| """ |
| Helper module for the *bbox_inches* parameter in `.Figure.savefig`. |
| """ |
|
|
| from matplotlib.transforms import Bbox, TransformedBbox, Affine2D |
|
|
|
|
| def adjust_bbox(fig, bbox_inches, fixed_dpi=None): |
| """ |
| Temporarily adjust the figure so that only the specified area |
| (bbox_inches) is saved. |
| |
| It modifies fig.bbox, fig.bbox_inches, |
| fig.transFigure._boxout, and fig.patch. While the figure size |
| changes, the scale of the original figure is conserved. A |
| function which restores the original values are returned. |
| """ |
| origBbox = fig.bbox |
| origBboxInches = fig.bbox_inches |
| _boxout = fig.transFigure._boxout |
|
|
| old_aspect = [] |
| locator_list = [] |
| sentinel = object() |
| for ax in fig.axes: |
| locator = ax.get_axes_locator() |
| if locator is not None: |
| ax.apply_aspect(locator(ax, None)) |
| locator_list.append(locator) |
| current_pos = ax.get_position(original=False).frozen() |
| ax.set_axes_locator(lambda a, r, _pos=current_pos: _pos) |
| |
| if 'apply_aspect' in ax.__dict__: |
| old_aspect.append(ax.apply_aspect) |
| else: |
| old_aspect.append(sentinel) |
| ax.apply_aspect = lambda pos=None: None |
|
|
| def restore_bbox(): |
| for ax, loc, aspect in zip(fig.axes, locator_list, old_aspect): |
| ax.set_axes_locator(loc) |
| if aspect is sentinel: |
| |
| del ax.apply_aspect |
| else: |
| ax.apply_aspect = aspect |
|
|
| fig.bbox = origBbox |
| fig.bbox_inches = origBboxInches |
| fig.transFigure._boxout = _boxout |
| fig.transFigure.invalidate() |
| fig.patch.set_bounds(0, 0, 1, 1) |
|
|
| if fixed_dpi is None: |
| fixed_dpi = fig.dpi |
| tr = Affine2D().scale(fixed_dpi) |
| dpi_scale = fixed_dpi / fig.dpi |
|
|
| fig.bbox_inches = Bbox.from_bounds(0, 0, *bbox_inches.size) |
| x0, y0 = tr.transform(bbox_inches.p0) |
| w1, h1 = fig.bbox.size * dpi_scale |
| fig.transFigure._boxout = Bbox.from_bounds(-x0, -y0, w1, h1) |
| fig.transFigure.invalidate() |
|
|
| fig.bbox = TransformedBbox(fig.bbox_inches, tr) |
|
|
| fig.patch.set_bounds(x0 / w1, y0 / h1, |
| fig.bbox.width / w1, fig.bbox.height / h1) |
|
|
| return restore_bbox |
|
|
|
|
| def process_figure_for_rasterizing(fig, bbox_inches_restore, fixed_dpi=None): |
| """ |
| A function that needs to be called when figure dpi changes during the |
| drawing (e.g., rasterizing). It recovers the bbox and re-adjust it with |
| the new dpi. |
| """ |
|
|
| bbox_inches, restore_bbox = bbox_inches_restore |
| restore_bbox() |
| r = adjust_bbox(fig, bbox_inches, fixed_dpi) |
|
|
| return bbox_inches, r |
|
|
