LeapGetDeviceTransform

leap_sys

Function LeapGetDeviceTransform 

Source 
pub unsafe extern "C" fn LeapGetDeviceTransform(
    hDevice: LEAP_DEVICE,
    transform: *mut f32,
) -> eLeapRS
Expand description

\ingroup Functions Get the transform to world coordinates from 3D Leap coordinates.

To get the transform, you must supply an array of 16 elements.

The function will return a an array representing a 4 x 4 matrix of the form:

R, t 0, 1

where: R is a 3 x 3 rotation matrix t is a 3 x 1 translation vector

Note that the matrix is in column major, e.g. transform[12] corresponds to the x coordinate of the translation vector t.

A possible pipeline would be, for example:

  1. Get “palm_pos” the position of the center of the palm (as a 3x1 vector)
  2. Construct a 4x1 vector using the palm_position: palm_pos_4 = (palm_pos.x; palm_pos.y; palm_pos.z; 1.0f)
  3. Create a 4x4 matrix “trans_mat” as illustrated above using the returned transform
  4. Get the position of the center of the palm in world coordinates by multiplying trans_mat and palm_pos_4: center_world_4 = trans_mat * palm_pos_4

This function returns eLeapRS_Unsupported in the case where this functionality is not yet supported.

@param hDevice A handle to the device to be queried. @param[out] transform A pointer to a single-precision float array of size 16, containing the coefficients of the 4x4 matrix in Column Major order. @returns The operation result code, a member of the eLeapRS enumeration. @since 5.4.0