003		- float to fixed point math conversions.		- frequency range locked to 100 steps between notes		  NOTE:need to test slow pitchbends with this, fast ones are fine			Aug 24, 2003		- optimized sample conversions		- optimized note handling and sample/envelope position checks			Aug 28, 2003		- compile level optimizations		  NOTE: gcc builtins used		- numerous bug fixes			Aug 30, 2003		- fixed sample inc calculation bug		- fixed panning volumes, now percieved volume of the sample is the same no matter		  panning position.`	Sep 2, 2003		- made noteoff/hold behaviour match midi standard		- added remove=sustain to patch line 		- added all sound off controller		- fixed all notes off to only effect notes that aren't being held		- changed envelope behaviour so that only non-sustaned samples hit envelope 4 		  while note is on.		- Added all controllers off event			Sep 4, 2003		- added master sample data lock		- improved performance of the resampling algo			========================================*/#include <ctype.h>#include <errno.h>#include <fcntl.h>#include <math.h>#ifndef _WIN32#include <pwd.h>#endif#include <stdarg.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/stat.h>#include <sys/types.h>#include <unistd.h>#ifdef _WIN32# include <windows.h>#endif#include "config.h"#include "wildmidi_lib.h"/* * ========================= * Global Data and Data Structs * ========================= */int WM_Initialized = 0;signed short int WM_MasterVolume = 948;unsigned short int WM_SampleRate = 0;unsigned short int WM_MixerOptions = 0;char WM_Version[] = "WildMidi Processing Library " WILDMIDILIB_VERSION;struct _lowpass {	signed long int in[2];	signed long int out[2];};struct _filter {	signed long int *delay[4][2];	unsigned long int delay_pos[4][2];	struct _lowpass lowpass[4][2];	signed long int in[2][2];	signed long int out[2][2];};struct _env {	float time;	float level;	unsigned char set;};struct _sample {	unsigned long int data_length;	unsigned long int loop_start;	unsigned long int loop_end;	unsigned long int loop_size;	unsigned char loop_fraction;	unsigned short int rate;	unsigned long int freq_low;	unsigned long int freq_high;	unsigned long int freq_root;	unsigned char modes;	unsigned long int env_rate[7];	unsigned long int env_target[7];	unsigned long int inc_div;	signed short *data;	signed short max_peek;	signed short min_peek;	signed long int peek_adjust;	struct _sample *next;};struct _patch {	unsigned short patchid;	unsigned char loaded;	char *filename;	signed short int amp;	unsigned char keep;	unsigned char remove;	struct _env env[6];	unsigned char note;	unsigned long int inuse_count;	struct _sample *first_sample;	struct _patch *next;};struct _patch *patch[128];int patch_lock;struct _channel {	unsigned char bank;	struct _patch *patch;