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Name functions and add comments in graphics.asm #10

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8cbd11f
Update graphics.asm Labels and Comments
ghostlink2027 Feb 13, 2026
cfdd9b2
Update spellanimations.asm
ghostlink2027 Feb 13, 2026
24756a1
Update sf1-01-0x000000-0x008000.asm
ghostlink2027 Feb 13, 2026
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167 changes: 98 additions & 69 deletions disasm/code/common/tech/graphics/graphics.asm
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Original file line number Diff line number Diff line change
Expand Up @@ -27,20 +27,31 @@ InitSprites:


; =============== S U B R O U T I N E =======================================

sub_157C:
movem.l d1,-(sp)
andi.w #$FF,d7
add.w d7,d7
move.w word_1594(pc,d7.w),d7
muls.w d6,d7
asr.w #7,d7
; Calculates the length of a line scaled by the sine of an angle
;
; In:
; D6 = Length of a line
; D7 = Angle in 1/256th of a rotation
;
; Out:
; D7 = Length * sin(theta)

lengthTimesSine:
movem.l d1,-(sp) ; Push unused register to sp
andi.w #$FF,d7 ; Clear byte above theta
add.w d7,d7 ; Double theta for lookup offset
move.w table_sineLookup(pc,d7.w),d7 ; Lookup sine value
muls.w d6,d7 ; Multiply length by sine (7 bits fixed-point)
asr.w #7,d7 ; Shift out fractional values (round down)
movem.l (sp)+,d1
rts

; End of function sub_157C
; End of function lengthTimesSine

; Sine lookup table

word_1594: dc.w 0
table_sineLookup:
dc.w 0
dc.w 3
dc.w 6
dc.w 9
Expand Down Expand Up @@ -298,78 +309,96 @@ word_1594: dc.w 0
dc.w $FFFD

; =============== S U B R O U T I N E =======================================

sub_1794:
; Calculates a square root using the Babylonian method
;
; In:
; D6 = Number to square root
;
; Out:
; D7 = Approximate square root

squareRoot:
movem.l d0-d2,-(sp)
ext.l d6
move.w d6,d0
moveq #$13,d2
lsr.w #1,d0
move.w d0,d7
loc_17A2:
move.w d7,d1
mulu.w d1,d1
lsr.w #1,d0
cmp.l d1,d6
beq.w loc_17BA
blt.s loc_17B4
add.w d0,d7
bra.s loc_17B6
loc_17B4:
sub.w d0,d7
loc_17B6:
dbf d2,loc_17A2
loc_17BA:
ext.l d6 ; Sign extend D6.w to long
move.w d6,d0 ; Copy input number to D0
moveq #$13,d2 ; Set D2 = max iterations - 1 (20 max)
lsr.w #1,d0 ; D0 / 2
move.w d0,d7 ; D7 (current guess) = input / 2
@Loop:
move.w d7,d1 ; D1 = current guess
mulu.w d1,d1 ; Square D1
lsr.w #1,d0 ; D0 / 2
cmp.l d1,d6 ; Is D1^2 = D6
beq.w @Return ; Yes -> Done
blt.s @TooBig ; Guess is too big -> TooBig
add.w d0,d7 ; Add D0 to D7
bra.s @ContLoop ; Finish this iteration
@TooBig:
sub.w d0,d7 ; Subtract D0 from D7
@ContLoop:
dbf d2,@Loop ; Decrement D2 and loop again if D2 > -1
@Return:
movem.l (sp)+,d0-d2
rts

; End of function sub_1794
; End of function squareRoot


; =============== S U B R O U T I N E =======================================

sub_17C0:
; Calculates an angle from the given coordinate
;
; In:
; D6 = x value of the point (a)
; D7 = y value of the point (b)
;
; Out:
; D7 = Rotational angle of the given point

