How do I make monster spawner tiles?

ProjectAsinus

ProjectAsinus

Member
Anyone know how to make a tile spawn a monster? I can create a monster that spawns mosnters, but that causes slowdown due to object limitations. If I try to take the monster spawner code and apply it to a tile type’s script, it does nothing. Probably because the code involves grabbing the location and direction of the object trying to spawn the monsters, when this is not an object. But how would I alter it to allow the tile to spawn them?
 
baardbi

baardbi

Well-known member
ProjectAsinus said:
Anyone know how to make a tile spawn a monster? I can create a monster that spawns mosnters, but that causes slowdown due to object limitations. If I try to take the monster spawner code and apply it to a tile type’s script, it does nothing. Probably because the code involves grabbing the location and direction of the object trying to spawn the monsters, when this is not an object. But how would I alter it to allow the tile to spawn them?
Click to expand...
Using a tile to spawn monsters can be a little tricky. It's much better to make a monster spawner object. You could use an AI like this (it will also limit monsters):

;;; Spawn a new monster
;;; (if there are less than 4 monsters on the screen)

CountObjects #%00001000 ;;; Monster object
CMP #4 ;;; Max monster objects
BCC createNewMonster
JMP maxMonsterObjects
createNewMonster:

LDA Object_x_hi,x
STA tempA

LDA Object_y_hi,x
STA tempB

;;; Spawn a monster
CreateObjectOnScreen tempA, tempB, #16, #0, camScreen ;;; 16 is the monster object to spawn
;; arg0 = x
;; arg1 = y
;; arg2 = object
;; arg3 = beginning state
;; arg4 = what screen do youw ant to create this object on?

maxMonsterObjects:
Click to expand...

Make an invisible monster and assign this AI action to the first action step. Give it a timer like 2 or 3 (or whatever), and EndAction = Repeat.
 
ProjectAsinus

ProjectAsinus

Member
baardbi said:
Using a tile to spawn monsters can be a little tricky. It's much better to make a monster spawner object. You could use an AI like this (it will also limit monsters):



Make an invisible monster and assign this AI action to the first action step. Give it a timer like 2 or 3 (or whatever), and EndAction = Repeat.
Click to expand...
I know how to do that, the problem is that that causes performance issues due to there being too many objects (right now I have a 3 enemy limit and one spawner object, which works fine enough, though with slight lag, but if I wanted enemies to spawn in multiple separate locations I would need additional spawners, which causes huge slowdown due to them being objects). Using tiles might be more difficult, but it would really help performance if I knew how to pull it off.
 
NightMusic

NightMusic

Member
ProjectAsinus said:
I know how to do that, the problem is that that causes performance issues due to there being too many objects (right now I have a 3 enemy limit and one spawner object, which works fine enough, though with slight lag, but if I wanted enemies to spawn in multiple separate locations I would need additional spawners, which causes huge slowdown due to them being objects). Using tiles might be more difficult, but it would really help performance if I knew how to pull it off.
Click to expand...
You're using a blank spawner? Have you tried the trick for making empty sprites not draw? That might save cpu/ram.

[4.5.6] Combating Sprite Limits - Forcing Blank Sprites to Not Draw

We all (hopefully) know that the NES can only draw 8 hardware sprites per scanline, and only 64 hardware sprites total. But working with NESmaker's Game Objects or Monster Objects can kind of suck because all sprites, even if they're completely blank and are mainly used to help with 16x16...
www.nesmakers.com www.nesmakers.com
Try this maybe?
 
ProjectAsinus

ProjectAsinus

Member
NightMusic said:
You're using a blank spawner? Have you tried the trick for making empty sprites not draw? That might save cpu/ram.

[4.5.6] Combating Sprite Limits - Forcing Blank Sprites to Not Draw

We all (hopefully) know that the NES can only draw 8 hardware sprites per scanline, and only 64 hardware sprites total. But working with NESmaker's Game Objects or Monster Objects can kind of suck because all sprites, even if they're completely blank and are mainly used to help with 16x16...
www.nesmakers.com www.nesmakers.com
Try this maybe?
Click to expand...
My drawing script is custom made, so by default nothing is drawn unless I manually code it in.
 
dale_coop

dale_coop

Moderator
Staff member
A tile script is executed only when an object collides with it.
You could use a createobject code in a tile script that would happen when the player touches it.
 
