float bs_blend(int i, int n, float u);
void drawArc (int xc, int yc, int b, int start_angle,int end_angle,
	     int color, float aspect);
void drawBezier(int segments,int color,...);
void drawBspline(int segments, int color,...);
void drawLine(int x1, int y1, int x2, int y2, int color);
void drawOval(int x, int y, int b, int color, float aspect);
void drawPoly(int color, ...);
void drawRect(int x1, int y1, int x2, int y2, int color);
void drawRoundRect(int x1, int y1, int x2, int y2, int b, int color);
void fillArc (int xc, int yc, int b, int start_angle,int end_angle,
	     int color, float aspect);
void fillArc1 (int xc, int yc,int x, int y, int sector,
	     int arcTest[], int x_start_test, int x_end_test, int color);
void fillOval(int x, int y, int r, int color, float aspect);
void fillPoly(int color, ...);
void fill2Poly(int color,int point[600]);
void fillRect(int x1, int y1, int x2, int y2, int color);
void fillRoundRect(int x1, int y1, int x2, int y2, int r, int color);
void plot(int x, int y, int color);
void plots(int x, int y, int color);
void plotArc1 (int x, int y, int sector, int color,
	     int arcTest[], int x_start_test, int x_end_test);
void plotArc2 (int x, int y, int sector, int color,
	     int arcTest[], int x_start_test, int x_end_test);
void plot_char(int x, int y, int char_offset,int color, int type);
void sort(int index, int x_coord[], int y_coord[]);
void write_horz_char(int x, int y, int ch, int color);
void write_vert_char(int x, int y, int ch, int color);
void write_horz_str(int x, int y, char *string, int color);
void write_vert_str(int x, int y, char *string, int color);
void write_big_char(int x, int y, int ch, int color);
void write_vid_char(int x, int y, int ch, int color);
void write_big_str(int x, int y, char *string, int color);
void write_vid_str(int x, int y, char *string, int color);

extern int OPERATOR, LINEWIDTH, ANGLE, XCENTER, YCENTER;
extern unsigned long PATTERN, style[8];

#define VGA

#ifdef VGA
#define convert(x,y)      {x = (x + 319);  y = (240 - y);}
#endif

#ifdef EGA
#define convert(x,y)      {x = (x + 319);  y = (175 - ((93*y) >> 7));}
#endif

#ifdef CGA
#define convert(x,y)      {x = ((x >> 1) + 159);  y = (100 - ((53*y) >> 7));}
#endif