rewrote main loop, cleaned up stuff, B button to step one frame

Code/automata.asm

@@ -282,20 +282,11 @@ SwapBuffers:
 	; set old and rendered pointers to buffer1
 	ld a, HIGH(Buffer1)
 	ldh [Old], a
-	ldh [Rendered + 1], a
 
 	; set new pointer to buffer0
 	ld a, HIGH(Buffer0)
 	ldh [New], a
 
-	; set video pointer to first tilemap
-	ld a, HIGH(_SCRN1)
-	ldh [Video + 1], a
-
-	; display bg 9800 that has just been filled
-	ld a, LCDCF_ON | LCDCF_BGON | LCDCF_BG9800
-	ld [rLCDC], a
-
 	jr InitAutomata.resetLow
 
 .newToBuffer1
@@ -303,20 +294,11 @@ InitAutomata:
 	; set old and rendered pointers to buffer0
 	ld a, HIGH(Buffer0)
 	ldh [Old], a
-	ldh [Rendered + 1], a
 
 	; set new pointer to buffer1
 	ld a, HIGH(Buffer1)
 	ldh [New], a
 
-	; set video pointer to second tilemap
-	ld a, HIGH(_SCRN0)
-	ldh [Video + 1], a
-
-	; display bg 9C00 that has just been filled
-	ld a, LCDCF_ON | LCDCF_BGON | LCDCF_BG9C00
-	ld [rLCDC], a
-
 .resetLow
 	; reset low bytes of pointers
 	xor a

Code/edit.asm

@@ -24,102 +24,15 @@ InitEdit:
 	ldh [Down], a
 	ld a, REPEAT_START_DELAY
 	ldh [RepeatDelay], a
-	ret
-	
-SECTION "Jingle", ROM0
-Jingle:
-
-	; load initial frequency into HL
-FREQUENCY = 330
-	ld hl, PULSE_FREQUENCY
-
-	; load step to be added to frequency in DE
-	; based on if a != 0 or not
-	or a
-	jr z, .up
-.down
-	ld de, 100
-	jr .do
-.up
-	ld de, -100	
-
-.do
-	; load note count
-	ld b, 3
-.loop
-
-	; play pulse channel 1 with frequency set in HL
-	xor a
-	ldh [rNR10], a ; sweep 
-	ld a, (%01 << 6) + 30
-	ldh [rNR11], a ; pattern + sound length
-	ld a, $43
-	ldh [rNR12], a ; init volume + envelope sweep
-	ld a, l
-	ldh [rNR13], a
-	ld a, h
-	or a, SOUND_START
-	ldh [rNR14], a
-	
-	; add DE to HL frequency
-	add hl, de
-	
-	; wait ~166ms
-	ld c, 6
-.delay
-	HaltAndClearInterrupts
-	dec c
-	jr nz, .delay
-	
-	; repeat a few times
-	dec b
-	ret z
-	jr .loop
-	
-EXPORT EditOldBuffer
-SECTION "Edit old buffer", ROM0
-EditOldBuffer:
-	; check start has been pressed
-	ldh a, [JoypadDown]
-	and a, PADF_START
-	ret z
-	
-	; sound ON
-	ld a, $80
-	ldh [rNR52], a
-	ld a, $77
-	ldh [rNR50], a ; max volume on both speakers
-	ld a, $99
-	ldh [rNR51], a ; channels 1 (pulse) and 4 (noise) on both speakers
-
-	; play jingle with notes going down
-	xor a
-	call Jingle
-
-	; wait v-blank
-	halt
-	
-	; show sprites
-	ldh a, [rLCDC]
-	or a, LCDCF_OBJON
-	ldh [rLCDC], a
-	
-	; init sprite animation
 	xor a
 	ldh [SpriteAnimation], a
 	ld a, SPRITE_ANIM_DELAY
 	ldh [SpriteDelay], a
+	ret	
 	
-	; set video address to displayed
+EXPORT EditOldBuffer
-	ldh a, [Video + 1]
+SECTION "Edit old buffer", ROM0
-	xor a, %100
+EditOldBuffer:
-	ldh [Video + 1], a
-
-	; clear interrupts
-	xor a
-	ldh [rIF], a
-
-.loop
 	; compute cursor X position
 	ldh a, [SelectX]
 	sla a
@@ -152,22 +65,16 @@ EditOldBuffer:
 	; update sprite in OAM
 	SetSprite 0, b, c, d, 0
 
-	call UpdateJoypad
+	; toggle targeted cell if A pressed
-	
-	; check A button has been pressed
 	ldh a, [JoypadDown]
 	and a, PADF_A
 	call nz, ToggleCell
 	
+	; clear if SELECT pressed
 	ldh a, [JoypadDown]
 	and a, PADF_SELECT
 	call nz, Clear
 
