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)