thorn/kep-hack
1
0
Fork 0
mirror of https://github.com/thornAvery/kep-hack.git synced 2026-02-06 15:45:24 +13:00
Code Issues Projects Releases Packages Wiki Activity Actions

Remove c1x*/c2x* comments, use struct offset constants

Browse source
This commit is contained in:
Rangi 2020-07-07 11:57:03 -04:00
parent 13129459f1
commit 1e593d8f8c
12 changed files with 304 additions and 247 deletions
Download patch file Download diff file Expand all files Collapse all files

72
engine/overworld/sprite_collisions.asm
View file

@ -1,15 +1,15 @@
_UpdateSprites::
ld h, $c1
inc h
ld a, wSpritePlayerStateData2ImageBaseOffset - wSpritePlayerStateData2
ld a, SPRITESTATEDATA2_IMAGEBASEOFFSET
.spriteLoop
ld l, a
sub wSpritePlayerStateData2ImageBaseOffset - wSpritePlayerStateData2
sub SPRITESTATEDATA2_IMAGEBASEOFFSET
ld c, a
ldh [hCurrentSpriteOffset], a
ld a, [hl]
and a
jr z, .skipSprite ; tests $c2Xe
jr z, .skipSprite ; tests SPRITESTATEDATA2_IMAGEBASEOFFSET
push hl
push de
push bc
@ -20,7 +20,7 @@ _UpdateSprites::
.skipSprite
ld a, l
add $10 ; move to next sprite
cp wSpritePlayerStateData2ImageBaseOffset - wSpritePlayerStateData2 ; test for overflow (back at beginning)
cp SPRITESTATEDATA2_IMAGEBASEOFFSET ; test for overflow (back at beginning)
jr nz, .spriteLoop
ret
.updateCurrentSprite
@ -43,11 +43,12 @@ UpdateNonPlayerSprite:
; This detects if the current sprite (whose offset is at hCurrentSpriteOffset)
; is going to collide with another sprite by looping over the other sprites.
; The current sprite's offset will be labelled with i (e.g. $c1i0).
; The loop sprite's offset will labelled with j (e.g. $c1j0).
; The current sprite's offset will be labelled with i (e.g. i#SPRITESTATEDATA1_PICTUREID).
; The loop sprite's offset will labelled with j (e.g. j#SPRITESTATEDATA1_PICTUREID).
;
; Note that the Y coordinate of the sprite (in [$c1k4]) is one of the following
; 9 values when the sprite is aligned with the grid: $fc, $0c, $1c, $2c, ..., $7c.
; Note that the Y coordinate of the sprite (in [k#SPRITESTATEDATA1_YPIXELS])
; is one of the following 9 values when the sprite is aligned with the grid:
; $fc, $0c, $1c, $2c, ..., $7c.
; The reason that 4 is added below to the coordinate is to make it align with a
; multiple of $10 to make comparisons easier.
DetectCollisionBetweenSprites:
@ -58,7 +59,7 @@ DetectCollisionBetweenSprites:
add LOW(wSpriteStateData1)
ld l, a
ld a, [hl] ; a = [$c1i0] (picture) (0 if slot is unused)
ld a, [hl] ; a = [i#SPRITESTATEDATA1_PICTUREID] (0 if slot is unused)
and a ; is this sprite slot slot used?
