working animation, but ugly

This commit is contained in:
Thorn Avery 2020-05-24 17:54:13 +12:00
parent f3fd560eae
commit aa5b06312e
12 changed files with 547 additions and 225 deletions

1
.gitignore vendored
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@ -1 +1,2 @@
build
*.swp

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@ -9,8 +9,9 @@ BUILD=./build
ENTRY=${SRC}/main.asm
ROM_OUTPUT=${BUILD}/${NAME}.gb
OBJECT_OUTPUT=${BUILD}/${NAME}.o
SYMFILE_OUTPUT=${BUILD}/${NAME}.sym
all : ${ENTRY}
${ASSEMBLER} -o ${OBJECT_OUTPUT} ${ENTRY} \
&& ${LINKER} -o ${ROM_OUTPUT} -n ${NAME}.sym ${OBJECT_OUTPUT} \
&& ${LINKER} -o ${ROM_OUTPUT} -n ${SYMFILE_OUTPUT} ${OBJECT_OUTPUT} \
&& ${POSTPROC} -v -p 0 ${ROM_OUTPUT}

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@ -1,54 +0,0 @@
; File generated by rgblink
00:0634 parecivo_tile_data
00:0234 Map
00:01F8 CheckBoundry
00:01E5 game_loop
00:0230 CheckBoundry.skipRender
00:021E CheckBoundry.swap
00:022C CheckBoundry.render
00:0150 Start
00:0017 dPlayerHeight
00:0016 dPlayerWidth
00:0018 dPlayerSpriteTiles
00:0008 CopyDMARoutine
00:0004 DMARoutine.wait
00:0000 DMARoutine
00:0008 DMARoutine.end
00:000F CopyDMARoutine.copy
00:0853 Read_Pad
00:084A MemCpy.copy
00:0883 Read_Pad.onenibble
00:086C Read_Pad.legalUpDown
00:0875 Read_Pad.legalLeftRight
00:084A MemCpy
00:0744 Wait_VBlank
00:0816 Clear_Map
00:0824 Load_Tiles
00:07D7 PC_Update
00:0750 Player_To_OAM
00:0747 Wait_VBlank.wait
00:07D1 Player_To_OAM.add4hl
00:0762 Player_To_OAM.finner
00:075E Player_To_OAM.fouter
00:0786 Player_To_OAM.sinner
00:077B Player_To_OAM.souter
00:07A5 Player_To_OAM.tloop1
00:07AA Player_To_OAM.tloop2
00:07C1 Player_To_OAM.lloop1
00:07C6 Player_To_OAM.lloop2
00:07E6 PC_Update.up
00:07F1 PC_Update.left
00:07FC PC_Update.right
00:0807 PC_Update.last
00:081D Clear_Map.loop
00:C005 rPlayerX
00:C006 rPlayerY
00:C004 ANS
00:C002 N
00:C000 X
00:C100 wShadowOAM
00:FF88 hVBlankFlag
00:FF89 hCurKeys
00:FF8A hNewKeys
00:FF80 hOAMDMA

