In GimpTransformGridTool, extend the functionality of the
"Readjust" button, such that if the transformation is already
adjusted to the view (i.e., when the button is clicked the second
time), readjust the transformation to the item bounds (as when
using the tool "normally"), and vice versa. This allows switching
back and forth between "normal" mode, and "adjusted-to-view" mode.
Additionally, disable readjustment when the current transforamtion
is invalid, and show an error when readjustment results in an
invalid transformation.
In GimpTransformGridTool, reset both transform directions in
response to the "Reset" button, so that the overall transformation
is restored to the identity. Previously, we would only reset the
active transform direction (possibly compensating in the opposite
direction, if both directions are linked). This was intentional,
but it's probably a bit too confusing, especially in conjunction
with the newly added "Readjust" button. Let's just go back to
resetting everything.
Add an optional GimpTransformGridTool::radjust() virtual function,
which subclasses can implement to radjust the transformation based
on the current state of the display, such that it's easy to
control. This is especially useful when the image is zoomed-in,
and the transform handles, which are initially across the layer
bounds, are out of view.
When a transform tool implements radjust(), show a "Readjust"
button in the tool GUI. While readjusting the transformation, we
modify the opposite transformation such that the overall transform
remains unchanged, as if both transform-directions were linked, so
that only the transform grid is readjusted.
In GimpTransformGridTool, fix weak-pointer initialization for the
out-of-bounds selection-boundary canvas item, to avoid a CRITICAL
when initializing the tool in transform-selection mode for a fully
out-of-bounds selection, and a subsequent segfault when re-
initializing the tool.
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.
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.
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.
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.
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.
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.
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.
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.
Ell