Apply noise generator notes minus required cross-channel event for psg3 mode

src/reskit/soundtrack/engines/echo/dmf.rs

@@ -2,7 +2,7 @@ use std::{collections::HashMap, cmp::{max, min}, error::Error};
 use convert_case::{Case, Casing};
 use samplerate::convert;
 use uuid::Uuid;
-use crate::reskit::{soundtrack::{formats::dmf::{DmfModule, ECHO_EWF_SAMPLE_RATE}, types::{InstrumentType, SampleFormat, Channel, PatternRow}}, utility::{print_warning, Ring, print_info}};
+use crate::reskit::{soundtrack::{formats::dmf::{DmfModule, ECHO_EWF_SAMPLE_RATE}, types::{InstrumentType, SampleFormat, Channel, PatternRow, Effect, DcsgChannelMode, NoiseType}}, utility::{print_warning, Ring, print_info}};
 use super::engine::{EchoFormat, ESF_FM_1, ESF_FM_2, ESF_FM_3, ESF_FM_4, ESF_FM_5, ESF_FM_6, ESF_PSG_1, ESF_PSG_2, ESF_PSG_3, ESF_PSG_4, EchoEvent, get_events_for_row, compact_delays};
 
 

src/reskit/soundtrack/engines/echo/engine.rs

@@ -1,6 +1,6 @@
 use std::{collections::HashMap, error::Error, cmp::{min, max}};
 use linked_hash_set::LinkedHashSet;
-use crate::reskit::{soundtrack::types::{PatternRow, Note, Channel, OctaveFrequency, Effect, Instrument}, utility::print_warning};
+use crate::reskit::{soundtrack::types::{PatternRow, Note, Channel, OctaveFrequency, Effect, Instrument, NoiseType, DcsgChannelMode}, utility::print_warning};
 
 // https://github.com/sikthehedgehog/Echo/blob/master/doc/esf.txt
 const ESF_NOTE_ON: u8 = 0x00;
@@ -32,6 +32,15 @@ pub const ESF_PSG_2: u8 = 0x09;
 pub const ESF_PSG_3: u8 = 0x0A;
 pub const ESF_PSG_4: u8 = 0x0B;
 
+pub const ESF_NOISE_PERIODIC_HIGH: u8   = 0x00;
+pub const ESF_NOISE_PERIODIC_MED: u8    = 0x01;
+pub const ESF_NOISE_PERIODIC_LOW: u8    = 0x02;
+pub const ESF_NOISE_PERIODIC_PSG_3: u8  = 0x03;
+pub const ESF_NOISE_WHITE_HIGH: u8      = 0x04;
+pub const ESF_NOISE_WHITE_MED: u8       = 0x05;
+pub const ESF_NOISE_WHITE_LOW: u8       = 0x06;
+pub const ESF_NOISE_WHITE_PSG_3: u8     = 0x07;
+
 pub const ESF_FM_6_PCM: u8 = 0x0C;
 
 const ESF_FM_PARAM_LEFT_SPEAKER: u8 = 0x80;
@@ -180,6 +189,45 @@ pub fn get_psg_octave_from_frequency( frequency: i16 ) -> u8 {
     }
 }
 
