/* Copyright (C) 1996-2001 Id Software, Inc. Copyright (C) 2002-2009 John Fitzgibbons and others Copyright (C) 2007-2008 Kristian Duske 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. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ // snd_mix.c -- portable code to mix sounds for snd_dma.c #include "quakedef.h" #define PAINTBUFFER_SIZE 512 /** * The paintbuffer is an array of struct { int left, int right } 's. * The int's are signed 24-bit samples which will be truncated to * signed 16-bit before output. */ portable_samplepair_t paintbuffer[PAINTBUFFER_SIZE]; int snd_scaletable[32][256]; int *snd_p, snd_linear_count, snd_vol; short *snd_out; void Snd_WriteLinearBlastStereo16 (void) { int i; int val; for (i=0 ; i>8; if (val > 32767) snd_out[i] = 32767; else if (val < -32768) snd_out[i] = -32768; else snd_out[i] = val; val = snd_p[i+1]>>8; if (val > 32767) snd_out[i+1] = 32767; else if (val < -32768) snd_out[i+1] = -32768; else snd_out[i+1] = val; } } void S_TransferStereo16 (int endtime) { int lpos; int lpaintedtime; snd_p = (int *) paintbuffer; lpaintedtime = paintedtime; while (lpaintedtime < endtime) { // handle recirculating buffer issues lpos = lpaintedtime & ((shm->samples >> 1) - 1); snd_out = (short *)shm->buffer + (lpos << 1); snd_linear_count = (shm->samples >> 1) - lpos; if (lpaintedtime + snd_linear_count > endtime) snd_linear_count = endtime - lpaintedtime; snd_linear_count <<= 1; // write a linear blast of samples Snd_WriteLinearBlastStereo16 (); snd_p += snd_linear_count; lpaintedtime += (snd_linear_count >> 1); } } void S_TransferPaintBuffer(int endtime) { int out_idx, out_mask; int count, step, val; int *p; if (shm->samplebits == 16 && shm->channels == 2) { S_TransferStereo16 (endtime); return; } p = (int *) paintbuffer; count = (endtime - paintedtime) * shm->channels; out_mask = shm->samples - 1; out_idx = paintedtime * shm->channels & out_mask; step = 3 - shm->channels; if (shm->samplebits == 16) { short *out = (short *)shm->buffer; while (count--) { val = *p >> 8; p+= step; if (val > 0x7fff) val = 0x7fff; else if (val < (short)0x8000) val = (short)0x8000; out[out_idx] = val; out_idx = (out_idx + 1) & out_mask; } } else if (shm->samplebits == 8) { unsigned char *out = shm->buffer; while (count--) { val = *p >> 8; p+= step; if (val > 0x7fff) val = 0x7fff; else if (val < (short)0x8000) val = (short)0x8000; out[out_idx] = (val >> 8) + 128; out_idx = (out_idx + 1) & out_mask; } } } /* =============================================================================== CHANNEL MIXING =============================================================================== */ void SND_PaintChannelFrom8 (channel_t *ch, sfxcache_t *sc, int endtime); void SND_PaintChannelFrom16 (channel_t *ch, sfxcache_t *sc, int endtime); void S_PaintChannels (int endtime) { int i; int end, ltime, count; int stream; channel_t *ch; sfxcache_t *sc; snd_vol = sfxvolume.value * 255; while (paintedtime < endtime) { // if paintbuffer is smaller than DMA buffer end = endtime; if (endtime - paintedtime > PAINTBUFFER_SIZE) end = paintedtime + PAINTBUFFER_SIZE; // clear the paint buffer and mix any raw samples... (e.g. OGG music) memset(paintbuffer, 0, sizeof(paintbuffer)); for (stream = 0; stream < MAX_RAW_STREAMS; stream++) { if ( s_rawend[stream] >= paintedtime ) { // copy from the streaming sound source const portable_samplepair_t *rawsamples = s_rawsamples[stream]; const int stop = (end < s_rawend[stream]) ? end : s_rawend[stream]; for ( i = paintedtime ; i < stop ; i++ ) { const int s = i&(MAX_RAW_SAMPLES-1); paintbuffer[i-paintedtime].left += rawsamples[s].left; paintbuffer[i-paintedtime].right += rawsamples[s].right; } } } // paint in the sfx channels. ch = snd_channels; for (i = 0; i < total_channels; i++, ch++) { if (!ch->sfx) continue; if (!ch->leftvol && !ch->rightvol) continue; sc = S_LoadSound (ch->sfx); if (!sc) continue; ltime = paintedtime; while (ltime < end) { // paint up to end if (ch->end < end) count = ch->end - ltime; else count = end - ltime; if (count > 0) { if (sc->width == 1) SND_PaintChannelFrom8(ch, sc, count); else SND_PaintChannelFrom16(ch, sc, count); ltime += count; } // if at end of loop, restart if (ltime >= ch->end) { if (sc->loopstart >= 0) { ch->pos = sc->loopstart; ch->end = ltime + (sc->length - ch->pos); } else { // channel just stopped ch->sfx = NULL; break; } } } } // transfer out according to DMA format S_TransferPaintBuffer(end); paintedtime = end; } } void SND_PaintChannelFrom8 (channel_t *ch, sfxcache_t *sc, int count) { int data; unsigned char *sfx; int i; if (ch->leftvol > 255) ch->leftvol = 255; if (ch->rightvol > 255) ch->rightvol = 255; sfx = (unsigned char *) ((unsigned char *)sc->data + ch->pos); for (i = 0; i < count; i++) { data = (sfx[i] - 128) * snd_vol; paintbuffer[i].left += data * ch->leftvol; paintbuffer[i].right += data * ch->rightvol; } ch->pos += count; } void SND_PaintChannelFrom16 (channel_t *ch, sfxcache_t *sc, int count) { int data; int left, right; int leftvol, rightvol; signed short *sfx; int i; if (ch->leftvol > 255) ch->leftvol = 255; if (ch->rightvol > 255) ch->rightvol = 255; leftvol = ch->leftvol * snd_vol; rightvol = ch->rightvol * snd_vol; sfx = (signed short *)sc->data + ch->pos; for (i = 0; i < count; i++) { data = sfx[i]; left = (data * leftvol) >> 8; right = (data * rightvol) >> 8; paintbuffer[i].left += left; paintbuffer[i].right += right; } ch->pos += count; }