-	; check start has been pressed
-	ldh a, [JoypadDown]
-	and a, PADF_START
-	jr nz, .exit
-	
 	; reset input
 	xor a
 	ldh [Down], a
@@ -251,38 +158,6 @@ EditOldBuffer:
 	ldh [SelectY], a
 .endDown
 	
-	; wait v-blank
-.skip
-	HaltAndClearInterrupts
-	
-	jp .loop
-	
-.exit
-	
-	ld a, 1
-	call Jingle
-
-	; hide sprites
-	ldh a, [rLCDC]
-	and a, ~LCDCF_OBJON
-	ldh [rLCDC], a
-		
-	; set video address to next displayed
-	ldh a, [Video + 1]
-	xor a, %100
-	ldh [Video + 1], a
-	
-	; wait for sound to finish
-	ld b, 10
-.waitSound
-	HaltAndClearInterrupts
-	dec b
-	jr nz, .waitSound
-	
-	; sound OFF
-	xor a
-	ldh [rNR52], a
-	
 	ret
 
 SECTION "Value to flag", ROM0, ALIGN[8]
@@ -330,6 +205,7 @@ ToggleCell:
 	ldh a, [Video]
 	ld l, a
 	ldh a, [Video + 1]
+	xor a, %100
 	ld h, a
 	MoveToCell 32
 	
@@ -352,10 +228,10 @@ ToggleCell:
 	
 	; do sound based on new value
 	and a, b
-	jr z, .blurp1
+	jr nz, .pulse
 
 	; do noisy sound
-.blurp0
+.noise
 	xor a
 	ldh [rNR41], a ; sound length
 	ld a, $F1
@@ -364,10 +240,10 @@ ToggleCell:
 	ldh [rNR43], a ; frequency
 	ld a, $80
 	ldh [rNR44], a ; start
-	jr .exit
+	ret
 
 	; do pulsy sound
-.blurp1
+.pulse
 	xor a
 	ldh [rNR10], a ; sweep 
 	ld a, (%01 << 6) + 30
@@ -379,8 +255,6 @@ FREQUENCY = 100
 	ldh [rNR13], a
 	ld a, SOUND_START | HIGH(PULSE_FREQUENCY)
 	ldh [rNR14], a
-
-.exit
 	ret
 
 SECTION "Clear buffers", ROM0
@@ -452,24 +326,4 @@ Clear:
 	or a, LCDCF_OBJON
 	ldh [rLCDC], a
 	
-	; reset video pointer
-	ld hl, Video
-	ld a, [hl+]
-	ld h, [hl]
-	ld l, a
-	ld de, -(32 * 18)
-	add hl, de
-	ld a, l
-	ldh [Video], a
-	ld a, h
-	ldh [Video + 1], a
-	
-	; reset rendered pointer
-	ldh a, [Progress]
-	ld l, a
-	ld [Rendered], a
-	ldh a, [Old]
-	ld h, a
-	ld [Rendered + 1], a
-	
 	ret

Code/main.asm

@@ -1,8 +1,14 @@
 INCLUDE "hardware.inc"
 INCLUDE "utils.inc"
 
-EMPTY_BG_TILE EQU 17
 _VRAM_BG_TILES EQU $9000
+EMPTY_BG_TILE EQU 17
+
+ANIMATE EQU %01
+STEP    EQU %10
+
+SECTION "Main Memory", HRAM
+Control: ds 1
 
 SECTION "Header", ROM0[$100]
 EntryPoint:
@@ -12,11 +18,69 @@ REPT $150 - $104
     db 0
 ENDR
 
+SECTION "Jingle", ROM0
+Jingle:
+
+	; load initial frequency into HL
+FREQUENCY = 330
+	ld hl, PULSE_FREQUENCY
+
+	; load step to be added to frequency in DE
+	; based on if a != 0 or not
+	or a
+	jr z, .up
+.down
+	ld de, 100
+	jr .do
+.up
+	ld de, -100	
+
+.do
+	; load note count
+	ld b, 3
+.loop
+
+	; play pulse channel 1 with frequency set in HL
+	xor a
+	ldh [rNR10], a ; sweep 
+	ld a, (%01 << 6) + 30
+	ldh [rNR11], a ; pattern + sound length
+	ld a, $43
+	ldh [rNR12], a ; init volume + envelope sweep
+	ld a, l
+	ldh [rNR13], a
+	ld a, h
+	or a, SOUND_START
+	ldh [rNR14], a
+	
+	; add DE to HL frequency
+	add hl, de
+	
+	; wait ~166ms
+	ld c, 6
+.delay
+	HaltAndClearInterrupts
+	dec c
+	jr nz, .delay
+	
+	; repeat a few times
+	dec b
+	ret z
+	jr .loop
+
 SECTION "Main", ROM0[$150]
 Start:	
 	; save gameboy type in B
 	ld b, a
 