ProjectAsinus

ProjectAsinus

Member
dale_coop said:
A tile script is executed only when an object collides with it.
You could use a createobject code in a tile script that would happen when the player touches it.
Click to expand...
That creates a problem because upon collision the script will be rapidly executed until it can’t anymore. I would need to find a way to implement some kind of timer, to space out the action.
 
smilehero65

smilehero65

Active member
ProjectAsinus said:
That creates a problem because upon collision the script will be rapidly executed until it can’t anymore. I would need to find a way to implement some kind of timer, to space out the action.
Click to expand...
I have an idea, maybe create a timer that spawns the monsters in desired X and Y positions.
This timer, however, is not an object, I'm referring to the script HandleGameTimer.asm

It executes every frame, so we should be careful to not broke the game with spawns.
 
dale_coop

dale_coop

Moderator
Staff member
ProjectAsinus said:
That creates a problem because upon collision the script will be rapidly executed until it can’t anymore. I would need to find a way to implement some kind of timer, to space out the action.
Click to expand...
Of course, you would have to create the object only of not already created... or maybe set the collision data to null just after the creation of the object, ...etc
Or use a timer if it's something that should happend repeatidly (like waves of monsters).

There are a lot of ways of doing that. It really depends of your project (how are your levels, how/when do you want to create the monster objects, ... for your game)
 
ProjectAsinus

ProjectAsinus

Member
dale_coop said:
Of course, you would have to create the object only of not already created... or maybe set the collision data to null just after the creation of the object, ...etc
Or use a timer if it's something that should happend repeatidly (like waves of monsters).

There are a lot of ways of doing that. It really depends of your project (how are your levels, how/when do you want to create the monster objects, ... for your game)
Click to expand...
Even with a limit, the tile will try to spawn up to that limit all at the same time, which is terrible for visibility sake. I tried implementing code to make it spawn on a different row each time it spawns something, but when applying it to a tile, it does not work. Likely because it's spawning them way too fast. The best solution would likely be to create a timer, but I'm not sure on exactly how to do that.
 
smilehero65

smilehero65

Active member
ProjectAsinus said:
Even with a limit, the tile will try to spawn up to that limit all at the same time, which is terrible for visibility sake. I tried implementing code to make it spawn on a different row each time it spawns something, but when applying it to a tile, it does not work. Likely because it's spawning them way too fast. The best solution would likely be to create a timer, but I'm not sure on exactly how to do that.
Click to expand...
I just remembered that Joe did a tile monster spawner with a timer in the Advanced Arcade Tutorial!

NESmaker: Arcade Platformer Tutorial - Advanced
 
TheRetroBro

TheRetroBro

Active member
baardbi said:
Using a tile to spawn monsters can be a little tricky. It's much better to make a monster spawner object. You could use an AI like this (it will also limit monsters):



Make an invisible monster and assign this AI action to the first action step. Give it a timer like 2 or 3 (or whatever), and EndAction = Repeat.
Click to expand...
Do we count the monster objects the same way we count game objects (IE vertically player 00, Object 01 (projectile) etc etc?
 
baardbi

baardbi

Well-known member
TheRetroBro said:
Do we count the monster objects the same way we count game objects (IE vertically player 00, Object 01 (projectile) etc etc?
Click to expand...
Well. We count objects with the CountObjects macro. So if you want to count player weapon objects for example, you do this:

CountObjects #%00000100 ;;; Player weapon
CMP #2 ;;; Two player weapon objects

If you want to count a specific object type you can use a macro I posted here a few months ago:

Count Object Type 4.5.9

In NESmaker there's a great macro that lets you count objects with a certain object flag set. However this does not work if you want to count certain objects without an object flag set or just a certain object type. I made a new modified macro based on the default one in NESmaker. It counts a...
www.nesmakers.com www.nesmakers.com

And yes, like ProjectAsinus said, monster objects start at 16. So game objects are 0 - 15, and monster objects are from 16 and up.
 
TheRetroBro

TheRetroBro

Active member
baardbi said:
Well. We count objects with the CountObjects macro. So if you want to count player weapon objects for example, you do this:

CountObjects #%00000100 ;;; Player weapon
CMP #2 ;;; Two player weapon objects

If you want to count a specific object type you can use a macro I posted here a few months ago:

Count Object Type 4.5.9

In NESmaker there's a great macro that lets you count objects with a certain object flag set. However this does not work if you want to count certain objects without an object flag set or just a certain object type. I made a new modified macro based on the default one in NESmaker. It counts a...
www.nesmakers.com www.nesmakers.com

And yes, like ProjectAsinus said, monster objects start at 16. So game objects are 0 - 15, and monster objects are from 16 and up.
Click to expand...
Perfect TY for claryfying
 
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