diff options
Diffstat (limited to 'engine/player_step.asm')
| -rwxr-xr-x | engine/player_step.asm | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/engine/player_step.asm b/engine/player_step.asm new file mode 100755 index 000000000..d0ae42451 --- /dev/null +++ b/engine/player_step.asm @@ -0,0 +1,271 @@ +_HandlePlayerStep:: ; d497 (3:5497) + ld a, [wPlayerStepFlags] + and a + ret z + bit 7, a ; starting step + jr nz, .update_overworld_map + bit 6, a ; finishing step + jr nz, .update_player_coords + bit 5, a ; ongoing step + jr nz, .finish + ret + +.update_overworld_map + ld a, 4 + ld [wHandlePlayerStep], a + call UpdateOverworldMap + jr .finish + +.update_player_coords + call UpdatePlayerCoords + jr .finish + +.finish + call HandlePlayerStep + ld a, [wPlayerStepVectorX] + ld d, a + ld a, [wPlayerStepVectorY] + ld e, a + ld a, [wFollowNotExactPersonX] + sub d + ld [wFollowNotExactPersonX], a + ld a, [wFollowNotExactPersonY] + sub e + ld [wFollowNotExactPersonY], a + ret + +ScrollScreen:: ; d4d2 (3:54d2) + ld a, [wPlayerStepVectorX] + ld d, a + ld a, [wPlayerStepVectorY] + ld e, a + ld a, [hSCX] + add d + ld [hSCX], a + ld a, [hSCY] + add e + ld [hSCY], a + ret + +HandlePlayerStep: ; d4e5 (3:54e5) + ld hl, wHandlePlayerStep + ld a, [hl] + and a + ret z + dec [hl] + ld a, [hl] + ld hl, .Jumptable + rst JumpTable + ret + +.Jumptable: ; d4f2 (3:54f2) + + dw GetMovementPermissions + dw BufferScreen + dw .mobile + dw .fail2 +; The rest are never used. Ever. + dw .fail1 + dw .fail1 + dw .fail1 + dw .fail1 + dw .fail1 + dw .fail1 + dw .fail1 + +.fail1: ; d508 (3:5508) + ret + +.mobile: ; d509 (3:5509) + callba MobileFn_10602e + ret + +.fail2: ; d510 (3:5510) + ret + +UpdatePlayerCoords: ; d511 (3:5511) + ld a, [wPlayerStepDirection] + and a + jr nz, .check_step_down + ld hl, YCoord + inc [hl] + ret + +.check_step_down + cp UP + jr nz, .check_step_left + ld hl, YCoord + dec [hl] + ret + +.check_step_left + cp LEFT + jr nz, .check_step_right + ld hl, XCoord + dec [hl] + ret + +.check_step_right + cp RIGHT + ret nz + ld hl, XCoord + inc [hl] + ret + +UpdateOverworldMap: ; d536 (3:5536) + ld a, [wPlayerStepDirection] + and a + jr z, .step_down + cp UP + jr z, .step_up + cp LEFT + jr z, .step_left + cp RIGHT + jr z, .step_right + ret + +.step_down + call .ScrollOverworldMapDown + call LoadMapPart + call ScrollMapUp + ret + +.step_up + call .ScrollOverworldMapUp + call LoadMapPart + call ScrollMapDown + ret + +.step_left + call .ScrollOverworldMapLeft + call LoadMapPart + call ScrollMapRight + ret + +.step_right + call .ScrollOverworldMapRight + call LoadMapPart + call ScrollMapLeft + ret + +.ScrollOverworldMapDown: ; d571 (3:5571) + ld a, [wBGMapAnchor] + add 2 * BG_MAP_WIDTH + ld [wBGMapAnchor], a + jr nc, .not_overflowed + ld a, [wBGMapAnchor + 1] + inc a + and $3 + or VBGMap0 / $100 + ld [wBGMapAnchor + 1], a +.not_overflowed + ld hl, wMetatileStandingY + inc [hl] + ld a, [hl] + cp 2 ; was 1 + jr nz, .done_down + ld [hl], 0 + call .Add6ToOverworldMapAnchor +.done_down + ret + +.Add6ToOverworldMapAnchor: ; d595 (3:5595) + ld hl, wOverworldMapAnchor + ld a, [MapWidth] + add 6 + add [hl] + ld [hli], a + ret nc + inc [hl] + ret + +.ScrollOverworldMapUp: ; d5a2 (3:55a2) + ld a, [wBGMapAnchor] + sub 2 * BG_MAP_WIDTH + ld [wBGMapAnchor], a + jr nc, .not_underflowed + ld a, [wBGMapAnchor + 1] + dec a + and $3 + or VBGMap0 / $100 + ld [wBGMapAnchor + 1], a +.not_underflowed + ld hl, wMetatileStandingY + dec [hl] + ld a, [hl] + cp -1 ; was 0 + jr nz, .done_up + ld [hl], $1 + call .Sub6FromOverworldMapAnchor +.done_up + ret + +.Sub6FromOverworldMapAnchor: ; d5c6 (3:55c6) + ld hl, wOverworldMapAnchor + ld a, [MapWidth] + add 6 + ld b, a + ld a, [hl] + sub b + ld [hli], a + ret nc + dec [hl] + ret + +.ScrollOverworldMapLeft: ; d5d5 (3:55d5) + ld a, [wBGMapAnchor] + ld e, a + and $e0 + ld d, a + ld a, e + sub $2 + and $1f + or d + ld [wBGMapAnchor], a + ld hl, wMetatileStandingX + dec [hl] + ld a, [hl] + cp -1 + jr nz, .done_left + ld [hl], 1 + call .DecrementwOverworldMapAnchor +.done_left + ret + +.DecrementwOverworldMapAnchor: ; d5f4 (3:55f4) + ld hl, wOverworldMapAnchor + ld a, [hl] + sub 1 + ld [hli], a + ret nc + dec [hl] + ret + +.ScrollOverworldMapRight: ; d5fe (3:55fe) + ld a, [wBGMapAnchor] + ld e, a + and $e0 + ld d, a + ld a, e + add $2 + and $1f + or d + ld [wBGMapAnchor], a + ld hl, wMetatileStandingX + inc [hl] + ld a, [hl] + cp 2 + jr nz, .done_right + ld [hl], 0 + call .IncrementwOverworldMapAnchor +.done_right + ret + +.IncrementwOverworldMapAnchor: ; d61d (3:561d) + ld hl, wOverworldMapAnchor + ld a, [hl] + add 1 + ld [hli], a + ret nc + inc [hl] + ret |