ref: e1ac9379f676b38d2c2c003efc41b81bcfcdb29c
dir: /midiproc/main.c/
//
// Copyright(C) 2012 James Haley
// Copyright(C) 2017 Alex Mayfield
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// DESCRIPTION:
//
// Win32/SDL_mixer MIDI Server
//
// Uses pipes to communicate with Doom. This allows this separate process to
// have its own independent volume control even under Windows Vista and up's
// broken, stupid, completely useless mixer model that can't assign separate
// volumes to different devices for the same process.
//
// Seriously, how did they screw up something so fundamental?
//
#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include "SDL.h"
#include "SDL_mixer.h"
#include "buffer.h"
#include "proto.h"
#include "config.h"
#include "doomtype.h"
static HANDLE midi_process_in; // Standard In.
static HANDLE midi_process_out; // Standard Out.
// Sound sample rate to use for digital output (Hz)
static int snd_samplerate = 0;
// Currently playing music track.
static Mix_Music *music = NULL;
//=============================================================================
//
// Private functions
//
//
// Write an unsigned integer into a simple CHAR buffer.
//
static boolean WriteInt16(CHAR *out, size_t osize, unsigned int in)
{
if (osize < 2)
{
return false;
}
out[0] = (in >> 8) & 0xff;
out[1] = in & 0xff;
return true;
}
//
// Cleanly close our in-use pipes.
//
static void FreePipes(void)
{
if (midi_process_in != NULL)
{
CloseHandle(midi_process_in);
midi_process_in = NULL;
}
if (midi_process_out != NULL)
{
CloseHandle(midi_process_out);
midi_process_out = NULL;
}
}
//
// Unregisters the currently playing song. This is never called from the
// protocol, we simply do this before playing a new song.
//
static void UnregisterSong()
{
if (music == NULL)
{
return;
}
Mix_FreeMusic(music);
music = NULL;
}
//
// Cleanly shut down SDL.
//
static void ShutdownSDL(void)
{
UnregisterSong();
Mix_CloseAudio();
SDL_Quit();
}
//=============================================================================
//
// SDL_mixer Interface
//
static boolean RegisterSong(const char *filename)
{
music = Mix_LoadMUS(filename);
// Remove the temporary MIDI file
remove(filename);
if (music == NULL)
{
return false;
}
return true;
}
static void SetVolume(int vol)
{
Mix_VolumeMusic(vol);
}
static void PlaySong(int loops)
{
Mix_PlayMusic(music, loops);
// [AM] BUG: In my testing, setting the volume of a MIDI track while there
// is no song playing appears to be a no-op. This can happen when
// you're mixing midiproc with vanilla SDL_Mixer, such as when you
// are alternating between a digital music pack (in the parent
// process) and MIDI (in this process).
//
// To work around this bug, we set the volume to itself after the MIDI
// has started playing.
Mix_VolumeMusic(Mix_VolumeMusic(-1));
}
static void StopSong()
{
Mix_HaltMusic();
}
//=============================================================================
//
// Pipe Server Interface
//
static boolean MidiPipe_RegisterSong(buffer_reader_t *reader)
{
char *filename = Reader_ReadString(reader);
if (filename == NULL)
{
return false;
}
return RegisterSong(filename);
}
static boolean MidiPipe_UnregisterSong(buffer_reader_t *reader)
{
UnregisterSong();
return true;
}
boolean MidiPipe_SetVolume(buffer_reader_t *reader)
{
int vol;
boolean ok = Reader_ReadInt32(reader, (uint32_t*)&vol);
if (!ok)
{
return false;
}
SetVolume(vol);
return true;
}
boolean MidiPipe_PlaySong(buffer_reader_t *reader)
{
int loops;
boolean ok = Reader_ReadInt32(reader, (uint32_t*)&loops);
if (!ok)
{
return false;
}
PlaySong(loops);
return true;
}
boolean MidiPipe_StopSong()
{
StopSong();
return true;
}
boolean MidiPipe_Shutdown()
{
exit(EXIT_SUCCESS);
}
//=============================================================================
//
// Server Implementation
//
//
// Parses a command and directs to the proper read function.
//
boolean ParseCommand(buffer_reader_t *reader, uint16_t command)
{
switch (command)
{
case MIDIPIPE_PACKET_TYPE_REGISTER_SONG:
return MidiPipe_RegisterSong(reader);
case MIDIPIPE_PACKET_TYPE_UNREGISTER_SONG:
return MidiPipe_UnregisterSong(reader);
case MIDIPIPE_PACKET_TYPE_SET_VOLUME:
return MidiPipe_SetVolume(reader);
case MIDIPIPE_PACKET_TYPE_PLAY_SONG:
return MidiPipe_PlaySong(reader);
case MIDIPIPE_PACKET_TYPE_STOP_SONG:
return MidiPipe_StopSong();
case MIDIPIPE_PACKET_TYPE_SHUTDOWN:
return MidiPipe_Shutdown();
default:
return false;
}
}
//
// Server packet parser
//
boolean ParseMessage(buffer_t *buf)
{
CHAR buffer[2];
DWORD bytes_written;
int bytes_read;
uint16_t command;
buffer_reader_t *reader = NewReader(buf);
// Attempt to read a command out of the buffer.