ret z ; return if not used
@ -66,10 +67,10 @@ DetectCollisionBetweenSprites:
add 3
ld l, a
ld a, [hli] ; a = [$c1i3] (delta Y) (-1, 0, or 1)
ld a, [hli] ; a = [i#SPRITESTATEDATA1_YSTEPVECTOR] (-1, 0, or 1)
call SetSpriteCollisionValues
ld a, [hli] ; a = [$C1i4] (Y screen coordinate)
ld a, [hli] ; a = [i#SPRITESTATEDATA1_YPIXELS]
add 4 ; align with multiple of $10
; The effect of the following 3 lines is to
@ -81,9 +82,9 @@ DetectCollisionBetweenSprites:
ldh [hFF90], a ; store Y coordinate adjusted for direction of movement
ld a, [hli] ; a = [$c1i5] (delta X) (-1, 0, or 1)
ld a, [hli] ; a = [i#SPRITESTATEDATA1_XSTEPVECTOR] (-1, 0, or 1)
call SetSpriteCollisionValues
ld a, [hl] ; a = [$C1i6] (X screen coordinate)
ld a, [hl] ; a = [i#SPRITESTATEDATA1_XPIXELS]
; The effect of the following 3 lines is to
; add 7 to a if moving east or
@ -99,13 +100,13 @@ DetectCollisionBetweenSprites:
ld l, a
xor a
ld [hld], a ; zero [$c1id] XXX what's [$c1id] for?
ld [hld], a ; zero [$c1ic] (directions in which collisions occurred)
ld [hld], a ; zero [i#SPRITESTATEDATA1_0D] XXX what's this for?
ld [hld], a ; zero [i#SPRITESTATEDATA1_COLLISIONDATA]
ldh a, [hFF91]
ld [hld], a ; [$c1ib] = adjusted X coordinate
ld [hld], a ; [i#SPRITESTATEDATA1_XADJUSTED]
ldh a, [hFF90]
ld [hl], a ; [$c1ia] = adjusted Y coordinate
ld [hl], a ; [i#SPRITESTATEDATA1_YADJUSTED]
xor a ; zero the loop counter
@ -118,13 +119,13 @@ DetectCollisionBetweenSprites:
jp z, .next ; go to the next sprite if they match
ld d, h
ld a, [de] ; a = [$c1j0] (picture) (0 if slot is unused)
ld a, [de] ; a = [j#SPRITESTATEDATA1_PICTUREID] (0 if slot is unused)
and a ; is this sprite slot slot used?
jp z, .next ; go the next sprite if not used
inc e
inc e
ld a, [de] ; a = [$c1j2] ($ff means the sprite is offscreen)
ld a, [de] ; a = [j#SPRITESTATEDATA1_IMAGEINDEX] ($ff means the sprite is offscreen)
inc a
jp z, .next ; go the next sprite if offscreen
@ -133,11 +134,11 @@ DetectCollisionBetweenSprites:
ld l, a
inc e
ld a, [de] ; a = [$c1j3] (delta Y)
ld a, [de] ; a = [j#SPRITESTATEDATA1_YSTEPVECTOR]
call SetSpriteCollisionValues
inc e
ld a, [de] ; a = [$C1j4] (Y screen coordinate)
ld a, [de] ; a = [j#SPRITESTATEDATA1_YPIXELS]
add 4 ; align with multiple of $10
; The effect of the following 3 lines is to
@ -147,7 +148,7 @@ DetectCollisionBetweenSprites:
and $f0
or c
sub [hl] ; subtract the adjusted Y coordinate of sprite i ([$c1ia]) from that of sprite j
sub [hl] ; subtract [i#SPRITESTATEDATA1_YADJUSTED] from [j#SPRITESTATEDATA1_YADJUSTED]
; calculate the absolute value of the difference to get the distance
jr nc, .noCarry1
@ -157,8 +158,8 @@ DetectCollisionBetweenSprites:
ldh [hFF90], a ; store the distance between the two sprites' adjusted Y values
; Use the carry flag set by the above subtraction to determine which sprite's
; Y coordinate is larger. This information is used later to set [$c1ic],
; which stores which direction the collision occurred in.
; Y coordinate is larger. This information is used later to set
; [i#SPRITESTATEDATA1_COLLISIONDATA].
; The following 5 lines set the lowest 2 bits of c, which are later shifted left by 2.
; If sprite i's Y is larger, set lowest 2 bits of c to 10.
; If sprite j's Y is larger or both are equal, set lowest 2 bits of c to 01.
