说明

面向对象风格 (method):

过程化风格:

Computes a bounding box in user coordinates covering the area that would be affected, (the “inked” area), by a CairoContext::fill() operation given the current path and fill parameters. If the current path is empty, returns an empty rectangle (0,0,0,0). Surface dimensions and clipping are not taken into account.

Contrast with CairoContext::pathExtents(), which is similar, but returns non-zero extents for some paths with no inked area, (such as a simple line segment).

Note that CairoContext::fillExtents() must necessarily do more work to compute the precise inked areas in light of the fill rule, so CairoContext::pathExtents() may be more desirable for sake of performance if the non-inked path extents are desired.