The Rotate Tool is used to rotate the active layer, selection or
path.
4.4.1. Overview
When you click on the image or the selection with this tool, a
grid or an outline is superimposed and a
Rotation Information dialog is opened.
There, you can set the
rotation axis, marked with a point, and the rotation angle. You
can do the same by dragging the mouse pointer on the image or
the rotation point.
4.4.2. Activate Tool
You can call the Rotate tool in the following
order, from the image-menu:
Tools → Transform Tools → Rotate
The Tool can also be called by clicking the tool icon:
in the Toolbox.
or by using the
Shift-R
key combination.
4.4.3. Key modifiers (Defaults)
Ctrl
Holding Ctrl will constrain the rotation
angles to those only evenly divisible by 15 degrees.
Options
Figure 8.47.
Rotation tool options
Overview
The available tool options for the Rotate Tool can be
accessed by double clicking the Rotate Tool icon.
Affect
The Rotate tool can affect the Layer, the Selection, and the
Path differently. These three buttons associate the
remainder of the options to one of those three elements.
Remind that this option persists when you quit the tool.
Transform Direction
The Transform Direction sets which way or direction a layer
is rotated. The Traditional mode will rotate the layer as one
might expect. If a layer is rotated 10 degrees to the right,
then the layer will be rendered as such. This behaviour is
contrary to Corrective rotation.
Corrective Rotation is primarily used to repair scanned
images that are not straight. If the image is 13 degrees
askew then you need not try to rotate by that angle. By
using Corrective Rotation you can rotate visually and line
up the layer with the image. Because the transformation is
reversed, or performed backwards, the image will be rotated
with sufficient angle to correct the error.
Interpolation
The Interpolation drop-down list allows
you to choose the quality of the transformation. For more
information about the different methods that can be employed,
see the glossary entry Interpolation.
This option will clip the transformated image to the original image
size.
Preview
Here, Preview is superimposed on the image. The
drop-down list gives you four possibilities:
Outline: Puts a frame to mark
the image outline, with a handle on each corner.
Movements will affect this frame only.
Grid: Puts a grid on the image,
with four handles. Movements will affect this grid
only.
Image: Here, the preview is a
copy of the image superimposed on the image, with an
outline. Movements affect this copy and the
underlying image appears.
Grid+Image: Both turn at the
same time.
Preview is only for greater convenience. Whatever your
choice, result will be the same when you clic on the
Rotate button in the Rotate
Informations dialog.
Options with grid activate a drop-list with two options:
Number of Grid Lines will allow control
over the total number of displayed grid lines. Use the
slider to set the number of grid lines.
Grid Line Spacing allows control over
the distance between the grid lines. Use the slider to set
the distance.
Note
When rotating a path, Preview options are not valid: only
Outline is active.
Constraints
15 Degrees will constrain the rotation
to angles divisible by 15 degrees.
The Rotation Information window
Figure 8.48.
The Rotation Information dialog window
Angle
Here you can set the rotation angle, from -180° to +180°, i.e
360°.
Center X/Y
This option allows you to set the position of the rotation center,
represented by a large point in the image. A click-and-drag on this
point also allows you to move this center. Default unit of
measurement is pixel, but you can change it by using the drop-down
list.
![[Note]](../images/note.png)
