Sprite and BG Movement

Validate if the sprite collide/exit the map in one axis at time. If the check return true, then set the speed of the sprite in that axis to 0. You can check the code of this project [QKYDE4QD] : - _EUTIL: There is a basic code to handle sprite movement based on collision with layer 3 on the function colBG. This will stop the sprite on that axis if there is a tile on the way. - __CAMERA: The function setSpeed handle when the camera is out of bound. This stop the backgrounds and the sprite that act as a camera when they would exit from the boundaries defined on the code by the rectangle formed by the points (LX%,LY%),(UX%,UY%). Also, the camera handle the position as integer. This is done in that way because the BGOFS doesn't work with decimal. It would be useful if you could write your current implementation (or post a key) so we could see if there is something wrong.

Thanks and here is what I have so far. It involves everything about how the sprite moves. This is what it looked like when I first noticed the problem:

BGSCREEN 0,128,127
OLD=496 'This is for the direction the sprite will face once it stops moving
MOVE=FALSE
'UP=FALSE 'These were about to be implemented instead of functions
'DOWN=FALSE
'LEFT=FALSE
'RIGHT=FALSE
S=5
ASP=0
AMAN=496
AX=190
AY=110

SPOFS ASP OUT X,Y
SPOFS ASP ASP,AX,AY,AZ
BGOFS 0,BGX,BGY

BTN=STKANDBTN()
IF MOVE=FALSE THEN SPCHR APS,OLD
IF BTN==1 AND BTN==17 AND BTN==33 THEN UP
IF BTN==2 AND BTN==18 AND BTN==34 THEN DOWN
IF BTN==4 AND BTN==20 AND BTN==36 THEN LEFT
IF BTN==8 AND BTN==24 AND BTN==40 THEN RIGHT
IF BTN==5 AND BTN==21 AND BTN==37 THEN UPLEFT
IF BTN==9 AND BTN==25 AND BTN==41 THEN UPRIGHT
IF BTN==6 AND BTN==22 AND BTN==38 THEN DOWNLEFT
IF BTN==10 AND BTN==26 AND BTN==42 THEN DOWNRIGHT
'The A and B buttons are used. A for attacking and B for speeding up/running

IF AX<0 THEN AX=0
IF AX>800 THEN AX=800
IF AY<0 THEN AY=0
IF AY>800 THEN AY=800
IF BGX<0 THEN BGX=0
IF BGX>600 THEN BGX=600
IF BGY<0 THEN BGY=0
IF BGY>768 THEN BGY=768

DEF UP
AY=AY-YMOVE
BGY=BGY-BGYMOVE
ANIM=ANIM+1
IF ANIM==S THEN SPCHR ASP,AMAN+13
IF ANIM==S*2 THEN SPCHR ASP,AMAN+14
IF ANIM==S*3 THEN SPCHR ASP,AMAN+15
IF ANIM==S*4 THEN  SPCHR ASP,AMAN+14
OLD=508:MOVE=TRUE
'The function updates the value of the x coordinate variables and counts for how many times it will change the frames.
END
'All of the other functions follow this formula

It was the moment I started implemented bgscreen movement. The sprite does not want to go into the corners or edges of the screen. What I had wrote was working as I wanted it to before.

Ok, I guess the problem is the function UP. You need to check the collision with the boundaries before moving the sprite. Here is a brief description of what's happening: 1.Sprite is at point 0,0(AX=0,AY=0) 2. You press up for a long time.(AY=-1*number of frame) 4. You press down (AY is still less than 0 so the sprite is stuck. You need to press down for a while until AY is greater than 0) I suggest you to always set xMove and yMove to 0, and only change them to -1 or 1 if you press the button. Then, after all the input logic, you must put the validations and the movement. Example:

yMove=0
if button and #UP then yMove=-1
if button and #DOWN then yMove=1

if AY+yMove>0 && AY+yMove<800 then AY=AY+yMove

So I keep xmove and ymove at 0 and change the value when i press the button and whatever that value is -1 or 1 will then be added to AY. Ok i got it. Thanks for your help.

I cannot understand what is wrong with my code. This is not all of it.

PSP=1
PX=201 'These move the sprite
PY=121
PLX=201 'These move the BG
PLY=121
XMIN=200 'The min and max distances that the screen can go up, down, left, or right without the screen showing black
XMAX=1400
YMIN=120
YMAX=1480

SPSET PSP,PX,PY

WHILE TRUE
 SPD=2
 VX=0
 VY=0
 AX=0
 AY=0

 BTN=STKANDBTN() 'Calls a function

 IF BTN AND #UP THEN VY=-SPD ELSEIF BTN AND #DOWN THEN VY=SPD
 IF BTN AND #LEFT THEN VX=-SPD ELSEIF BTN AND #RIGHT THEN VX=SPD

 IF (PLY>=0 AND PLY<=YMIN) OR (PLY>=YMAX AND PLY<=1575) THEN VY=0
 IF (PLX>=0 AND PLX<=XMIN) OR (PLX>=XMAX AND PLX<=1575) THEN VX=0

 IF (PLY>=0 AND PLY<=YMIN) AND (BTN AND #UP) THEN AY=-SPD ELSEIF (PLY>=YMAX AND PLY<=1575) AND (BTN AND #DOWN) THEN AY=SPD
 IF (PLX>=0 AND PLX<=XMIN) AND (BTN AND #LEFT) THEN AX=-SPD ELSEIF (PLX>=XMAX AND PLX<=1575) AND (BTN AND #RIGHT) THEN AX=SPD

 PLX=PLX+VX
 PLY=PLY+VY

 PX=PX+AX
 PY=PY+AY

VSYNC
WEND

So this is supposed to stop the velocities once they get to a certain range, which it does. It does stop the background from moving but the sprite will not move along the x axis when in a corner and only moves up on the y axis and not back down. I only tried it in one corner too (top left). I would also try to debug it myself, but I am confused as to why this doesn't work. Any guidance helping me figure this out is greatly appreciated.

It might be because you're using AND instead of &&. && checks if both values are not 0, while AND compares individual bits. You should use && everywhere here except when checking BTN.

Ok thanks, that makes sense. I will try it out.

Ok that helped the sprite to move along the x axis. I think I realize now what I have to do to get the sprite to move up and down in corners or left and right. And if I can do that, the rest of the code should work. Thanks! EDIT: (I feel so dumb right now)