Struct trackball::Orbit

pub struct Orbit<N: Copy + RealField> { /* private fields */ }

Orbit induced by displacement on screen.

Implements Default and can be created with Orbit::default().

Both its methods must be invoked on matching events fired by your 3D graphics library of choice.

Implementations

impl Orbit<f32>

pub fn compute( &mut self, pos: &Point2<f32>, max: &Point2<f32> ) -> Option<UnitQuaternion<f32>>

Available on crate feature cc only.

Computes rotation between previous and current cursor/finger position.

Normalization of previous position is cached and has to be discarded on button/finger release via Self::discard(). Current position pos is clamped between origin and maximum position max as screen’s width and height.

Screen space with origin in top left corner:

• x-axis from left to right,
• y-axis from top to bottom.

Camera space with origin at its target, the trackball’s center:

• x-axis from left to right,
• y-axis from bottom to top,
• z-axis from far to near.

Returns None:

• on first invocation and after Self::discard() as there is no previous position yet,
• in the unlikely case that a position event fires twice resulting in zero displacements.

pub fn discard(&mut self)

Available on crate feature cc only.

Discards cached normalization of previous cursor/finger position on button/finger release.

pub fn cast<M: Copy + RealField>(self) -> Orbit<M>where f32: SubsetOf<M>,

Available on crate feature cc only.

Casts components to another type, e.g., to f64.

impl Orbit<f64>

pub fn compute( &mut self, pos: &Point2<f64>, max: &Point2<f64> ) -> Option<UnitQuaternion<f64>>

Available on crate feature cc only.

Computes rotation between previous and current cursor/finger position.

Normalization of previous position is cached and has to be discarded on button/finger release via Self::discard(). Current position pos is clamped between origin and maximum position max as screen’s width and height.

Screen space with origin in top left corner:

• x-axis from left to right,
• y-axis from top to bottom.

Camera space with origin at its target, the trackball’s center:

• x-axis from left to right,
• y-axis from bottom to top,
• z-axis from far to near.

Returns None:

• on first invocation and after Self::discard() as there is no previous position yet,
• in the unlikely case that a position event fires twice resulting in zero displacements.

pub fn discard(&mut self)

Available on crate feature cc only.

Discards cached normalization of previous cursor/finger position on button/finger release.

pub fn cast<M: Copy + RealField>(self) -> Orbit<M>where f64: SubsetOf<M>,

Available on crate feature cc only.

Casts components to another type, e.g., to f32.

Trait Implementations

impl<N: Clone + Copy + RealField> Clone for Orbit<N>

fn clone(&self) -> Orbit<N>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<N: Debug + Copy + RealField> Debug for Orbit<N>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<N: Default + Copy + RealField> Default for Orbit<N>

fn default() -> Orbit<N>

Returns the “default value” for a type.