ref: d372d65b3de579fe40207a308c3f7c4bf3076c0a
parent: 556f7291ea0199144794166af2757aa7ad832a7a
author: Simon Howard <fraggle@gmail.com>
date: Mon Sep 7 14:11:25 EDT 2009
Implement pitch bend. Subversion-branch: /branches/opl-branch Subversion-revision: 1658
--- a/src/i_oplmusic.c
+++ b/src/i_oplmusic.c
@@ -91,6 +91,11 @@
// Volume level
int volume;
+
+ // Pitch bend value:
+
+ int bend;
+
} opl_channel_data_t;
// Data associated with a track that is currently playing.
@@ -127,7 +132,12 @@
// The channel currently using this voice.
opl_channel_data_t *channel;
- // The note that this voice is playing.
+ // The midi key that this voice is playing.
+ unsigned int key;
+
+ // The note being played. This is normally the same as
+ // the key, but if the instrument is a fixed pitch
+ // instrument, it is different.
unsigned int note;
// The frequency value being used.
@@ -153,18 +163,120 @@
// Frequency values to use for each note.
-static const unsigned int note_frequencies[] = {+static const unsigned short frequency_curve[] = {- // These frequencies are only used for the first seven
- // MIDI note values:
+ 0x133, 0x133, 0x134, 0x134, 0x135, 0x136, 0x136, 0x137, // -1
+ 0x137, 0x138, 0x138, 0x139, 0x139, 0x13a, 0x13b, 0x13b,
+ 0x13c, 0x13c, 0x13d, 0x13d, 0x13e, 0x13f, 0x13f, 0x140,
+ 0x140, 0x141, 0x142, 0x142, 0x143, 0x143, 0x144, 0x144,
- 0x158, 0x16d, 0x183, 0x19a, 0x1b2, 0x1cc, 0x1e7,
+ 0x145, 0x146, 0x146, 0x147, 0x147, 0x148, 0x149, 0x149, // -2
+ 0x14a, 0x14a, 0x14b, 0x14c, 0x14c, 0x14d, 0x14d, 0x14e,
+ 0x14f, 0x14f, 0x150, 0x150, 0x151, 0x152, 0x152, 0x153,
+ 0x153, 0x154, 0x155, 0x155, 0x156, 0x157, 0x157, 0x158,
- // These frequencies are used repeatedly, cycling around
- // for each octave:
+ // These are used for the first seven MIDI note values:
- 0x204, 0x223, 0x244, 0x266, 0x28b, 0x2b1,
- 0x2da, 0x306, 0x334, 0x365, 0x398, 0x3cf,
+ 0x158, 0x159, 0x15a, 0x15a, 0x15b, 0x15b, 0x15c, 0x15d, // 0
+ 0x15d, 0x15e, 0x15f, 0x15f, 0x160, 0x161, 0x161, 0x162,
+ 0x162, 0x163, 0x164, 0x164, 0x165, 0x166, 0x166, 0x167,
+ 0x168, 0x168, 0x169, 0x16a, 0x16a, 0x16b, 0x16c, 0x16c,
+
