expand_float_wrap
Tcl_Obj* imageObj
int ww
int hn
int we
int hs

/*
 * Border expansion by toroidal wrapping, also called cyclic expansion.
 */

crimp_image* image;
crimp_input (imageObj, image, float);

/*
 * This is the simple definition. Might be better to generate macros
 * specialized to each quadrant. Except, even they have to perform modulo
 * arithmetic, as the border may be larger than image's width or height,
 * causing muliple wrapping.
 */

#define FILL(xo,yo) {				\
	int xi = xo - ww;			\
	int yi = yo - hn;			\
	while (xi < 0) { xi += image->w; }	\
	while (yi < 0) { yi += image->h; }	\
	xi %= image->w;				\
	yi %= image->h;				\
						\
	FLOATP (result, xo, yo) = FLOATP (image, xi, yi); \
    }

#define COPY(xo,yo,xi,yi) {			\
	FLOATP (result, xo, yo) = FLOATP (image, xi, yi); \
    }

#include <expand_op.c>

/* vim: set sts=4 sw=4 tw=80 et ft=c: */
/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */