This implied a lot of other core changes, which also pushed me into
improving some of the edit actions and PDB calls to be multi-layer aware
in the same time.
Note that it is still work-in-progress, but I just had to commit
something in an acceptable intermediate state otherwise I was just going
crazy.
In particular now the various transform tools are multi-layer aware and
work simultaneously on all selected layers (and the linked layers if any
of the selected layers is linked too). Both preview and final transform
processing works.
In the limitations, preview doesn't work well (only one layer in the
preview) when there is a selection (though the actual transform works).
Also I am left to wonder how we should process this case of canvas
selection+transform on multi-layers. Indeed currently I am just creating
a floating selection (like we used to for the selection+transform case)
containing a transform result of the composited version of all selected
layers. This is a possible expected result, but another could be to get
several transformed layers (without composition). But then should the
"Floating Selection" concept allow for multiple Floating Selections?
Sooo many questions left to answer.
... which copies a TransInfo array to the current info array,
possibly with modifications. While the default implementation
simply copies the array as-is, the following commit will override
the function for the Unified Transform tool, to avoid copying the
pivot position when the pivot is locked.
Use the function in GimpTransformGridTool, instead of copying the
array directly, as necessary.
Add a new "Preview linked items" option to the transform-grid
tools. When this option is enabled, together with composited
previews, the transform preview includes all linked layers/channels
when transforming a layer/channel. Note that paths aren't included
for now.
Ultimately, we'd probably want to cut down on the various preview
options and enable this by default, but let's make this optional
for now.
This commit also improves composited-preview clipping in some
cases.
Add a "Composited preview" option to all transform-grid tools,
which displays the transform preview as part of the image
composition (i.e., as it would actually look when applying the
transformation, keeping the layer at the right position in the
stack, and with the right layer mode), instead of using an overlay.
This option is off by default, since it's generally slower to
render than an overlay, due to the lack of mipmap rendering. We're
also still using an overlay when transfoming a selection, and not a
whole layer.
Add a boolean 'compress' parameter to
gimp_transform_grid_tool_push_internal_undo(). When TRUE,
successive undo steps added rapidly are compressed into a single
step.
In the various subclasses, compress undo steps for dialog changes,
since we push an undo step for every intermediate change for those
(such as while dragging a spin-scale). In contrast, we only push
tool-widget undo steps upon button release, hence there's no need
to compress them.
Add a new "Image" transform type to the transform tools, in
addition to the existing "Layer", "Selection", and "Path" transform
types. The "Image" mode transforms the entire image, rather than a
single item. In tools with a preview, the preview shows the
transformed image projection. The clipping mode controls how the
canvas is clipped during the transform; in particular, the ADJUST
clipping mode resizes the canvas to fit its transformed size.
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.
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.
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.
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.
Jehan