ptarray_affine()

void ptarray_affine	(	POINTARRAY *	pa,
		const AFFINE *	a
	)

Affine transform a pointarray.

Definition at line 1877 of file ptarray.c.

{
        if (FLAGS_GET_Z(pa->flags))
        {
                for (uint32_t i = 0; i < pa->npoints; i++)
                {
                        POINT4D *p4d = (POINT4D *)(getPoint_internal(pa, i));
                        double x = p4d->x;
                        double y = p4d->y;
                        double z = p4d->z;
                        p4d->x = a->afac * x + a->bfac * y + a->cfac * z + a->xoff;
                        p4d->y = a->dfac * x + a->efac * y + a->ffac * z + a->yoff;
                        p4d->z = a->gfac * x + a->hfac * y + a->ifac * z + a->zoff;
                }
        }
        else
        {
                for (uint32_t i = 0; i < pa->npoints; i++)
                {
                        POINT2D *pt = (POINT2D *)(getPoint_internal(pa, i));
                        double x = pt->x;
                        double y = pt->y;
                        pt->x = a->afac * x + a->bfac * y + a->xoff;
                        pt->y = a->dfac * x + a->efac * y + a->yoff;
                }
        }
}

References AFFINE::afac, AFFINE::bfac, AFFINE::cfac, AFFINE::dfac, AFFINE::efac, AFFINE::ffac, POINTARRAY::flags, FLAGS_GET_Z, getPoint_internal(), AFFINE::gfac, AFFINE::hfac, AFFINE::ifac, POINTARRAY::npoints, POINT2D::x, POINT4D::x, pixval::x, AFFINE::xoff, POINT2D::y, POINT4D::y, pixval::y, AFFINE::yoff, POINT4D::z, and AFFINE::zoff.

Referenced by lwgeom_affine().

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