vgp.tutor.linear

Class PjLinear

java.lang.Object

jv.object.PsObject

jv.project.PjProject

vgp.tutor.linear.PjLinear

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, PsTimeListenerIf, PsUpdateIf, PvPickListenerIf

public class PjLinear
extends PjProject

Simple interactive linear algebra applet performs vector calculations on two vectors and shows the result vector.

The result vector has 3D coordinates because of the possible cross product mode. Nevertheless, the dimension of the two argument vectors has been chosen 2D since then the vectors always lie in the xy-plane in the display, even if the camera is in perspective mode. This makes the dragging of the argument vectors in cross product mode more intuitive. Note, the method computeResult() may be simplified a little if one chooses 3D coordinates for all vectors.

See Also:

Serialized Form

Author:

Konrad Polthier

Version:

05.11.02, 1.30 revised (ep) Use perspective camera for cross product.
04.03.01, 1.20 revised (kp) Converted into a tutorial, and moved to vgp.tutor.
26.11.00, 1.10 revised (kp) Use global instead of local polygon colors.
22.10.00, 1.00 created (kp)

Field Summary

Fields

Modifier and Type	Field and Description
static int	MODE_ADD Summation mode, result is sum of two argument vectors.
static int	MODE_CROSS Cross product mode, result is cross product of two argument vectors.
static int	MODE_SUB Difference mode, result is difference of two argument vectors.

Fields inherited from class jv.object.PsObject

HAS_BOUNDARY_PANEL, HAS_CONFIG_PANEL, HAS_INFO_PANEL, HAS_LABEL_PANEL, HAS_MATERIAL_PANEL, HAS_TEXTURE_PANEL, HAS_VECTOR_PANEL, INSPECTOR_INFO, INSPECTOR_INFO_EXT, IS_DELETED, IS_FIXED, IS_FOCUSSED, IS_PICKED, IS_SELECTED, IS_USED, NUM_TAGS

Constructor Summary

Constructors

Constructor and Description
PjLinear() Constructors creates two argument vectors and a result vector.

Method Summary

Modifier and Type	Method and Description
void	computeResult(int mode) Perform vector arithmetic on two argument vectors to compute the result vector.
int	getMode() Get the current computation mode, possibly values are MODE_... constants.
void	init() Initialize all instance variables of this project.
int	setMode(int mode) Set the current computation mode, possibly values are MODE_... constants.
void	start() Method is invoked during loading of a project in JavaView.
boolean	update(java.lang.Object event) Perform recomputations whenever a child has changed.

Methods inherited from class jv.project.PjProject

addDisplay, addGeometry, addGeometry, dispose, dragDisplay, dragInitial, dragVertex, fitDisplays, getAnimation, getDisplay, getDisplays, getGeometry, getGeometry, getNumGeometries, getParameter, getParameterInfo, getViewer, hasAnimation, hasDisplay, isEnabledAutoFit, markVertices, pickDisplay, pickInitial, pickVertex, removeDisplay, removeGeometries, removeGeometry, selectDisplay, selectGeometry, setAnimation, setBackColor, setBorderType, setDisplay, setEnabledAutoFit, setGeometry, setParameterInfo, setTime, setViewer, stop, unmarkVertices

Methods inherited from class jv.object.PsObject

addInspector, addUpdateListener, assureInspector, clearTag, clone, clone, clone, copy, getFather, getInfoPanel, getInspector, getName, getNumObjects, getSymbol, hasInspector, hasTag, hasUpdateListener, instanceOf, instanceOf, newInspector, newInspector, removeInspector, removeInspector, removeUpdateListener, setName, setParent, setSymbol, setTag, toString, updatePanels

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface jv.anim.PsTimeListenerIf

getName

Methods inherited from interface jv.project.PvPickListenerIf

getName

Field Detail

MODE_ADD

public static final int MODE_ADD

Summation mode, result is sum of two argument vectors.

See Also:

Constant Field Values

MODE_SUB

public static final int MODE_SUB

Difference mode, result is difference of two argument vectors.

See Also:

Constant Field Values

MODE_CROSS

public static final int MODE_CROSS

Cross product mode, result is cross product of two argument vectors.

See Also:

Constant Field Values

Constructor Detail

PjLinear

public PjLinear()

Constructors creates two argument vectors and a result vector. Initializations of instance variables should be performed within the init() method to allow resetting the project later by simply calling the init() method.

Method Detail

init

public void init()

Initialize all instance variables of this project. This method is invoked during the construction of this project and whenever this project is reset. Therefore, allocations of instance variables should be performed in the constructor of the project.

Overrides:

init in class PjProject

start

public void start()

Description copied from class: PjProject

Method is invoked during loading of a project in JavaView.

If a project has an animation object, then the animation panel is shown when the project's this start() method is invoked during loading of the project. Use setAnimation(PsAnimation) to register an animation.

If auto fit is enabled then scenery is scaled to fit in each display.

Overrides:

start in class PjProject

See Also:

PvViewerIf.start(), PjProject.isEnabledAutoFit()

getMode

public int getMode()

Get the current computation mode, possibly values are MODE_... constants.

setMode

public int setMode(int mode)

Set the current computation mode, possibly values are MODE_... constants. Method also recomputes the result vector and initiates a redraw.

computeResult

public void computeResult(int mode)

Perform vector arithmetic on two argument vectors to compute the result vector. This method could be made simpler if one uses 3D coordinates for argument vectors too.

update

public boolean update(java.lang.Object event)

Perform recomputations whenever a child has changed. Here the two argument vectors have registered this class as parent, therefore, we are able to catch their update events and recompute the result vectors if they have changed. Method is usually invoked from the children.

Specified by:

update in interface PsUpdateIf

Overrides:

update in class PsObject

Parameters:

event - carries a lot of information

Returns:

true if event has been handled, otherwise false

See Also:

PsObject.setParent(PsUpdateIf), PsObject.getFather(), PsObject.addUpdateListener(PsUpdateIf)