MGL_diffRegion

Compute the Boolean difference of two regions.

Declaration

ibool MGLAPI MGL_diffRegion(
    region_t *r1,
    const region_t *r2)

Prototype In

mgraph.h

Parameters

r1

Region from which r2 is subtracted, which also becomes the result region.

r2

Region to be subtracted from r1

 

Return Value

True if the difference is valid, false if an empty region was created.

Description

Computes the Boolean difference of two regions by subtracting the area covered by region r2 from region r1, computing the resulting region in r1, which may result in an empty region. If you need to retain the value of r1, you need to first copy r1 to a temporary region.

See Also

MGL_diffRegionRect, MGL_unionRegion, MGL_sectRegion

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