setlinestyle() function in C

The header file graphics.h contains setlinestyle() function which sets the style for all lines drawn by line, lineto, rectangle, drawpoly, and so on.

Syntax :

void setlinestyle(int linestyle, unsigned upattern,
                                   int thickness);

Examples :

Input : x = 200, y = 100
Output : 

x and y are initialized as (200, 100). 
For every line, value of y increments 
by 25 to change the position. 
The line style keep changing corresponding
to value of first parameter(c). 

Explanation : linestyle specifies in which of several styles subsequent lines will be drawn (such as solid, dotted, centered, dashed).

upattern is a 16-bit pattern that applies only if linestyle is USERBIT_LINE (4). In that case, whenever a bit in the pattern word is 1, the corresponding pixel in the line is drawn in the current drawing color. A value for ‘upattern’ must always be supplied. It is simply ignored if ‘linestyle’ is not USERBIT_LINE (4).
thickness specifies whether the width of subsequent lines drawn will be normal or thick.

Below is the implementation of setlinestyle() function :

// C Implementation for setlinestyle()
#include <graphics.h>

// driver code
int main()
{
    // gm is Graphics mode which is
    // a computer display mode that
    // generates image using pixels.
    // DETECT is a macro defined in
    // "graphics.h" header file
    int gd = DETECT, gm;

    // variable to change the
    // line styles
    int c;

    // initial coordinate to
    // draw line
    int x = 200, y = 100;

    // initgraph initializes the
    // graphics system by loading a
    // graphics driver from disk
    initgraph(&gd, &gm, "");

    // To keep track of lines
    for ( c = 0 ; c < 5 ; c++ )
   {
       // setlinestyle function
       setlinestyle(c, 0, 1);

       // Drawing line
       line(x, y, x+200, y);
       y = y + 25;
   }

    getch();

    // closegraph function closes the
    // graphics mode and deallocates
    // all memory allocated by
    // graphics system .
    closegraph();

    return 0;
}

Output :