Change the default mode of the 3D Transform tool from CAMERA to
ROTATE. Canvas interaction is limited in camera mode, while
rotation is the main function of the tool.
Add a "Unified interaction" option to the 3D Transform tool, and a
corresponding "unified" property to GimpToolTransform3DGrid. When
active, all three interaction modes of the grid (camera, move, and
rotate) are available simultaneously, regardless of the active
dialog page. In this mode, the inner and outer regions of the item
are used for moving and rotation, respectively, and the vanishing-
point is controlled through through a handle.
Add a new 3D Transform tool, based on GimpToolTransform3DGrid,
added in the previous commit. The tool UI provides a notbook with
three tabs, corresponding to the three GimpToolTransform3DGrid
modes:
Camera - allows setting the primary vanishing point, as well as
the camera's focal length, expressed either directly, or as the
camera's angle of view, relative to the whole image or the
transformed item. By default, the vanishing point is aligned
with the item's center, and the angle of view is fixed relative
to the item; this essentially means that each item is transformed
using a local perspective, independent of its position and size
relative to the image. A global perspective can be achieved by
using a common vanishing point and focal length (or an image-
relative angle of view).
Move - allows moving the item using X, Y, and Z offsets.
Rotate - allows rotating the item using X, Y, and Z Euler angles.
The order of rotation of the different axes can be controlled by
a set of numbered buttons next to the sliders, and the rotation's
pivot can be controlled using a pivot selector.
Ell