moar comments, moar constants

Code/intro.asm

@@ -44,7 +44,8 @@ Intro:
 	jr z, .setBGPalette
 
 	; fade bg palette
-	ld b, 8
+FADE_DELAY = 8 ; frames
+	ld b, FADE_DELAY
 .fadeDelay0
 	HaltAndClearInterrupts
 	dec b
@@ -53,7 +54,7 @@ Intro:
 	ld a, %11111100
 	ldh [rBGP], a
 
-	ld b, 8
+	ld b, FADE_DELAY
 .fadeDelay1
 	HaltAndClearInterrupts
 	dec b
@@ -62,7 +63,7 @@ Intro:
 	ld a, %11111000
 	ldh [rBGP], a
 
-	ld b, 8
+	ld b, FADE_DELAY
 .fadeDelay2
 	HaltAndClearInterrupts
 	dec b
@@ -127,7 +128,7 @@ Intro:
 	ld a, LCDCF_ON | LCDCF_BGON | LCDCF_BG9800
 	ldh [rLCDC], a
 	
-	; sound
+	; sweep sound while transforming nintendo logo into game of life of it
 	ld a, $77
 	ldh [rNR10], a ; sweep 
 	ld a, (%00 << 6) + 0
@@ -146,22 +147,23 @@ FREQUENCY = 146
 	ld b, 20
 .loopX
 	ld c, 2
+	; 3 frame delay
 	HaltAndClearInterrupts
 	HaltAndClearInterrupts
 	HaltAndClearInterrupts
 .loopY
-	; copy 8 tiles (that's how many there is before L and E overflow)
+	; copy 8 tiles from (that's how many there is before L and E overflow)
 REPT 8
 	ld a, [hl]
 	ld [de], a
 	ld a, l
-	add a, $20
+	add a, SCRN_VX_B
 	ld l, a
 	ld a, e
-	add a, $20
+	add a, SCRN_VX_B
 	ld e, a
 ENDR
-	; L and E overflowed, we can increment H and L
+	; L and E overflowed, we can increment high byte of pointers (h and d)
 	inc h
 	inc d
 	dec c
@@ -171,10 +173,10 @@ REPT 2
 	ld a, [hl]
 	ld [de], a
 	ld a, l
-	add a, $20
+	add a, SCRN_VX_B
 	ld l, a
 	ld a, e
-	add a, $20
+	add a, SCRN_VX_B
 	ld e, a
 ENDR
 	; back to beginning (high byte)
@@ -187,10 +189,10 @@ ENDR
 	
 	; back to beginning + next column (low byte)
 	ld a, l
-	sub a, $3F
+	sub a, SCRN_VX_B * 2 - 1
 	ld l, a
 	ld a, e
-	sub a, $3F
+	sub a, SCRN_VX_B * 2 - 1
 	ld e, a
 	
 	dec b