Jcalcomp:Calcomp Simulator in Java

Ver.0.95         Sept. 1,1997
Hiroshi Sakuta
1-380 MIT
Dept. of Civil & Environmental Engineering
Phone)617-253-8925
hsakuta@mit.edu

Samples

Preface

"Jcalcomp" simulator is developed mainly for Calcomp plotter users. It is composed with class libraries which have common methods with subroutines and/or functions in the flat bed pen plotter, which has been used as a graphical output device from the main-frame age. Many potential programmers used to make their own codes for Calcomp plotter.
Facilities for Calcomp plottter are extended to Java graphical environmrnt here. Then, all functions are implemented methods in class libraries. The features of this class library are 1) interactivity(controlled by scroll bar or radio button on a browser), 2) perspective/isometric projective view and its animation, 3) ray tracing 4) contour plotting, and 5) original vector fonts for ASCII character sets which can be applied by users to their superset.  The style of code seems to be classic but understandable for beginners.

The language

The language applied for this simulator is Java. The reasons of this application are 1) compact load module, 2) friendly interface of Web documents, 3) portability, and 4) good advantage in graphical interface. Java is, of course, one of Object Oriented Languages, and programming in Java need some pieces of knowledge for this subject. However, this simulator provide a kind of template and will be understandable for C/FORTRAN programmer. This means that a lot of graphic codes for Calcomp plotter in archives can get their role in Web contents. Also, senior programmers can make their graphic code in Java and give advise to younger programmer in this field.
There are many textbook for OOPS, in which B. Meyer's work is very instructive.

Class and Method

In this version, the class library is not clearly separated with user code , and is supplied as a source library, which means that users can make their own class library by the source code.
Following descriptions, therefore, are tentative until version 1.0.

Coordinate system

This class library applies three types of coordinates, which is well known for graphic programmer and, of course, for Calcomp programmer.

1) Screen coordinates

Screen monitor coordinates corresponds to pixcel-wise bitmap picture. The origin is specified by its launching browser/viewer, and usually the left-up corner in the browser/viewer is default. The increment of coordinate is then integer number.

2) World coordinates

World coordinates is an user's section paper. Users can fit it to the screen coordinate by specification of two point, which are (x,y) coodinates of left-up and right-down corner of section paper corresponding the screen coordinate. Our mathematical coordinate system has oppisite direnction to the screen y-coordinate(vertical), which are considered in this library. Users can use their section paper normally.
3D coordinte is used in this library for perspective or isometric projection. Then the world coordinate is used in projection viewing. The 3D users view objects through this section paper.

3) User's coordinates

The user's coordinate is graduation in the section paper written by them.
The graduation is usually applied for curve plotting of some functions and representations of experimetal result. Then this coordinates is only for curve plotting. Users can draw their curve by methods of "lline" and "lgline". The former is for linear plotting and the latter is for logarithm scale. Both have own axis presentation methods "axis" and "lgaxis".
In 3D viewing of curve plotting, however, the user's coordinate is not applied. It is because that if 3D viewing has user's coordinate system, the projection plane( section paper) has to make new coordinate system corrresponding to 3D user's coordinate system. While this conversion is not difficult for the computer, conversion of user's own coordinate to world coordinates is more comprehensive for the user. This means user have to caculate the coordinates without graduation in the section paper. In spite of this, there are two 3D axis plotting method, which are "paxis" and "plgaxis".
They are corresponding to "axis" and "lgaxis" in 2D, respectively.

---

Class and Method description

Jcalcomp

Syntax
public abstract class Jcalcomp

Description
This Jcalcomp class is basic engineering drawing tool by usage of Graphics. It provides user's riginal coordinates, contour line graph and 3D graph.
Jcalcomp is extended from Applet class and user should make thier own class extended from Jcalcomp.
This class is named after Calcomp plotter library, which has been used as a flatbet plotter library in FORTRAN library.

MEMBER SUMMARY

Constructors & Destructors

Calcomp()        Construct a new Calcomp simulator area

Basic 2D Drawing Methods

u_plot()         Basic plotting method

symbol()        draw ASCII character in vector font

number()        draw double number in arbitrary format

marker()        draw plotting symbol, whose identification point is its center

2D Function Drawing Methods

axis()            draw linear axis in world coordinates

lgaxis()        draw logarithm axis in world coordinates

lline()            draw 2D line in user's coordinates by linear scale

lgline()            draw 2D logarithm line in user's coordinate by log/log, log/linear, and linear/log for x/y.

scale()           output converting factor from user's linear coordinates to world ones.

lgscale()        output converting factor from user's linear coordinates to world ones.

