GameMaker Setting image_speed on a draw_sprite_ext()

[Gregory Tapper]

Hi!

Having trouble animating a sprite I'm drawing. Setting image_speed in the create/draw event doesn't seem to be doing anything. The sprite remains static The object itself is a parent object that draws an animated river sprite (2 frames) and then itself (the children will draw static river edges).

Here's the code in the Draw Event :

draw_sprite_ext(spr_river,image_index,x,y,1,1,0,col,1);
image_speed = 1;
draw_self();

Any suggestions? Thank you!

 

[Simon Gust]

I believe that the image_speed is just too high.
You have set it to an insane speed for only 2 frames of animation.
Try 0.12

 

[Gregory Tapper]

I believe that the image_speed is just too high.
You have set it to an insane speed for only 2 frames of animation.
Try 0.12

Ahh, good suggestion. But nope I tried 0.01 too just to be sure.

 

[NightFrost]

Do you have any code in step event or scripts it calls that set image_index value? Setting your animation speed through image_speed helps you none if a piece of code elsewhere interferes by setting the current animation frame.

 

[Gregory Tapper]

Do you have any code in step event or scripts it calls that set image_index value? Setting your animation speed through image_speed helps you none if a piece of code elsewhere interferes by setting the current animation frame.

Unfortunately, it was just added. Hasn't been manipulated anywhere else yet.

 

[Perseus]

The problem here is that you're using image_index for its subimage argument. Since the child object running this code has been assigned a sprite that has a single subimage only, image_index can never be larger than 0, regardless of what image_speed is being set to. This causes your animated spr_river sprite to be drawn static as its first (index 0) subimage.

The solution is to use a custom instance variable whose value is to be incremented and reset as per your needs. For instance, the current setup can be fixed using a variable that sets its value this way every step:

my_image = 1 - my_image;

 

[Gregory Tapper]

The solution is to use a custom instance variable whose value is to be incremented and reset as per your needs. For instance, the current setup can be fixed using a variable that sets its value this way every step:

my_image = 1 - my_image;

Thank you @Ragarnak ! This worked! And thanks for the explanation.

For anyone running into the same issue, here's what I did:

//Create Event
imgdex = 0;
river_speed = room_speed/2;
alarm[0] = river_speed;

//Step Event
image_index = imgdex;

//Alarm[0]
imgdex = 1 - imgdex;
alarm[0] = river_speed;

//Draw Event
draw_sprite_ext(spr_river,image_index,x,y,1,1,0,-1,1);
draw_self();

 

[Perseus]

Thank you @Ragarnak ! This worked! And thanks for the explanation.

You're welcome. Glad I could help you.

Just for the record, you can skip using image_index whatsoever. Not only is it a better practice, it also eliminates your chances of running into issues.

Create:

imgdex = 0;
river_speed = room_speed / 2;
alarm[0] = river_speed;

Alarm 0:

imgdex = 1 - imgdex;
alarm[0] = river_speed;

Draw:

draw_sprite_ext(spr_river, imgdex, x, y, 1, 1, 0, -1, 1);
draw_self();