-int gp_init_2(void);
-int window2(double xmin, double ymin, double xmax, double ymax);
-int window_2(double xmin, double ymin, double xmax, double ymax);
-int viewprt2(double xmin, double ymin, double xmax, double ymax);
-int viewport_2(double xmin, double ymin, double xmax, double ymax);
-int framevpt(void);
-int calc_wc_to_ndc(void);
-int calc_ndc_to_mc(void);
-int wc_to_ndc(double xw, double yw, double *xn, double *yn);
-int ndc_to_wc(double xn, double yn, double *xw, double *yw);
-int color(int icol);
-int linestyle(int style);
-int line_abs_2(double x, double y);
-int lineabs2(double x, double y);
-int move_abs_2(double x, double y);
-int moveabs2(double x, double y);
-int line_rel_2(double x, double y);
-int linerel2(double x, double y);
-int move_rel_2(double x, double y);
-int moverel2(double x, double y);
-int draw_text(char *message);
-int drawtext(char *message);
-int polylnabs2(double x[], double y[], int n);
-int markabs2(double x, double y);
-int markrel2(double x, double y);
-int pntabs2(double x, double y);
-int pntrel2(double x, double y);
-int ctm_clr_2(void);
-int ctm_get_2(GRFMTX_2D m);
-int ctm_set_2(GRFMTX_2D m);
-int ctm_pre_mult_2(GRFMTX_2D m);
-int ctm_post_mult_2(GRFMTX_2D m);
+SGP_ID sgp2_init (int xsize, int ysize, const char *title);
+void sgp2_close (SGP_ID gid);
+void sgp2_set_active_win (SGP_ID);
+SGP_ID sgp2_get_active_win (void);
+void sgp2_clear (void);
+void sgp2_window(double xmin, double ymin, double xmax, double ymax);
+void sgp2_viewport(double xmin, double ymin, double xmax, double ymax);
+void sgp2_frame_vpt(void);
+void calc_wc_to_ndc(void);
+void calc_ndc_to_mc(void);
+void wc_to_ndc(double xw, double yw, double *xn, double *yn);
+void ndc_to_wc(double xn, double yn, double *xw, double *yw);
+void sgp2_color(int icol);
+void sgp2_line_style(int style);
+void sgp2_line_abs(double x, double y);
+void sgp2_move_abs(double x, double y);
+void sgp2_line_rel(double x, double y);
+void sgp2_move_rel(double x, double y);
+void sgp2_draw_text(char *message);
+void sgp2_polyline_abs(double x[], double y[], int n);
+void sgp2_mark_abs(double x, double y);
+void sgp2_mark_rel(double x, double y);
+void sgp2_point_abs(double x, double y);
+void sgp2_point_rel(double x, double y);
+void charsize(double wid, double height);
+void textangle(double angle);
+void ctm_clr_2(void);
+void ctm_get_2(GRFMTX_2D m);
+void ctm_set_2(GRFMTX_2D m);
+void ctm_pre_mult_2(GRFMTX_2D m);
+void ctm_post_mult_2(GRFMTX_2D m);
+