2D Contour Line Drawing Methods

mesh_plot()    draw 2D mesh system for contour plotting in physical and virtual coordinates.

contour()        draw 22D contour line in physical and virtual coordinates.

3D Drawing Methods

bprep()

pplot()

psymbol()

pnumber()

paxis()

plgaxis()

3D Contour Line Drawing Methods

p_contor()

void Jcalcomp()

SYNTAX : Jcalcomp(int igx0,int igy0,int igx1,int igy1,double gx0,double gy0,double wid,double hei,int iback,int ibord)
Jcalcomp(int igx0,int igy0,int igx1,int igy1,double gx0,double gy0,double wid,double hei,int iback,int ibord)

DESCRIPTION : Fix 2 points specified by left-up and right down corners. Corresponding world coordinate system is developed.

PARAMETERS : int igx0,int igy0,int igx1,int igy1,double gx0,double gy0,double wid,double hei,int iback,int ibord

RETURNS : none

SEEALSO :

EXAMPLE :

void u_plot()

PURPOSE : 2D Plotting in User's Coordinates

SYNTAX : plot(Graphics g,double x,double y,int n)

DESCRIPTION : Fix 2 points specified by left-up and right down corners. Corresponding world coordinate system is developed.

PARAMETERS :

Graphics g:
double x:
double y:
int n:

SEEALSO :

EXAMPLE : 

void symbol()

SYNTAX :

DESCRIPTION :

PARAMETERS :

x,y,h,text,theta,in

SEEALSO :

EXAMPLE : 

void number()

SYNTAX :

DESCRIPTION :

PARAMETERS :

x,y,h,fpn,theta,n

SEEALSO :

EXAMPLE : 

void marker()

SYNTAX :

DESCRIPTION :

PARAMETERS : x,y,n

RETURNS :

SEEALSO :

EXAMPLE :

SYNTAX :

DESCRIPTION :

PARAMETERS :

n

SEEALSO :

EXAMPLE : 

void axis()

SYNTAX :

DESCRIPTION :

PARAMETERS :

x0,y0,d,t,theta,title,n,m,md,sm,smd

SEEALSO :

EXAMPLE : 

void lgaxis() 

---

SYNTAX :

DESCRIPTION :

PARAMETERS :

x0,y0,t,theta,isep,title,n,m

SEEALSO :

EXAMPLE : 

void lline() 

---

SYNTAX :

DESCRIPTION :

PARAMETERS :

xp,yp,x,y,nn,isym

SEEALSO :

EXAMPLE : 

void lgline() 

---

SYNTAX :

DESCRIPTION :

PARAMETERS :

xp , yp , x , y , nn , ils , isym

SEEALSO :

EXAMPLE : 

void lstyle() 

---

SYNTAX :

DESCRIPTION :

PARAMETERS :

n

SEEALSO :

EXAMPLE : 

void scale() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

x,n,dx

RETURNS :

SEEALSO :

EXAMPLE : 

void lgscal() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

x,n,dx

SEEALSO :

EXAMPLE : 

void wcircle() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

x,y,r

SEEALSO :

EXAMPLE : 

void wpieslice() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

x,y,r,color

SEEALSO :

EXAMPLE : 

void wlattice() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

x,y,dx,dy,m,n

SEEALSO :

EXAMPLE : 

void box_plt() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

x0,y0,x1,y1

SEEALSO :

EXAMPLE : 

void mshplt() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

mod,frm,x,y,flg,m,n,xdim,ydim,fdim,wid,hei

SEEALSO :

EXAMPLE : 

void fmxmn() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

flg,f,m,n,lvl,fdim,vdim,setlvl

SEEALSO :

EXAMPLE : 

void contor() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

mod,title,x,y,f,flg,setlvl,stclr,stlsy,lvl,m,n, xdim,ydim,vdim,fdim,wid,hei

SEEALSO :

EXAMPLE : 

int find() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

g,k1,p,q

SEEALSO :

EXAMPLE : 

void bprep() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

ang,idf,h1d,h2d,h3d,phaid,psaid,cvdd,x,y,z

SEEALSO :

EXAMPLE : 

void pplot() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

x,y,z,n

SEEALSO :

EXAMPLE : 

void prect() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

x,y,z,dx,dy,dz,phai,psai

SEEALSO :

EXAMPLE : 

void phline() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

RETURNS :

SEEALSO :

EXAMPLE : 

void pcontor() 

---

URPOSE :

DESCRIPTION :

PARAMETERS :

RETURNS :

SEEALSO :

EXAMPLE :