+/**
+ * Get the setting for the noise generator based on the active noise mode effect.
+ */
+pub fn get_noise_generator_setting( note: &Note, noise_mode: Option<&Effect> ) -> Result<u8, Box<dyn Error>> {
+    Ok(
+        if let Some( noise_mode ) = noise_mode {
+            if let Effect::DcsgNoiseMode { mode, noise_type } = noise_mode {
+                match noise_type {
+                    NoiseType::PeriodicNoise => match mode {
+                        DcsgChannelMode::Ch3Frequency => ESF_NOISE_PERIODIC_PSG_3,
+                        DcsgChannelMode::FixedFrequency => match note {
+                            Note::NoteOff => return Err( "internal error: attempted to get noise generator setting for NoteOff" )?,
+                            Note::C(_) => ESF_NOISE_PERIODIC_LOW,
+                            Note::CSharp(_) => ESF_NOISE_PERIODIC_MED,
+                            Note::D(_) | _ => ESF_NOISE_PERIODIC_HIGH
+                        }
+                    },
+                    NoiseType::WhiteNoise => match mode {
+                        DcsgChannelMode::Ch3Frequency => ESF_NOISE_WHITE_PSG_3,
+                        DcsgChannelMode::FixedFrequency => match note {
+                            Note::NoteOff => return Err( "internal error: attempted to get noise generator setting for NoteOff" )?,
+                            Note::C(_) => ESF_NOISE_WHITE_LOW,
+                            Note::CSharp(_) => ESF_NOISE_WHITE_MED,
+                            Note::D(_) | _ => ESF_NOISE_WHITE_HIGH
+                        }
+                    }
+                }
+            } else {
+                return Err( "internal error: non-DcsgNoiseMode effect passed to get_noise_generator_setting" )?
+            }
+        } else {
+            match note {
+                Note::NoteOff => return Err( "internal error: attempted to get noise generator setting for NoteOff" )?,
+                _ => ESF_NOISE_WHITE_PSG_3
+            }
+        }
+    )
+}
+
 pub fn get_fm_note_byte( octave: u8, semitone: u8 ) -> u8 {
     32 * octave + 2 * semitone + 1
 }
@@ -243,9 +291,9 @@ pub fn get_events_for_channel( channel: &mut Channel, row: &PatternRow, pcm_offs
             channel.active_instrument = Some( *instrument );
         }
     } else {
-        // This is SN1, SN2, or SN3 with no active instrument
+        // This is SN1, SN2, SN3, or SN4 with no active instrument
         // Check if the channel needs "__reskit_default_psg_instrument" set before a note is set
-        if channel.active_instrument.is_none() && ( ESF_PSG_1..=ESF_PSG_3 ).contains( &channel.id ) {
+        if channel.active_instrument.is_none() && ( ESF_PSG_1..=ESF_PSG_4 ).contains( &channel.id ) {
             if row.note.is_some() {
                 // Set "__reskit_default_psg_instrument"
                 let instrument = default_psg_instr_index.ok_or( "internal error: no default psg instrument to apply" )?;
@@ -267,6 +315,11 @@ pub fn get_events_for_channel( channel: &mut Channel, row: &PatternRow, pcm_offs
                     octave: note.get_octave()?,
                     frequency: if ( ESF_PSG_1..=ESF_PSG_3 ).contains( &channel.id ) {
                         get_psg_semitone_frequency( note.get_octave()?, get_semitone( note )? )?
+                    } else if channel.id == ESF_PSG_4 {
+                        // probably doesn't matter a damn what we put here, the OctaveFrequency is used only for portamentos.
+                        // and you can't portamento on PSG_4 (you can, however, portamento the frequency set on PSG_3, but
+                        // we'll get to cross-channel generated events in a bit.)
+                        0
                     } else {
                         get_fm_semitone_frequency( get_semitone( note )? )?
                     }
@@ -275,6 +328,10 @@ pub fn get_events_for_channel( channel: &mut Channel, row: &PatternRow, pcm_offs
 
             if channel.id == ESF_FM_6_PCM {
                 events.push( vec![ ESF_NOTE_ON | channel.id, get_pcm_index( note )? + pcm_offset ] );
+            } else if channel.id == ESF_PSG_4 {
+                // Find the single (and it should only ever be a single) Effect::DcsgNoiseMode attached to the channel
+                let dcsg_noise_mode = channel.active_effects.iter().find( | effect | matches!( effect, Effect::DcsgNoiseMode { mode: _, noise_type: _ } ) );
+                events.push( vec![ ESF_NOTE_ON | channel.id, get_noise_generator_setting( note, dcsg_noise_mode )? ] );
             } else {
                 let note = get_note( note, channel.id )?;
                 events.push( vec![ ESF_NOTE_ON | channel.id, note ] );
@@ -395,6 +452,22 @@ pub fn apply_effects_to_channel( channel: &mut Channel, effects: &LinkedHashSet<
                     }
                 }
             },
+            Effect::DcsgNoiseMode { mode, noise_type } => {
+                let mode = *mode;
+                let noise_type = *noise_type;
+
+                if channel.id == ESF_PSG_4 {
+                    channel.active_effects = channel.active_effects
+                                                    .clone()
+                                                    .into_iter()
+                                                    .filter( | effect | !( matches!( effect, Effect::DcsgNoiseMode { mode: _, noise_type: _ } ) ) )
+                                                    .collect();
+
+                    channel.active_effects.insert( Effect::DcsgNoiseMode { mode, noise_type } );
+                } else {
+                    print_warning( "Effect:DcsgNoiseMode can only be applied to SN4. ignoring..." );
+                }
+            },
             unsupported_effect => print_warning( &format!( "effect unsupported: {:?}. your soundtrack may sound different than expected.", unsupported_effect ) )
         }
     }
@@ -465,9 +538,9 @@ pub fn compact_delays( events: Vec<EchoEvent> ) -> Result<Vec<EchoEvent>, Box<dy
  */
 pub fn get_portamento( channel: &mut Channel, portamento_effect: &Effect ) -> Result<EchoEvent, Box<dyn Error>> {
     Ok(
-        if channel.id == ESF_FM_6_PCM {
+        if channel.id == ESF_FM_6_PCM || channel.id == ESF_PSG_4 {
             // Generate no events if channel is set to pcm
-            print_warning( "attempted to portamento on FM6 when it is set to pcm. this makes no sense and does nothing" );
+            print_warning( "attempted to portamento on FM6 when it is set to pcm, or on SN4. this makes no sense and does nothing" );
             vec![]
         } else if let Some( octave_frequency ) = channel.active_note {
             let ( octave, frequency ) = {