+ 0x16d, 0x16e, 0x16e, 0x16f, 0x170, 0x170, 0x171, 0x172, // 1
+ 0x172, 0x173, 0x174, 0x174, 0x175, 0x176, 0x176, 0x177,
+ 0x178, 0x178, 0x179, 0x17a, 0x17a, 0x17b, 0x17c, 0x17c,
+ 0x17d, 0x17e, 0x17e, 0x17f, 0x180, 0x181, 0x181, 0x182,
+
+ 0x183, 0x183, 0x184, 0x185, 0x185, 0x186, 0x187, 0x188, // 2
+ 0x188, 0x189, 0x18a, 0x18a, 0x18b, 0x18c, 0x18d, 0x18d,
+ 0x18e, 0x18f, 0x18f, 0x190, 0x191, 0x192, 0x192, 0x193,
+ 0x194, 0x194, 0x195, 0x196, 0x197, 0x197, 0x198, 0x199,
+
+ 0x19a, 0x19a, 0x19b, 0x19c, 0x19d, 0x19d, 0x19e, 0x19f, // 3
+ 0x1a0, 0x1a0, 0x1a1, 0x1a2, 0x1a3, 0x1a3, 0x1a4, 0x1a5,
+ 0x1a6, 0x1a6, 0x1a7, 0x1a8, 0x1a9, 0x1a9, 0x1aa, 0x1ab,
+ 0x1ac, 0x1ad, 0x1ad, 0x1ae, 0x1af, 0x1b0, 0x1b0, 0x1b1,
+
+ 0x1b2, 0x1b3, 0x1b4, 0x1b4, 0x1b5, 0x1b6, 0x1b7, 0x1b8, // 4
+ 0x1b8, 0x1b9, 0x1ba, 0x1bb, 0x1bc, 0x1bc, 0x1bd, 0x1be,
+ 0x1bf, 0x1c0, 0x1c0, 0x1c1, 0x1c2, 0x1c3, 0x1c4, 0x1c4,
+ 0x1c5, 0x1c6, 0x1c7, 0x1c8, 0x1c9, 0x1c9, 0x1ca, 0x1cb,
+
+ 0x1cc, 0x1cd, 0x1ce, 0x1ce, 0x1cf, 0x1d0, 0x1d1, 0x1d2, // 5
+ 0x1d3, 0x1d3, 0x1d4, 0x1d5, 0x1d6, 0x1d7, 0x1d8, 0x1d8,
+ 0x1d9, 0x1da, 0x1db, 0x1dc, 0x1dd, 0x1de, 0x1de, 0x1df,
+ 0x1e0, 0x1e1, 0x1e2, 0x1e3, 0x1e4, 0x1e5, 0x1e5, 0x1e6,
+
+ 0x1e7, 0x1e8, 0x1e9, 0x1ea, 0x1eb, 0x1ec, 0x1ed, 0x1ed, // 6
+ 0x1ee, 0x1ef, 0x1f0, 0x1f1, 0x1f2, 0x1f3, 0x1f4, 0x1f5,
+ 0x1f6, 0x1f6, 0x1f7, 0x1f8, 0x1f9, 0x1fa, 0x1fb, 0x1fc,
+ 0x1fd, 0x1fe, 0x1ff, 0x200, 0x201, 0x201, 0x202, 0x203,
+
+ // First note of looped range used for all octaves:
+
+ 0x204, 0x205, 0x206, 0x207, 0x208, 0x209, 0x20a, 0x20b, // 7
+ 0x20c, 0x20d, 0x20e, 0x20f, 0x210, 0x210, 0x211, 0x212,
+ 0x213, 0x214, 0x215, 0x216, 0x217, 0x218, 0x219, 0x21a,
+ 0x21b, 0x21c, 0x21d, 0x21e, 0x21f, 0x220, 0x221, 0x222,
+
+ 0x223, 0x224, 0x225, 0x226, 0x227, 0x228, 0x229, 0x22a, // 8
+ 0x22b, 0x22c, 0x22d, 0x22e, 0x22f, 0x230, 0x231, 0x232,
+ 0x233, 0x234, 0x235, 0x236, 0x237, 0x238, 0x239, 0x23a,
+ 0x23b, 0x23c, 0x23d, 0x23e, 0x23f, 0x240, 0x241, 0x242,
+
+ 0x244, 0x245, 0x246, 0x247, 0x248, 0x249, 0x24a, 0x24b, // 9
+ 0x24c, 0x24d, 0x24e, 0x24f, 0x250, 0x251, 0x252, 0x253,
+ 0x254, 0x256, 0x257, 0x258, 0x259, 0x25a, 0x25b, 0x25c,
