Zombie: Difference between revisions
Content deleted Content added
Piranhaplant (talk | contribs) No edit summary |
Piranhaplant (talk | contribs) No edit summary |
||
| (17 intermediate revisions by 2 users not shown) | |||
Line 1:
{{Infobox Monster
|img=Zombie.png
|hp=1
|points=100
|special=-
|resists=-
|weak_to=-
}}
{{Infobox Entity
|entity_pointer=$81:87F8
|pointer1_type=normal
|entity_pointer2=$81:88CA
|pointer2_type=hard
}}
The zombie is a [[respawning monster]]. Zombies attack via contact damage, have no special powers and aren't resistant or vulnerable to any [[weapon]]. They can be found in all [[tileset]]s, only have 1 hit point and award 100 points to the player when killed. There are two different types of zombies: normal and hard. They behave mostly the same, but there are slight differences that make the hard version more aggressive.
== Behavior ==
Line 10 ⟶ 24:
* '''Targeting:''' Move towards the nearest targetable sprite. A zombie enters this state when it comes within a certain distance of a targetable sprite. The zombie will leave this state and go back to the wandering state if there is no longer a targetable sprite within another (slightly larger) distance.
{{BPMN_embed|BPMN:Zombie state diagram|288}}
Zombies will despawn if they are a distance of 208 pixels or more on a single axis from the closest player, and are not within target range of any targetable sprites. The SNES screen has a width of 256 pixels, so this means it is possible for a zombie to despawn while still on screen if all players are on the very left or right of the screen and the zombie is on the opposite side.
=== Differences in hard version ===
==== Major differences ====
* Start targeting at distance of 159 pixels (instead of 64 pixels for normal). They continue targeting while there is a target within 179 pixels (instead of 69 pixels for normal).
* Moves at a speed of 1 px/frame when wandering and following wall (instead of 0.5 px/frame for normal). The speed when targeting is 1 px/frame for both versions.
==== Minor differences ====
[[File:Zombie follow wall comparison.gif|class=notpageimage|frame|Normal (left) vs. hard (right) targeting through a wall]]
* Position update logic is different when targeting. When targeting through a wall, normal zombies will get stuck, but the hard version will still follow along the wall.
* The angle to rotate when following a wall is stored in a variable instead of being hardcoded. However, this variable is never initialized, so it will retain whatever value happened to be in RAM previously. This generally results in the zombie sticking to the wall instead of following it.
Line 27 ⟶ 46:
Zombies have a four frame animation cycle, with 8 frames in between each animation frame. There is a separate set of animation frames for each of the 4 orthogonal directions, chosen based on which direction the zombie is moving. If the zombie is moving diagonal, it uses the left or right animation.
== Bugs ==
* Hard zombies do not generally follow walls like they should. See [[#Differences in hard version|Differences in hard version]].
* The hard zombies have a partially implemented feature that appears to be something that would make them stop targeting for a certain amount of time. In its incomplete state, it generally does not affect their behavior, but if a zombie stays following a wall for around 9 minutes, the timer will underflow. This will cause the zombie to stop targeting for around another 9 minutes until the timer reaches zero again.
== Trivia ==
*With 152 spawners for normal zombies and 127 spawners for hard zombies, this is the most common monster that players will face in the game.