calculateAngleFromXAndY:
movem.l d0-d2,-(sp)
move.w d6,d0
move.w d7,d1
muls.w d6,d6
muls.w d7,d7
add.w d7,d6
bsr.s sub_1794
move.w d7,d6
move.w d1,d7
bge.s loc_17D8
neg.w d7
loc_17D8:
lsl.w #6,d7
divs.w d6,d7
move.b byte_1814(pc,d7.w),d7
andi.w #$FF,d7
movem.l d0,-(sp)
muls.w d1,d0
movem.l (sp)+,d0
blt.s loc_1800
move.w d6,d0 ; Store D6 in D0
move.w d7,d1 ; Store D7 in D1
muls.w d6,d6 ; Square D6 (a^2)
muls.w d7,d7 ; Square D7 (b^2)
add.w d7,d6 ; Add D7 to D6 (a^2 + b^2)
bsr.s squareRoot ; D7 = hypotenuse (c)
move.w d7,d6 ; D6 = D7
move.w d1,d7 ; Restore D7
bge.s @SkipNegate ; If b >= 0, skip next instruction
neg.w d7 ; D7 = |b|
@SkipNegate:
lsl.w #6,d7 ; Shift in 6 bits for fixed-point math
divs.w d6,d7 ; Divide D7 by D6
move.b table_arcsineLookup(pc,d7.w),d7 ; D7 = asin(b / a)
andi.w #$FF,d7 ; Mask D7 to bottom 8 bits
movem.l d0,-(sp) ; Push D0 (a) to sp
muls.w d1,d0 ; Multiply D0 by D1 (a * b)
movem.l (sp)+,d0 ; Pull D0 from stack (a)
blt.s @OneNeg ; If (a * b) < 0 -> OneNegative
tst.w d1
bge.s loc_17FA
addi.w #$40,d7
bra.s loc_17FE
loc_17FA:
addi.w #$C0,d7
loc_17FE:
bra.s loc_180E
loc_1800:
subi.w #$40,d7
neg.w d7
bge.s @NotNeg ; If D1 not negative -> NotNeg
addi.w #$40,d7 ; Add a quarter rotation to D7
bra.s @Done ; Done -> End
@NotNeg:
addi.w #$C0,d7 ; Add 3/4 rotation to D7
@Done:
bra.s @Return ; End
@OneNeg:
subi.w #$40,d7 ; Subtract a quarter rotation from D7
neg.w d7 ; Negate D7
tst.w d1
bge.s loc_180E
addi.w #$80,d7
loc_180E:
bge.s @Return ; If D1 not negative -> End
addi.w #$80,d7 ; Add a half rotation to D7
@Return:
movem.l (sp)+,d0-d2
rts

; End of function sub_17C0
; End of function calculateAngleFromXAndY

byte_1814: dc.b 0
; Arcsine lookup table

table_arcsineLookup: ; In 1/256th of a rotation
dc.b 0
dc.b 1
dc.b 1
dc.b 2
Expand Down Expand Up @@ -433,7 +462,7 @@ byte_1814: dc.b 0
dc.b $35
dc.b $37
dc.b $3B
dc.b $40
dc.b $40 ; 1/4 of a rotation (90 degrees)
dc.b 0

