In my game I have a gif that walk back and forth with a speed of 1, and when it hits a wall the gif changes it speed to -1. How can I make my gif flip it self when it changes speed to -1 and stay that way until it changes it speed again.
FCG wrote ...
2013/5/13
GIF Help Fast Please :)
Check the GreenfootImage API documentation for what methods might come in handy, here.
danpost wrote...
Check the GreenfootImage API documentation for what methods might come in handy, here.
That is the correct method, but not the correct place for it. You should have something like this
1 2 3 4 5 | if ((speed == -1 && getX() < 10) || (speed == 1 && getX() > getWorld().getWidth()-10)){ getImage().mirrorHorizontally(); speed = -speed;} |
danpost wrote...
That is the correct method, but not the correct place for it. You should have something like this
1 2 3 4 5 | if ((speed == -1 && getX() < 10) || (speed == 1 && getX() > getWorld().getWidth()-10)){ getImage().mirrorHorizontally(); speed = -speed;} |
danpost wrote...
It should not make any difference that the image is a gif.Oh, so you are using an animation! After calling 'super.act();', execute this statement:
And remove the image flipping from within the 'if' statement given previously (just negate 'speed').
1 | if (speed < 0) getImage().mirrorHorizontally(); |
danpost wrote...
Oh, so you are using an animation! After calling 'super.act();', execute this statement:
1 | if (speed < 0) getImage().mirrorHorizontally(); |
danpost wrote...
It might be better if you show what code you have so far.public void addedToWorld(World world)
{
setImage("dog.gif"); //You must use the setImage method and not just right click + setImage in the GUI.
}
public void act()
{
super.act();
im using the gif sub class that is available in Greenfoot: http://www.greenfoot.org/scenarios/260
So I want the image to flip horizontally and stay that way when speed is -1.Apparently, as the GifActor class is right now, there is no way to mirror the animation without creating a new 'gif' file with mirrored images in it, as you can only set the 'gif animation' images by using 'setImage(String)'.
But, maybe there is a way to modify the class. Add a method to the GifActor class that mirrors all the images in its gif array and call it each time your actor changes direction.
Then, you would use the following:
1 2 3 4 | public void mirrorImagesHorizontally(){ for (int i=0, i<images.length; i++) images[i].mirrorHorizontally();} |
1 2 3 4 5 | if ((speed == -1 && getX() < 10) || (speed == 1 && getX() > getWorld().getWidth()-10)){ speed = -speed; mirrorImagesHorizontally();} |
danpost wrote...
Apparently, as the GifActor class is right now, there is no way to mirror the animation without creating a new 'gif' file with mirrored images in it, as you can only set the 'gif animation' images by using 'setImage(String)'.
But, maybe there is a way to modify the class. Add a method to the GifActor class that mirrors all the images in its gif array and call it each time your actor changes direction.
1 2 3 4 | public void mirrorImagesHorizontally(){ for (int i=0, i<images.length; i++) images[i].mirrorHorizontally();} |
1 2 3 4 5 | if ((speed == -1 && getX() < 10) || (speed == 1 && getX() > getWorld().getWidth()-10)){ speed = -speed; mirrorImagesHorizontally();} |
I am sure you caught it, but there was a typo in the 'mirrorImagesHorizontally' method. The 'for' statement has a comma that should be a semi-colon.
If you are placing your actor too close (10 or less pixels) to the left or right side of the world, you may get that. If that is the case, you can either change the '10's in the code above to a smaller number or start your character further from the edge of the world.
Other than that, I cannot say what the problem is. I have tested the code given in the gif animation scenario you mentioned above and it seems to work properly.
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