Programming and Graphics

216 Introduction to C++ Programming and Graphics

float ysize = 0.02*yrange;

// move to the point:

move2(x, y);

if (marker==1)

circle (x,y,0.005*xrange) ; // circle

else if(marker==2) // triangle

{

rmove2 (0.0,0.5*ysize);

rdraw2 (-0.4*xsize,-0.75*ysize);

rdraw2 (0.8*xsize,0.0);

rdraw2 (-0.4*xsize,0.75*ysize);

rmove2 (0.0,-0.5*ysize);

}

else if(marker==4) // square

{

rmove2 (0.25*xsize,0.25*ysize);

rdraw2 (-0.5*xsize,0.0);

rdraw2 (0.0, -0.5*ysize);

rdraw2 (0.5*xsize,0.0);

rdraw2 (0.0, 0.5*ysize);

rmove2 (-0.25*xsize,-0.25*ysize);

}

else if(marker==5)

{

rmove2 (0.0,0.5*ysize);

rdraw2 (-0.5*xsize,-0.5*ysize);

rdraw2 (0.5*xsize,-0.5*ysize);

rdraw2 (0.5*xsize,0.5*ysize);

rdraw2 (-0.5*xsize,0.5*ysize);

rmove2 (0.0,-0.5*ysize);

}

else if(marker==6)

circle (x,y,0.00001*xrange);

}

Note that the “move to”(move2) and “draw to” (draw2)Voglefunctions have
been used to move the pen lifted up or pressed down.

Function drawline2d

The implementation of the line drawing functiondrawline2dis: