sprite_index not working gamemaker studio 2 (GML)

Question

I have a small script that changes the sprite index when I press a certain key.

 if (key_right)
    {
    sprite_index = playerRightSpr;//<-------------
    image_speed = 1;                           //|
    }                                          //|
    if (key_left)                              //|
    {                                          //|
    sprite_index = playerLeftSpr;              //|
    image_speed = 1;                           //|
    }                                          //|
    if (key_left) && (key_right)               //|
    {                                          //|
    sprite_index = playerSpr;                  //|
    image_speed = 0;                           //|
    }                                          //|
    if (!key_right or key_left) //add this and this, doesn't work
    {                           //but it does when I remove this code.
    sprite_index = playerSpr;
    image_speed = 0;
    }

Is there another way to say when standing still make sprite playerSpr because the way i'm trying seems to cause conflict. Thanks in advance Bhodi

Looks like your bottom if statement is missing the `!` on the last statement, that looks likely the cause. As `!` should be declared for each statement. I've also a different solution I can show in case it didn't worked out. — Steven, Sep 19 '18 at 05:59
That didn't work, could you please tell me the other solution? — AnUnnamedPerson, Sep 19 '18 at 06:50

score 2 · Accepted Answer · 2018-09-19T08:36:08.080

2

If your entity moves you can just use the speed variable to make this. For example :

if your entity has a positive speed (go right) you will use PlayerRightSpr
if your entity has a negative speed (go left) you will use PlayerLeftSpr
And if speed is 0 you use PlayerSpr

(Instead of using two different sprites you can use image_xscale too)

image_xscale = 1; (normal sprite)

image_xscale = -1; (flip on x axis : mirror)

And finally instead of this :

if (!key_right or key_left)

Use this :

if (!key_right || !key_left)

Or this :

if (key_right == 0 || key_left == 0)

But you are right it's not the correct way to do this

I hope this way is good

edited Sep 19 '18 at 08:36

answered Sep 19 '18 at 08:29

1

Thanks for you help. My syntax was a bit off but this worked. – AnUnnamedPerson Sep 20 '18 at 01:18
No problem. It's a little difficult to understand Game maker at first times but it's really powerful – Sep 20 '18 at 06:13
Nice job in solving the code as-is. I think I went a little overcompilated on my answer. – Steven Sep 20 '18 at 06:19

Steven · Answer 2 · 2019-01-22T09:15:53.467

Here's my second solution. This went from my own project, so it does require changing the whole code.

I've explained each section with comments next to each lines.

Step event:

var hinput = 0; //hinput = Horizontal Input
hinput = keyboard_check(vk_right) - keyboard_check(vk_left); //the trick I've used to declare the movement system, based on the arrow keys. 
                                                             //pressing right = 1, pressing left = -1, pressing both or none = 0.

if (hinput != 0) //it is not 0, so the player is moving
{
    sprite_index = s_player_walk; //changes the current sprite to the walking animation
    image_xscale = hinput;        //changes the direction it's facing: 1 = right, -1 = left.
                                  //when it's 0, it keeps the last direction it faced.
} 
else //the player is not moving
{
    sprite_index = s_player_idle; //changes the current sprite to the idle animation
}

As for the images itself. I've used 2 seperate sprites for this:
s_player_idle, which exists of only 1 frame, and
s_player_walk, which exists of 3 looping frames.

The image speed is already defined in the image editor for each seperate sprite, so it doesn't need to be defined again in the code.

sprite_index not working gamemaker studio 2 (GML)

2 Answers2