Certainly for divisions there is no reason to keep them immutable. For
fixedEyeAtCameraZero, I don't think the reasons for keeping it immutable
are compelling.
Making either change in FX 8 is a different matter, though, given how
late we are. The implementation assumes immutability and we would need
to change it, implement it, test it, and then fix any bugs as a result.
Seems like we could add mutability in a subsequent release.
-- Kevin
Richard Bair wrote:
I would turn that around and say that unless there is a compelling reason for
something to be immutable, it should be mutable. Mutability is important for
tools as well as for FXML as well as for developers.
Immutable state is awesome for thread-safety or any type of concurrency. But these types
of classes are not of that nature, they're UI only classes, and as such their state
should be mutable (and like all mutable state in FX, the range of possible values should
not be hindered by the evil "unbind" pattern).
Richard
On Oct 4, 2013, at 12:46 PM, Kevin Rushforth <kevin.rushfo...@oracle.com> wrote:
Yes, that pretty much captures the thinking behind it.
My thought is that there is no real reason that subdivisions need to be
immutable, although I wouldn't want to change it at this late date for FX 8
unless it is needed for FXML support.
The fixedEyeAtCameraZero mode is not something I think should be mutable, since
the camera behaves fairly differently in each mode. Having said that, there is
no reason it couldn't be made mutable in a subsequent release if there was a
good reason to do so.
-- Kevin
Chien Yang wrote:
We did discuss making divisions in the predefined 3D shapes mutable in earlier
meeting. However we decided against it since it is a heavy weight operation as
the supporting mesh will has to be regenerated. I believe the constructor with
the divisions argument will not have much use in the future when we move away
from mesh implementation of our predefined 3D shapes.
The fixedEyeAtCameraZero flag in PerspectiveCamera is a setup flag to the
camera and once set it shouldn't be changed. The perspective projection matrix
is constructed differently depending on the flag. In the default mode, JavaFX
controls the eye to achieve a projection plane at Z=0 so that simple adding of
3D shapes into a 2D scene looks intuitive. The other mode, where eye is fixed a
camera zero, is well suitable for movable camera in the 3d space.
- Chien
On 10/4/2013 9:28 AM, Richard Bair wrote:
Why are they not? It isn't immediately obvious to me why these are not mutable?
I was reading https://javafx-jira.kenai.com/browse/RT-29577 and this struck me
as odd.
Richard
