wavy
Tcl_Obj* imageObj float offset float adj1 float adj2

crimp_image*     result;
crimp_image*     image;
int              x, y, w, h;

int              oy, ox, c, iy, ix;

crimp_input (imageObj, image, rgba);

w = image->w;
h = image->h;

result = crimp_new_like (image);


for (oy = 0; oy < h; ++oy) {
    for (ox = 0; ox < w; ++ox) {

	/*
	 * The output coordinates (ox, oy) are converted into the coordinates
	 * in the input image from which to pull the pixel(s). I.e. this is a
	 * special geometry deformation.
	 */

        float r = sinf(hypotf(oy - h/2, ox - w/2) * adj1/w + offset)/adj2 + 1;
        float iyf = (oy - h / 2) * r + h/2;
        float ixf = (ox - w / 2) * r + w/2;
        int   iyw = iyf;
        int   ixw = ixf;
	float val;

        iyf -= iyw;
        ixf -= ixw;

	/*
	 * All channels in the image are handled in the same way.  A rectangle
	 * around the chosen location in the input is scanned and the colors
	 * added together in some weighted scheme.
	 */

        for (c = 0; c < 4; ++c) {

            val = 0;

            for (iy = MAX(iyw, 0); iy < MIN(iyw + 2, h); ++iy) {
                iyf = 1 - iyf;
                for (ix = MAX(ixw, 0); ix < MIN(ixw + 2, w); ++ix) {
                    ixf = 1 - ixf;
		    val += CH (image, c, ix, iy) * iyf * ixf;
                }
            }

	    CH (result, c, ox, oy) = val;
        }
    }
}


Tcl_SetObjResult(interp, crimp_new_image_obj (result));
return TCL_OK;

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