Every `rendered.png` is now the output of houstonzhang/w2c-render:1.3.1, and
238 of the 2,822 changed. The other 2,584 are byte-identical to what was here.
The old renderer did not draw the same source the same way twice. Chromium
reused a tile from an earlier frame when only part of it was invalidated, so
about one chart render in two hundred came back a different picture; and a
chart that did not disable its own animation -- recharts 3 leaves that on by
default -- was screenshotted at whichever frame the clock allowed. 236 of the
changes are the first cause and are sub-pixel antialiasing: the worst is SSIM
0.999451, the median 0.999999, and none reach the 0.999 gate the SFT build
applies. Two are a `<ReferenceLine>` returning to the paint order an
unperturbed first render gives it, worth 5 and 8 pixels.
One is not cosmetic. `test/image_1873` leaves `isAnimationActive` off one of
its two series, so the old image was a frame of a running animation: the same
source produced six differ…