367
inc/structs.asm Normal file
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@ -0,0 +1,367 @@
; MIT License
;
; Copyright (c) 2018-2019 Eldred Habert
; Originally hosted at https://github.com/ISSOtm/rgbds-structs
;
; Permission is hereby granted, free of charge, to any person obtaining a copy
; of this software and associated documentation files (the "Software"), to deal
; in the Software without restriction, including without limitation the rights
; to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
; copies of the Software, and to permit persons to whom the Software is
; furnished to do so, subject to the following conditions:
;
; The above copyright notice and this permission notice shall be included in all
; copies or substantial portions of the Software.
;
; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
; AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
; SOFTWARE.
; !!! WARNING ABOUT READABILITY OF THIS CODE !!!
;
; RGBDS, being the venerable/old/decrepit (pick on depending on mood) assembler that it is, requires
; all label, variable etc. definitions to be on column 0. As in, no whitespace allowed (otherwise, syntax error)
; Meanwhile, these macros tend to use a lot of nesting (requiring indenting for readability),
; as well as variable definitions (requiring none to work).
; As you can probably tell, those two conflict and result in very poor readability
; Sadly, there is nothing I can do against that short of using a special preprocessor,
; which I refuse to do for usability's sake.
; You have all my apologies, how little they may matter, if you are trying to read this code
; I still did my best to use explicit comments and variable names, hope they will help!
; strreplace variable_name, original_char, new_char
strreplace: MACRO
DOT_POS = STRIN("{\1}", \2)
IF DOT_POS != 0
TMP equs STRCAT(STRSUB("{\1}", 1, DOT_POS + (-1)), STRCAT(\3, STRSUB("{\1}", DOT_POS + 1, STRLEN("{\1}") - DOT_POS)))
PURGE \1
\1 equs "{TMP}"
PURGE TMP
strreplace \1, \2, \3
ENDC
IF DEF(DOT_POS)
PURGE DOT_POS
ENDC
ENDM
; rgbds_structs_version version_string
; Call with the expected version string to ensure you're using a compatible version
; Example: rgbds_structs_version 1.0.0
rgbds_structs_version: MACRO
CURRENT_VERSION equs "1,2,1"
EXPECTED_VERSION equs "\1"
strreplace EXPECTED_VERSION, ".", "\,"
check_ver: MACRO
IF \1 != \4 || \2 > \5 || \3 > \6
PURGE EXPECTED_VERSION
ENDC
ENDM
CHECK_VER_CALL equs "check_ver {EXPECTED_VERSION},{CURRENT_VERSION}"
CHECK_VER_CALL
IF !DEF(EXPECTED_VERSION)
strreplace CURRENT_VERSION, "\,", "."
FAIL "RGBDS-structs version \1 is required, which is incompatible with current version {CURRENT_VERSION}"
ENDC
PURGE CHECK_VER_CALL
PURGE check_ver
PURGE CURRENT_VERSION
PURGE EXPECTED_VERSION
ENDM
; struct struct_name
; Begins a struct declaration
struct: MACRO
IF DEF(NB_FIELDS)
FAIL "Please close struct definitions using `end_struct`"
ENDC
STRUCT_NAME equs "\1"
NB_FIELDS = 0
RSRESET
ENDM
; end_struct
; Ends a struct declaration
end_struct: MACRO
; Set nb of fields
STRUCT_NB_FIELDS equs "{STRUCT_NAME}_nb_fields"
STRUCT_NB_FIELDS = NB_FIELDS
PURGE STRUCT_NB_FIELDS
; Set size of struct
STRUCT_SIZEOF equs "sizeof_{STRUCT_NAME}"
STRUCT_SIZEOF RB 0
PURGE STRUCT_SIZEOF
PURGE NB_FIELDS
PURGE STRUCT_NAME
ENDM
; get_nth_field_info field_id
; Defines EQUS strings pertaining to a struct's Nth field
; For internal use, please do not use externally
get_nth_field_info: MACRO
; Field's name
