ref: 02a26802ffbd64ebf993119e1599920ffee01ef0
dir: /sys/src/games/doom/i_sound.c/
/* i_sound.c */ #include "i_system.h" #include "i_sound.h" #include "w_wad.h" // W_GetNumForName() #include "z_zone.h" /* The number of internal mixing channels, ** the samples calculated for each mixing step, ** the size of the 16bit, 2 hardware channel (stereo) ** mixing buffer, and the samplerate of the raw data. */ /* Needed for calling the actual sound output. */ #define SAMPLECOUNT (512<<2) #define NUM_CHANNELS 8 /* The actual lengths of all sound effects. */ int lengths[NUMSFX]; /* The actual output device. */ static int audio_fd; /* The global mixing buffer. ** Basically, samples from all active internal channels ** are modified and added, and stored in the buffer ** that is submitted to the audio device. */ signed short mixbuffer[SAMPLECOUNT*2]; /* The channel step amount... */ uint channelstep[NUM_CHANNELS]; /* ... and a 0.16 bit remainder of last step. */ uint channelstepremainder[NUM_CHANNELS]; /* The channel data pointers, start and end. */ uchar* channels[NUM_CHANNELS]; uchar* channelsend[NUM_CHANNELS]; /* Time/gametic that the channel started playing, ** used to determine oldest, which automatically ** has lowest priority. ** In case number of active sounds exceeds ** available channels. */ int channelstart[NUM_CHANNELS]; /* The sound in channel handles, ** determined on registration, ** might be used to unregister/stop/modify, ** currently unused. */ int channelhandles[NUM_CHANNELS]; /* SFX id of the playing sound effect. ** Used to catch duplicates (like chainsaw). */ int channelids[NUM_CHANNELS]; /* Pitch to stepping lookup, unused. */ int steptable[256]; /* Volume lookups. */ int vol_lookup[128*256]; /* Hardware left and right channel volume lookup. */ int* channelleftvol_lookup[NUM_CHANNELS]; int* channelrightvol_lookup[NUM_CHANNELS]; static void* getsfx(char *sfxname, int *len) { uchar *sfx; uchar *paddedsfx; int i; int size; int paddedsize; char name[20]; int sfxlump; /* Get the sound data from the WAD, allocate lump ** in zone memory. */ sprintf(name, "ds%s", sfxname); /* Now, there is a severe problem with the ** sound handling, in it is not (yet/anymore) ** gamemode aware. That means, sounds from ** DOOM II will be requested even with DOOM ** shareware. ** The sound list is wired into sounds.c, ** which sets the external variable. ** I do not do runtime patches to that ** variable. Instead, we will use a ** default sound for replacement. */ if ( W_CheckNumForName(name) == -1 ) sfxlump = W_GetNumForName("dspistol"); else sfxlump = W_GetNumForName(name); size = W_LumpLength( sfxlump ); sfx = (uchar *)W_CacheLumpNum(sfxlump, PU_STATIC); /* Pads the sound effect out to the mixing buffer size. ** The original realloc would interfere with zone memory. */ paddedsize = ((size-8 + (SAMPLECOUNT-1)) / SAMPLECOUNT) * SAMPLECOUNT; /* Allocate from zone memory. */ paddedsfx = (uchar *)Z_Malloc(paddedsize+8, PU_STATIC, 0); /* Now copy and pad. */ memcpy(paddedsfx, sfx, size); for (i=size ; i<paddedsize+8 ; i++) paddedsfx[i] = 128; /* Remove the cached lump. */ Z_Free(sfx); /* Preserve padded length. */ *len = paddedsize; /* Return allocated padded data. */ return (void *)(paddedsfx + 8); } void I_InitSound(void) { int i; audio_fd = open("/dev/audio", OWRITE); if(audio_fd < 0) printf("WARN Failed to open /dev/audio, sound disabled\n"); /* Initialize external data (all sounds) at start, keep static. */ for (i=1 ; i<NUMSFX ; i++) { if (!S_sfx[i].link) { /* Load data from WAD file. */ S_sfx[i].data = getsfx( S_sfx[i].name, &lengths[i] ); } } /* Alias? Example is the chaingun sound linked to pistol. */ for (i=1 ; i<NUMSFX ; i++) { if (S_sfx[i].link) { /* Previously loaded already? */ S_sfx[i].data = S_sfx[i].link->data; lengths[i] = lengths[S_sfx[i].link - S_sfx]; } } /* Now initialize mixbuffer with zero. */ memset(mixbuffer, 0, sizeof mixbuffer); } /* This function loops all active (internal) sound ** channels, retrieves a given number of samples ** from the raw sound data, modifies it according ** to the current (internal) channel parameters, ** mixes the per-channel samples into the global ** mixbuffer, clamping it to the allowed range, ** and sets up everything for transferring the ** contents of the mixbuffer to the (two) ** hardware channels (left and right, that is). ** ** This function currently supports only 16bit. */ void I_UpdateSound(void) { /* Mix current sound data. ** Data, from raw sound, for right and left. */ register uint sample; register int dl; register int dr; /* Pointers in global mixbuffer, left, right, end. */ signed short *leftout; signed short *rightout; signed short *leftend; /* Step in mixbuffer, left and right, thus two. */ int step; /* Mixing channel index. */ int chan; /* Left and right channel ** are in global mixbuffer, alternating. */ leftout = mixbuffer; rightout = mixbuffer+1; step = 2; /* Determine end, for left channel only ** (right channel is implicit). */ leftend = mixbuffer + SAMPLECOUNT*step; /* Mix sounds into the mixing buffer. ** Loop over step*SAMPLECOUNT ** that is 512 values for two channels. */ while (leftout != leftend) { /* Reset left/right value. */ dl = 0; dr = 0; /* Love thy L2 cache - made this a loop. ** Now more channels could be set at compile time ** as well. Thus loop those channels. */ for(chan=0; chan < NUM_CHANNELS; chan++) { /* Check channel, if active. */ if(channels[ chan ]) { /* Get the raw data from the channel. */ sample = *channels[ chan ]; /* Add left and right part ** for this channel (sound) ** to the current data. ** Adjust volume accordingly. */ dl += channelleftvol_lookup[ chan ][sample]; dr += channelrightvol_lookup[ chan ][sample]; /* Increment index ??? */ channelstepremainder[ chan ] += channelstep[ chan ]; /* MSB is next sample??? */ channels[ chan ] += channelstepremainder[ chan ] >> 16; /* Limit to LSB??? */ channelstepremainder[ chan ] &= 65536-1; /* Check whether we are done. */ if (channels[ chan ] >= channelsend[ chan ]) channels[ chan ] = 0; } } /* Clamp to range. */ if (dl > 0x7fff) dl = 0x7fff; else if (dl < -0x8000) dl = -0x8000; if (dr > 0x7fff) dr = 0x7fff; else if (dr < -0x8000) dr = -0x8000; *leftout = dl; *rightout = dr; /* Increment current pointers in mixbuffer. */ leftout += step; rightout += step; *leftout = dl; *rightout = dr; leftout += step; rightout += step; *leftout = dl; *rightout = dr; leftout += step; rightout += step; *leftout = dl; *rightout = dr; leftout += step; rightout += step; } } void I_SubmitSound(void) { if(audio_fd >= 0) write(audio_fd, mixbuffer, sizeof mixbuffer); } void I_ShutdownSound(void) { if(audio_fd >= 0) { close(audio_fd); audio_fd = -1; } } void I_SetChannels(void) { /* Init internal lookups (raw data, mixing buffer, channels). ** This function sets up internal lookups used during ** the mixing process. */ int i; int j; int *steptablemid = steptable + 128; /* This table provides step widths for pitch parameters. ** I fail to see that this is currently used. */ for (i=-128 ; i<128 ; i++) steptablemid[i] = (int)(pow(2.0, (i/64.0))*65536.0); /* Generates volume lookup tables ** which also turn the unsigned samples ** into signed samples. */ for (i=0 ; i<128 ; i++) for (j=0 ; j<256 ; j++) vol_lookup[i*256+j] = (i*(j-128)*256)/127; } int I_GetSfxLumpNum(sfxinfo_t *sfxinfo) { char namebuf[9]; sprintf(namebuf, "ds%s", sfxinfo->name); return W_GetNumForName(namebuf); } /* This function adds a sound to the ** list of currently active sounds, ** which is maintained as a given number ** (eight, usually) of internal channels. ** eturns a handle. */ static int addsfx(int id, int