#include <ggi/ggi.h>
int ggiDrawVLine(ggi_visual_t vis, int x, int y, int h);
int ggiDrawVLine
int ggiPutVLine(ggi_visual_t vis, int x, int y, int h, void *buf);
int ggiPutVLine
int ggiGetVLine(ggi_visual_t vis, int x, int y, int h, void *buf);
int ggiGetVLine
Draw, put, or get a vertical line from (x,y), extending h pixels in the positive y direction (normally down). The width of the line is one pixel.
All three functions return 0 to indicate success. Any other value indicates an error.