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-rw-r--r--src/i_oplmusic.c178
1 files changed, 12 insertions, 166 deletions
diff --git a/src/i_oplmusic.c b/src/i_oplmusic.c
index dd62076d..e9e722e4 100644
--- a/src/i_oplmusic.c
+++ b/src/i_oplmusic.c
@@ -326,149 +326,11 @@ static unsigned int num_tracks;
static unsigned int running_tracks = 0;
static boolean song_looping;
-// In the initialisation stage, register writes are spaced by reading
-// from the register port (0). After initialisation, spacing is
-// peformed by reading from the data port instead. I have no idea
-// why.
-
-static boolean init_stage_reg_writes = false;
-
// Configuration file variable, containing the port number for the
// adlib chip.
int opl_io_port = 0x388;
-static unsigned int GetStatus(void)
-{
- return OPL_ReadPort(OPL_REGISTER_PORT);
-}
-
-// Write an OPL register value
-
-static void WriteRegister(int reg, int value)
-{
- int i;
-
- OPL_WritePort(OPL_REGISTER_PORT, reg);
-
- // For timing, read the register port six times after writing the
- // register number to cause the appropriate delay
-
- for (i=0; i<6; ++i)
- {
- // An oddity of the Doom OPL code: at startup initialisation,
- // the spacing here is performed by reading from the register
- // port; after initialisation, the data port is read, instead.
-
- if (init_stage_reg_writes)
- {
- OPL_ReadPort(OPL_REGISTER_PORT);
- }
- else
- {
- OPL_ReadPort(OPL_DATA_PORT);
- }
- }
-
- OPL_WritePort(OPL_DATA_PORT, value);
-
- // Read the register port 25 times after writing the value to
- // cause the appropriate delay
-
- for (i=0; i<24; ++i)
- {
- GetStatus();
- }
-}
-
-// Detect the presence of an OPL chip
-
-static boolean DetectOPL(void)
-{
- int result1, result2;
- int i;
-
- // Reset both timers:
- WriteRegister(OPL_REG_TIMER_CTRL, 0x60);
-
- // Enable interrupts:
- WriteRegister(OPL_REG_TIMER_CTRL, 0x80);
-
- // Read status
- result1 = GetStatus();
-
- // Set timer:
- WriteRegister(OPL_REG_TIMER1, 0xff);
-
- // Start timer 1:
- WriteRegister(OPL_REG_TIMER_CTRL, 0x21);
-
- // Wait for 80 microseconds
- // This is how Doom does it:
-
- for (i=0; i<200; ++i)
- {
- GetStatus();
- }
-
- OPL_Delay(1);
-
- // Read status
- result2 = GetStatus();
-
- // Reset both timers:
- WriteRegister(OPL_REG_TIMER_CTRL, 0x60);
-
- // Enable interrupts:
- WriteRegister(OPL_REG_TIMER_CTRL, 0x80);
-
- return (result1 & 0xe0) == 0x00
- && (result2 & 0xe0) == 0xc0;
-}
-
-// Initialise registers on startup
-
-static void InitRegisters(void)
-{
- int r;
-
- // Initialise level registers
-
- for (r=OPL_REGS_LEVEL; r <= OPL_REGS_LEVEL + OPL_NUM_OPERATORS; ++r)
- {
- WriteRegister(r, 0x3f);
- }
-
- // Initialise other registers
- // These two loops write to registers that actually don't exist,
- // but this is what Doom does ...
- // Similarly, the <= is also intenational.
-
- for (r=OPL_REGS_ATTACK; r <= OPL_REGS_WAVEFORM + OPL_NUM_OPERATORS; ++r)
- {
- WriteRegister(r, 0x00);
- }
-
- // More registers ...
-
- for (r=1; r < OPL_REGS_LEVEL; ++r)
- {
- WriteRegister(r, 0x00);
- }
-
- // Re-initialise the low registers:
-
- // Reset both timers and enable interrupts:
- WriteRegister(OPL_REG_TIMER_CTRL, 0x60);
- WriteRegister(OPL_REG_TIMER_CTRL, 0x80);
-
- // "Allow FM chips to control the waveform of each operator":
- WriteRegister(OPL_REG_WAVEFORM_ENABLE, 0x20);
-
- // Keyboard split point on (?)
