ref: 2ebbb0d95eead4f40ec0bb7e9edd19526c2b2f3a
dir: /engine/overworld/trainers.asm/
_GetSpritePosition1:: ld hl, wSpriteStateData1 ld de, $4 ld a, [wSpriteIndex] ld [H_SPRITEINDEX], a call GetSpriteDataPointer ld a, [hli] ; c1x4 (screen Y pos) ld [$ffeb], a inc hl ld a, [hl] ; c1x6 (screen X pos) ld [$ffec], a ld de, (wSpriteStateData2 + $4) - (wSpriteStateData1 + $6) add hl, de ld a, [hli] ; c2x4 (map Y pos) ld [$ffed], a ld a, [hl] ; c2x5 (map X pos) ld [$ffee], a ret _GetSpritePosition2:: ld hl, wSpriteStateData1 ld de, $4 ld a, [wSpriteIndex] ld [H_SPRITEINDEX], a call GetSpriteDataPointer ld a, [hli] ; c1x4 (screen Y pos) ld [wSavedSpriteScreenY], a inc hl ld a, [hl] ; c1x6 (screen X pos) ld [wSavedSpriteScreenX], a ld de, (wSpriteStateData2 + $4) - (wSpriteStateData1 + $6) add hl, de ld a, [hli] ; c2x4 (map Y pos) ld [wSavedSpriteMapY], a ld a, [hl] ; c2x5 (map X pos) ld [wSavedSpriteMapX], a ret _SetSpritePosition1:: ld hl, wSpriteStateData1 ld de, $4 ld a, [wSpriteIndex] ld [H_SPRITEINDEX], a call GetSpriteDataPointer ld a, [$ffeb] ; c1x4 (screen Y pos) ld [hli], a inc hl ld a, [$ffec] ; c1x6 (screen X pos) ld [hl], a ld de, (wSpriteStateData2 + $4) - (wSpriteStateData1 + $6) add hl, de ld a, [$ffed] ; c2x4 (map Y pos) ld [hli], a ld a, [$ffee] ; c2x5 (map X pos) ld [hl], a ret _SetSpritePosition2:: ld hl, wSpriteStateData1 ld de, 4 ld a, [wSpriteIndex] ld [H_SPRITEINDEX], a call GetSpriteDataPointer ld a, [wSavedSpriteScreenY] ld [hli], a ; c1x4 (screen Y pos) inc hl ld a, [wSavedSpriteScreenX] ld [hl], a ; c1x6 (screen X pos) ld de, (wSpriteStateData2 + $4) - (wSpriteStateData1 + $6) add hl, de ld a, [wSavedSpriteMapY] ld [hli], a ; c2x4 (map Y pos) ld a, [wSavedSpriteMapX] ld [hl], a ; c2x5 (map X pos) ret TrainerWalkUpToPlayer:: ld a, [wSpriteIndex] swap a ld [wTrainerSpriteOffset], a call ReadTrainerScreenPosition ld a, [wTrainerFacingDirection] and a ; SPRITE_FACING_DOWN jr z, .facingDown cp SPRITE_FACING_UP jr z, .facingUp cp SPRITE_FACING_LEFT jr z, .facingLeft jr .facingRight .facingDown ld a, [wTrainerScreenY] ld b, a ld a, $3c ; (fixed) player screen Y pos call CalcDifference cp $10 ; trainer is right above player ret z swap a dec a ld c, a ; bc = steps yet to go to reach player xor a ld b, a ; a = direction to go to jr .writeWalkScript .facingUp ld a, [wTrainerScreenY] ld b, a ld a, $3c ; (fixed) player screen Y pos call CalcDifference cp $10 ; trainer is right below player ret z swap a dec a ld c, a ; bc = steps yet to go to reach player ld b, $0 ld a, $40 ; a = direction to go to jr .writeWalkScript .facingRight ld a, [wTrainerScreenX] ld b, a ld a, $40 ; (fixed) player screen X pos call CalcDifference cp $10 ; trainer is directly left of player ret z swap a dec a ld c, a ; bc = steps yet to go to reach player ld b, $0 ld a, $c0 ; a = direction to go to jr .writeWalkScript .facingLeft ld a, [wTrainerScreenX] ld b, a ld a, $40 ; (fixed) player screen X pos call CalcDifference cp $10 ; trainer is directly right of player ret z swap a dec a ld c, a ; bc = steps yet to go to reach player ld b, $0 ld a, $80 ; a = direction to go to .writeWalkScript ld hl, wNPCMovementDirections2 ld de, wNPCMovementDirections2 call FillMemory ; write the necessary steps to reach player ld [hl], $ff ; write end of list sentinel ld a, [wSpriteIndex] ld [H_SPRITEINDEX], a jp MoveSprite_ ; input: de = offset within sprite entry ; output: hl = pointer to sprite data GetSpriteDataPointer: push de add hl, de ld a, [H_SPRITEINDEX] swap a ld d, $0 ld e, a add hl, de pop de ret ; tests if this trainer is in the right position to engage the player and do so if she is. TrainerEngage: push hl push de ld a, [wTrainerSpriteOffset] add $2 ld d, $0 ld e, a ld hl, wSpriteStateData1 add hl, de ld a, [hl] ; c1x2: sprite image index sub $ff jr nz, .spriteOnScreen ; test if sprite is on screen jp .noEngage .spriteOnScreen