STRUCT_FIELD equs "{STRUCT_NAME}_field{d:\1}"
STRUCT_FIELD_NAME equs "{STRUCT_FIELD}_name"
STRUCT_FIELD_TYPE equs "{STRUCT_FIELD}_type"
STRUCT_FIELD_NBEL equs "{STRUCT_FIELD}_nb_el" ; Number of elements
STRUCT_FIELD_SIZE equs "{STRUCT_FIELD}_size" ; sizeof(type) * nb_el
ENDM
; new_field nb_elems, rs_type, field_name
; For internal use, please do not use externally
new_field: MACRO
IF !DEF(STRUCT_NAME) || !DEF(NB_FIELDS)
FAIL "Please start defining a struct, using `define_struct`"
ENDC
get_nth_field_info NB_FIELDS
; Set field name (keep in mind `STRUCT_FIELD_NAME` is *itself* an EQUS!)
STRUCT_FIELD_NAME equs "\"\3\""
PURGE STRUCT_FIELD_NAME
; Set field offset
STRUCT_FIELD \2 (\1)
; Alias this in a human-comprehensive manner
STRUCT_FIELD_NAME equs "{STRUCT_NAME}_\3"
STRUCT_FIELD_NAME = STRUCT_FIELD
; Compute field size
CURRENT_RS RB 0
STRUCT_FIELD_SIZE = CURRENT_RS - STRUCT_FIELD
; Set properties
STRUCT_FIELD_NBEL = \1
STRUCT_FIELD_TYPE equs STRSUB("\2", 2, 1)
PURGE STRUCT_FIELD
PURGE STRUCT_FIELD_NAME
PURGE STRUCT_FIELD_TYPE
PURGE STRUCT_FIELD_NBEL
PURGE STRUCT_FIELD_SIZE
PURGE CURRENT_RS
NB_FIELDS = NB_FIELDS + 1
ENDM
; bytes nb_bytes, field_name
; Defines a field of N bytes
bytes: MACRO
new_field \1, RB, \2
ENDM
; words nb_words, field_name
; Defines a field of N*2 bytes
words: MACRO
new_field \1, RW, \2
ENDM
; longs nb_longs, field_name
; Defines a field of N*4 bytes
longs: MACRO
new_field \1, RL, \2
ENDM
; dstruct struct_type, INSTANCE_NAME[, ...]
; Allocates space for a struct in memory
; If no further arguments are supplied, the space is simply allocated (using `ds`)
; Otherwise, the data is written to memory using the appropriate types
; For example, a struct defined with `bytes 1, Field1` and `words 3, Field2` would have four extra arguments, one byte then three words.
dstruct: MACRO
NB_FIELDS equs "\1_nb_fields"
IF !DEF(NB_FIELDS)
FAIL "Struct \1 isn't defined!"
ELIF _NARG != 2 && _NARG != NB_FIELDS + 2 ; We must have either a RAM declaration (no data args) or a ROM one (RAM args + data args)
EXPECTED_NARG = 2 + NB_FIELDS
FAIL "Invalid number of arguments, expected 2 or {d:EXPECTED_NARG} but got {d:_NARG}"
ENDC
; Define the two fields required by `get_nth_field_info`
STRUCT_NAME equs "\1" ; Which struct `get_nth_field_info` should pull info about
INSTANCE_NAME equs "\2" ; The instance's base name
; RGBASM always expands `\X` macro args, so `IF _NARG > 2 && STRIN("\3", "=")` will error out when there are only 2 args
; Therefore, the condition is checked here (we can't nest the `IF`s over there because that doesn't translate well to `ELSE`)
IS_NAMED_INVOCATION = 0
IF _NARG > 2
IF STRIN("\3", "=")
IS_NAMED_INVOCATION = 1
ENDC
ENDC
IF IS_NAMED_INVOCATION
; This is a named instantiation, translate that to an ordered one
; This is needed because data has to be laid out in order, so some translation is needed anyways
; And finally, it's better to re-use the existing code at the cost of a single nested macro, I believe
MACRO_CALL equs "dstruct \1, \2" ; This will be used later, but define it now because `SHIFT` will be run
; In practice `SHIFT` has no effect outside of one when invoked inside of a REPT block, but I hope this behavior is changed (causes a problem elsewhere)
ARG_NUM = 3
REPT NB_FIELDS
; Find out which argument the current one is
CUR_ARG equs "\3"
; Remove all whitespace to obtain something like ".name=value" (whitespace are unnecessary and complexify parsing)
strreplace CUR_ARG, " ", ""
strreplace CUR_ARG, "\t", ""