== RAM map ==
Line 34 ⟶ 62:
{| class="wikitable"
|-
! Address !! Length !! [[Data types|Type]] !! Name !! Description
|-
| $00 || 2 || int16 || x || X position
|-
| $02 || 2 || int16 || y || Y position
|}
Line 45 ⟶ 73:
{| class="wikitable"
|-
! Address !! Length !! [[Data types|Type]] !! Name !! Description
|-
| $08 || 2 || pointer16 || sprite || Pointer to sprite
|-
| $0A || 2 || uint16 || cyclesUntilAnimUpdate || Number of 2-frame cycles until next animation frame
|-
| $0C || 2 || uint16 x2 || animationFrame || Current animation frame
|-
| $0E || 2 || direction x2 || direction || Current direction
|-
| $10 || 2 || direction x2 || newDirection || New direction
|-
| $12 || 2 || uint16 || deathStatus || Death status. 0 = alive, 0xF5F5 = killed, other = despawned
|-
| $14 || 2 || pointer16 || state || Current state subroutine pointer
|-
| $16 || 2 || int16 || x || X position
|-
| $18 || 2 || int16 || y || Y position
|-
| $1A || 2 || int16 || newX || New X position
|-
| $1C || 2 || int16 || newY || New Y position
|-
| $1E || 2 || int16 0-based || health || Health
|-
| $20 || 2 || direction x4 || targetDirection || Direction to target
|-
| $22 || 2 || sprite type || collidedSpriteType || Type of sprite collided with
|-
| $24 || 2 ||
|-
| $26 || 2 || int16 || tempX || Temp X position (hard only)
|-
| $28 || 2 || int16 || tempY || Temp Y position (hard only)
|-
| $2A || 2 || uint16 || moveCounter || Number of times left to move when targeting (hard only)
|-
| $2C || 2 || int16 || wallRotateAngle || Amount to rotate when following wall (hard only)
|-
| $2E || 2 || pointer16 || targetSprite || Pointer to target sprite (not used) (normal only)
|- class="breakrow"
| $7E || 2 ||
|}
{{Pseudocode header}}
moveAmount_Normal = { // $81:858B
{ 0, 0 },
{ 0, -1 },
{ 1, -1 },
{ 1, 0 },
{ 1, 1 },
{ 0, 1 },
{ -1, 1 },
{ -1, 0 },
{ -1, -1 }
}
moveAmount_Hard = { // $81:85AF
{ 0, 0 },
{ 0, -2 },
{ 2, -2 },
{ 2, 0 },
{ 2, 2 },
{ 0, 2 },
{ -2, 2 },
{ -2, 0 },
{ -2, -2 }
}
newPositionIsBlocked() { // $81:85D3
return {{ROM name|$80:AE97}}(this.newX, this.newY) ||
{{ROM name|$80:BF67}}(this.sprite, this.newX, this.newY)
}
wanderInRandomDirection_Normal() { // $81:85EB
this.direction = ({{ROM name|$80:9D39}}() % 4) * 2 + 1
setStateToWandering_Normal()
}
setStateToWandering_Normal() { // $81:85FB
this.state = wanderingState_Normal
wanderingState_Normal()
}
wanderingState_Normal() { // $81:8600
this.newX = this.x + moveAmount_Normal[this.direction][0]
this.newY = this.y + moveAmount_Normal[this.direction][1]
if (!{{ROM name|$80:AE97}}(this.newX, this.newY)) {
if (!{{ROM name|$80:BF67}}(this.sprite, this.newX, this.newY)) {
this.x = this.newX
this.sprite.x = this.newX
this.y = this.newY
this.sprite.y = this.newY
}
} else {
followWall_Normal()
}
}
followWall_Normal() { // $81:863E
this.direction = ((this.direction - 1) + 2) % 8 + 1 // Rotate 90 degrees clockwise
setStateToFollowingWall_Normal()
}
setStateToFollowingWall_Normal() { // $81:8650
this.state = followingWallState_Normal
}
followingWallState_Normal() { // $81:8656
this.newDirection = ((this.direction - 1) - 2) % 8 + 1 // Rotate 90 degrees counterclockwise
this.newX = this.x + moveAmount_Normal[this.newDirection][0]
this.newY = this.y + moveAmount_Normal[this.newDirection][1]
if (!newPositionIsBlocked()) {
this.direction = this.newDirection
}
this.newX = this.x + moveAmount_Normal[this.direction][0]
this.newY = this.y + moveAmount_Normal[this.direction][1]
if (!newPositionIsBlocked()) {
this.x = this.newX
this.sprite.x = this.newX
this.y = this.newY
this.sprite.y = this.newY
} else {
followWall_Normal()
}
}
setStateToTargeting_Normal() { // $81:86AD
this.state = targetingState_Normal
}
targetingState_Normal() { // $81:86B3
distance, this.targetSprite = {{ROM name|$80:B123}}(this.x, this.y)
if (distance >= 70) {
wanderInRandomDirection_Normal()
return
}
{{ROM name|$80:B3F1}}(this.sprite, this.targetSprite)
this.direction = {{ROM name|$80:B22A}}(this.sprite, this.targetSprite)
if (this.direction == 0) {
wanderInRandomDirection_Normal()
return
}
this.targetDirection = this.direction
for (i = 0; i < 2; i++) {
this.newX = this.x + moveAmount_Normal[this.targetDirection][0]
this.newY = this.y + moveAmount_Normal[this.targetDirection][1]
if (!newPositionIsBlocked()) {
this.x = this.newX
this.sprite.x = this.newX
this.y = this.newY
this.sprite.y = this.newY
}
}
}
checkForTarget_Normal() { // $81:8706
distance = {{ROM name|$80:B123}}(this.x, this.y)
if (distance < 65) {
setStateToTargeting_Normal()
return
}
direction = {{ROM name|$80:B2A5}}(208, this.x, this.y)
if (direction == NONE) {
this.deathStatus -= 1
}
}
killed() { // $81:8727
{{ROM name|$80:C7D9}}(this.collidedSpriteType & 0x8000, 100)
this.deathStatus = 0xF5F5
}
updateAnimation() { // $81:8736
this.cyclesUntilAnimUpdate -= 1
if (this.cyclesUntilAnimUpdate == 0) {
this.cyclesUntilAnimUpdate = 4
this.animationFrame = (this.animationFrame + 1) % 4
this.sprite.tileData.lowBytes = walkingAnimations[this.direction][this.animationFrame]
this.sprite.tileData.bank = 0x90
if (this.direction < DOWN_LEFT) {
this.sprite.flipX = false
} else {
this.sprite.flipX = true
}
}
}
walkingAnimations = { // $81:8776
{ 0xCABC, 0xCADD, 0xCAFE, 0xCB1F },
{ 0xCB40, 0xCB61, 0xCB82, 0xCBA3 },
{ 0xCA28, 0xCA51, 0xCA72, 0xCA9B },
{ 0xCA28, 0xCA51, 0xCA72, 0xCA9B },
{ 0xCA28, 0xCA51, 0xCA72, 0xCA9B },
{ 0xCABC, 0xCADD, 0xCAFE, 0xCB1F },
{ 0xCA28, 0xCA51, 0xCA72, 0xCA9B },
{ 0xCA28, 0xCA51, 0xCA72, 0xCA9B },
{ 0xCA28, 0xCA51, 0xCA72, 0xCA9B }
}
init() { // $81:87BE
{{ROM name|$81:8000}}()
this.animationFrame = 0
this.x = args.x
this.sprite.x = args.x
this.sprite.z = 0
this.y = args.y
this.sprite.y = args.y
this.sprite.tileData = $90:C98A
this.sprite.visible = true
this.sprite.alternatePalette = 6
this.collidedSpriteType = 0
this.freezeTimer = 0
}
main_Normal() { // $81:87F8
