NAME

       tickit_renderbuffer_hline_at, tickit_renderbuffer_vline_at - create line regions

SYNOPSIS

       #include <tickit.h>

       void tickit_renderbuffer_hline_at(TickitRenderBuffer *rb,
               int line, int startcol, int endcol,
               TickitLineStyle style, TickitLineCaps caps);
       void tickit_renderbuffer_vline_at(TickitRenderBuffer *rb,
               int startline, int endline, int col,
               TickitLineStyle style, TickitLineCaps caps);

       Link with -ltickit.

DESCRIPTION

       tickit_renderbuffer_hline_at() creates a horizontal line segment on the given line between
       the given columns; both inclusive. tickit_renderbuffer_vline_at() creates a vertical  line
       segment on the given column between the given lines; both inclusive.

       The style argument should be one of the following TickitLineStyle constants:

       TICKIT_LINE_SINGLE
              A single thin line

       TICKIT_LINE_DOUBLE
              A pair of double thin lines

       TICKIT_LINE_THICK
              A single thick line

       Note  that  as  line  drawing  is performed using the Unicode line-drawing characters, not
       every possible combination of line segments of differing  styles  meeting  in  a  cell  is
       supported by Unicode. The following sets of styles may be relied upon:

       *      Any possible combination of only SINGLE segments, THICK segments, or both.

       *      Any  combination  of  only  DOUBLE segments, except cells that only have one of the
              four borders occupied.

       *      Any combination of SINGLE and  DOUBLE  segments  except  where  the  style  changes
              between SINGLE to DOUBLE on a vertical or horizontal run.

       Other combinations are not directly supported (i.e. any combination of DOUBLE and THICK in
       the same cell, or any attempt to change from SINGLE to DOUBLE in either  the  vertical  or
       horizontal  direction).  To handle these cases, a cell may be rendered with a substitution
       character which replaces a DOUBLE or THICK segment with a SINGLE one within that cell. The
       effect  will be the overall shape of the line is retained, but close to the edge or corner
       it will have the wrong segment type.

       Conceptually, every cell involved in line drawing has a potential  line  segment  type  at
       each of its four borders to its neighbours. Horizontal lines are drawn though the vertical
       centre of each cell, and vertical lines are drawn through the horizontal centre.

       There is a choice of how to handle the ends of line segments, as to  whether  the  segment
       should  go  to  the centre of each cell, or should continue through the entire body of the
       cell and stop at the boundary. By default line segments will start and end at  the  centre
       of  the  cells,  so  that horizontal and vertical lines meeting in a cell will form a neat
       corner. When drawing isolated lines such as horizontal or vertical rules, it is preferable
       that  the line go right through the cells at the start and end. To control this behaviour,
       the caps bitmask argument should be one of the following TickitLineCaps constants:

       CAP_START
              indicates that the line should consume the entire start cell

       CAP_END
              indicates that the line should consume the entire end cell

       CAP_BOTH
              is a convenient shortcut specifying both behaviours

RETURN VALUE

       This function returns no value.

SEE ALSO

       tickit_renderbuffer_new(3),                                   tickit_renderbuffer_blit(3),
       tickit_renderbuffer_flush_to_term(3), tickit_renderbuffer(7), tickit(7)

                                                                  TICKIT_RENDERBUFFER_HLINE_AT(3)