pokered/engine/battle/wild_encounters.asm

104 lines
2.7 KiB
NASM

; try to initiate a wild pokemon encounter
; returns success in Z
TryDoWildEncounter:
ld a, [wNPCMovementScriptPointerTableNum]
and a
ret nz
ld a, [wd736]
and a
ret nz
callfar IsPlayerStandingOnDoorTileOrWarpTile
jr nc, .notStandingOnDoorOrWarpTile
.CantEncounter
ld a, $1
and a
ret
.notStandingOnDoorOrWarpTile
callfar IsPlayerJustOutsideMap
jr z, .CantEncounter
ld a, [wRepelRemainingSteps]
and a
jr z, .next
dec a
jr z, .lastRepelStep
ld [wRepelRemainingSteps], a
.next
; determine if wild pokemon can appear in the half-block we're standing in
; is the bottom right tile (9,9) of the half-block we're standing in a grass/water tile?
hlcoord 9, 9
ld c, [hl]
ld a, [wGrassTile]
cp c
ld a, [wGrassRate]
jr z, .CanEncounter
ld a, $14 ; in all tilesets with a water tile, this is its id
cp c
ld a, [wWaterRate]
jr z, .CanEncounter
; even if not in grass/water, standing anywhere we can encounter pokemon
; so long as the map is "indoor" and has wild pokemon defined.
; ...as long as it's not Viridian Forest or Safari Zone.
ld a, [wCurMap]
cp FIRST_INDOOR_MAP ; is this an indoor map?
jr c, .CantEncounter2
ld a, [wCurMapTileset]
cp FOREST ; Viridian Forest/Safari Zone
jr z, .CantEncounter2
ld a, [wGrassRate]
.CanEncounter
; compare encounter chance with a random number to determine if there will be an encounter
ld b, a
ldh a, [hRandomAdd]
cp b
jr nc, .CantEncounter2
ldh a, [hRandomSub]
ld b, a
ld hl, WildMonEncounterSlotChances
.determineEncounterSlot
ld a, [hli]
cp b
jr nc, .gotEncounterSlot
inc hl
jr .determineEncounterSlot
.gotEncounterSlot
; determine which wild pokemon (grass or water) can appear in the half-block we're standing in
ld c, [hl]
ld hl, wGrassMons
lda_coord 8, 9
cp $14 ; is the bottom left tile (8,9) of the half-block we're standing in a water tile?
jr nz, .gotWildEncounterType ; else, it's treated as a grass tile by default
ld hl, wWaterMons
; since the bottom right tile of a "left shore" half-block is $14 but the bottom left tile is not,
; "left shore" half-blocks (such as the one in the east coast of Cinnabar) load grass encounters.
.gotWildEncounterType
ld b, 0
add hl, bc
ld a, [hli]
ld [wCurEnemyLVL], a
ld a, [hl]
ld [wcf91], a
ld [wEnemyMonSpecies2], a
ld a, [wRepelRemainingSteps]
and a
jr z, .willEncounter
ld a, [wPartyMon1Level]
ld b, a
ld a, [wCurEnemyLVL]
cp b
jr c, .CantEncounter2 ; repel prevents encounters if the leading party mon's level is higher than the wild mon
jr .willEncounter
.lastRepelStep
ld [wRepelRemainingSteps], a
ld a, TEXT_REPEL_WORE_OFF
ldh [hSpriteIndexOrTextID], a
call EnableAutoTextBoxDrawing
call DisplayTextID
.CantEncounter2
ld a, $1
and a
ret
.willEncounter
xor a
ret
INCLUDE "data/wild/probabilities.asm"