rasterStep
open override fun rasterStep(region: KiteRectangle, ctm: KiteMatrix, step: KiteRasterStep): Boolean(source)
The raster step (#209, #308): its box is region under ctm, in the units of the draw scope, cut to the clip and rounded out to whole units. It works at magnification pixels a unit, so a step on a zoomed Vectorized page keeps the detail on screen, and past STEP_MAX_PIXELS at a lower resolution. Only a rasterizer's canvas, which knows the bitmap it draws into, reads a backdrop, and only outside every layer.