vol, int step, int sep) { static unsigned short handlenums = 0; int i; int rc; int oldest = gametic; int oldestnum = 0; int slot; int rightvol; int leftvol; /* Chainsaw troubles. ** Play these sound effects only one at a time. */ if ( id == sfx_sawup || id == sfx_sawidl || id == sfx_sawful || id == sfx_sawhit || id == sfx_stnmov || id == sfx_pistol ) { /* Loop all channels, check. */ for (i=0 ; i < NUM_CHANNELS ; i++) { /* Active and using the same SFX? */ if( (channels[i]) && (channelids[i] == id) ) { /* Reset. */ channels[i] = 0; /* We are sure that iff, ** there will only be one. */ break; } } } /* Loop all channels to find oldest SFX. */ for (i=0 ; (i<NUM_CHANNELS) && (channels[i]) ; i++) { if(channelstart[i] < oldest) { oldestnum = i; oldest = channelstart[i]; } } /* Tales from the cryptic. ** If we found a channel, fine. ** If not, we simply overwrite the first one, 0. ** Probably only happens at startup. */ if (i == NUM_CHANNELS) slot = oldestnum; else slot = i; /* Okay, in the less recent channel, ** we will handle the new SFX. ** Set pointer to raw data. */ channels[slot] = (uchar*) S_sfx[id].data; /* Set pointer to end of raw data. */ channelsend[slot] = channels[slot] + lengths[id]; /* Reset current handle number, limited to 0..100. */ if (!handlenums) handlenums = 100; /* Assign current handle number. ** Preserved so sounds could be stopped (unused). */ channelhandles[slot] = rc = handlenums++; /* Set stepping??? ** Kinda getting the impression this is never used. */ channelstep[slot] = step; /* ??? */ channelstepremainder[slot] = 0; /* Should be gametic, I presume. */ channelstart[slot] = gametic; /* Separation, that is, orientation/stereo. ** range is : 1 - 256 */ sep += 1; /* Per left/right channel. ** x^2 seperation, ** adjust volume properly. */ leftvol = vol - ((vol*sep*sep) >> 16); // /(256*256); sep = sep - 257; rightvol = vol - ((vol*sep*sep) >> 16); /* Sanity check, clamp volume. */ if (rightvol < 0 || rightvol > 127) I_Error("rightvol out of bounds"); if (leftvol < 0 || leftvol > 127) I_Error("leftvol out of bounds"); /* Get the proper lookup table piece ** for this volume level??? */ channelleftvol_lookup[slot] = &vol_lookup[leftvol*256]; channelrightvol_lookup[slot] = &vol_lookup[rightvol*256]; /* Preserve sound SFX id, ** e.g. for avoiding duplicates of chainsaw. */ channelids[slot] = id; /* You tell me. */ return rc; } int I_StartSound(int id, int vol, int sep, int pitch, int priority) { USED(priority); id = addsfx(id, vol, steptable[pitch], sep); return id; } void I_StopSound(int handle) { USED(handle); // printf("PORTME i_sound.c I_StopSound\n"); } int I_SoundIsPlaying(int handle) { /* Ouch. */ return gametic < handle; } void I_UpdateSoundParams(int handle, int vol, int sep, int pitch) { /* I fail to see that this is used. ** Would be using the handle to identify ** on which channel the sound might be active, ** and resetting the channel parameters. */ USED(handle, vol, sep, pitch); } void I_InitMusic(void) { // printf("PORTME i_sound.c I_InitMusic\n"); } void I_ShutdownMusic(void) { // printf("PORTME i_sound.c I_ShutdownMusic\n"); } void I_SetMusicVolume(int volume) { USED(volume); // printf("PORTME i_sound.c I_SetMusicVolume\n"); } void I_PauseSong(int handle) { USED(handle); // printf("PORTME i_sound.c I_PauseSong\n"); } void I_ResumeSong(int handle) { USED(handle); // printf("PORTME i_sound.c I_ResumeSong\n"); } int I_RegisterSong(void *data) { USED(data); // printf("PORTME i_sound.c I_RegisterSong\n"); return 0; } void I_PlaySong(int handle, int looping) { USED(handle, looping); // printf("PORTME i_sound.c I_PlaySong\n"); } void I_StopSong(int handle) { USED(handle); // printf("PORTME i_sound.c I_StopSong\n"); } void I_UnRegisterSong(int handle) { USED(handle); // printf("PORTME i_sound.c I_UnregisterSong\n"); }