if (!Reader_ReadInt16(reader, &command))
{
goto fail;
}
// Attempt to parse a complete message.
if (!ParseCommand(reader, command))
{
goto fail;
}
// We parsed a complete message! We can now safely shift
// the prior message off the front of the buffer.
bytes_read = Reader_BytesRead(reader);
DeleteReader(reader);
Buffer_Shift(buf, bytes_read);
// Send acknowledgement back that the command has completed.
if (!WriteInt16(buffer, sizeof(buffer), MIDIPIPE_PACKET_TYPE_ACK))
{
goto fail;
}
WriteFile(midi_process_out, buffer, sizeof(buffer),
&bytes_written, NULL);
return true;
fail:
// We did not read a complete packet. Delete our reader and try again
// with more data.
DeleteReader(reader);
return false;
}
//
// The main pipe "listening" loop
//
boolean ListenForever()
{
BOOL wok = FALSE;
CHAR pipe_buffer[8192];
DWORD pipe_buffer_read = 0;
boolean ok = false;
buffer_t *buffer = NewBuffer();
for (;;)
{
// Wait until we see some data on the pipe.
wok = PeekNamedPipe(midi_process_in, NULL, 0, NULL,
&pipe_buffer_read, NULL);
if (!wok)
{
break;
}
else if (pipe_buffer_read == 0)
{
SDL_Delay(1);
continue;
}
// Read data off the pipe and add it to the buffer.
wok = ReadFile(midi_process_in, pipe_buffer, sizeof(pipe_buffer),
&pipe_buffer_read, NULL);
if (!wok)
{
break;
}
ok = Buffer_Push(buffer, pipe_buffer, pipe_buffer_read);
if (!ok)
{
break;
}
do
{
// Read messages off the buffer until we can't anymore.
ok = ParseMessage(buffer);
} while (ok);
}
return false;
}
//=============================================================================
//
// Main Program
//
//
// InitSDL
//
// Start up SDL and SDL_mixer.
//
boolean InitSDL()
{
if (SDL_Init(SDL_INIT_AUDIO) == -1)
{
return false;
}
if (Mix_OpenAudioDevice(snd_samplerate, MIX_DEFAULT_FORMAT, 2, 2048, NULL, SDL_AUDIO_ALLOW_FREQUENCY_CHANGE) < 0)
{
return false;
}
atexit(ShutdownSDL);
return true;
}
//
// InitPipes
//
// Ensure that we can communicate.
//
void InitPipes(HANDLE in, HANDLE out)
{
midi_process_in = in;
midi_process_out = out;
atexit(FreePipes);
}
//
// main
//
// Application entry point.
//
int main(int argc, char *argv[])
{
HANDLE in, out;
// Make sure we're not launching this process by itself.
if (argc < 5)
{
MessageBox(NULL, TEXT("This program is tasked with playing Native ")
TEXT("MIDI music, and is intended to be launched by ")
TEXT(PACKAGE_NAME) TEXT("."),
TEXT(PACKAGE_STRING), MB_OK | MB_ICONASTERISK);
return EXIT_FAILURE;
}
// Make sure our Choccolate Doom and midiproc version are lined up.
if (strcmp(PACKAGE_STRING, argv[1]) != 0)
{
char message[1024];
_snprintf(message, sizeof(message),
"It appears that the version of %s and %smidiproc are out "
"of sync. Please reinstall %s.\r\n\r\n"
"Server Version: %s\r\nClient Version: %s",
PACKAGE_NAME, PROGRAM_PREFIX, PACKAGE_NAME,
PACKAGE_STRING, argv[1]);
message[sizeof(message) - 1] = '\0';
MessageBox(NULL, TEXT(message),
TEXT(PACKAGE_STRING), MB_OK | MB_ICONASTERISK);
return EXIT_FAILURE;
}
// Parse out the sample rate - if we can't, default to 44100.
snd_samplerate = strtol(argv[2], NULL, 10);
if (snd_samplerate == LONG_MAX || snd_samplerate == LONG_MIN ||
snd_samplerate == 0)
{
snd_samplerate = 44100;
}
// Parse out our handle ids.
in = (HANDLE) strtol(argv[3], NULL, 10);
if (in == 0)
{
return EXIT_FAILURE;
}
out = (HANDLE) strtol(argv[4], NULL, 10);
if (out == 0)
{
return EXIT_FAILURE;
}
InitPipes(in, out);
if (!InitSDL())
{
return EXIT_FAILURE;
}
if (!ListenForever())
{
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
#endif // #ifdef _WIN32