ref: 73a1d06182b142d412cee5099ad619174604e6e4
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); } // // Cleanly shut down SDL. // static void ShutdownSDL(void) { UnregisterSong(); Mix_CloseAudio(); SDL_Quit(); } //============================================================================= // // SDL_mixer Interface // static boolean RegisterSong(const char *filename) { UnregisterSong(); music = Mix_LoadMUS(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 buffer[2]; DWORD bytes_written; char *filename = Reader_ReadString(reader); if (filename == NULL) { return false; } RegisterSong(filename); if (!WriteInt16(buffer, sizeof(buffer), MIDIPIPE_PACKET_TYPE_REGISTER_SONG_ACK)) { return false; } WriteFile(midi_process_out, buffer, sizeof(buffer), &bytes_written, NULL); 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_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) { 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); 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_OpenAudio(snd_samplerate, MIX_DEFAULT_FORMAT, 2, 2048) < 0) { return false; } atexit(ShutdownSDL); return true; } // // InitPipes // // Ensure that we can communicate. // boolean InitPipes() { midi_process_in = GetStdHandle(STD_INPUT_HANDLE); if (midi_process_in == INVALID_HANDLE_VALUE) { goto fail; } midi_process_out = GetStdHandle(STD_OUTPUT_HANDLE); if (midi_process_out == INVALID_HANDLE_VALUE) { goto fail; } atexit(FreePipes); return true; fail: FreePipes(); return false; } // // main // // Application entry point. // int main(int argc, char *argv[]) { // Make sure we're not launching this process by itself. if (argc < 3) { 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; } if (!InitPipes()) { return EXIT_FAILURE; } if (!InitSDL()) { return EXIT_FAILURE; } if (!ListenForever()) { return EXIT_FAILURE; } return EXIT_SUCCESS; } #endif // #ifdef _WIN32