Computer Graphics CG Point Circle Method circle

Circle

Last name:

Student ID:

Class:

Date: 2012-4

Lab: Circle

Lab content:

I am using the MidPoint Circle Method (improved (2) algorithm)

Core algorithms:

// Draw 8 symmetric points

Public
Static voidDraweightpoint (IntX,IntY, graphics g)

{

G. filloval (Offsetx+ X,Offsety+ Y,Pointsize,Pointsize);

G. filloval (Offsetx+ X,Offsety-2 *R+ (Offsety-Y ),Pointsize,Pointsize);

G. filloval (Offsetx-3 *R+ (Offsetx-X ),Offsety+ Y,Pointsize,Pointsize);

G. filloval (Offsetx-3 *R+ (Offsetx-X ),Offsety-2 *R+ (Offsety-Y ),Pointsize,Pointsize);

G. filloval (Offsetx+ Y,Offsety+ X,Pointsize,Pointsize);

G. filloval (Offsetx+ Y,Offsety-2 *R+ (Offsety-X ),Pointsize,Pointsize);

G. filloval (Offsetx-3 *R+ (Offsetx-Y ),Offsety+ X,Pointsize,Pointsize);

G. filloval (Offsetx-3 *R+ (Offsetx-Y ),Offsety-2 *R+ (Offsety-X ),Pointsize,Pointsize);

}

// The core algorithm of the MidPoint Circle

Public
StaticvoidDrawcircle (Graphics g ){

IntX, Y, D;

X = 0;

Y =R;

IntDeltax = 3;

IntDeltay = 2-R-R;

D = 1-R;

Draweightpoint(X, y, G );

While(X <= y ){

If(D <0 ){

D + = deltax;

Deltax + = 2;

}Else{

D + = deltax + deltay;

Deltax + = 2;

Deltay + = 2;

Y --;

}

X ++;

Draweightpoint(X, y, G );

}

Experiment results :()

Program source code:

PackageCs0904.no200942094;

ImportJava. AWT. graphics;

ImportJavax. Swing. jframe;

ImportJavax. Swing. jpanel;

Public
ClassDrawcircleExtendsJpanel {

Private
Static int Framewidth= 600;

Private
Static int Frameheight= 600;

Private
Static int Offsetx= 300,Offsety= 200;

// Coordinates of the start point and focus

// Radius

Private
Static int R= 100;

// Define the vertex size

Private
Static int Pointsize= 5;

// Calculate a cell for every 20 cells

Private
Static intTurnbigger (IntTemp ){

ReturnTemp * 20;

}

Public
Static voidMain (string [] ARGs ){

Jframeframe =NewJframe ("drawline ");

Frame. getcontentpane (). Add (NewDrawcircle ());

Frame. setdefaclocloseoperation (jframe.Exit_on_close);

Frame. setsize (Framewidth,Frameheight);

Frame. setlocation (200,10 );

Frame. setvisible (True);

}

// Draw 8 symmetric points

Public
Static voidDraweightpoint (IntX,IntY, graphics g)

{

G. filloval (Offsetx+ X,Offsety+ Y,Pointsize,Pointsize);

G. filloval (Offsetx+ X,Offsety-2 *R+ (Offsety-Y ),Pointsize,Pointsize);

G. filloval (Offsetx-3 *R+ (Offsetx-X ),Offsety+ Y,Pointsize,Pointsize);

G. filloval (Offsetx-3 *R+ (Offsetx-X ),Offsety-2 *R+ (Offsety-Y ),Pointsize,Pointsize);

G. filloval (Offsetx+ Y,Offsety+ X,Pointsize,Pointsize);

G. filloval (Offsetx+ Y,Offsety-2 *R+ (Offsety-X ),Pointsize,Pointsize);

G. filloval (Offsetx-3 *R+ (Offsetx-Y ),Offsety+ X,Pointsize,Pointsize);

G. filloval (Offsetx-3 *R+ (Offsetx-Y ),Offsety-2 *R+ (Offsety-X ),Pointsize,Pointsize);

}

Public
Static voidDrawcircle (Graphics g ){

IntX, Y, D;

X = 0;

Y =R;

IntDeltax = 3;

IntDeltay = 2-R-R;

D = 1-R;

Draweightpoint(X, y, G );

While(X <= y ){

If(D <0 ){

D + = deltax;

Deltax + = 2;

}Else{

D + = deltax + deltay;

Deltax + = 2;

Deltay + = 2;

Y --;

}

X ++;

Draweightpoint(X, y, G );

}

G. drawstring ("", x + 20, Y + 20 );

}

 

Protected
VoidPaintcomponent (graphicsg ){

Super. Paintcomponent (g );

For(IntI = 0; I <Frameheight; I + =Turnbigger(1 )){

G. drawline (0, I,Framewidth, I );

}

For(IntI = 0; I <Framewidth; I + =Turnbigger(1 )){

G. drawline (I, 0, I,Frameheight);

}

Drawcircle(G );

}

}