ggiDrawLine : Draw a line on a visual
#include <ggi/ggi.h> int ggiDrawLine(ggi_visual_t vis, int x, int y, int xe, int ye);
Draws any line, using the current foreground color, from (:p:`x`, :p:`y`) to (:p:`xe`, :p:`ye`). The line is exact; the pixel set is no more than 0.5 pixels off the place it should be.
This function returns 0 to indicate success.