; =============== S U B R O U T I N E =======================================
Expand Down
28 changes: 14 additions & 14 deletions disasm/code/gameflow/battle/spellanimations.asm
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2861,7 +2861,7 @@ loc_127CB8:
clr.w d2
move.w (a0),d6
move.w SPELLENTITY_OFFSET_Y(a0),d7
jsr (sub_314).l
jsr (j_lengthTimesSine).l
addi.w #$48,d7
move.w d7,d3
move.w (a0),d7
Expand All @@ -2870,7 +2870,7 @@ loc_127CB8:
move.w SPELLENTITY_OFFSET_Y(a0),d7
lsr.w #2,d6
subi.w #$40,d7
jsr (sub_314).l
jsr (j_lengthTimesSine).l
addi.w #$80,d7
move.w d7,d4
move.w (a0),d7
Expand Down Expand Up @@ -3066,13 +3066,13 @@ loc_127E82:
lsr.w #2,d3
move.w d7,-(sp)
lsr.w #1,d6
jsr (sub_314).l
jsr (j_lengthTimesSine).l
addi.w #$80,d7
sub.w d3,d7
move.w d7,d3
move.w (sp)+,d7
subi.w #$40,d7
jsr (sub_314).l
jsr (j_lengthTimesSine).l
addi.w #$70,d7
move.w d7,d4
subi.w #$C,SPELLENTITY_OFFSET_Y(a0)
Expand Down Expand Up @@ -3197,14 +3197,14 @@ loc_127FD4:
add.w d4,d3
lsr.w #2,d3
move.w d7,-(sp)
jsr (sub_314).l
jsr (j_lengthTimesSine).l
addi.w #$80,d7
sub.w d3,d7
move.w d7,d3
move.w (sp)+,d7
lsr.w #1,d6
subi.w #$40,d7
jsr (sub_314).l
jsr (j_lengthTimesSine).l
addi.w #$70,d7
move.w d7,d4
subq.w #8,SPELLENTITY_OFFSET_Y(a0)
Expand Down Expand Up @@ -3359,13 +3359,13 @@ spellanimationUpdate_Desoul:
move.w #$80,d3
move.w (a0),d6
move.w SPELLENTITY_OFFSET_Y(a0),d7
jsr (sub_314).l
jsr (j_lengthTimesSine).l
add.w d7,d3
move.w #$60,d4
lsr.w #2,d6
move.w SPELLENTITY_OFFSET_Y(a0),d7
subi.w #$40,d7
jsr (sub_314).l
jsr (j_lengthTimesSine).l
add.w d7,d4
move.w SPELLENTITY_OFFSET_Y(a0),d7
lsr.w #6,d7
Expand Down Expand Up @@ -3589,14 +3589,14 @@ loc_12840C:
sub_128424:
move.w #120,d6
move.w SPELLENTITY_OFFSET_FRAME(a0),d7
jsr (sub_314).l
jsr (j_lengthTimesSine).l
addi.w #96,d7
move.w d7,d3
move.w d3,(a0)
move.w SPELLENTITY_OFFSET_FRAME(a0),d7
lsr.w #2,d6
subi.w #72,d7
jsr (sub_314).l
jsr (j_lengthTimesSine).l
addi.w #64,d7
move.w d7,d4
move.w d4,SPELLENTITY_OFFSET_Y(a0)
Expand All @@ -3623,14 +3623,14 @@ return_12847A:
sub_12847C:
move.w #60,d6
move.w SPELLENTITY_OFFSET_FRAME(a0),d7
jsr (sub_314).l
jsr (j_lengthTimesSine).l
addi.w #156,d7
move.w d7,d3
move.w d3,(a0)
move.w SPELLENTITY_OFFSET_FRAME(a0),d7
lsr.w #2,d6
subi.w #72,d7
jsr (sub_314).l
jsr (j_lengthTimesSine).l
addi.w #64,d7
move.w d7,d4
move.w d4,SPELLENTITY_OFFSET_Y(a0)
Expand Down Expand Up @@ -3659,14 +3659,14 @@ loc_1284D8:
sub_1284E0:
move.w #120,d6
move.w SPELLENTITY_OFFSET_FRAME(a0),d7
jsr (sub_314).l
jsr (j_lengthTimesSine).l
addi.w #216,d7
move.w d7,d3
move.w d3,(a0)
move.w SPELLENTITY_OFFSET_FRAME(a0),d7
lsr.w #2,d6
subi.w #72,d7
jsr (sub_314).l
jsr (j_lengthTimesSine).l
addi.w #64,d7
move.w d7,d4
move.w d4,SPELLENTITY_OFFSET_Y(a0)
Expand Down
18 changes: 9 additions & 9 deletions disasm/layout/sf1-01-0x000000-0x008000.asm
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -613,26 +613,26 @@ j_InitSprites:

; =============== S U B R O U T I N E =======================================

sub_314:
bra.w sub_157C
j_lengthTimesSine:
bra.w lengthTimesSine

; End of function sub_314
; End of function j_lengthTimesSine


; =============== S U B R O U T I N E =======================================

sub_318:
bra.w sub_1794
j_squareRoot:
bra.w squareRoot

; End of function sub_318
; End of function j_squareRoot


; =============== S U B R O U T I N E =======================================

sub_31C:
bra.w sub_17C0
j_calculateAngleFromXAndY:
bra.w calculateAngleFromXAndY

; End of function sub_31C
; End of function j_calculateAngleFromXAndY


; =============== S U B R O U T I N E =======================================
Expand Down