- WriteRegister(OPL_REG_FM_MODE, 0x40);
-}
-
// Load instrument table from GENMIDI lump:
static boolean LoadInstrumentTable(void)
@@ -584,11 +446,11 @@ static void LoadOperatorData(int operator, genmidi_op_t *data,
level |= 0x3f;
}
- WriteRegister(OPL_REGS_LEVEL + operator, level);
- WriteRegister(OPL_REGS_TREMOLO + operator, data->tremolo);
- WriteRegister(OPL_REGS_ATTACK + operator, data->attack);
- WriteRegister(OPL_REGS_SUSTAIN + operator, data->sustain);
- WriteRegister(OPL_REGS_WAVEFORM + operator, data->waveform);
+ OPL_WriteRegister(OPL_REGS_LEVEL + operator, level);
+ OPL_WriteRegister(OPL_REGS_TREMOLO + operator, data->tremolo);
+ OPL_WriteRegister(OPL_REGS_ATTACK + operator, data->attack);
+ OPL_WriteRegister(OPL_REGS_SUSTAIN + operator, data->sustain);
+ OPL_WriteRegister(OPL_REGS_WAVEFORM + operator, data->waveform);
}
// Set the instrument for a particular voice.
@@ -629,8 +491,8 @@ static void SetVoiceInstrument(opl_voice_t *voice,
// two operators. Turn on bits in the upper nybble; I think this
// is for OPL3, where it turns on channel A/B.
- WriteRegister(OPL_REGS_FEEDBACK + voice->index,
- data->feedback | 0x30);
+ OPL_WriteRegister(OPL_REGS_FEEDBACK + voice->index,
+ data->feedback | 0x30);
// Hack to force a volume update.
@@ -669,7 +531,7 @@ static void SetVoiceVolume(opl_voice_t *voice, unsigned int volume)
{
voice->reg_volume = reg_volume;
- WriteRegister(OPL_REGS_LEVEL + voice->op2, reg_volume);
+ OPL_WriteRegister(OPL_REGS_LEVEL + voice->op2, reg_volume);
// If we are using non-modulated feedback mode, we must set the
// volume for both voices.
@@ -679,7 +541,7 @@ static void SetVoiceVolume(opl_voice_t *voice, unsigned int volume)
if ((opl_voice->feedback & 0x01) != 0)
{
- WriteRegister(OPL_REGS_LEVEL + voice->op1, reg_volume);
+ OPL_WriteRegister(OPL_REGS_LEVEL + voice->op1, reg_volume);
}
}
}
@@ -731,17 +593,7 @@ static boolean I_OPL_InitMusic(void)
{
if (!OPL_Init(opl_io_port))
{
- return false;
- }
-
- init_stage_reg_writes = true;
-
- // Doom does the detection sequence twice, for some reason:
-
- if (!DetectOPL() || !DetectOPL())
- {
printf("Dude. The Adlib isn't responding.\n");
- OPL_Shutdown();
return false;
}
@@ -753,14 +605,8 @@ static boolean I_OPL_InitMusic(void)
return false;
}
- InitRegisters();
InitVoices();
- // Now that initialisation has finished, switch the
- // register writing mode:
-
- init_stage_reg_writes = false;
-
music_initialised = true;
return true;
@@ -789,7 +635,7 @@ static void I_OPL_SetMusicVolume(int volume)
static void VoiceKeyOff(opl_voice_t *voice)
{
- WriteRegister(OPL_REGS_FREQ_2 + voice->index, voice->freq >> 8);
+ OPL_WriteRegister(OPL_REGS_FREQ_2 + voice->index, voice->freq >> 8);
}
// Get the frequency that we should be using for a voice.
@@ -947,8 +793,8 @@ static void UpdateVoiceFrequency(opl_voice_t *voice)
if (voice->freq != freq)
{
- WriteRegister(OPL_REGS_FREQ_1 + voice->index, freq & 0xff);
- WriteRegister(OPL_REGS_FREQ_2 + voice->index, (freq >> 8) | 0x20);
+ OPL_WriteRegister(OPL_REGS_FREQ_1 + voice->index, freq & 0xff);
+ OPL_WriteRegister(OPL_REGS_FREQ_2 + voice->index, (freq >> 8) | 0x20);
voice->freq = freq;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-26 12:39:58 +0000