pt3: add looping support

pt3_player/README.pt3_player

@@ -51,11 +51,12 @@ Using the PT3_PLAYER
 		Right/Left arrow	Switch songs
 		Spacebar		Pause playback.
 		M			Switch from 1MHz to 1.77MHz mode
+		L			Enables looping in the song
 
 	FUTURE FEATURES:
 		Key to disable visualization
 		Key to skip ahead/back in pattern list
-		L to enable looping in the song
+
 
 ZX Compatability:
 ~~~~~~~~~~~~~~~~~

pt3_player/interrupt_handler.s

@@ -42,6 +42,19 @@ pt3_play_music:
 	lda	DONE_SONG
 	beq	mb_write_frame
 
+	lda	LOOP			; see if looping
+	beq	move_to_next
+
+	lda	pt3_loop
+	sta	current_pattern
+	lda	#$0
+	sta	current_line
+	sta	current_subframe
+	sta	DONE_SONG
+
+	jmp	done_interrupt
+
+move_to_next:
 	; same as "press right"
 	lda	#$40
 	jmp	quiet_exit
@@ -197,7 +210,7 @@ lowbar:
 
 key_M:
 	cmp	#'M'
-	bne	key_left
+	bne	key_L
 
 	lda	convert_177
 	eor	#$1
@@ -218,6 +231,34 @@ at_1MHz:
 
 	jmp	done_key
 
+
+	;===========================
+	; L enables loop mode
+
+key_L:
+	cmp	#'L'
+	bne	key_left
+
+	lda	LOOP
+	eor	#$1
+	sta	LOOP
+	beq	music_looping
+
+	; update text on screen
+
+	lda	#'L'+$80
+	sta	$7D0+18
+	sta	$BD0+18
+	jmp	done_key
+
+music_looping:
+	lda	#'/'+$80
+	sta	$7D0+18
+	sta	$BD0+18
+
+	jmp	done_key
+
+
 	;======================
 	; left key, to next song
 
@@ -250,6 +291,9 @@ quiet_exit:
 	sta	DONE_PLAYING
 	jsr	clear_ay_both
 
+	lda	#$ff		; also mute the channel
+	sta	REGISTER_DUMP+7 ; just in case
+
 exit_interrupt:
 
 ;	pla			; restore a				; 4

pt3_player/pt3_lib.s

@@ -192,7 +192,7 @@ note_c:
 pt3_version:		.byte	$0
 pt3_frequency_table:	.byte	$0
 pt3_speed:		.byte	$0
-pt3_num_patterns:	.byte	$0
+;pt3_num_patterns:	.byte	$0
 pt3_loop:		.byte	$0
 
 pt3_noise_period:	.byte	$0
@@ -227,6 +227,7 @@ convert_177:		.byte	$1
 PT3_VERSION		= $D
 PT3_HEADER_FREQUENCY	= $63
 PT3_SPEED		= $64
+PT3_LOOP		= $66
 PT3_PATTERN_LOC_L	= $67
 PT3_PATTERN_LOC_H	= $68
 PT3_SAMPLE_LOC_L	= $69
@@ -444,6 +445,12 @@ not_ascii_number:
 	lda	PT3_LOC+PT3_SPEED
 	sta	pt3_speed
 
+	;=======================
+	; load default speed
+
+	lda	PT3_LOC+PT3_LOOP
+	sta	pt3_loop
+
 	rts
 
 

pt3_player/pt3_player.s

@@ -54,6 +54,7 @@ apple_iie:
 	sta	DRAW_PAGE
 	sta	DONE_PLAYING
 	sta	WHICH_FILE
+	sta	LOOP
 
 	;=======================
 	; Detect mockingboard

pt3_player/zp.inc

@@ -110,7 +110,7 @@ WHICH_FILE	EQU $98
 COLOR_MASK	EQU $99
 RASTERBARS_ON	EQU $9A
 RANDOM_POINTER	EQU $9B
-;FRAME_COUNT	EQU $9C
+LOOP		EQU $9C
 MB_VALUE	EQU $9D
 ;MB_CHUNK	EQU $9E
 MB_ADDRL	EQU $9F