{{RAM name|$7E:00DE}} += 0x14
this.cyclesUntilAnimUpdate = 7
init()
{{ROM name|$81:832C}}(spawnAnimation_Normal)
this.sprite.type = MONSTER
wanderInRandomDirection_Normal()
this.health = 0
{{ROM name|$80:8475}}(collisionHandler)
this.deathStatus = 0
while (this.deathStatus == 0) {
{{ROM name|$80:8353}}(2)
checkForTarget_Normal()
this.state()
updateAnimation()
}
if (this.deathStatus == 0xF5F5) {
{{RAM name|$7E:1F64}} += 1
{{ROM name|$81:83A3}}(mummy.deathAnimation, this.deathStatus, 0x90)
}
{{RAM name|$7E:00DE}} -= 0x14
while ({{RAM name|$7E:00DE}} < 0) { }
{{ROM name|$80:BE41}}(this.sprite)
}
spawnAnimation_Normal = { // $81:886C
{ 0xC98A, 10 }, { 0xC993, 10 }, { 0xC9A4, 10 }, { 0xC9B5, 10 },
{ 0xC9D6, 10 }, { 0xC9FF, 10 }, { 0, 0 }
}
collisionHandler(spriteType) { // $81:8888
if (spriteType < SQUIRT_GUN) {
return false
}
this.collidedSpriteType = spriteType
weaponType = spriteType & 0x7FFF
if (weaponType == MARTIAN_BUBBLE_GUN) {
return {{ROM name|$81:83C6}}()
} else if (weaponType == FIRE_EXTINGUISHER) {
return {{ROM name|$81:847E}}()
} else {
newHealth = this.health - {{ROM name|$81:8561}}[weaponType - SQUIRT_GUN]
if (newHealth < 0) {
this.health = newHealth
this.freezeTimer = 0
killed()
return true
} else if (newHealth != this.health) {
this.health = newHealth
return {{ROM name|$81:8506}}()
}
return false
}
}
main_Hard() { // $81:88CA
{{RAM name|$7E:00DE}} += 0x14
this.cyclesUntilAnimUpdate = 7
init()
{{ROM name|$81:832C}}(spawnAnimation_Hard)
this.sprite.type = MONSTER
wanderInRandomDirection_Hard()
this.health = 0
this.dontTargetTimer = -1
{{ROM name|$80:8475}}(collisionHandler)
this.deathStatus = 0
while (this.deathStatus == 0) {
{{ROM name|$80:8353}}(2)
if (this.collidedSpriteType != 0) {
this.sprite.useAlternatePalette = false
this.collidedSpriteType = 0
} else {
checkForTarget_Hard()
}
this.state()
updateAnimation()
}
if (this.deathStatus == 0xF5F5) {
{{RAM name|$7E:1F64}} += 1
{{ROM name|$81:83A3}}(mummy.deathAnimation, this.deathStatus, 0x90)
}
{{RAM name|$7E:00DE}} -= 0x14
while ({{RAM name|$7E:00DE}} < 0) { }
{{ROM name|$80:BE41}}(this.sprite)
}
spawnAnimation_Hard = { // $81:8956
{ 0xC98A, 10 }, { 0xC993, 10 }, { 0xC9A4, 10 }, { 0xC9B5, 10 },
{ 0xC9D6, 10 }, { 0xC9FF, 10 }, { 0, 0 }
}
// Unused. Exactly equivalent to the other animations table
walkingAnimations_Hard = { // $81:8972
{ 0xCABC, 0xCADD, 0xCAFE, 0xCB1F },
{ 0xCB40, 0xCB61, 0xCB82, 0xCBA3 },
{ 0xCA28, 0xCA51, 0xCA72, 0xCA9B },
{ 0xCA28, 0xCA51, 0xCA72, 0xCA9B },
{ 0xCA28, 0xCA51, 0xCA72, 0xCA9B },
{ 0xCABC, 0xCADD, 0xCAFE, 0xCB1F },
{ 0xCA28, 0xCA51, 0xCA72, 0xCA9B },
{ 0xCA28, 0xCA51, 0xCA72, 0xCA9B },
{ 0xCA28, 0xCA51, 0xCA72, 0xCA9B }
}
setStateToWandering_Hard() { // $81:89BA
this.state = wanderingState_Hard
wanderingState_Hard()
}
wanderingState_Hard() { // $81:89BF
this.newX = this.x + moveAmount_Hard[this.direction][0]
this.newY = this.y + moveAmount_Hard[this.direction][1]
