full: the body (and any border) is distinguishable from the wick, so all
of it is drawn.
wick: the body would repaint exactly the pixels the wick already covered,
so it is skipped. This is not an approximation: optimalBarWidth matches
the body's odd/even parity to the wick's, which collapses the two to the
same width and the same x once bars get tight, and the wick's high-low
span always contains the body's open-close span. Same rect, same colour,
twice the work.
Level-of-detail tier for one candle.
full: the body (and any border) is distinguishable from the wick, so all of it is drawn.wick: the body would repaint exactly the pixels the wick already covered, so it is skipped. This is not an approximation:optimalBarWidthmatches the body's odd/even parity to the wick's, which collapses the two to the same width and the samexonce bars get tight, and the wick's high-low span always contains the body's open-close span. Same rect, same colour, twice the work.