Add a GimpTransformGridTool::matrix_to_info() virtual function,
which should extract the tool-specific transformation parameters
given a transformation matrix, and the old parameter set (which is
needed in some tools, to derive the parameters that aren't encoded
in the matrix, such as the pivot point). The transformation matrix
can be any combination of matrices calculated by the tool, and
their inverses. Subclasses should only implement this function if
every such matrix can be mapped back to transformation parameters.
This is currently the case for all the transform-grid tools, except
for the shear tool (since it only supports shearing along one of
the horizontal or the vertical directions, however, the combined
matrix may require shearing in both directions).
When a transform-grid tool implements this function, show a chain-
button between the two transform-direction radio-buttons in the
tool options. When the chain-button is linked, whenever the
transform corresponding to the active direction is modified, adjust
the transform corresponding to the non-active direction such that
the overall transform remains the same.
One notable workflow that this enables is transforming a layer
while adjusting a different area than its boundary, by first
defining the area while the transform-directions are linked, and
then transforming the area while the transform-directions are
unlinked.
(cherry picked from commit 39e23267f7)
In GimpTransformGridTool, allow performing simultaneous forward
(normal) and backward (corrective) transforms, by having each
transform direction operate on an independent set of parameters.
In other words, whereas the transform-grid tools previously had a
single transform, which could be applied either normally or
correctively using the "direction" tool-option, they now have two
independent transforms, one applied normally and the other
applied correctively, which are toggled using the "direction"
option. The overall transform is the combination of the backward
transform, followed by the forward transform.
Another way to think about it, is that the tool transforms a source
shape into a destination shape. The source shape is defined by the
backward transform, and the destination shape is defined by the
forward transform. Wherewas previously only one of these shapes
could be controlled (the other shape always being the item bounds),
it's now possible to control both shapes in a single transform.
The next commit will allow modifying both shapes simultaneously,
making this even more useful.
Note that since both transforms start off as the identity, using
only one of the transform directions has the same behavior as
before.
(cherry picked from commit de8e81f81f)
In GimpTransformGridTool, when the "show-preview" tool-option
changes, don't take the transform validity into account when
deciding whether to hide the current layer -- it should only affect
the visibility of the preview, not the layer.
(cherry picked from commit 7ed512040e)
Replace GimpTransformTool's 'drawable' field with an 'item' field,
and have GimpTransformGridTool set it to the active item, to which
the transformation is applied, during its initialization. In
gimp_transform_tool_get_active_item(), return the value of the
transform tool's 'item' field, if not NULL, instead of the image's
active item. This makes sure we apply that transform-grid tools
apply the transformation for the item for which they were
activated, even if the image's active item has changed.
(cherry picked from commit 3eaae58595)
Get rid of GimpTransformGridTool::recalc_matrix() and
gimp_transform_grid_tool_recalc_matrix(), and have
GimpTransformGridTool and its subclasses use
GimpTransformTool::recalc_matrix() and
gimp_transform_tool_recalc_matrix() directly instead.
In order to break the GimpToolWidget::changed/
GimpTransformTool::recalc_matrix() loop, add a
GimpTransformGridTool::update_widget() vfunc, which subclasses
should override to update their tool-widget (instead of doing this
in ::recalc_matrix()), and ::widget_changed(), which is called when
the tool-widget changes (and which subclasses should override
instead of connecting to the tool-widget's "changed" signal
directly.) GimpTransformGridTool calls these functions as
necessary, instead of relying on extra parameters passed to
recalc_matrix().
Adapt all the direct and indirect subclasses of
GimpTransformGridTool to the change.
(cherry picked from commit 6a3fc6c1b9)
Last commit reintroduced this bug.
Allow transforming invisible layers using transform-grid tools, by
adding a 'drawable' member to GimpTransformTool, and setting/
clearing it when initializing/halting a GimpTransformTool. In
gimp_transform_tool_check_active_item(), skip the visibility check
if the active item equals the GimpTransformTool's 'drawable'
member.
(cherry picked from commit cea6f1dc73)
Split gimp_transform_tool_get_active_item() into two functions:
gimp_transform_tool_get_active_item(), which returns the item
without checking for errors, and
gimp_transform_tool_check_active_item(), which returns the active
item while checking for errors. Adapt the rest of the code to the
change.
Remove the invisible_layer_ok parameter of
gimp_transform_tool_check_active_item(), and always return an error
when the active layer is invisible. This causes the flip and
measure tools to correctly reject invisible layers. Un-hide the
active item in GimpTransformGridTool before transforming, to avoid
rejecting layers that were hidden by the tool.
(cherry picked from commit 360b25b9a8)
While most of our transform tools use an interactive transform
grid, and have similar behavior, the flip tool is an odd one out.
The new "auto straighten" function of the measure tool introduces
another tool that performs transformations, while not behaving like
the rest of the transform tools.
Factor out the parts of GimpTransformTool that handle user
interaction into GimpTransformGridTool (with corresponding
GimpTransformGridOptions, and GimpTransformGridToolUndo), and only
leave the basic transform functionality and options in
GimpTransformTool (and GimpTransformOptions).
Derive all the transform tools (and transform-tool base classes)
that previously derived from GimpTransformTool, from
GimpTransformGridTool. The one exception is GimpFlipTool, which
still derives from GimpTransformTool directly. The next commit
will derive GimpMeasureTool from GimpTransformTool as well.
