Fix: playing of instrument without note.

When an instrument is played without a note, the current playing sample should restart its envelope, keeping its position. So it's important not to change the current instrument. Also, the same behavior happens even if the instrument is invalid (and no note is specified); on the other hand, if the instrument is invalid and a note is specified, the current note is being cut. Co-developed with @bryc, who also prepared the tests
Artefact2 · Apr 12, 2021 · 7759aec · 7759aec
1 parent 0b464e8
commit 7759aec
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Showing 4 changed files with 4 additions and 5 deletions.
diff --git a/src/play.c b/src/play.c
@@ -410,18 +410,17 @@ static void xm_handle_note_and_instrument(xm_context_t* ctx, xm_channel_context_
 		if(HAS_TONE_PORTAMENTO(ch->current) && ch->instrument != NULL && ch->sample != NULL) {
 			/* Tone portamento in effect, unclear stuff happens */
 			xm_trigger_note(ctx, ch, XM_TRIGGER_KEEP_PERIOD | XM_TRIGGER_KEEP_SAMPLE_POSITION);
+		} else if(s->note == 0 && ch->sample != NULL) {
+			/* Ghost instrument, trigger note */
+			/* Sample position is kept, but envelopes are reset */
+			xm_trigger_note(ctx, ch, XM_TRIGGER_KEEP_SAMPLE_POSITION);
 		} else if(s->instrument > ctx->module.num_instruments) {
 			/* Invalid instrument, Cut current note */
 			xm_cut_note(ch);
 			ch->instrument = NULL;
 			ch->sample = NULL;
 		} else {
 			ch->instrument = ctx->module.instruments + (s->instrument - 1);
-			if(s->note == 0 && ch->sample != NULL) {
-				/* Ghost instrument, trigger note */
-				/* Sample position is kept, but envelopes are reset */
-				xm_trigger_note(ctx, ch, XM_TRIGGER_KEEP_SAMPLE_POSITION);
-			}
 		}
 	}
 

diff --git a/tests/ins-without-note1.xm b/tests/ins-without-note1.xm
diff --git a/tests/ins-without-note2.xm b/tests/ins-without-note2.xm
diff --git a/tests/ins-without-note3.xm b/tests/ins-without-note3.xm