Player teleporting when jumping!

[Grady Boudreaux]

Hey! So I'm making a platformer game, but whenever I try to jump, the player teleports down and to the left. I've looked around a bit but had no idea why this was happening. Hopefully, someone with more experience than me can swoop in and fix the problem. Here's the code:

The Step Event:
//Get Player Input
key_left = keyboard_check(vk_left) or keyboard_check(ord("A"));
key_right = keyboard_check(vk_right) or keyboard_check(ord("D"));
key_jump = keyboard_check_pressed(vk_space) or keyboard_check(vk_up) or keyboard_check(ord("W"));

//Calculate Movement
var move = key_right - key_left;

hsp = move * walksp;
vsp = vsp + grv;

//Jumping
if (place_meeting(x, y + 1, obj_block)) and (key_jump) {
vsp = -7;
}

//Horizontal Collision
if (place_meeting(x + hsp, y, obj_block)) {
while (!place_meeting(x + sign(hsp), y, obj_block)) {
x = x + sign(hsp);
}
hsp = 0;
}

//Vertical Collision
if (place_meeting(x, y + vsp, obj_block)) {
while (!place_meeting(x, y + sign(vsp), obj_block)) {
y = y + sign(vsp);
}
vsp = 0;
}

//Animation / Graphics
if (!place_meeting(x, y + 1, obj_block)) {
sprite_index = spr_player_airborne;
image_speed = 0;
if (sign(vsp) > 0) image_index = 1; else image_index = 0;
}
else {
image_speed = 1;
if (hsp == 0) {
sprite_index = spr_player_two
}
else {
sprite_index = spr_player_running;
}
}


x = x + hsp;
y = y + vsp;

The Create Event:

hsp = 0;
vsp = 0;
grv = 0.3;
walksp = 4;

 

[TheouAegis]

Check the origin of your airborne Sprite. Compare it to the origin of your normal standing or running sprites.

 

[Megax60]

First of all changue:

vsp = vsp + grv

To

vsp += grv

Also grv should be 1 or 0.5, also it should be below the jump code, also it should run only if player is on air, also changue:

x = x + hsp

To

x += hsp

Also it should be below horizontal code and above vertical code

Im not on the pc to test the code so thats probably all i can do

Did you fixed it?

 

[TheouAegis]

None of those will make any significant difference to his project, they are mostly minor syntax changes. His grv can be whatever value he wants and he can add it to vsp whenever he wants.

 

[Grady Boudreaux]

Thanks to all of you! I fixed it! (I don't know how I didn't notice the origin point was off...). Although the other things are just small syntax errors, I will still change them.

Gardy

 

[TheouAegis]

Although the other things are just small syntax errors, I will still change them.

They are not errors at all. They are strictly preferences. You can ignore his post. Using += is faster to type out, but that's it. The rest of his post is just nonsensical.

 

[Megax60]

@TheouAegis im still here you know, you should show more respect instead of calling my post nonsensical, and im "her" not "his"
i helped fixing his code
first i told him to change vsp = vsp + grv to take away that bad habit, so he can improve
grav should be 0.2, 0.5 or 1, because if vsp surpasses the grav limit (if he implements it(i repeat, if he implements it)) it will just ignore the limit
the rest is to fix a bug that sometimes causes the player to get stuck in the corner

i have better things to do

 

[TheouAegis]

Sorry. ^"HER post."

0.2 doesn't even work. Rounding errors. So his grv can be whatever. If it surpasses the limit, that's what > is for.

vsp=vsp+grv can be run first just fine and is how gravity works in the real world. His collision code is to prevent gravity from accelerating him through the ground.

X += hsp

Also it should be below horizontal code and above vertical code

the rest is to fix a bug that sometimes causes the player to get stuck in the corner

Ok, that I agree with, but the way your post was worded, it was kind of vague what your intended meaning was there. So to clarify for anyone else reading:

x+=hsp (or x=x+hsp) should be run immediately after horizontal collision checks with this style of collision checking, but before any vertical collision code. Or if you run your vertical collision checks first, you need to make sure y+=vsp is handled before the horizontal collision check. Concave corners shouldn't be an issue, but you will easily get stuck on convex corners like cliff edges and stairs if x+=hsp and y+=vsp are handled at the same time, as there could be no immediate collision detected horizontally nor vertically, but if there is one horizontally AND vertically, you would move into it after the collision check failed to find it.

 

[rIKmAN]

x = x + hsp

To

X += hsp

This change would break his code.

X is not the same as x.

 

[Megax60]

This change would break his code.

X is not the same as x.

i know, but i was on phone, it automatically sets the first letter to capital

 

[rIKmAN]

i know, but i was on phone, it automatically sets the first letter to capital

If you knew, then you should have changed it.

If you are going to give advice, then please make sure the code changes you are telling people to make are correct.