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Updating ESFMu - accuracy improvements for noise mode

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Kagamiin~ 2023-10-22 16:49:23 -03:00
parent 64baa7c97f
commit 96fbd1524a
3 changed files with 54 additions and 12 deletions
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6
extern/ESFMu/MODIFIED.md vendored
View file

@ -1,6 +0,0 @@
# Modification disclaimer
This is a modified version of ESFMu v1.0.1 which implements a function for reading the waveform output of the individual FM channels. The modification was made by Kagamiin~ (original author of ESFMu) herself.
Kagamiin~ notes:
> In hindsight, I might merge back this functionality into a future version of the core, as it could be be useful for generating oscilloscope views in other tools.

58
extern/ESFMu/esfm.c vendored
View file

@ -196,11 +196,13 @@ static int13
ESFM_envelope_calc_sin0(uint10 phase, uint10 envelope)
{
uint16 out = 0;
int13 neg = 0;
uint13 neg = 0;
bool inc = 0;
phase &= 0x3ff;
if (phase & 0x200)
{
neg = ~(0);
inc = 1;
}
if (phase & 0x100)
{
@ -210,7 +212,7 @@ ESFM_envelope_calc_sin0(uint10 phase, uint10 envelope)
{
out = logsinrom[phase & 0xff];
}
return ESFM_envelope_calc_exp(out + (envelope << 3)) ^ neg;
return (int13)(((uint13)ESFM_envelope_calc_exp(out + (envelope << 3)) ^ neg) + inc);
}
/* ------------------------------------------------------------------------- */
@ -274,10 +276,12 @@ ESFM_envelope_calc_sin4(uint10 phase, uint10 envelope)
{
uint16 out = 0;
int13 neg = 0;
bool inc = 0;
phase &= 0x3ff;
if ((phase & 0x300) == 0x100)
{
neg = ~(0);
inc = 1;
}
if (phase & 0x200)
{
@ -291,7 +295,7 @@ ESFM_envelope_calc_sin4(uint10 phase, uint10 envelope)
{
out = logsinrom[(phase << 1) & 0xff];
}
return ESFM_envelope_calc_exp(out + (envelope << 3)) ^ neg;
return (int13)(((uint13)ESFM_envelope_calc_exp(out + (envelope << 3)) ^ neg) + inc);
}
/* ------------------------------------------------------------------------- */
@ -320,12 +324,14 @@ static int13
ESFM_envelope_calc_sin6(uint10 phase, uint10 envelope)
{
int13 neg = 0;
bool inc = 0;
phase &= 0x3ff;
if (phase & 0x200)
{
neg = ~(0);
inc = 1;
}
return ESFM_envelope_calc_exp(envelope << 3) ^ neg;
return (int13)(((uint13)ESFM_envelope_calc_exp(envelope << 3) ^ neg) + inc);
}
/* ------------------------------------------------------------------------- */
@ -334,14 +340,16 @@ ESFM_envelope_calc_sin7(uint10 phase, uint10 envelope)
{
uint16 out = 0;
int13 neg = 0;
bool inc = 0;
phase &= 0x3ff;
if (phase & 0x200)
{
neg = ~(0);
inc = 1;
phase = (phase & 0x1ff) ^ 0x1ff;
}
out = phase << 3;
return ESFM_envelope_calc_exp(out + (envelope << 3)) ^ neg;
return (int13)(((uint13)ESFM_envelope_calc_exp(out + (envelope << 3)) ^ neg) + inc);
}
/* ------------------------------------------------------------------------- */
@ -791,6 +799,37 @@ ESFM_phase_generate_emu(esfm_slot *slot)
chip->lfsr = (noise >> 1) | (n_bit << 22);
}
/**
* TODO: Figure out what's ACTUALLY going on inside the real chip!
* This is not accurate at all, but it's the closest I was able to get with
* empirical testing (and it's closer than nothing).
*/
/* ------------------------------------------------------------------------- */
static int16
ESFM_slot3_noise3_mod_input_calc(esfm_slot *slot)
{
esfm_channel *channel = slot->channel;
envelope_sinfunc wavegen = envelope_sin[channel->slots[2].waveform];
int16 phase;
int13 output_buf = *channel->slots[1].in.mod_input;
int i;
// Go through previous slots' partial results and recalculate outputs
// (we skip slot 0 because its calculation happens at the end, not at the beginning)
for (i = 1; i < 3; i++)
{
// double the pitch
phase = channel->slots[i].in.phase_acc >> 8;
if (channel->slots[i].mod_in_level)
{
phase += output_buf >> (7 - channel->slots[i].mod_in_level);
}
output_buf = wavegen((uint10)(phase & 0x3ff), channel->slots[i].in.eg_output);
}
return output_buf >> (8 - slot->mod_in_level);
}
/* ------------------------------------------------------------------------- */
static void
ESFM_slot_generate(esfm_slot *slot)
@ -799,7 +838,14 @@ ESFM_slot_generate(esfm_slot *slot)
int16 phase = slot->in.phase_out;
if (slot->mod_in_level)
{
phase += *slot->in.mod_input >> (7 - slot->mod_in_level);
if (slot->slot_idx == 3 && slot->rhy_noise == 3)
{
phase += ESFM_slot3_noise3_mod_input_calc(slot);
}
else
{
phase += *slot->in.mod_input >> (7 - slot->mod_in_level);
}
}
slot->in.output = wavegen((uint10)(phase & 0x3ff), slot->in.eg_output);
if (slot->output_level)

2
extern/ESFMu/esfm.h vendored
View file

@ -91,6 +91,7 @@ typedef uint_fast16_t uint9;
typedef uint_fast16_t uint10;
typedef uint_fast16_t uint11;
typedef uint_fast16_t uint12;
typedef uint_fast16_t uint13;
typedef uint_fast16_t uint16;
typedef uint_fast32_t uint19;
typedef uint_fast32_t uint23;
@ -114,6 +115,7 @@ typedef uint16_t uint9;
typedef uint16_t uint10;
typedef uint16_t uint11;
typedef uint16_t uint12;
typedef uint16_t uint13;
typedef uint16_t uint16;
typedef uint32_t uint19;
typedef uint32_t uint23;