if (!{{ROM name|$80:AE97}}(this.newX, this.newY)) {
if (!{{ROM name|$80:BF67}}(this.sprite, this.newX, this.newY)) {
this.x = this.newX
this.sprite.x = this.newX
this.y = this.newY
this.sprite.y = this.newY
}
} else {
followWall_Hard()
}
}
tryToMoveWhileTargeting() { // $81:89FD
this.tempX = this.x
this.tempY = this.y
if (!{{ROM name|$80:AE97}}(this.newX, this.y) &&
!{{ROM name|$80:BF67}}(this.sprite, this.newX, this.y)) {
this.x = this.newX
}
if (!{{ROM name|$80:AE97}}(this.x, this.newY) &&
!{{ROM name|$80:BF67}}(this.sprite, this.x, this.newY)) {
this.y = this.newY
}
if (this.x != this.tempX || this.y != this.tempY) {
this.dontTargetTimer = 0
return false
} else {
return true
}
}
followWall_Hard() { // $81:8A4B
this.direction = ((this.direction - 1) + this.wallRotateAngle) % 8 + 1
setStateToFollowingWall_Hard()
}
wanderInRandomDirection_Hard() { // $81:8A5C
this.direction = ({{ROM name|$80:9D39}}() % 4) * 2 + 1
setStateToWandering_Hard()
}
setStateToFollowingWall_Hard() { // $81:8A6C
this.state = followingWallState_Hard
}
followingWallState_Hard() { // $81:8A72
this.dontTargetTimer -= 1
this.newDirection = ((this.direction - 1) - this.wallRotateAngle) % 8 + 1
this.newX = this.x + moveAmount_Hard[this.newDirection][0]
this.newY = this.y + moveAmount_Hard[this.newDirection][1]
if (!newPositionIsBlocked()) {
this.direction = this.newDirection
}
this.newX = this.x + moveAmount_Hard[this.direction][0]
this.newY = this.y + moveAmount_Hard[this.direction][1]
if (!newPositionIsBlocked()) {
this.x = this.newX
this.sprite.x = this.newX
this.y = this.newY
this.sprite.y = this.newY
} else {
followWall_Hard()
}
}
unused818ACA() { // $81:8ACA
this.dontTargetTimer = 0
wanderInRandomDirection_Hard()
}
setStateToTargeting_Hard() { // $81:8AD2
this.state = targetingState_Hard
}
targetingState_Hard() { // $81:8AD8
distance, this.targetSprite = {{ROM name|$80:B123}}(this.x, this.y)
if (distance >= 180) {
wanderInRandomDirection_Hard()
return
}
{{ROM name|$80:B3F1}}(this.sprite, this.targetSprite)
this.direction = {{ROM name|$80:B22A}}(this.sprite, this.targetSprite)
if (this.direction == 0) {
wanderInRandomDirection_Hard()
return
}
this.targetDirection = this.direction
this.moveCounter = 1
while (this.moveCounter > 0) {
this.newX = this.x + moveAmount_Hard[this.targetDirection][0]
this.newY = this.y + moveAmount_Hard[this.targetDirection][1]
if (tryToMoveWhileTargeting()) {
this.dontTargetTimer = 0
wanderInRandomDirection_Hard()
return
}
this.sprite.x = this.x
this.sprite.y = this.y
this.moveCounter -= 1
}
}
checkForTarget_Hard() { // $81:8B30
this.dontTargetTimer -= 1
if (this.dontTargetTimer >= 0) {
return
}
distance = {{ROM name|$80:B123}}(this.x, this.y)
if (distance < 160) {
setStateToTargeting_Hard()
return
}
direction = {{ROM name|$80:B2A5}}(208, this.x, this.y)
if (direction == NONE) {
this.deathStatus -= 1
}
}
{{Pseudocode footer}}
[[Category:Respawning monster]]
[[Category:Bug]]
| |||