+/* clip.c */
+int clip_rect(double *x1, double *y1, double *x2, double *y2, const double rect[4]);
+int clip_segment(double *x1, double *y1, double *x2, double *y2, const double u, const double v);
+int clip_sector(double *x1, double *y1, double *x2, double *y2, const double u, const double v);
+int clip_circle(double *x1, double *y1, double *x2, double *y2, const double cx, const double cy, const double radius, double t1, double t2);
+int clip_triangle(double *x1, double *y1, double *x2, double *y2, const double u, const double v, const int clip_xaxis);
+
+/* lnearest.c */
+long int lnearest(double x);
+