NAME

XDrawLines — draw multiple connected lines. 

SYNOPSIS

XDrawLines(display, drawable, gc, points, npoints, mode) Display ∗display;  Drawable drawable;  GC gc;  XPoint ∗points;  int npoints;  int mode;

ARGUMENTS

displaySpecifies a connection to an X server; returned from XOpenDisplay(). 

drawableSpecifies the drawable. 

gcSpecifies the graphics context. 

pointsSpecifies a pointer to an array of points. 

npointsSpecifies the number of points in the array. 

modeSpecifies the coordinate mode.  Pass either CoordModeOrigin or CoordModePrevious. 

DESCRIPTION

XDrawLines() draws a series of lines joined end-to-end. 

It draws lines connecting each point in the list (points array) to the next point in the list.  The lines are drawn in the order listed in the points array.  For any given line, no pixel is drawn more than once.  If thin (zero line width) lines intersect, pixels will be drawn multiple times.  If the first and last points coincide, the first and last lines will join correctly.  If wide lines intersect, the intersecting pixels are drawn only once, as though the entire multiline request were a single filled shape. 

There is a limit to the number of lines that can be drawn in a single call, which varies according to the server.  To determine how many lines you can draw in a single call, find out your server’s maximum request size using XMaxRequestSize().  Subtract three and divide by two, and this is the maximum number of lines you can draw in a single XDrawLines() call. 

The mode argument may have two values:

•CoordModeOrigin indicates that all points are relative to the drawable’s origin. 

•CoordModePrevious indicates that all points after the first are relative to the previous point.  (The first point is always relative to the drawable’s origin.) 

XDrawLines() uses the following components of the specified graphics context to draw multiple connected lines in the specified drawable: function, plane_mask, line_width, line_style, cap_style, join_style, fill_style, subwindow_mode, clip_x_origin, clip_y_ origin, and clip_mask.  This function also uses these graphics context mode-dependent components:  foreground, background, tile, stipple, ts_x_origin, ts_y_origin, dash_offset, and dashes. 

For more information, see Volume One, Chapter 6, Drawing Graphics and Text, and Chapter 5, The Graphics Context. 

STRUCTURES

typedef struct {
    short x, y; } XPoint;

ERRORS

BadDrawable
Specified drawable is invalid.

BadGCSpecified GC is invalid, or does not match the depth of drawable. 

BadMatchSpecified drawable is an InputOnly window. 

BadValueInvalid coordinate_mode. 

SEE ALSO

XClearArea(), XClearWindow(), XCopyArea(), XCopyPlane(), XDraw, XDrawArc(), XDrawArcs(), XDrawFilled(), XDrawLine(), XDrawPoint(), XDrawPoints(), XDrawRectangle(), XDrawRectangles(), XDrawSegments(), XFillArc(), XFillArcs(), XFillPolygon(), XFillRectangle(), XFillRectangles(). 

Xlib Reference Manual