k3d/share/shaders/k3d_checkerboard.sl:12:  float filters, filtert, filterst;
k3d/share/shaders/k3d_checkerboard.sl:19:	filters = mod((s * TileS * 2.0) - 1.0, 2.0);
k3d/share/shaders/k3d_checkerboard.sl:25:	filters = filteredpulse(1.0 - filterwidths, 1.0 + filterwidths, filters, filterwidths);
k3d/share/shaders/k3d_checkerboard.sl:28:	filterst = filters + filtert;
k3d/share/shaders/k3d_lensflare.sl:200:	    int = 1 - filterstep(radius, axisdist - dPndc / 2,
k3d/share/shaders/k3d_lensflare.sl:214:	    int = smoothstep(0, radius, axisdist) - filterstep(radius,
