diff options
| -rw-r--r-- | src/i_oplmusic.c | 70 |
1 files changed, 51 insertions, 19 deletions
diff --git a/src/i_oplmusic.c b/src/i_oplmusic.c index 1d482595..51a609d9 100644 --- a/src/i_oplmusic.c +++ b/src/i_oplmusic.c @@ -137,7 +137,8 @@ struct opl_voice_s unsigned int note_volume; // The current volume that has been set for this channel. - unsigned int volume; + unsigned int carrier_volume; + unsigned int modulator_volume; // Next in freelist opl_voice_t *next; @@ -442,14 +443,22 @@ static void LoadOperatorData(int operator, genmidi_op_t *data, static void SetVoiceInstrument(opl_voice_t *voice, genmidi_instr_t *instr) { genmidi_voice_t *data; + unsigned int modulating; voice->current_instr = instr; data = &instr->opl2_voice; + // Are we usind modulated feedback mode? + + modulating = (data->feedback & 0x01) == 0; + // Doom loads the second operator first, then the first. + // The carrier is set to minimum volume until the voice volume + // is set in SetVoiceVolume (below). If we are not using + // modulating mode, we must set both to minimum volume. LoadOperatorData(voice->op2, &data->carrier, true); - LoadOperatorData(voice->op1, &data->modulator, false); + LoadOperatorData(voice->op1, &data->modulator, !modulating); // Set feedback register that control the connection between the // two operators. Turn on bits in the upper nybble; I think this @@ -460,38 +469,61 @@ static void SetVoiceInstrument(opl_voice_t *voice, genmidi_instr_t *instr) // Hack to force a volume update. - voice->volume = 999; + voice->carrier_volume = 999; + voice->modulator_volume = 999; } -static void SetVoiceVolume(opl_voice_t *voice, unsigned int volume) +// Calculate the volume level to use for a given operator. + +static void SetOperatorVolume(genmidi_op_t *op, unsigned int volume, + unsigned int opnum, + unsigned int *current_volume) { - unsigned int full_volume; - unsigned int instr_volume; + unsigned int op_volume; unsigned int reg_volume; - voice->note_volume = volume; - - // Multiply note volume and channel volume to get the actual volume. - - full_volume = (voice->note_volume * voice->channel->volume) / 127; - // The volume of each instrument can be controlled via GENMIDI: - instr_volume = 0x3f - voice->current_instr->opl2_voice.carrier.level; + op_volume = 0x3f - op->level; // The volume value to use in the register: - reg_volume = ((instr_volume * volume_mapping_table[full_volume]) / 128); - reg_volume = (0x3f - reg_volume) - | voice->current_instr->opl2_voice.carrier.scale; + reg_volume = ((op_volume * volume_mapping_table[volume]) / 128); + reg_volume = (0x3f - reg_volume) | op->scale; // Update the register, if necessary: - if (voice->volume != reg_volume) + if (*current_volume != reg_volume) { - voice->volume = reg_volume; + *current_volume = reg_volume; + + WriteRegister(OPL_REGS_LEVEL + opnum, reg_volume); + } +} - WriteRegister(OPL_REGS_LEVEL + voice->op2, reg_volume); +static void SetVoiceVolume(opl_voice_t *voice, unsigned int volume) +{ + genmidi_voice_t *opl_voice; + unsigned int full_volume; + + voice->note_volume = volume; + + opl_voice = &voice->current_instr->opl2_voice; + + // Multiply note volume and channel volume to get the actual volume. + + full_volume = (voice->note_volume * voice->channel->volume) / 127; + + SetOperatorVolume(&opl_voice->carrier, full_volume, + voice->op2, &voice->carrier_volume); + + // If we are using non-modulated feedback mode, we must set the + // volume for both voices. + + if ((opl_voice->feedback & 0x01) != 0) + { + SetOperatorVolume(&opl_voice->modulator, full_volume, + voice->op1, &voice->modulator_volume); } } |