Collision between two sprites

...
IF SPHITSP(PAC, 1)!=-1 THEN 
 SPOFS 0, OLDX, Y
 IF SPHITSP(PAC, 1)==-1 THEN X=OLDX
ENDIF
IF SPHITSP(PAC, 1)!=-1 THEN 
 SPOFS 0,X,OLDY
 IF SPHITSP(PAC, 1)==-1 THEN Y=OLDY
ENDIF
'NOPE DOESN'T WORK

You cannot use -1 here. SPHITSP has 2 arguments which outputs differently. You've used this: SPHITSP(Sprite,Opponent sprite) It checks whether Pac-Man collides with the opponent sprite. It returns TRUE when collision was made and FALSE if it didn't. -1 works as expected if you only use 1 argument as: SPHITSP(Sprite) Then it outputs the opponent sprite ID or -1 if it doesn't. Using 1 argument isn't often viable because if Pacman hits a cherry e.g. he'll ignore the ghosts.

...
IF SPHITSP(PAC, 1)!=-1 THEN 
 SPOFS 0, OLDX, Y
 IF SPHITSP(PAC, 1)==-1 THEN X=OLDX
ENDIF
IF SPHITSP(PAC, 1)!=-1 THEN 
 SPOFS 0,X,OLDY
 IF SPHITSP(PAC, 1)==-1 THEN Y=OLDY
ENDIF
'NOPE DOESN'T WORK

You cannot use -1 here. SPHITSP has 2 arguments which outputs differently. You've used this: SPHITSP(Sprite,Opponent sprite) It checks whether Pac-Man collides with the opponent sprite. It returns TRUE when collision was made and FALSE if it didn't. -1 works as expected if you only use 1 argument as: SPHITSP(Sprite) Then it outputs the opponent sprite ID or -1 if it doesn't. Using 1 argument isn't often viable because if Pacman hits a cherry e.g. he'll ignore the ghosts.

Ok so now I've edited my code to look like this

...
IF SPHITSP(PAC, 1)==TRUE THEN
 SPOFS PAC, OLDX, OLDY
ENDIF

Is this correct?

...
IF SPHITSP(PAC, 1)!=-1 THEN 
 SPOFS 0, OLDX, Y
 IF SPHITSP(PAC, 1)==-1 THEN X=OLDX
ENDIF
IF SPHITSP(PAC, 1)!=-1 THEN 
 SPOFS 0,X,OLDY
 IF SPHITSP(PAC, 1)==-1 THEN Y=OLDY
ENDIF
'NOPE DOESN'T WORK

You cannot use -1 here. SPHITSP has 2 arguments which outputs differently. You've used this: SPHITSP(Sprite,Opponent sprite) It checks whether Pac-Man collides with the opponent sprite. It returns TRUE when collision was made and FALSE if it didn't. -1 works as expected if you only use 1 argument as: SPHITSP(Sprite) Then it outputs the opponent sprite ID or -1 if it doesn't. Using 1 argument isn't often viable because if Pacman hits a cherry e.g. he'll ignore the ghosts.

Ok so now I've edited my code to look like this

...
IF SPHITSP(PAC, 1)==TRUE THEN
 SPOFS PAC, OLDX, OLDY
ENDIF

Is this correct?

Well that would only collide with one sprite. There's another option though, with 3 arguments. SPHITSP(sprite, start range, end range) This basically detects collision in a defined range of sprites. I don't remember what it returns, but I think it's a true/false situation. EDIT: Nope, it returns the colliding sprite ID.

Well that would only collide with one sprite. There's another option though, with 3 arguments. SPHITSP(sprite, start range, end range) This basically detects collision in a defined range of sprites. I don't remember what it returns, but I think it's a true/false situation. EDIT: Nope, it returns the colliding sprite ID.

Well right now I only have two sprites down, pac-man and a wall. I just want to get pac-man to stop at this wall so I can expand off of that. I tested the code I made (didn't use it before lol) and pac-man went through the wall still.

Well I would check whether it's actually detecting collision, by putting a beep in the IF statement or something to listen for.

IF CONDITION THEN
 BEEP
 DOSTUFF
ENDIF

Then you could figure out from there if the problem is in the IF statement or what it's doing in response.

