jvx.numeric

Class PnLIC

java.lang.Object

jvx.numeric.PnLIC

public class PnLIC
extends java.lang.Object

Line Integral Convolution for vector field visualization.

After constructing an instance of this class one can immediately get the resulting LIC texture size by methods getTextureWidth() and getTextureHeight().

Author:

Eike Preuss

Version:

15.04.06, 2.10 revised (kp) Calculation of planar texture coordinates makeElementTextureCoords() moved to PwTexture.
15.04.06, 2.00 revised (kp) Formatting and removal of long-time deprecated method getOutline() for computing outline of triangle.
01.03.06, 1.95 revised (ah) Storage of last polygon removed.
02.07.03, 1.90 revised (ep) Do not do LIC for degenerated elements; pixel array is only allocated when LIC is performed, not when size is set.
24.06.03, 1.85 revised (kp) Class ScannedData moved to new class jv.objectGui.PsScanline.
05.02.03, 1.80 revised (ep) Increased vertical gap in texture image.
21.01.03, 1.70 revised (ep) Better texture filling.
15.01.03, 1.60 revised (ep) Handling of degenerated elements.
06.01.03, 1.50 revised (ep) Create nearly square texture images.
17.12.02, 1.40 revised (ep) Added (optional) contrast parameter to getPixArray and implemented other scanline algorithm (isn't used here yet).
20.07.02, 1.30 revised (ep) Array length bug removed.
08.07.01, 1.20 revised (ep) Optimized getPixels, and computation by using floats and no variable declarations in loops.
16.01.01, 1.10 revised (ep) Triangle packing optimized.
09.03.00, 1.06 revised (ep) Bug-fixes.
20.02.00, 1.05 revised (ep) Corrected "integralh-bug".
11.12.99, 1.02 revised (ep) Adaptive kernel width.

Constructor Summary

Constructors

Constructor and Description
PnLIC() Creates a new LIC processor.
PnLIC(PgElementSet geom) Creates a new LIC processor for given geometry.
PnLIC(PgElementSet geom, int size, PnGeodesicRK rk) Creates a new LIC processor for given geometry.

Method Summary

Modifier and Type	Method and Description
double	getCoarseness()
int	getConvolutionWidth() Deprecated. Use getWorldConvolutionWidth().
int	getMinConvolutionWidth()
int[]	getPixArray(int[] pix)
int[]	getPixArray(int[] pix, double contrast) Puts actual LIC texture line by line with offset 0 and scan width 'texturewidth' into given alphaRGB pixel array.
double	getStepSize()
int	getTextureHeight() Call this to get information about the actual height of the texture image that is used for the LIC image.
int	getTextureWidth() Call this to get information about the actual width of the texture image that is used for the LIC image.
double	getWorldConvolutionWidth() Normal (one-velocity) convolution width along integral lines in world coordinates.
void	makeElement(int elemIndex) Computes Line Integral Convolution texture along all integral lines that begin in given element.
void	makeFastElement(int elem, PdVector[] texvector, PdBaryDir[] baryvector, double[] veclen, PdVector[] pixTexCoord, boolean[] computedVec, boolean[] computedCoord) First try to make LIC *VERY* fast :-), experimental.
void	makeFastLIC() First try to make LIC *VERY* fast :-), experimental.
void	makeLIC() Computes LIC texture for all elements of geometry.
void	reset() Initialize pixel array with zeroes.
boolean	setCoarseness(double coarse) Sets the coarseness of noise that is convoluted to create the LIC image.
boolean	setConvolutionWidth(int numPixels) Deprecated. Use setWorldConvolutionWidth(double).
void	setGeometry(PgElementSet geom) Set the size of the LIC texture.
boolean	setMinConvolutionWidth(int numPixels) At every point their is a minimal number of pixels that are convoluted, even if convolutionwidth*(velocity of vector field) is less than this number (minconvolutionwidth).
void	setRungeKutta(PnGeodesicRK rk) Sets the vector field for integration and the integration method.
void	setSize(int size) Set the size of the LIC texture.
void	setStepSize(double h) Sets the stepsize of the runge-kutta integration method.
boolean	setWorldConvolutionWidth(double width) Sets normal (one-velocity) convolution width along integral lines in world coordinates.

Methods inherited from class java.lang.Object

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

Constructor Detail

PnLIC

public PnLIC()

Creates a new LIC processor. Later geometry, size and ode solver must be assigned.

Since:

JavaView 3.98.005

Version:

07.09.07, 1.00 created

PnLIC

public PnLIC(PgElementSet geom)

Creates a new LIC processor for given geometry.

Parameters:

geom - underlying geometry

PnLIC

public PnLIC(PgElementSet geom,
             int size,
             PnGeodesicRK rk)

Creates a new LIC processor for given geometry. The vector field that shall be visualized is implicitly given by the geodesic Runge-Kutta class.

Parameters:

geom - underlying geometry

size - width in pixels of longest edge of the geometry

rk - geodesic Runge-Kutta method with vector field.

See Also:

PnGeodesicRK

Version:

03.09.07, 1.10 revised (kp) Obsolete parameter time removed.

Method Detail

setGeometry

public void setGeometry(PgElementSet geom)

Set the size of the LIC texture. Method allocates element texture in geometry based on size parameter.

Parameters:

geom - Geometry on which we operate.