@ -170,7 +171,7 @@ DetectCollisionBetweenSprites:
; If sprite i's delta Y is 0, then b = 7, else b = 9.
ld b, 7
ld a, [hl] ; a = [$c1ia] (adjusted Y coordinate)
ld a, [hl] ; a = [i#SPRITESTATEDATA1_YADJUSTED]
and $f
jr z, .next1
ld b, 9
@ -186,7 +187,7 @@ DetectCollisionBetweenSprites:
; If sprite j's delta Y is 0, then b = 7, else b = 9.
ld b, 7
dec e
ld a, [de] ; a = [$c1j3] (delta Y)
ld a, [de] ; a = [j#SPRITESTATEDATA1_YSTEPVECTOR]
inc e
and a
jr z, .next2
@ -201,13 +202,13 @@ DetectCollisionBetweenSprites:
.checkXDistance
inc e
inc l
ld a, [de] ; a = [$c1j5] (delta X)
ld a, [de] ; a = [j#SPRITESTATEDATA1_XSTEPVECTOR]
push bc
call SetSpriteCollisionValues
inc e
ld a, [de] ; a = [$c1j6] (X screen coordinate)
ld a, [de] ; a = [j#SPRITESTATEDATA1_XPIXELS]
; The effect of the following 3 lines is to
; add 7 to a if moving east or
@ -218,7 +219,7 @@ DetectCollisionBetweenSprites:
pop bc
sub [hl] ; subtract the adjusted X coordinate of sprite i ([$c1ib]) from that of sprite j
sub [hl] ; subtract [i#SPRITESTATEDATA1_XADJUSTED] from [j#SPRITESTATEDATA1_XADJUSTED]
; calculate the absolute value of the difference to get the distance
jr nc, .noCarry2
@ -228,8 +229,8 @@ DetectCollisionBetweenSprites:
ldh [hFF91], a ; store the distance between the two sprites' adjusted X values
; Use the carry flag set by the above subtraction to determine which sprite's
; X coordinate is larger. This information is used later to set [$c1ic],
; which stores which direction the collision occurred in.
; X coordinate is larger. This information is used later to set
; [i#SPRITESTATEDATA1_COLLISIONDATA].
; The following 5 lines set the lowest 2 bits of c.
; If sprite i's X is larger, set lowest 2 bits of c to 10.
; If sprite j's X is larger or both are equal, set lowest 2 bits of c to 01.
@ -241,7 +242,7 @@ DetectCollisionBetweenSprites:
; If sprite i's delta X is 0, then b = 7, else b = 9.
ld b, 7
ld a, [hl] ; a = [$c1ib] (adjusted X coordinate)
ld a, [hl] ; a = [i#SPRITESTATEDATA1_XADJUSTED]
and $f
jr z, .next3
ld b, 9
@ -257,7 +258,7 @@ DetectCollisionBetweenSprites:
; If sprite j's delta X is 0, then b = 7, else b = 9.
ld b, 7
dec e
ld a, [de] ; a = [$c1j5] (delta X)
ld a, [de] ; a = [j#SPRITESTATEDATA1_XSTEPVECTOR]
inc e
and a
jr z, .next4
@ -287,11 +288,12 @@ DetectCollisionBetweenSprites:
.next6
ld a, c ; c has 2 bits set (one of bits 0-1 is set for the X axis and one of bits 2-3 for the Y axis)
and b ; we select either the bit in bits 0-1 or bits 2-3 based on the calculation immediately above
or [hl] ; or with existing collision direction bits in [$c1ic]
or [hl] ; or with existing collision direction bits in [i#SPRITESTATEDATA1_COLLISIONDATA]
ld [hl], a ; store new value
ld a, c ; useless code because a is overwritten before being used again
; set bit in [$c1ie] or [$c1if] to indicate which sprite the collision occurred with
; set bit in [i#SPRITESTATEDATA1_0E] or [i#SPRITESTATEDATA1_0F]
; to indicate which sprite the collision occurred with
inc l
inc l
ldh a, [hFF8F] ; a = loop counter