ld a, [wTrainerSpriteOffset] add $9 ld d, $0 ld e, a ld hl, wSpriteStateData1 add hl, de ld a, [hl] ; c1x9: facing direction ld [wTrainerFacingDirection], a call ReadTrainerScreenPosition ld a, [wTrainerScreenY] ; sprite screen Y pos ld b, a ld a, $3c cp b jr z, .linedUpY ld a, [wTrainerScreenX] ; sprite screen X pos ld b, a ld a, $40 cp b jr z, .linedUpX xor a jp .noEngage .linedUpY ld a, [wTrainerScreenX] ; sprite screen X pos ld b, a ld a, $40 ; (fixed) player X position call CalcDifference ; calc distance jr z, .noEngage ; exact same position as player call CheckSpriteCanSeePlayer jr c, .engage xor a jr .noEngage .linedUpX ld a, [wTrainerScreenY] ; sprite screen Y pos ld b, a ld a, $3c ; (fixed) player Y position call CalcDifference ; calc distance jr z, .noEngage ; exact same position as player call CheckSpriteCanSeePlayer jr c, .engage xor a jp .noEngage .engage call CheckPlayerIsInFrontOfSprite ld a, [wTrainerSpriteOffset] and a jr z, .noEngage ld hl, wFlags_0xcd60 set 0, [hl] call EngageMapTrainer ld a, $ff .noEngage ld [wTrainerSpriteOffset], a pop de pop hl ret ; reads trainer's Y position to wTrainerScreenY and X position to wTrainerScreenX ReadTrainerScreenPosition: ld a, [wTrainerSpriteOffset] add $4 ld d, $0 ld e, a ld hl, wSpriteStateData1 add hl, de ld a, [hl] ; c1x4 (sprite Y pos) ld [wTrainerScreenY], a ld a, [wTrainerSpriteOffset] add $6 ld d, $0 ld e, a ld hl, wSpriteStateData1 add hl, de ld a, [hl] ; c1x6 (sprite X pos) ld [wTrainerScreenX], a ret ; checks if the sprite is properly lined up with the player with respect to the direction it's looking. Also checks the distance between player and sprite ; note that this does not necessarily mean the sprite is seeing the player, he could be behind it's back ; a: distance player to sprite CheckSpriteCanSeePlayer: ld b, a ld a, [wTrainerEngageDistance] ; how far the trainer can see cp b jr nc, .checkIfLinedUp jr .notInLine ; player too far away .checkIfLinedUp ld a, [wTrainerFacingDirection] ; sprite facing direction cp SPRITE_FACING_DOWN jr z, .checkXCoord cp SPRITE_FACING_UP jr z, .checkXCoord cp SPRITE_FACING_LEFT jr z, .checkYCoord cp SPRITE_FACING_RIGHT jr z, .checkYCoord jr .notInLine .checkXCoord ld a, [wTrainerScreenX] ; sprite screen X position ld b, a cp $40 jr z, .inLine jr .notInLine .checkYCoord ld a, [wTrainerScreenY] ; sprite screen Y position ld b, a cp $3c jr nz, .notInLine .inLine scf ret .notInLine and a ret ; tests if the player is in front of the sprite (rather than behind it) CheckPlayerIsInFrontOfSprite: ld a, [wCurMap] cp POWER_PLANT jp z, .engage ; bypass this for power plant to get voltorb fake items to work ld a, [wTrainerSpriteOffset] add $4 ld d, $0 ld e, a ld hl, wSpriteStateData1 add hl, de ld a, [hl] ; c1x4 (sprite screen Y pos) cp $fc jr nz, .notOnTopmostTile ; special case if sprite is on topmost tile (Y = $fc (-4)), make it come down a block ld a, $c .notOnTopmostTile ld [wTrainerScreenY], a ld a, [wTrainerSpriteOffset] add $6 ld d, $0 ld e, a ld hl, wSpriteStateData1 add hl, de ld a, [hl] ; c1x6 (sprite screen X pos) ld [wTrainerScreenX], a ld a, [wTrainerFacingDirection] ; facing direction cp SPRITE_FACING_DOWN jr nz, .notFacingDown ld a, [wTrainerScreenY] ; sprite screen Y pos cp $3c jr c, .engage ; sprite above player jr .noEngage ; sprite below player .notFacingDown cp SPRITE_FACING_UP jr nz, .notFacingUp ld a, [wTrainerScreenY] ; sprite screen Y pos cp $3c jr nc, .engage ; sprite below player jr .noEngage ; sprite above player .notFacingUp cp SPRITE_FACING_LEFT jr nz, .notFacingLeft ld a, [wTrainerScreenX] ; sprite screen X pos cp $40 jr nc, .engage ; sprite right of player jr .noEngage ; sprite left of player .notFacingLeft ld a, [wTrainerScreenX] ; sprite screen X pos cp $40 jr nc, .noEngage ; sprite right of player .engage ld a, $ff jr .done .noEngage xor a .done ld [wTrainerSpriteOffset], a ret