Since:

JavaView 3.98.005

Version:

07.09.07, 1.00 created

setSize

public void setSize(int size)

Set the size of the LIC texture. Method allocates element texture in geometry based on size parameter.

Parameters:

size - length in pixels of longest edge of the geometry.

setRungeKutta

public void setRungeKutta(PnGeodesicRK rk)

Sets the vector field for integration and the integration method.

Parameters:

rk - geodesic runge-kutta method that contains the vector field that shall be visualized

See Also:

PnGeodesicRK

getTextureWidth

public int getTextureWidth()

Call this to get information about the actual width of the texture image that is used for the LIC image.

Returns:

width of the texture image in pixels

getTextureHeight

public int getTextureHeight()

Call this to get information about the actual height of the texture image that is used for the LIC image.

Returns:

height of the texture image in pixels

setCoarseness

public boolean setCoarseness(double coarse)

Sets the coarseness of noise that is convoluted to create the LIC image.

Parameters:

coarse - 0 = fine; 1 = constant

getCoarseness

public double getCoarseness()

setConvolutionWidth

public boolean setConvolutionWidth(int numPixels)

Deprecated. Use setWorldConvolutionWidth(double).

Sets normal (one-velocity) convolution width along integral lines in pixels. This value is only synchronized with getWorldConvolutionWidth() after makeElement(int) or makeLIC() is called. If worldConvolutionWidth has a value > 0, then the value of convolutionWidth is ignored!

Parameters:

numPixels - new width given in texture pixels

getConvolutionWidth

public int getConvolutionWidth()

Deprecated. Use getWorldConvolutionWidth().

This value is only synchronized with getWorldConvolutionWidth() after makeElement(int) or makeLIC() is called. If worldConvolutionWidth has a value > 0, then the value of convolutionWidth is ignored!

setWorldConvolutionWidth

public boolean setWorldConvolutionWidth(double width)

Sets normal (one-velocity) convolution width along integral lines in world coordinates. This value is only synchronized with getConvolutionWidth() after makeElement(int) or makeLIC() is called. If worldConvolutionWidth has a value > 0, then the value of convolutionWidth is ignored!
The given length is only used approximately - in fact it is transformed to a number of texture pixels.

Parameters:

width - new width given in world coordinate length

Returns:

true if worldConvolutionWidth is set, false if convolutionWidth will be used (caused by invalid parameter 'width')

Since:

JavaView 2.49.009

getWorldConvolutionWidth

public double getWorldConvolutionWidth()

Normal (one-velocity) convolution width along integral lines in world coordinates. This value is only synchronized with getConvolutionWidth() after makeElement(int) or makeLIC() is called. If worldConvolutionWidth has a value > 0, then the value of convolutionWidth is ignored!
The given length is only used approximately - in fact it is transformed to a number of texture pixels.

Since:

JavaView 2.49.009

setMinConvolutionWidth

public boolean setMinConvolutionWidth(int numPixels)

At every point their is a minimal number of pixels that are convoluted, even if convolutionwidth*(velocity of vector field) is less than this number (minconvolutionwidth). Of course this number may be zero. minconvolutionwidth may not be less than convolutionwidth.

getMinConvolutionWidth

public int getMinConvolutionWidth()

setStepSize

public void setStepSize(double h)

Sets the stepsize of the runge-kutta integration method.

Parameters:

h - stepsize

getStepSize

public double getStepSize()

makeElement

public void makeElement(int elemIndex)

Computes Line Integral Convolution texture along all integral lines that begin in given element. These integral lines may leave the element.

Parameters:

elemIndex - global element index in underlying geometry

Version:

09.03.00, 1.10 revised (ep) Handle degenerated triangles.

getPixArray

public int[] getPixArray(int[] pix)

See Also:

getPixArray(int[], double)

getPixArray

public int[] getPixArray(int[] pix,
                         double contrast)

Puts actual LIC texture line by line with offset 0 and scan width 'texturewidth' into given alphaRGB pixel array. It also performs a histogram transformation (boosting the contrast of image), so you should avoid calling this method if the LIC texture did not change since last call. The given integer array should be of sufficient size width*height, see getTextureWidth() and getTextureHeight(), or may be null. If parameter is null then a new integer array of the correct size is returned.

Parameters:

pix - output: actual LIC texture; should be of size texturewidth*textureheight

Returns:

the same as in parameter pix, or a new integer array that contains the results if pix is null

Since:

JavaView 2.48.005

See Also:

getTextureWidth(), getTextureHeight()

makeLIC

public void makeLIC()

Computes LIC texture for all elements of geometry. Method getPixArray(int[]) returns the texture image. You need to call setSize before.

See Also:

getPixArray(int[]), getPixArray(int[],double)

reset

public void reset()

Initialize pixel array with zeroes.

makeFastLIC

public void makeFastLIC()

First try to make LIC *VERY* fast :-), experimental. You need to call setSize(int) before.

Since:

JavaView 2.65.000

makeFastElement

public void makeFastElement(int elem,
                            PdVector[] texvector,
                            PdBaryDir[] baryvector,
                            double[] veclen,
                            PdVector[] pixTexCoord,
                            boolean[] computedVec,
                            boolean[] computedCoord)

First try to make LIC *VERY* fast :-), experimental. You need to call setSize(int) before.

Since:

JavaView 2.65.000