From 33b16767db7abb7c2585315e1456adedb604b367 Mon Sep 17 00:00:00 2001
From: ashley <ne0ndrag0n@ne0ndrag0n.com>
Date: Tue, 29 Aug 2023 22:22:02 -0400
Subject: [PATCH] Support for effect Bxx (looping)

---
 src/reskit/soundtrack/engines/echo/dmf.rs    | 14 ++++++++++----
 src/reskit/soundtrack/engines/echo/engine.rs |  9 ++++++---
 src/reskit/soundtrack/formats/dmf.rs         |  8 +++++++-
 3 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/src/reskit/soundtrack/engines/echo/dmf.rs b/src/reskit/soundtrack/engines/echo/dmf.rs
index 98b3594..ada429a 100644
--- a/src/reskit/soundtrack/engines/echo/dmf.rs
+++ b/src/reskit/soundtrack/engines/echo/dmf.rs
@@ -3,7 +3,7 @@ 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}};
-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};
+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, ESF_SET_LOOP, ESF_GO_TO_LOOP, ESF_STOP};
 
 
 impl EchoFormat for DmfModule {
@@ -332,10 +332,16 @@ impl EchoFormat for DmfModule {
                 self.instruments.len() as u8
             )?;
 
+            // Is this the pattern matrix row that we repeat to?
+            // If so, insert an ESF_LOOP_SET here.
+            if let Some( repeat_row ) = self.loop_at {
+                if row_number == repeat_row {
+                    all_events.push( vec![ ESF_SET_LOOP ] );
+                }
+            }
+
             // Transfer ESF events to the main stream
             all_events.extend( events_this_row );
-
-            // Any jumps?
         }
 
         // Compact sequences of delays to save rom space
@@ -344,7 +350,7 @@ impl EchoFormat for DmfModule {
             esf.extend( event );
         }
 
-        esf.push( 0xFF );   // Terminate the stream
+        esf.push( if let None = self.loop_at { ESF_STOP } else { ESF_GO_TO_LOOP } );   // Terminate the stream
 
         Ok( esf )
     }
diff --git a/src/reskit/soundtrack/engines/echo/engine.rs b/src/reskit/soundtrack/engines/echo/engine.rs
index 97f4ef7..e825361 100644
--- a/src/reskit/soundtrack/engines/echo/engine.rs
+++ b/src/reskit/soundtrack/engines/echo/engine.rs
@@ -15,10 +15,10 @@ const ESF_SET_FM_DIRECT_0: u8 = 0xF8;
 const ESF_SET_FM_DIRECT_1: u8 = 0xF9;
 const ESF_SET_FLAGS: u8 = 0xFA;
 const ESF_CLEAR_FLAGS: u8 = 0xFB;
-const ESF_GOTO: u8 = 0xFC;
-const ESF_LOOP_SET: u8 = 0xFD;
+pub const ESF_GO_TO_LOOP: u8 = 0xFC;
+pub const ESF_SET_LOOP: u8 = 0xFD;
 const ESF_DELAY_LONG: u8 = 0xFE;
-const ESF_STOP: u8 = 0xFF;
+pub const ESF_STOP: u8 = 0xFF;
 
 pub const ESF_FM_1: u8 = 0x00;
 pub const ESF_FM_2: u8 = 0x01;
@@ -537,6 +537,9 @@ fn apply_effects_to_channel( channel: &mut Channel, effects: &LinkedHashSet<Effe
                     print_warning( "Effect:DcsgNoiseMode can only be applied to SN4. ignoring..." );
                 }
             },
+            Effect::PositionJump { pattern: _ } => {
+                // Nothing to do - handled as we iterate through the rows.
+            },
             unsupported_effect => print_warning( &format!( "effect unsupported: {:?}. your soundtrack may sound different than expected.", unsupported_effect ) )
         }
     }
diff --git a/src/reskit/soundtrack/formats/dmf.rs b/src/reskit/soundtrack/formats/dmf.rs
index ab4895e..63631cc 100644
--- a/src/reskit/soundtrack/formats/dmf.rs
+++ b/src/reskit/soundtrack/formats/dmf.rs
@@ -37,6 +37,7 @@ pub struct DmfModule {
     frame_mode: FrameMode,
     pub rows_per_pattern: u32,
     pattern_matrix: Vec<Vec<u16>>,
+    pub loop_at: Option<u32>,
     pub channel_patterns: Vec<Vec<PatternRow>>,
     pub instruments: Vec<Instrument>,
     pub samples: Vec<Sample>
@@ -449,6 +450,7 @@ impl DmfModule {
         }
 
         // (channel, patterns)
+        let mut loop_at: Option<u32> = None;
         let mut channel_patterns: Vec<Vec<PatternRow>> = Vec::new();
         for channel in 0..system_total_channels {
             let mut channel_rows: Vec<PatternRow> = Vec::new();
@@ -527,6 +529,10 @@ impl DmfModule {
                                     DMF_EFFECT_POSITION_JUMP => {
                                         let pattern = effect_value.ok_or( "invalid file: expected effect value for position jump" )?;
 
+                                        if let None = loop_at {
+                                            loop_at = Some( pattern as u32 * rows_per_pattern );
+                                        }
+
                                         Effect::PositionJump { pattern }
                                     },
                                     DMF_EFFECT_PATTERN_BREAK => {
@@ -659,7 +665,7 @@ impl DmfModule {
         Ok(
             DmfModule {
                 path: path.to_string(), platform, version, time_base, speed_a, speed_b, frame_mode, rows_per_pattern,
-                pattern_matrix, channel_patterns, instruments, samples
+                pattern_matrix, loop_at, channel_patterns, instruments, samples
             }
          )
     }