+	; enable sound
+	ld a, $80
+	ld [rNR52], a ; sound ON
+	ld a, $77
+	ldh [rNR50], a ; max volume on both speakers
+	ld a, $99
+	ldh [rNR51], a ; channels 1 (pulse) and 4 (noise) on both speakers
+	
 	; enable v-blank interrupt
 	ld a, IEF_VBLANK
 	ld [rIE], a
@@ -70,6 +134,10 @@ ENDC
 	ldh [rSCX], a
 	ldh [rSCY], a
 	
+	; animate by default
+	ld a, ANIMATE
+	ldh [Control], a
+	
 	; clear screen (both buffers)
 	ld hl, _SCRN0
 	ld d, EMPTY_BG_TILE
@@ -84,6 +152,7 @@ ENDC
 	
 	call InitJoypad
 	call InitAutomata
+	call InitRender
 	call InitEdit
 	
 	; enable h-blank interrupt in lcd stat
@@ -95,11 +164,68 @@ ENDC
 	ldh [rLCDC], a
 	
 	ClearAndEnableInterrupts
+
 .mainloop
+	; animate if a control bit is set
+	ldh a, [Control]
+	or a
+	jr z, .interact
+
 	call StartRender
 	call UpdateAutomata
 	call WaitRender
 	call SwapBuffers
-	call UpdateJoypad
+
+	; clear step bit
+	ldh a, [Control]
+	and a, ~STEP
+	ldh [Control], a
+
+	jr .checkpause
+
+.interact
+	HaltAndClearInterrupts
+
 	call EditOldBuffer
-	jp .mainloop
+
+	; step if B is pressed
+	ldh a, [JoypadDown]
+	and a, PADF_B
+	jr z, .checkpause
+
+	; enable step bit in control
+	ld a, STEP
+	ldh [Control], a
+	
+	; do sound
+	ld a, $6E
+	ldh [rNR10], a ; sweep 
+	ld a, (%01 << 6) + 30
+	ldh [rNR11], a ; pattern + sound length
+	ld a, $62
+	ldh [rNR12], a ; init volume + envelope sweep
+FREQUENCY = 220
+	ld a, LOW(PULSE_FREQUENCY)
+	ldh [rNR13], a
+	ld a, SOUND_START | HIGH(PULSE_FREQUENCY)
+	ldh [rNR14], a
+	
+.checkpause
+	call UpdateJoypad
+
+	ldh a, [JoypadDown]
+	and a, PADF_START
+	jr z, .mainloop
+	
+	ldh a, [Control]
+	xor a, ANIMATE
+	ldh [Control], a
+	and a, ANIMATE
+	call Jingle
+	
+	; toggle sprites
+	ldh a, [rLCDC]
+	xor a, LCDCF_OBJON
+	ldh [rLCDC], a
+
+	jr .mainloop

Code/nintendo-out.asm

@@ -18,14 +18,6 @@ ScrollNintendoOut:
 	dec b
 	jr nz, .wait
 	
-	; sound ON
-	ld a, $80
-	ldh [rNR52], a
-	ld a, $77
-	ldh [rNR50], a ; max volume on both speakers
-	ld a, $88
-	ldh [rNR51], a ; noise channel on both speakers
-
 	; make noise
 	xor a
 	ldh [rNR41], a ; set sound duration
@@ -93,8 +85,4 @@ ScrollNintendoOut:
 	cp a, 88
 	jp nz, .scrollup
 	
-	; sound off
-	xor a
-	ldh [rNR52], a
-	
 	ret

Code/render.asm

@@ -115,9 +115,26 @@ LCDStatInterruptHandler:
 	; return from v-blank or lcd interrupt
 	reti
 
+EXPORT InitRender
+SECTION "Init render", ROM0
+InitRender:
+	ld a, $9C
+	ldh [Video + 1], a
+	xor a
+	ldh [Video], a
+	ret
+
 EXPORT StartRender	
 SECTION "StartRender", ROM0
 StartRender:	
+	; set rendered pointer to old buffer
+	ldh a, [Progress]
+	ld l, a
+	ld [Rendered], a
+	ldh a, [Old]
+	ld h, a
+	ld [Rendered + 1], a
+
 	; start rendering
 	ld a, 20
 	ldh [TilesLeft], a
@@ -152,4 +169,19 @@ IF RENDER_IN_HBL != 0
 	HaltAndClearInterrupts
 ENDC
 
+	; swap video pointer
+	ldh a, [Video + 1]
+	dec a
+	dec a
+	xor a, %100
+	ldh [Video + 1], a
+	xor a
+	ldh [Video], a
+
+	; swap displayed BG
+	ldh a, [rLCDC]
+	xor a, LCDCF_BG9C00
+	or a, LCDCF_ON | LCDCF_BGON
+	ldh [rLCDC], a
+
 	ret

todo.txt

@@ -1,4 +1,3 @@
-- skip nintendo intro on gbc/gba
 - step by step on B button (rewrite main loop to remove second main loop in edit)
 - music
 - intro screen