Well I would check whether it's actually detecting collision, by putting a beep in the IF statement or something to listen for.

IF CONDITION THEN
 BEEP
 DOSTUFF
ENDIF

Then you could figure out from there if the problem is in the IF statement or what it's doing in response.

Ok, I did this and the problem is that it won't detect collision. I checked with a

LOCATE 0,0
PRINT SPHITSP(PAC,1)

And it doesn't change when I collide with the other sprite.

I’d recommend going to chat for your problem. It would be a lot faster and you can fix your problem in a few minutes rather than a few days (usually) (sometimes chat is dead).

I’d recommend going to chat for your problem. It would be a lot faster and you can fix your problem in a few minutes rather than a few days (usually) (sometimes chat is dead).

I've tried to check the chat a few times, and it is usually dead. If I saw any activity, I would ask there, but I never see any activity

what are your walls? sprites or bg?

I've tried to check the chat a few times, and it is usually dead. If I saw any activity, I would ask there, but I never see any activity

Lol did you get past the /accept when you first enter chat? I tried talking to you earlier today on there and you never responded, and you don’t have any chat stats.

I've tried to check the chat a few times, and it is usually dead. If I saw any activity, I would ask there, but I never see any activity

Lol did you get past the /accept when you first enter chat? I tried talking to you earlier today on there and you never responded, and you don’t have any chat stats.

I did before, I was at school when you sent those. lol it didn't show /accept when I did before so I thought it was empty :|

what are your walls? sprites or bg?

Sprites, though I have taken the recommendation of using maps

ok

saving for a rainy day

Just saw you entering and leaving chat a bunch; you still don't have any chat statistics, which means you haven't accepted chat policy yet. if you see a message like this: then read the whole thing, please. If you don't, just send /accept and you'll join chat.

Just saw you entering and leaving chat a bunch; you still don't have any chat statistics, which means you haven't accepted chat policy yet. if you see a message like this: then read the whole thing, please. If you don't, just send /accept and you'll join chat.

I sent /accept, and that was me just checking to make sure of something lol

chat stuff

I sent /accept, and that was me just checking to make sure of something lol

Hmm, seems like our test for seeing if someone could access chat was wrong this entire time. I wonder how many newcomers actually did join chat without us knowing...

chat stuff

I sent /accept, and that was me just checking to make sure of something lol

Hmm, seems like our test for seeing if someone could access chat was wrong this entire time. I wonder how many newcomers actually did join chat without us knowing...

( ͡° ͜ʖ ͡°)

WAIT I THINK I KNOW YOUR PROBLEM!!! YOU NEED TO CALL SPCOL ON EACH SPRITE BEFORE USING SPHITSP! It's simple to use:

SPCOL sprite ID

SPSET 1, 6
SPOFS 1,36,36
SPSET 2,96,16
SPOFS 2,52,36
SPSET 3,6
SPOFS 3,60,60
SPHOME 3,8,8
SPROT 3,90
SPCOL PAC,TRUE
SPCOL 1,TRUE

It helps to look through all the code lol

another question: are the walls a single big sprite or multiple sprites?

Something like this tends to work:

if x1 + w1 > x2 and x1 < x2 + w2 and y1 + h1 > y2 and y1 < y2 + h2 then whateverYouWantHere = true

For blocks four smaller hit boxes that each do different things one for top, bottom etc. Also and additional check to make sure the player doesnt run past the hitbox, and that only the bottom of the player collides with this hitbox:

if x1 + w1 > x2 and x1 < x2 + w2 and y1 + h1 > y2 and y1 + h1 < y2 + 0.1 + velY and velY > 0 then y1=y2-h1

To save memory, only check the hit boxes around the player, like this(assuming tilemap is 16 by 16 in actual space)

startX = floor(playerX / 16)
startY = floor(playerY / 16)
endX = ceil((playerX + playerW) / 16)
endY = ceil((playerY + playerH) / 16)

If startX<0 then startX = 0 elseif startX> levelLengthX then startX= levelLengthX
'Same for y

For j=startY to endY
  For i=startX to endX
    If levelMap[j][i] == "1" then collider i*16,j*16,16,16
  Next
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