Castlevania (USA) (Rev 1), read in the ROM and measured in Mesen

In Simon's standing state, the frame A goes down starts a jump, unless a block is over his head (ceiling-takeoff); the take-off code points his arc at a fixed table and copies the d-pad's Left and Right bits into his direction. castlevania/jump-start

About: Castlevania Jump

The press frame takes the standing state's walk step if Right or Left is held (takeoff-x), but no arc step; the jumping state takes its first step on the next frame (arc).

Cited by: Castlevania, Jump, Variable jump height

Simon's jump rises by a fixed table of per-frame steps, 5, 5, 3, 3, 3, 3, 3, 2, 2, 2, 1, 1, 1, 1, 0, 1, 0, 0, 0, and 0 px, 36 px in all. castlevania/jump-table

About: Castlevania Jump

[
 5,
 5,
 3,
 3,
 3,
 3,
 3,
 2,
 2,
 2,
 1,
 1,
 1,
 1,
 0,
 1,
 0,
 0,
 0,
 0
]

Screen Y grows downward, so the bytes are negative; the statement gives the rises as positive pixels.

Cited by: Castlevania, Gravity, Jump, Variable jump height

At the table's turn marker the arc routine reverses and reads the same steps backward, negated, so Simon falls the way he rose. castlevania/table-turn

About: Castlevania Jump

The turn frame steps back onto the last step, so each of the table's 4 closing zeros is read once each way, and Simon holds his 36 px top for 8 frames.

Cited by: Castlevania, Variable jump height

Once the reversed table runs out, the arc routine moves Simon down 8 px every frame until he lands, so a jump that ends below its take-off point falls at 8 px per frame. castlevania/table-end-fall

About: Castlevania Gravity

Value: 8 px/frame

Measured on ground built in the collision map; the courtyard itself is flat.

Cited by: Castlevania, Gravity

Measured in the game, Simon's standing jump is the same with A held 1, 2, 5, 10, 20, or 40 frames, 36 px high on frame 17 and back on the ground on frame 41. castlevania/apex-by-hold

About: Castlevania Variable jump height

{
 "holds": [
  1,
  2,
  5,
  10,
  20,
  40
 ],
 "tap": {
  "apex": 36,
  "apexAt": 17,
  "airtime": 41
 },
 "full": {
  "apex": 36,
  "apexAt": 17,
  "airtime": 41
 }
}

Frame 1 is the press frame. Heights are Simon's Y ($3F) above the take-off row.

Cited by: Castlevania, Jump, Super Castlevania IV, Variable jump height

Measured frame by frame, Simon's standing jump follows the table exactly, from a motionless press frame to a landing 40 frames later. castlevania/arc

About: Castlevania Jump

[
 0,
 0,
 5,
 10,
 13,
 16,
 19,
 22,
 25,
 27,
 29,
 31,
 32,
 33,
 34,
 35,
 35,
 36,
 36,
 36,
 36,
 36,
 36,
 36,
 36,
 36,
 35,
 35,
 34,
 33,
 32,
 31,
 29,
 27,
 25,
 22,
 19,
 16,
 13,
 10,
 5,
 0
]

Height above take-off after each frame, from frame 0 (before the press) to frame 41.

Cited by: Castlevania, Jump, Variable jump height

Measured in the game, a jump keeps the direction held at take-off, 1 px per frame that way or none, whatever the d-pad does in the air. castlevania/air-direction

About: Castlevania Air control

Value: 1 px/frame

The press frame already moves him, since the walking state runs before the jump starts.

Cited by: Air control, Castlevania, Variable jump height

Measured in the game, Simon walks 40 px in 40 frames, 1 px per frame. castlevania/walk-speed

About: Castlevania Running

Value: 1 px/frame

Cited by: Castlevania

Simon has no acceleration; each frame on the ground his direction bits are set from the d-pad's held Left and Right, and the move routine shifts him by his speed bytes, 1 px/frame, in that direction or not at all. castlevania/walk-rule

About: Castlevania Running

{
 "speed": 256
}

$3E is whole pixels and $3D the fraction. Bit 2 of $3C chooses whether Simon moves on the screen ($038C, fraction $03A8) or the camera scrolls under him ($2D-$2F); his level X ($40/$41) is screen X plus camera either way. Stairs and moving platforms set other speeds (0.5 px/frame on stairs). Private notes: research/private/castlevania-movement.md.