EQUAL_POS = STRIN("{CUR_ARG}", "=")
IF EQUAL_POS == 0
FAIL "Argument #{ARG_NUM} (\3) does not contain an equal sign in this named instantiation"
ELIF STRCMP(STRSUB("{CUR_ARG}", 1, 1), ".")
FAIL "Argument #{ARG_NUM} (\3) does not start with a period"
ENDC
FIELD_ID = -1
CUR_FIELD_ID = 0
REPT NB_FIELDS
; Get the name of the Nth field and compare
TMP equs "{STRUCT_NAME}_field{d:CUR_FIELD_ID}_name"
CUR_FIELD_NAME equs TMP
PURGE TMP
IF !STRCMP(STRUPR("{CUR_FIELD_NAME}"), STRUPR(STRSUB("{CUR_ARG}", 2, EQUAL_POS - 2)))
; Match found!
IF FIELD_ID == -1
FIELD_ID = CUR_FIELD_ID
ELSE
TMP equs "{STRUCT_NAME}_field{d:CUR_FIELD_ID}_name"
CONFLICTING_FIELD_NAME equs TMP
PURGE TMP
FAIL "Fields {CUR_FIELD_NAME} and {CONFLICTING_FIELD_NAME} have conflicting names (case-insensitive), cannot perform named instantiation"
ENDC
ENDC
PURGE CUR_FIELD_NAME
CUR_FIELD_ID = CUR_FIELD_ID + 1
ENDR
PURGE CUR_FIELD_ID
IF FIELD_ID == -1
FAIL "Argument #{d:ARG_NUM} (\3) does not match any field of the struct"
ENDC
INITIALIZER_NAME equs "FIELD_{d:FIELD_ID}_INITIALIZER"
INITIALIZER_NAME equs STRSUB("{CUR_ARG}", EQUAL_POS + 1, STRLEN("{CUR_ARG}") - EQUAL_POS)
PURGE INITIALIZER_NAME
; Go to next arg
ARG_NUM = ARG_NUM + 1
SHIFT
PURGE CUR_ARG
ENDR
; Now that we matched each named initializer to their order, invoke the macro again but without names
FIELD_ID = 0
REPT NB_FIELDS
TMP equs "{MACRO_CALL}"
PURGE MACRO_CALL
INITIALIZER_VALUE equs "{FIELD_{d:FIELD_ID}_INITIALIZER}"
DELETE_INITIALIZER equs "PURGE FIELD_{d:FIELD_ID}_INITIALIZER"
DELETE_INITIALIZER
PURGE DELETE_INITIALIZER
MACRO_CALL equs "{TMP}, {INITIALIZER_VALUE}"
PURGE TMP
PURGE INITIALIZER_VALUE
FIELD_ID = FIELD_ID + 1
ENDR
PURGE FIELD_ID
; Clean up vars for nested invocation, otherwise some `equs` will be expanded
PURGE INSTANCE_NAME
PURGE STRUCT_NAME
PURGE IS_NAMED_INVOCATION
PURGE NB_FIELDS
MACRO_CALL ; Now do call the macro
PURGE MACRO_CALL
ELSE
INSTANCE_NAME:: ; Declare the struct's root
; Define instance's properties from struct's
\2_nb_fields = NB_FIELDS
sizeof_\2 = sizeof_\1
; Start defining fields
FIELD_ID = 0
REPT NB_FIELDS
get_nth_field_info FIELD_ID
FIELD_NAME equs STRCAT("{INSTANCE_NAME}_", STRUCT_FIELD_NAME)
FIELD_NAME::
; We have defined a label, but now we also need the data backing it
; There are basically two options:
IF _NARG == 2 ; RAM definition, no data
ds STRUCT_FIELD_SIZE
ELSE
DATA_TYPE equs STRCAT("D", {{STRUCT_FIELD_TYPE}})
REPT STRUCT_FIELD_NBEL
DATA_TYPE \3
SHIFT
ENDR
PURGE DATA_TYPE
ENDC
; Clean up vars for next iteration
PURGE STRUCT_FIELD
PURGE STRUCT_FIELD_NAME
PURGE STRUCT_FIELD_TYPE
PURGE STRUCT_FIELD_NBEL
PURGE STRUCT_FIELD_SIZE
PURGE FIELD_NAME
FIELD_ID = FIELD_ID + 1
ENDR
; Clean up
PURGE FIELD_ID
; Make sure to keep what's here in sync with cleanup at the end of a named invocation
PURGE INSTANCE_NAME
PURGE STRUCT_NAME
PURGE IS_NAMED_INVOCATION
PURGE NB_FIELDS
ENDC
ENDM
; dstructs nb_structs, struct_type, INSTANCE_NAME
; Allocates space for an array of structs in memory
; Each struct will have the index appended to its name **as hex**
; (for example: `dstructs 32, NPC, wNPC` will define wNPC0, wNPC1, and so on until wNPC1F)
; This is a limitation because RGBASM does not provide an easy way to get the decimal representation of a number
; Does not support data declarations because I think each struct should be defined individually for that purpose
dstructs: MACRO
STRUCT_ID = 0
REPT \1
dstruct \2, \3{X:STRUCT_ID}
STRUCT_ID = STRUCT_ID + 1
ENDR
PURGE STRUCT_ID
ENDM

