k3d/share/shaders/k3d_checkerboard.sl:13:  float filterwidths, filterwidtht;
k3d/share/shaders/k3d_checkerboard.sl:23:	filterwidtht = TFILTERWIDTH * TileT;
k3d/share/shaders/k3d_checkerboard.sl:26:	filtert = filteredpulse(1.0 - filterwidtht, 1.0 + filterwidtht, filtert, filterwidtht);
