Optimize SVG opening: ignore most rects when measuring grid

This brings it down from around 20 seconds to less than a second,
for moderately sized documents (i.e. default size).
For larger documents, it can still be slow.
This commit is contained in:
Isaiah Odhner 2023-05-20 02:05:02 -04:00
parent dae8e809c4
commit c3d6c24596

View File

@ -1330,6 +1330,17 @@ class AnsiArtDocument:
return float(rect.attrib[coord_attrib]) + float(rect.attrib[size_attrib]) / 2
axes: list[tuple[str, str, float]] = [("x", "width", min_width), ("y", "height", min_height)]
for (coord_attrib, size_attrib, min_rect_size) in axes:
# Can't have too many rects or this will be slow.
# Note: this optimization invalidates most of the grid estimation strategy here,
# without the second sort in the opposite axis.
# (But it still worked without it, for the few cases I tested,
# but probably more through luck of the first rect being the right size or something like that.
# Um, not that, because it's using the spacing between rects, right? but something like that.)
# (At any rate, just look at the debug.svg output to see what I mean.)
# TODO: is the first sort even necessary?
rects.sort(key=lambda rect: float(rect.attrib[coord_attrib]))
rects.sort(key=lambda rect: float(rect.attrib["x" if coord_attrib == "y" else "y"]))
max_rects = 30
# Have to ignore rects that span multiple cells, since their centers can be half-off the grid
# of cell-sized rect centers (which is normally half-off from the grid of cell corners).
max_rect_size = min_rect_size * 1.5
@ -1339,7 +1350,7 @@ class AnsiArtDocument:
rect_center(rect, coord_attrib, size_attrib),
rect_center(rect, coord_attrib, size_attrib),
)
for rect in rects if float(rect.attrib[size_attrib]) <= max_rect_size
for rect in rects[:max_rects] if float(rect.attrib[size_attrib]) <= max_rect_size
]
joined = True
while joined and len(tracks) > 1: