|
| 1 | +""" |
| 2 | +Helper module for the *bbox_inches* parameter in `.Figure.savefig`. |
| 3 | +""" |
| 4 | + |
| 5 | +from matplotlib.transforms import Bbox, TransformedBbox, Affine2D |
| 6 | + |
| 7 | + |
| 8 | +def adjust_bbox(fig, bbox_inches, fixed_dpi=None): |
| 9 | + """ |
| 10 | + Temporarily adjust the figure so that only the specified area |
| 11 | + (bbox_inches) is saved. |
| 12 | +
|
| 13 | + It modifies fig.bbox, fig.bbox_inches, |
| 14 | + fig.transFigure._boxout, and fig.patch. While the figure size |
| 15 | + changes, the scale of the original figure is conserved. A |
| 16 | + function which restores the original values are returned. |
| 17 | + """ |
| 18 | + origBbox = fig.bbox |
| 19 | + origBboxInches = fig.bbox_inches |
| 20 | + orig_tight_layout = fig.get_tight_layout() |
| 21 | + _boxout = fig.transFigure._boxout |
| 22 | + |
| 23 | + fig.set_tight_layout(False) |
| 24 | + |
| 25 | + old_aspect = [] |
| 26 | + locator_list = [] |
| 27 | + sentinel = object() |
| 28 | + for ax in fig.axes: |
| 29 | + locator_list.append(ax.get_axes_locator()) |
| 30 | + current_pos = ax.get_position(original=False).frozen() |
| 31 | + ax.set_axes_locator(lambda a, r, _pos=current_pos: _pos) |
| 32 | + # override the method that enforces the aspect ratio on the Axes |
| 33 | + if 'apply_aspect' in ax.__dict__: |
| 34 | + old_aspect.append(ax.apply_aspect) |
| 35 | + else: |
| 36 | + old_aspect.append(sentinel) |
| 37 | + ax.apply_aspect = lambda pos=None: None |
| 38 | + |
| 39 | + def restore_bbox(): |
| 40 | + for ax, loc, aspect in zip(fig.axes, locator_list, old_aspect): |
| 41 | + ax.set_axes_locator(loc) |
| 42 | + if aspect is sentinel: |
| 43 | + # delete our no-op function which un-hides the original method |
| 44 | + del ax.apply_aspect |
| 45 | + else: |
| 46 | + ax.apply_aspect = aspect |
| 47 | + |
| 48 | + fig.bbox = origBbox |
| 49 | + fig.bbox_inches = origBboxInches |
| 50 | + fig.set_tight_layout(orig_tight_layout) |
| 51 | + fig.transFigure._boxout = _boxout |
| 52 | + fig.transFigure.invalidate() |
| 53 | + fig.patch.set_bounds(0, 0, 1, 1) |
| 54 | + |
| 55 | + if fixed_dpi is None: |
| 56 | + fixed_dpi = fig.dpi |
| 57 | + tr = Affine2D().scale(fixed_dpi) |
| 58 | + dpi_scale = fixed_dpi / fig.dpi |
| 59 | + |
| 60 | + fig.bbox_inches = Bbox.from_bounds(0, 0, *bbox_inches.size) |
| 61 | + x0, y0 = tr.transform(bbox_inches.p0) |
| 62 | + w1, h1 = fig.bbox.size * dpi_scale |
| 63 | + fig.transFigure._boxout = Bbox.from_bounds(-x0, -y0, w1, h1) |
| 64 | + fig.transFigure.invalidate() |
| 65 | + |
| 66 | + fig.bbox = TransformedBbox(fig.bbox_inches, tr) |
| 67 | + |
| 68 | + fig.patch.set_bounds(x0 / w1, y0 / h1, |
| 69 | + fig.bbox.width / w1, fig.bbox.height / h1) |
| 70 | + |
| 71 | + return restore_bbox |
| 72 | + |
| 73 | + |
| 74 | +def process_figure_for_rasterizing(fig, bbox_inches_restore, fixed_dpi=None): |
| 75 | + """ |
| 76 | + A function that needs to be called when figure dpi changes during the |
| 77 | + drawing (e.g., rasterizing). It recovers the bbox and re-adjust it with |
| 78 | + the new dpi. |
| 79 | + """ |
| 80 | + |
| 81 | + bbox_inches, restore_bbox = bbox_inches_restore |
| 82 | + restore_bbox() |
| 83 | + r = adjust_bbox(fig, bbox_inches, fixed_dpi) |
| 84 | + |
| 85 | + return bbox_inches, r |
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