Cited by: Castlevania, Running

While Left or Right is held, the crouching state, and the standing state on a frame that doesn't start a fall, a stair climb, a whip, a jump, or a crouch, set Simon's facing ($0450) from it, so he turns on the first frame, and crouching he can turn without moving. A frame that starts any of those keeps the facing he had. castlevania/facing

About: Castlevania Running

The jump keeps the take-off direction instead (air-direction). The jump and crouch frames are measured; the fall, stair, and whip frames are read in the code only.

Cited by: Running

Down on the ground puts Simon in the crouching state 4 px lower, where the d-pad no longer moves him; letting go stands him back up, and that frame he doesn't move either. castlevania/crouch

About: Castlevania Running

The press frame still walks, since the standing state moves Simon before it reads Down.

Cited by: Running

The standing state moves Simon before it checks A, so the press frame walks at 1 px/frame; the take-off then fixes the jump's direction from the d-pad held on that frame, and the jumping state moves him 1 px/frame that way or not at all. castlevania/takeoff-x

About: Castlevania Jump

The jumping state never rewrites $0584, so the direction routine keeps reading the buttons held at take-off.

Cited by: Air control

A jump lands during the jumping state's frame, after that frame's move in the take-off direction; from the next frame the standing state takes the d-pad again, so Simon stops at once or walks at 1 px/frame. castlevania/landing

About: Castlevania Jump

Nothing carries over horizontally; Simon has no momentum to keep.

Walking off a ledge puts Simon in a falling state that moves him on in his facing direction at 1 px/frame and down 8 px/frame; landing after 8 or more falling frames drops him into a crouch for 16 frames. castlevania/ledge-fall

About: Castlevania Jump

{
 "dx": 1,
 "dy": 8,
 "hardAfter": 8,
 "crouchFrames": 16
}

The landing frame counts as a falling frame. The 18 frames are the landing frame, 16 crouching frames, and a frame standing up. The jump's own fall (table-end-fall) is a different state.

Simon's floor is tested at x−4 and x+4, 16 px below his Y; walls at x+8 or x−8 at five heights from 9 px above to 15 px below it; and a jump needs clear space 19 px above at x−7, x, and x+7. castlevania/terrain-points

About: Castlevania Hitbox

{
 "floor": {
  "x": [
   -4,
   4
  ],
  "y": 16
 },
 "wall": {
  "x": 8,
  "y": [
   -9,
   -4,
   0,
   8,
   15
  ],
  "yFalling": [
   -9,
   -4,
   0,
   8,
   16
  ]
 },
 "ceiling": {
  "x": [
   -7,
   0,
   7
  ],
  "y": -19
 }
}

X is $40/$41 and Y is $3F (screen Y, growing downward), both Simon's center; he stands with Y 16 px above the floor tile's top. Crouching moves Y down 4 px. His box against enemies is a separate routine, not read yet.

Cited by: Hitbox

Each frame, the standing and crouching states test Simon's floor points before they move him or read A; with no ground under either point, they put him in the falling state and end the frame there, so he doesn't move and A isn't read. The frame whose step carries his second floor point past an edge still reads A after the step, so a press on that frame jumps. castlevania/walk-off-order

About: Castlevania Coyote time

Walking right off an edge at x = r, the floor points x−4 and x+4 have no ground once x reaches r + 4; the next frame starts the fall. Before the floor test the state also checks the moving platforms ($AC70), which aren't modeled.

Cited by: Coyote time

Simon has no coyote time. The falling state reads no buttons: A after he walks off doesn't jump, B doesn't whip, and the d-pad doesn't steer, since the direction routine reads the direction the fall's entry wrote from his facing. castlevania/no-coyote-time

About: Castlevania Coyote time

The frame he walks off is lost too, since the standing state ends before its A check (walk-off-order).

