Orthographic camera rotation

Question

I can rotate the camera with this code

camera.zoom = 3//in constructor if(camera.zoom>1) { camera.zoom-=0.01f; camera.rotate(15); } 

this is done in rendering mode, now the zoom effect works correctly, but when the zoom completes, my screen remains rotated with the current angle. as shown below.

I want my screen to stop after scaling 0 degrees.

Answer 1

In code snippet

 **camera.zoom=3;** 

and at each iteration you scale the camera 0.01 to camera.zoom> 1 so you have a general iteration to scale

Then rotate with a power angle of 18 after iteration, it will rotate to a power of 360 .

Answer 2

I wrote this method to calculate the current camera angle:

 public float getCameraCurrentXYAngle(Camera cam) { return (float)Math.atan2(cam.up.x, cam.up.y)*MathUtils.radiansToDegrees; } 

Then I call the rotate method as follows:

 camera.rotate(rotationAngle - getCameraCurrentXYAngle(camera)); 

This code works, but it will rotate immediately in one call. To rotate it at speed, you need to calculate the corresponding "rotationAngle" for each frame.

Answer 3

Have you tried to rotate a multiple of 1.8 degrees with each iteration? Then you must complete the full number of revolutions after 200 iterations have passed.

Answer 4

attention, the computer cannot correctly represent most real numbers!

in binary format, 0.01 is a periodic number, so it will be truncated / rounded.

Substituting / adding floating-point numbers will add a rounding error a few hundred times and thus give you terribly wrong results.

(for example, after 200 tweaks, the value of your .zoom camera will be ~ 1.0000019 - NOT 1.0!)

why does your loop repeat 201 times, giving you a scaling value of 0.9900019 and a rotation of 361.7996 ~ 361.8 (when using 1.8, as in alex's answer).

you can use libGDX interpolation functions:

 time += Gdx.graphics.getDeltaTime(); //the rounding error is futile here, //because it'll increase the animation time by max. 1 frame camera.zoom = Interpolation.linear.apply(3, 1, Math.min(time, 1)); camera.rotate = Interpolation.linear.apply(0, 360, Math.min(time, 1)); 

this code will create an animation with a duration of one second from 3 to 1 and a rotation from 0 to 360 (just one whole rotation)