Incorporate the rest of the audio engine.

2 files changed, 117 insertions, 13 deletions

diff --git a/macros/code.asm b/macros/code.asm
new file mode 100644
index 00000000..9429884c
--- /dev/null
+++ b/macros/code.asm
@@ -0,0 +1,106 @@
+; Syntactic sugar macros
+
+lb: MACRO ; r, hi, lo
+	ld \1, ((\2) & $ff) << 8 | ((\3) & $ff)
+ENDM
+
+ln: MACRO ; r, hi, lo
+	ld \1, ((\2) & $f) << 4 | ((\3) & $f)
+ENDM
+
+ldpixel: MACRO
+if _NARG >= 5
+	lb \1, \2 * 8 + \4, \3 * 8 + \5
+else
+	lb \1, \2 * 8, \3 * 8
+endc
+ENDM
+
+depixel EQUS "ldpixel de,"
+bcpixel EQUS "ldpixel bc,"
+
+; Design patterns
+
+jumptable: MACRO
+	ld a, [\2]
+	ld e, a
+	ld d, 0
+	ld hl, \1
+	add hl, de
+	add hl, de
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	jp hl
+ENDM
+
+maskbits: MACRO
+; masks just enough bits to cover the first argument
+; the second argument is an optional shift amount
+; e.g. "maskbits 26" becomes "and %00011111" (since 26 - 1 = %00011001)
+; and "maskbits 3, 2" becomes "and %00001100" (since "maskbits 3" becomes %00000011)
+; example usage in rejection sampling:
+; .loop
+; 	call Random
+; 	maskbits 26
+; 	cp 26
+; 	jr nc, .loop
+x = 1
+rept 8
+if x + 1 < (\1)
+x = x << 1 | 1
+endc
+endr
+if _NARG == 2
+	and x << (\2)
+else
+	and x
+endc
+ENDM
+
+calc_sine_wave: MACRO
+; input: a = a signed 6-bit value
+; output: a = d * sin(a * pi/32)
+	and %111111
+	cp  %100000
+	jr nc, .negative\@
+	call .apply\@
+	ld a, h
+	ret
+.negative\@
+	and %011111
+	call .apply\@
+	ld a, h
+	xor $ff
+	inc a
+	ret
+.apply\@
+	ld e, a
+	ld a, d
+	ld d, 0
+if _NARG == 1
+	ld hl, \1
+else
+	ld hl, .sinetable\@
+endc
+	add hl, de
+	add hl, de
+	ld e, [hl]
+	inc hl
+	ld d, [hl]
+	ld hl, 0
+.multiply\@ ; factor amplitude
+	srl a
+	jr nc, .even\@
+	add hl, de
+.even\@
+	sla e
+	rl d
+	and a
+	jr nz, .multiply\@
+	ret
+if _NARG == 0
+.sinetable\@
+	sine_table 32
+endc
+ENDM
diff --git a/macros/wram.asm b/macros/wram.asm
index d7ba1834..1df2ee28 100755
--- a/macros/wram.asm
+++ b/macros/wram.asm
@@ -119,7 +119,7 @@ channel_struct: MACRO
 ; Addreses are Channel1 (c101).
 \1MusicID::           dw
 \1MusicBank::         db
-\1Flags::             db ; 0:on/off 1:subroutine 3:sfx 4:noise 5:rest
+\1Flags1::            db ; 0:on/off 1:subroutine 3:sfx 4:noise 5:rest
 \1Flags2::            db ; 0:vibrato on/off 2:duty 4:cry pitch
 \1Flags3::            db ; 0:vibrato up/down
 \1MusicAddress::      dw
@@ -129,14 +129,12 @@ channel_struct: MACRO
 \1Condition::         db ; conditional jumps
 \1DutyCycle::         db ; bits 6-7 (0:12.5% 1:25% 2:50% 3:75%)
 \1Intensity::         db ; hi:pressure lo:velocity
-\1Frequency:: ; 11 bits
-\1FrequencyLo::       db
-\1FrequencyHi::       db
+\1Frequency::         dw ; 11 bits
 \1Pitch::             db ; 0:rest 1-c:note
 \1Octave::            db ; 7-0 (0 is highest)
-\1StartingOctave::    db ; raises existing octaves (to repeat phrases)
+\1PitchOffset::       db ; raises existing octaves (to repeat phrases)
 \1NoteDuration::      db ; frames remaining for the current note
-\1Field0x16::         ds 1 ; c117
+\1Field16::           ds 1 ; c117
                       ds 1 ; c118
 \1LoopCount::         db
 \1Tempo::             dw
@@ -149,16 +147,16 @@ channel_struct: MACRO
 \1PitchWheelTarget::  dw ; frequency endpoint for pitch wheel
 \1PitchWheelAmount::  db ; c124
 \1PitchWheelAmountFraction::   db ; c125
-\1Field0x25::         ds 1 ; c126
+\1Field25::           ds 1 ; c126
                       ds 1 ; c127
 \1CryPitch::          dw
-\1Field0x29::         ds 1
-\1Field0x2a::         ds 2
-\1Field0x2c::         ds 1
+\1Field29::           ds 1
+\1Field2a::           ds 2
+\1Field2c::           ds 1
 \1NoteLength::        db ; frames per 16th note
-\1Field0x2e::         ds 1 ; c12f
-\1Field0x2f::         ds 1 ; c130
-\1Field0x30::         ds 1 ; c131
+\1Field2e::           ds 1 ; c12f
+\1Field2f::           ds 1 ; c130
+\1Field30::           ds 1 ; c131
                       ds 1 ; c132
 ENDM