Cited by: Castlevania, Coyote time

Above screen Y 208 and off moving platforms, each falling frame tests the floor at Simon's position before he moves: with ground under either floor point he lands that frame without moving, his Y snapped up to a multiple of 16; otherwise he moves 1 px and drops 8 px. From Y 208 on, the floor test finds no ground. castlevania/fall-order

About: Castlevania Gravity

Standing Y is a multiple of 16 and floors sit on 16 px rows, so an 8 px fall from a standing start meets a floor exactly; the snap doesn't move him. Read in the code only (T3): in stage $0A the landing doesn't snap Y to 16.

A wall stops Simon without pushing him out. Before each move, in the standing, jumping, and falling states, the direction routine tests the wall points on the side he's moving toward; if any is in solid ground it clears his direction bits, so he doesn't move that frame and nothing else changes. A jump keeps rising and falling, and moves on again once the points are clear. castlevania/wall-stop

About: Castlevania Hitbox

The direction bits are rebuilt each frame, from the pad on the ground or from the take-off or fall direction in the air. The wall test is skipped in states 4 and 6.

From the turn of its table on, the jumping state tests the floor after each frame's step, so a jump lands on any top its floor points meet on the way down, above or below take-off height; the landing snaps Y up to a multiple of 16. Each 8 px frame past the table's end counts in the fall counter the take-off zeroed, and landing with it at 8 or more starts the 16-frame landing crouch. This holds outside stage $0A and when he isn't whipping as he lands (see notes). castlevania/jump-landing

About: Castlevania Jump

The moving-down flag flips on the turn frame's step, so the floor test runs from that frame. The rises are at most 5 px a frame and the fall 8, so the snap puts his feet on the top he met. Read in the code only (T3), not measured: in stage $0A the landing snaps Y to a multiple of 8 but not 16, and a landing while whipping goes to the standing whip, with neither the 16 px snap nor the landing crouch.

Simon dies when his Y reaches 224 ($E0) in the falling state, before its 8 px drop, or 224 to 239 in the jumping state, at the start of its frame. castlevania/pit-death

About: Castlevania Gravity

Value: 224 px (screen Y)

Screen Y grows downward; standing on the first courtyard's floor, Y is 176.

Simon can't jump from under a block on his head. On the frame A goes down, after that frame's walk step, the standing state tests three points 19 px above his center, at x−7, x, and x+7; if any is solid (below screen Y 48), the press is dropped. That frame then runs as one with neither A nor Down: he turns to the d-pad but doesn't crouch or whip, and holding A out from under the block doesn't jump, since only a new press does. castlevania/ceiling-takeoff

About: Castlevania Jump

Y is his center, 16 px above the floor's top, so the points sit 35 px above that top. The game's collision cells are 8 px squares: a block whose underside is 32 px above his feet fills the row the points read, and one 40 px up doesn't. The collision lookup ($F9A0) finds nothing above screen Y 48, so near the top of the screen nothing stops the take-off.

Once Simon is in the air, no ceiling is tested: a block over his head doesn't cut a jump short. The jumping state calls no ceiling test; it runs the direction and move routines, the arc step, and from the turn on the floor test. His head rises into the block on the same arc as in the open, and the block stops him moving sideways only where his wall points meet it. castlevania/ceiling-rise

About: Castlevania Jump

It follows that on a 16 px grid a jump from below can't land inside a block: a block low enough for his feet to reach at the apex (36 px) is low enough for the take-off test, and from the side his wall points stop him before his feet get under it.

Under a block on his head, a hit doesn't knock Simon back. Outside state 4, whose hit sets only $47 and $5B, the routine that starts the knockback (state 5, a short arc away from what hit him) first runs the take-off's ceiling test; with a block there it puts him straight into the 16-frame crouch (state 9) that also ends a knockback's landing. castlevania/hurt-ceiling

About: Castlevania Knockback

Read in the code only (T3). State 4 isn't identified yet; its hit has no knockback either way. $96AD also sets $5B to 48, which reads as an invincibility timer but isn't confirmed.