flightclub.framework3d
Class CameraMan

java.lang.Object
  |
  +--flightclub.framework3d.CameraMan

public class CameraMan

extends java.lang.Object

This class implements camera functionality such as cutting smoothly between different camera subjects and mapping (x, y, z) onto the screen (y_, z_)). The projection from (x, y, z) onto the screen (y_, z_) is determined by two vectors, eye and focus.

Using these two vectors we calculate the rotation and translation needed to position the eye on the (+ve) x_ axis looking towards the focus at origin_. Given a point (x, y, z) we translate it and apply the rotation to get (x_, y_, z_). We then scale the y_ and z_ by 1/x_ to complete the perspective projection by forshortening y_ and z_ according to their distance from the camera.

See Also:

ModelViewer.createCameraMan(), ModelCanvas.paintModel()

Field Summary

static int	CUT_LEN
protected float	depthOfVision
protected float	LENS_ANGLE_INVERSE This field tells us how far away from a 1 unit tall object must the camera be in order for it to fill the height of the screen.
protected ModelViewer	modelViewer
protected static float	ZOOM_STEP

Constructor Summary

CameraMan(ModelViewer modelViewer)
Creates a CameraMan.

Method Summary

float	getDistance()
float[]	getEye()
float[]	getFocus()
float[][]	getMatrix()
void	init() Sets the scale according to the canvas height.
void	pullIn() Move eye closer to the focus.
void	pullOut() Move eye further away from the focus.
void	rotate(float dtheta, float dz) Rotates the eye about the focus by dtheta (L/R) and moves the eye up or down by dz.
void	scaleToScreen(float[] v_) Scales the y_ and z_ co-ords so a 1 unit tall tree fills the screen height when viewed from a distance of LENS_ANGLE_INVERSE away.
void	setSubject(CameraSubject cameraSubject, boolean track) Sets the camera subject.
void	setSubjectNow(CameraSubject cameraSubject, boolean track) Sets the camera subject.
void	tick() Update camera position, only if we are mid cut or the subject is moving.
java.lang.String	toString() Returns a string that may be handy for debugging.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

modelViewer

protected ModelViewer modelViewer

depthOfVision

protected float depthOfVision

CUT_LEN

public static final int CUT_LEN

See Also:

Constant Field Values

LENS_ANGLE_INVERSE

protected float LENS_ANGLE_INVERSE

This field tells us how far away from a 1 unit tall object must the camera be in order for it to fill the height of the screen. Of course, we measure the lens angle in radians.

ZOOM_STEP

protected static final float ZOOM_STEP

See Also:

Constant Field Values

Constructor Detail

CameraMan

public CameraMan(ModelViewer modelViewer)

Creates a CameraMan.

Parameters:

modelViewer - an instance of ModelViewer.

Method Detail

init

public void init()

Sets the scale according to the canvas height. Do not call this method until the ModelCanvas knows how big it is.

tick

public void tick()

Update camera position, only if we are mid cut or the subject is moving.

See Also:

ModelViewer.tick(float, float)

setSubject

public void setSubject(CameraSubject cameraSubject,
                       boolean track)

Sets the camera subject. The camera will gradually move to its new position over CUT_LEN ticks.

Parameters:

cameraSubject - the subject to film.

track - if true then track the subject as it moves.

setSubjectNow

public void setSubjectNow(CameraSubject cameraSubject,
                          boolean track)

Sets the camera subject. The camera moves immediately to the new position defined by the subject.

getDistance

public float getDistance()

getMatrix

public float[][] getMatrix()

getFocus

public float[] getFocus()

getEye

public float[] getEye()

rotate

public void rotate(float dtheta,
                   float dz)

Rotates the eye about the focus by dtheta (L/R) and moves the eye up or down by dz.

scaleToScreen

public final void scaleToScreen(float[] v_)

Scales the y_ and z_ co-ords so a 1 unit tall tree fills the screen height when viewed from a distance of LENS_ANGLE_INVERSE away.

Also translates y_ and z_ so that (x_, 0, 0) appears center screen.

See Also:

Obj3d.transform()

pullIn

public void pullIn()

Move eye closer to the focus.

pullOut

public void pullOut()

Move eye further away from the focus.

toString

public java.lang.String toString()

Returns a string that may be handy for debugging.

Overrides:

toString in class java.lang.Object