+ 0x25d, 0x25e, 0x25f, 0x260, 0x262, 0x263, 0x264, 0x265,
+
+ 0x266, 0x267, 0x268, 0x269, 0x26a, 0x26c, 0x26d, 0x26e, // 10
+ 0x26f, 0x270, 0x271, 0x272, 0x273, 0x275, 0x276, 0x277,
+ 0x278, 0x279, 0x27a, 0x27b, 0x27d, 0x27e, 0x27f, 0x280,
+ 0x281, 0x282, 0x284, 0x285, 0x286, 0x287, 0x288, 0x289,
+
+ 0x28b, 0x28c, 0x28d, 0x28e, 0x28f, 0x290, 0x292, 0x293, // 11
+ 0x294, 0x295, 0x296, 0x298, 0x299, 0x29a, 0x29b, 0x29c,
+ 0x29e, 0x29f, 0x2a0, 0x2a1, 0x2a2, 0x2a4, 0x2a5, 0x2a6,
+ 0x2a7, 0x2a9, 0x2aa, 0x2ab, 0x2ac, 0x2ae, 0x2af, 0x2b0,
+
+ 0x2b1, 0x2b2, 0x2b4, 0x2b5, 0x2b6, 0x2b7, 0x2b9, 0x2ba, // 12
+ 0x2bb, 0x2bd, 0x2be, 0x2bf, 0x2c0, 0x2c2, 0x2c3, 0x2c4,
+ 0x2c5, 0x2c7, 0x2c8, 0x2c9, 0x2cb, 0x2cc, 0x2cd, 0x2ce,
+ 0x2d0, 0x2d1, 0x2d2, 0x2d4, 0x2d5, 0x2d6, 0x2d8, 0x2d9,
+
+ 0x2da, 0x2dc, 0x2dd, 0x2de, 0x2e0, 0x2e1, 0x2e2, 0x2e4, // 13
+ 0x2e5, 0x2e6, 0x2e8, 0x2e9, 0x2ea, 0x2ec, 0x2ed, 0x2ee,
+ 0x2f0, 0x2f1, 0x2f2, 0x2f4, 0x2f5, 0x2f6, 0x2f8, 0x2f9,
+ 0x2fb, 0x2fc, 0x2fd, 0x2ff, 0x300, 0x302, 0x303, 0x304,
+
+ 0x306, 0x307, 0x309, 0x30a, 0x30b, 0x30d, 0x30e, 0x310, // 14
+ 0x311, 0x312, 0x314, 0x315, 0x317, 0x318, 0x31a, 0x31b,
+ 0x31c, 0x31e, 0x31f, 0x321, 0x322, 0x324, 0x325, 0x327,
+ 0x328, 0x329, 0x32b, 0x32c, 0x32e, 0x32f, 0x331, 0x332,
+
+ 0x334, 0x335, 0x337, 0x338, 0x33a, 0x33b, 0x33d, 0x33e, // 15
+ 0x340, 0x341, 0x343, 0x344, 0x346, 0x347, 0x349, 0x34a,
+ 0x34c, 0x34d, 0x34f, 0x350, 0x352, 0x353, 0x355, 0x357,
+ 0x358, 0x35a, 0x35b, 0x35d, 0x35e, 0x360, 0x361, 0x363,
+
+ 0x365, 0x366, 0x368, 0x369, 0x36b, 0x36c, 0x36e, 0x370, // 16
+ 0x371, 0x373, 0x374, 0x376, 0x378, 0x379, 0x37b, 0x37c,
+ 0x37e, 0x380, 0x381, 0x383, 0x384, 0x386, 0x388, 0x389,
+ 0x38b, 0x38d, 0x38e, 0x390, 0x392, 0x393, 0x395, 0x397,
+
+ 0x398, 0x39a, 0x39c, 0x39d, 0x39f, 0x3a1, 0x3a2, 0x3a4, // 17
+ 0x3a6, 0x3a7, 0x3a9, 0x3ab, 0x3ac, 0x3ae, 0x3b0, 0x3b1,
+ 0x3b3, 0x3b5, 0x3b7, 0x3b8, 0x3ba, 0x3bc, 0x3bd, 0x3bf,
+ 0x3c1, 0x3c3, 0x3c4, 0x3c6, 0x3c8, 0x3ca, 0x3cb, 0x3cd,
+
+ // The last note has an incomplete range, and loops round back to
+ // the start. Note that the last value is actually a buffer overrun
+ // and does not fit with the other values.