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@ -2,23 +2,15 @@
; Actor Animation
;-----------------
SECTION "Actor Variables Struct", WRAM, ALIGN[8]
wWorldX: dw
wWorldY: dw
wActorState: db
wActorCounter: db
wActorData: dw
wActorTile: dw
SECTION "Actor", ROM0
Actor::
ActorROM::
.structs:
dw ActorIdle
.tiles:
ActorIdle::
db 60
db 15
dw .framePa
db 15
dw .frameRe

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@ -2,20 +2,33 @@
; Animation Subs
;----------------
SECTION "Animation Variables", HRAM
struct Actor
bytes 1, YPos
bytes 1, XPos
bytes 1, GFXCounter
bytes 1, GFXState
words 1, GFXData
bytes 1, TileData
end_struct
hCameraX: dw
hCameraY: dw
SECTION "Actor STructs", WRAM0
hWorkingX: dw
hWorkingY: dw
hWorkingScreenX: db
hWorkingScreenY: db
hWorkingState: db
hWorkingCounter: db
hWorkingData: dw
hWorkingTile: dw
hWorkingEnd:
dstruct Actor, Player
SECTION "Animation Variables", WRAM0
wCameraX: dw
wCameraY: dw
wWorkingX: dw
wWorkingY: dw
wWorkingScreenX: db
wWorkingScreenY: db
wWorkingState: db
wWorkingCounter: db
wWorkingData: dw
wWorkingTile: db
wWorkingEnd:
SECTION "Animations Subs", ROM0
@ -32,28 +45,119 @@ SECTION "Animations Subs", ROM0
; copied to shadowOAM (wShadowOAM)
RenderActor::
; load world X and Y to temp RAM
; @input: hl <- Player
; @input: de <- ShadowOAM place
ld a, [hli] ; a <- YPos
ld [wWorkingScreenY], a
ld a, [hli] ; a <- XPos
ld [wWorkingScreenX], a
push hl
ld a, [hli] ; a <- GFXCounter
ld [wWorkingCounter], a
ld a, [hli] ; a <- GFXState
ld [wWorkingState], a
ld a, [hli] ; a <- GFXData(Low)
ld [wWorkingData+1], a
ld a, [hli] ; a <- GFXData (High)
ld [wWorkingData], a
ld a, [hl] ; a <- TileData
ld [wWorkingTile], a
; fin loading data
ld a, [wWorkingData]
ld l, a
ld a, [wWorkingData+1]
ld h, a
; add actor struct offset saved in wWorkingState
ld a, [wWorkingState]
rlca ; double state offset because of word length
add a, l
ld l, a
adc a, h
sub l
ld h, a ; hl contains state struct pointer
ld a, [hli]
ld [hWorkingX], a
ld a, [hli]
ld [hWorkingX+1], a
ld a, [hli]
ld [hWorkingY], a
ld a, [hli]
ld [hWorkingY+1], a
; done loading X and Y
; figure out if within 256 of camera
; ---------
; first compare upper byte of XXYY
; if this is more than 1 away, break
ld a, [hCameraX]
ld b, a
ld a, [hWorkingX]
; b = camera byte
; a = actor byte
; work out if actor minus camera is <= 1
ld a, [hl]
ld l, b
ld h, a
ld a, [hli] ; a <- state frame limit
ld b, a
ld a, [wWorkingCounter]
inc a
ld c, a
ld a, b
ld b, c
cp b
ld a, b
jr nc, .continueAnimation
xor a
.continueAnimation
; TODO: make counter 0 indexed so doesnt skip first frame
ld [wWorkingCounter], a
ld b, h
ld c, l
pop hl
ld [hl], a
ld h, b
ld l, c
.loopFrameFind
ld b, a ; b <- current frame count
ld a, [hli] ; a <- next frame block
ld c, a
ld a, b
ld b, c
sub b
; ---------
jr z, .foundFrame
jr c, .foundFrame
inc hl
inc hl
jr .loopFrameFind
.foundFrame
ld a, [hli]
ld b, a
ld a, [hl]
ld h, a
ld l, b ; hl <- pointer to frame data
ld a, [hli]
ld b, a ; b <- sprite counter
.spriteLoop
; load Y position, then offset by -16
ld a, [hli]
ld c, a
ld a, [wWorkingScreenY]
add c
ld c, 16
add c
ld [de], a ; store YPos in shadowOAM
inc de
; load X position, then offset by -8
ld a, [hli]
ld c, a
ld a, [wWorkingScreenX]
add c
ld c, 8
add c
ld [de], a ; store YPos in shadowOAM
inc de
; load tile offset, and add to base tile pointer
ld a, [hli]
ld c, a
ld a, [wWorkingTile]
add c
ld [de], a
inc de
; load attributes and xor them
ld a, [hli]
ld c, a
ld a, 0 ; TO DO: set base attributes
xor c
ld [de], a
inc de
; end of single sprite
dec b
jr nz, .spriteLoop
ret
.skipRendering
BUFFER EQU 160
TRUE EQU $42
FALSE EQU $69

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@ -57,3 +57,4 @@ hOAMDMA:
SECTION "Shadow OAM", WRAM0,ALIGN[8]
wShadowOAM::
ds 4*40
wShadowOAMEnd::

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@ -2,9 +2,7 @@
; Program Start
;----------------
BUFFER EQU 160
TRUE EQU $42
FALSE EQU $69
INCLUDE "src/actor.asm"
SECTION "Program Start", ROM0[$150]
Start:
@ -17,6 +15,7 @@ Start:
xor a
ldh [rLCDC], a
call Clear_Map
call Clear_OAM
call Load_Tiles
; call Load_Map
ld a, %11100100
@ -32,129 +31,26 @@ Start:
call CopyDMARoutine
ld a, 72
ld [rPlayerX], a
ld a, 88
ld [rPlayerY], a
;----
; Testing
;----
ld a, HIGH(ANS)
ld h, a
ld a, LOW(ANS)
ld l, a
; Case One: Camera@E100 vs Actor@E195 (Pass)
ld a, $E1
ld [N], a
ld a, $E1
ld [X], a
ld a, $00
ld [N+1], a
ld a, $95
ld [X+1], a
call CheckBoundry
; Case One: Camera@E095 vs Actor@E120 (Pass)
ld a, $E0
ld [N], a
ld a, $E1
ld [X], a
ld a, $95
ld [N+1], a
ld a, $20
ld [X+1], a
call CheckBoundry
; Case One: Camera@E100 vs Actor@E1FF (Fail)
ld a, $E1
ld [N], a
ld a, $E1
ld [X], a
ld a, $00
ld [N+1], a
ld a, $FF
ld [X+1], a
call CheckBoundry
; Case One: Camera@E1F0 vs Actor@E2DE (Fail)
ld a, $E1
ld [N], a
ld a, $E2
ld [X], a
ld a, $F0
ld [N+1], a
ld a, $DE
ld [X+1], a
call CheckBoundry
ld [Player_YPos], a
ld a, 80
ld [Player_XPos], a
xor a
ld [Player_GFXCounter], a
ld [Player_GFXState], a
ld [Player_TileData], a
ld a, HIGH(ActorROM)
ld [Player_GFXData], a
ld a, LOW(ActorROM)
ld [Player_GFXData + 1], a
game_loop:
call Wait_VBlank
call Read_Pad
call PC_Update
call Player_To_OAM
call Clear_OAM
ld de, wShadowOAM
ld hl, Player
call RenderActor
ld a, HIGH(wShadowOAM)
call hOAMDMA
jr game_loop
CheckBoundry::
;-----
; Check if word X is within BUFFER ahead of N
; BUFFER is always <= 255
; hl contains address to save result to
;-----
;= load high bytes
ld a, [N]
ld b, a
ld a, [X]
sub b
;= if carry is set, N is behind X, so skip
jr c, .skipRender
ld b, a
ld a, 2
cp b
;= if the difference is 2 or greater
;= we are not within BUFFER, so skip
jr c, .skipRender
jr z, .skipRender
dec a
cp b
;= if the high byte differ by 1, we
;= need to check over a a page
jr z, .swap
;= load the low bytes
ld a, [N+1]
ld b, a
ld a, [X+1]
sub b
ld b, a
ld a, BUFFER
cp b
;= if the difference is greater than
;= the buffer, skip
jr c, .skipRender
jr .render
.swap
;= load the low bytes in the opposite order
ld a, [X+1]
ld b, a
ld a, [N+1]
sub b
ld b, a
ld a, $FF - BUFFER
cp b
;= if they differ by the inverse of the buffer
;= they will not be within the gap between pages
jr nc, .skipRender
.render
;= success, do rendering stuff
; beep boop rendering stuff
ld a, TRUE
ld [hli], a
ret
.skipRender
;= failure, skip this one
; doing other stuff here
ld a, FALSE
ld [hli], a
ret

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@ -1,7 +1,9 @@
INCLUDE "inc/hardware.inc"
INCLUDE "inc/structs.asm"
INCLUDE "ass/parecivo.ass"
INCLUDE "ass/tiles.ass"
INCLUDE "ass/map.ass"
INCLUDE "src/animation.asm"
INCLUDE "src/entry.asm"
INCLUDE "src/header.asm"
INCLUDE "src/defines.asm"

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@ -134,16 +134,28 @@ PC_Update:
ret
Clear_Map:
xor a
ld hl, _SCRN0
ld bc, _SCRN0_END - _SCRN0
Clear_OAM:
ld hl, wShadowOAM
ld bc, wShadowOAMEnd - wShadowOAM
.loop:
xor a
ld [hli], a
dec bc
ld a, b
or c
jr z, .loop
jr nz, .loop
ret
Clear_Map:
ld hl, _SCRN0
ld bc, _SCRN0_END - _SCRN0
.loop:
xor a
ld [hli], a
dec bc
ld a, b
or c
jr nz, .loop
ret
Load_Tiles: