# 1.3 Game 2302-0110: updating the game math library for graphics  (Page 9/20)

 Page 9 / 20
Listing 10 . The draw method of the GM2D02.Point class.
```public void draw(Graphics2D g2D){ Ellipse2D.Double circle =new Ellipse2D.Double(getData(0)-3, getData(1)-3,6, 6);g2D.draw(circle); }//end draw```

The logic behind this method is very similar to the logic that I explained relative to Listing 8 . The constructor for the Java standard Ellipse2D.Double class requires four incoming parameters that specify the coordinates of the upper-left corner of a rectangle followed by thewidth and the height of the rectangle. The new object of type Ellipse2D.Double represents an ellipse that is bounded by the four sides of the rectangle. If therectangle is square, the ellipse becomes a circle.

(In this case, the rectangle is a 6x6 square, thus producing a circle with a diameter of six pixels.)

Listing 10 calls the draw method of the Graphics2D class to render the ellipse (circle) at the specified location on the graphics context specified by the incoming parameter. Thus the code in Listing 9 produces a visual manifestation of a point at the origin of the current coordinate frame.The visual manifestation consists of a small circle centered on the location of the point, resulting in the small circle at the center of the left image in Figure 1 .

Draw the vertices of a hexagon

Returning once more to the drawOffScreen method of the program named PointLine03 , Listing 11 instantiates six GM2D02.Point objects that represent the vertices of a hexagon that is symmetrically located relative to the origin inthe current coordinate frame

Listing 11 . Draw the vertices of a hexagon.
```//First define three constants to make it easier to // write the code.final double aVal = osiWidth/4.0*0.5; final double bVal = osiWidth/4.0*0.866;final double cVal = osiWidth/4.0; //Now define the points.GM2D02.Point point0 = new GM2D02.Point( new GM2D02.ColMatrix(cVal,0.0));GM2D02.Point point1 = new GM2D02.Point( new GM2D02.ColMatrix(aVal,bVal));GM2D02.Point point2 = new GM2D02.Point( new GM2D02.ColMatrix(-aVal,bVal));GM2D02.Point point3 = new GM2D02.Point( new GM2D02.ColMatrix(-cVal,0.0));GM2D02.Point point4 = new GM2D02.Point( new GM2D02.ColMatrix(-aVal,-bVal));GM2D02.Point point5 = new GM2D02.Point( new GM2D02.ColMatrix(aVal,-bVal));//Now draw a visual manifestation of each of the six// points on g2Da. point0.draw(g2Da);point1.draw(g2Da); point2.draw(g2Da);point3.draw(g2Da); point4.draw(g2Da);point5.draw(g2Da);```

Then Listing 11 calls the draw method of the GM2D02.Point class six times in succession to cause small circles that represent the six points to be rendered on the specified off-screen image. You can seethose six circles in the left image in Figure 1 .

Draw six lines connecting the vertices of the hexagon

Listing 12 instantiates six objects of the GM2D02.Line class whose endpoints are specified by the six GM2D02.Point objects from Listing 11 , taken in pairs.

#### Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
how did you get the value of 2000N.What calculations are needed to arrive at it
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