+
+ 0x3cf, 0x3d1, 0x3d2, 0x3d4, 0x3d6, 0x3d8, 0x3da, 0x3db, // 18
+ 0x3dd, 0x3df, 0x3e1, 0x3e3, 0x3e4, 0x3e6, 0x3e8, 0x3ea,
+ 0x3ec, 0x3ed, 0x3ef, 0x3f1, 0x3f3, 0x3f5, 0x3f6, 0x3f8,
+ 0x3fa, 0x3fc, 0x3fe, 0x36c,
};
// Mapping from MIDI volume level to OPL level value.
@@ -501,7 +613,7 @@
reg_volume = (op_volume * volume) / 128;
reg_volume = (0x3f - reg_volume) | op->scale;
- // Update the register, if necessary:
+ // Update the register, if neccessary:
if (*current_volume != reg_volume)
{@@ -673,13 +785,13 @@
current_music_volume = volume;
}
-static opl_voice_t *FindVoiceForNote(opl_channel_data_t *channel, int note)
+static opl_voice_t *FindVoiceForKey(opl_channel_data_t *channel, int key)
{unsigned int i;
for (i=0; i<OPL_NUM_VOICES; ++i)
{- if (voices[i].channel == channel && voices[i].note == note)
+ if (voices[i].channel == channel && voices[i].key == key)
{return &voices[i];
}
@@ -693,6 +805,8 @@
WriteRegister(OPL_REGS_FREQ_2 + voice->index, voice->freq >> 8);
}
+// Get the frequency that we should be using for a voice.
+
static void NoteOffEvent(opl_track_data_t *track, midi_event_t *event)
{opl_voice_t *voice;
@@ -707,7 +821,7 @@
// Find the voice being used to play the note.
- voice = FindVoiceForNote(channel, event->data.channel.param1);
+ voice = FindVoiceForKey(channel, event->data.channel.param1);
if (voice == NULL)
{@@ -721,29 +835,47 @@
ReleaseVoice(voice);
}
-// Given a MIDI note number, get the corresponding OPL
-// frequency value to use.
-
-static unsigned int FrequencyForNote(unsigned int note)
+static unsigned int FrequencyForVoice(opl_voice_t *voice)
{+ unsigned int freq_index;
unsigned int octave;
- unsigned int key_num;
+ unsigned int sub_index;
- // The first seven frequencies in the frequencies array are used
- // only for the first seven MIDI notes. After this, the frequency
- // value loops around the same twelve notes, increasing the
- // octave.
+ freq_index = 64 + 32 * voice->note + voice->channel->bend;
- if (note < 7)
+ // The first 7 notes use the start of the table, while
+ // consecutive notes loop around the latter part.
+
+ if (freq_index < 284)
{- return note_frequencies[note];
+ return frequency_curve[freq_index];
}
- else
+
+ sub_index = (freq_index - 284) % (12 * 32);
+ octave = (freq_index - 284) / (12 * 32);
+
+ // Calculate the resulting register value to use for the frequency.
+
+ return frequency_curve[sub_index + 284] | (octave << 10);
+}
+
+// Update the frequency that a voice is programmed to use.
+
+static void UpdateVoiceFrequency(opl_voice_t *voice)
+{+ unsigned int freq;
+
+ // Calculate the frequency to use for this voice and update it
+ // if neccessary.
+
+ freq = FrequencyForVoice(voice);
+
+ if (voice->freq != freq)
{- octave = (note - 7) / 12;
- key_num = (note - 7) % 12;
+ WriteRegister(OPL_REGS_FREQ_1 + voice->index, freq & 0xff);
+ WriteRegister(OPL_REGS_FREQ_2 + voice->index, (freq >> 8) | 0x20);
- return note_frequencies[key_num + 7] | (octave << 10);
+ voice->freq = freq;
}
}
@@ -752,7 +884,7 @@
genmidi_instr_t *instrument;
opl_voice_t *voice;
opl_channel_data_t *channel;
- unsigned int note;
+ unsigned int key;
unsigned int volume;
printf("note on: channel %i, %i, %i\n",@@ -763,19 +895,19 @@
// The channel.
channel = &track->channels[event->data.channel.channel];
- note = event->data.channel.param1;
+ key = event->data.channel.param1;
volume = event->data.channel.param2;
- // Percussion channel (10) is treated differently to normal notes.
+ // Percussion channel (10) is treated differently.
if (event->data.channel.channel == 9)
{- if (note < 35 || note > 81)
+ if (key < 35 || key > 81)
{return;
}
- instrument = &percussion_instrs[note - 35];
+ instrument = &percussion_instrs[key - 35];
}
else
{@@ -793,8 +925,20 @@
}
voice->channel = channel;
- voice->note = note;
+ voice->key = key;
+ // Work out the note to use. This is normally the same as
+ // the key, unless it is a fixed pitch instrument.
+
+ if ((instrument->flags & GENMIDI_FLAG_FIXED) != 0)
+ {+ voice->note = instrument->fixed_note;
+ }
+ else
+ {+ voice->note = key;
+ }
+
// Program the voice with the instrument data:
SetVoiceInstrument(voice, instrument);
@@ -803,19 +947,10 @@
SetVoiceVolume(voice, volume);
- // Fixed pitch?
-
- if ((instrument->flags & GENMIDI_FLAG_FIXED) != 0)
- {- note = instrument->fixed_note;
- }
-
// Write the frequency value to turn the note on.
- voice->freq = FrequencyForNote(note);
-
- WriteRegister(OPL_REGS_FREQ_1 + voice->index, voice->freq & 0xff);
- WriteRegister(OPL_REGS_FREQ_2 + voice->index, (voice->freq >> 8) | 0x20);
+ voice->freq = 0;
+ UpdateVoiceFrequency(voice);
}
static void ProgramChangeEvent(opl_track_data_t *track, midi_event_t *event)
@@ -877,6 +1012,30 @@
}
}
+// Process a pitch bend event.
+
+static void PitchBendEvent(opl_track_data_t *track, midi_event_t *event)
+{+ opl_channel_data_t *channel;
+ unsigned int i;
+
+ // Update the channel bend value. Only the MSB of the pitch bend
+ // value is considered: this is what Doom does.
+
+ channel = &track->channels[event->data.channel.channel];
+ channel->bend = event->data.channel.param2 - 64;
+
+ // Update all voices for this channel.
+
+ for (i=0; i<OPL_NUM_VOICES; ++i)
+ {+ if (voices[i].channel == channel)
+ {+ UpdateVoiceFrequency(&voices[i]);
+ }
+ }
+}
+
// Process a meta event.
static void MetaEvent(opl_track_data_t *track, midi_event_t *event)
@@ -931,6 +1090,10 @@
ProgramChangeEvent(track, event);
break;
+ case MIDI_EVENT_PITCH_BEND:
+ PitchBendEvent(track, event);
+ break;
+
case MIDI_EVENT_META:
MetaEvent(track, event);
break;
@@ -1029,6 +1192,7 @@
channel->instrument = &main_instrs[0];
channel->volume = 127;
+ channel->bend = 0;
}
// Start a MIDI track playing: