Package gov.nih.mipav.model.algorithms

Class ContourPlot

java.lang.Object

java.lang.Thread

gov.nih.mipav.model.algorithms.AlgorithmBase

gov.nih.mipav.model.algorithms.ContourPlot

All Implemented Interfaces:

ActionListener, WindowListener, Runnable, EventListener

public class ContourPlot
extends AlgorithmBase

The Contours class provides methods to compute contour lines and contour bands from a 2D regular grid of scalar values. See computeContourLines(double[][], double, int) and computeContourBands(double[][], double, double, int, int)

Author:

hageldave

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	ContourPlot.AdaptableView	The AdaptableView interface defines the ContourPlot.AdaptableView.setView(Rectangle2D) method.
class	ContourPlot.BarycentricGradientPaint	The BarycentricGradientPaint class provides a way to fill a Shape with a triangular color gradient.
class	ContourPlot.BarycentricGradientPaintContext	This class is implements the PaintContext for ContourPlot.BarycentricGradientPaint.
class	ContourPlot.BlankCanvasFallback	Fallback implementation for invalid reference BlankCanvas for systems that do not support OpenGL 3 through invalid reference org.lwjgl.opengl.awt.AWTGLCanvas (e.g. macOS).
static class	ContourPlot.BufferedImageFactory	Class providing convenience methods for converting Images to BufferedImages.
static class	ContourPlot.CharacterAtlas	The CharacterAtlas class is a texture atlas for looking up character textures.
static interface	ContourPlot.ColorMap	The ColorMap interface defines discrete mapping from a fixed integer interval [0..N-1] to colors through the ContourPlot.ColorMap.getColor(int) method.
static class	ContourPlot.ColorOperations	The ColorOperations class contains methods for manipulating 32bit ARGB color values.
class	ContourPlot.ColorScheme	The ColorScheme is responsible for storing and providing color information, which other components can use.
class	ContourPlot.CompleteRenderer	The ContourPlot.CompleteRenderer comprises a ContourPlot.LinesRenderer, a invalid reference PointsRenderer , a ContourPlot.TextRenderer and a ContourPlot.TrianglesRenderer.
static interface	ContourPlot.CoordinateViewListener	The CoordinateViewListener is a listener that listens on changes to a ContourPlot.CoordSysRenderer's coordinate view (i.e.
class	ContourPlot.CoordSysPanning	The CoordSysPanning class implements a invalid reference MouseListener and invalid reference MouseMotionListener that realize panning functionality for the coordinate view of the ContourPlot.CoordSysRenderer.
class	ContourPlot.CoordSysRenderer	The CoordSysRenderer is a ContourPlot.Renderer that displays a coordinate system.
class	ContourPlot.CoordSysScrollZoom	The CoordSysScrollZoom class implements a MouseWheelListener that realize zooming functionality for the coordinate view of the ContourPlot.CoordSysRenderer.
static enum	ContourPlot.DefaultColorMap
static enum	ContourPlot.DefaultColorScheme	Enum containing predefined ContourPlot.ColorSchemes, which can be accessed through ContourPlot.DefaultColorScheme.get().
static class	ContourPlot.ExtendedWilkinson	Implementation of the extended Wilkinson algorithm for tick label positioning.
static final class	ContourPlot.FontProvider
class	ContourPlot.GenericKey	The GenericKey class can be used as key in HashMaps when multiple objects should be combined to a single key.
class	ContourPlot.GenericRenderer<T extends ContourPlot.Renderable>
static interface	ContourPlot.Glyph	The Glyph interface has to be implemented by a class that realizes a graphical representation of a 2D point (e.g. a cross or a circle).
static class	ContourPlot.ImageSaver	Class providing convenience methods for saving Images to file.
class	ContourPlot.Img	Image class with data stored in an int array.
static interface	ContourPlot.ImgBase<P extends ContourPlot.PixelBase>	Base interface for imagingkit's Img classes.
static interface	ContourPlot.InteractionConstants
static final class	ContourPlot.Iterators	Class holding all of the Iterator and Spliterator classes used in the ContourPlot.ImgBase interface.
static interface	ContourPlot.JPlotterCanvas	This interface defines the methods required by an implementation of a canvas Component for use with JPlotter ContourPlot.Renderers such as invalid reference BlankCanvas or ContourPlot.BlankCanvasFallback.
static class	ContourPlot.Legend	The Legend class is ContourPlot.Renderable and its own ContourPlot.Renderer at once.
class	ContourPlot.Lines	The Lines class is a collection of linear line segments.
class	ContourPlot.LinesRenderer	The LinesRenderer is an implementation of the ContourPlot.GenericRenderer for ContourPlot.Lines.
static class	ContourPlot.Pair<T1,T2>	Pair class.
final class	ContourPlot.ParallelForEachExecutor<T>	CountedCompleter class for multithreaded execution of a Consumer on a Spliterator.
static interface	ContourPlot.PDFRenderer	The PDFRenderer interface defines the method ContourPlot.PDFRenderer.renderPDF(PDDocument, PDPage, int, int, int, int) which 'renders' the PDFRenderers's content as pdf objects in content streams, i.e. fills content streams with elements and appends them to the specified page.
class	ContourPlot.Pixel	Pixel class for retrieving a value from an ContourPlot.Img.
static interface	ContourPlot.PixelBase	Basic interface for Pixel classes of ContourPlot.ImgBase implementations.
static class	ContourPlot.PixelConvertingSpliterator<P extends ContourPlot.PixelBase,T>	The PixelConvertingSpliterator enables iterating an ContourPlot.Img with a different datatype than ContourPlot.Pixel (ContourPlot.ImgBase.spliterator()).
static interface	ContourPlot.PixelManipulator<P extends ContourPlot.PixelBase,T>	The PixelManipulator interface defines an action to be performed on a pixel.
static class	ContourPlot.PointDetails	Class for storing all the details of a single point to be rendered.
class	ContourPlot.PointeredPoint2D	The PointeredPoint2D class is an implementation of the Point2D class that uses two double arrays of size 1 to store its x and y coordinate.
class	ContourPlot.Points	The Points class is a collection of 2D points that are to be represented using the same ContourPlot.Glyph (the graphical representation of a point).
static interface	ContourPlot.Renderable	Interface for an object that can be rendered by a ContourPlot.Renderer e.g. the ContourPlot.GenericRenderer.
static interface	ContourPlot.Renderer	The Renderer interface defines methods to initialize the renderer, execute a rendering pass, close the renderer.
class	ContourPlot.SegmentDetails	Specification of a line segment which comprises vertex locations, colors, picking color, and thicknesses.
static class	ContourPlot.SignedDistanceCharacters	The SignedDistanceCharacters class comprises signed distance fields of a set of characters.
class	ContourPlot.SimpleColorMap	Implementation of the ContourPlot.ColorMap interface.
class	ContourPlot.Text	Abstract class for ContourPlot.Renderables representing text that can be rendered using the ContourPlot.TextRenderer.
class	ContourPlot.TextRenderer	The TrianglesRenderer is an implementation of the ContourPlot.GenericRenderer for ContourPlot.Text.
static interface	ContourPlot.TickMarkGenerator	The TickMarkGenerator interface provides the ContourPlot.TickMarkGenerator.genTicksAndLabels(double, double, int, boolean) method.
class	ContourPlot.TranslatedPoint2D	The TranslatedPoint2D is an implementation of Point2D that references another Point2D and has a certain fixed translation from that point.
class	ContourPlot.TriangleDetails	Specification of a triangle which comprises vertex locations, colors and picking color.
class	ContourPlot.Triangles	The Triangles class is a collection of 2D triangles.
class	ContourPlot.TrianglesRenderer	The TrianglesRenderer is an implementation of the ContourPlot.GenericRenderer for ContourPlot.Triangles.
static class	ContourPlot.Utils	Class containing utility methods

Nested classes/interfaces inherited from class java.lang.Thread

Thread.Builder, Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields

Modifier and Type	Field	Description
private static ContourPlot	cp	Example from source ContourPlot.java draws contour plot of function surface correctly.

Fields inherited from class gov.nih.mipav.model.algorithms.AlgorithmBase

destFlag, destImage, image25D, mask, maxProgressValue, minProgressValue, multiThreadingEnabled, nthreads, progress, progressModulus, progressStep, runningInSeparateThread, separable, srcImage, threadStopped

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor	Description
ContourPlot()

Method Summary

Modifier and Type	Method	Description
static final int	a(int color)
static final double	a_normalized(int color)
static final int	argb_bounded(int a, int r, int g, int b)	Packs 8bit ARGB color components into a single 32bit integer value.
static final int	argb_fast(int a, int r, int g, int b)	Packs 8bit ARGB color components into a single 32bit integer value.
static final int	argb_fromNormalized(double a, double r, double g, double b)	Packs normalized ARGB color components (values in [0.0 .. 1.0]) into a single 32bit integer value.
static final int	b(int color)
static final double	b_normalized(int color)
(package private) static int	celltype(boolean v1, boolean v2, boolean v3)
(package private) static int	celltype(boolean v11, boolean v21, boolean v31, boolean v12, boolean v22, boolean v32)
static double	clamp_0_1(double val)	Clamps a value to the range [0.0, 1.0].
final int	clamp_0_255(int val)	Clamps a value to the range [0,255].
static List<ContourPlot.TriangleDetails>	computeContourBands(double[][] X, double[][] Y, double[][] Z, double isoValue1, double isoValue2, int c1, int c2)	Computes the contour bands from the grid samples of a bivariate function z(x,y).
static List<ContourPlot.TriangleDetails>	computeContourBands(double[][] uniformGridSamples, double isoValue1, double isoValue2, int c1, int c2)	Computes the contour bands from the grid samples of a bivariate function z(x,y) with implicit integer valued (x,y) = (i,j). The resulting triangles are solutions to the equation { (x,y) | iso1 < z(x,y) < iso2 } within the grid.
static List<ContourPlot.SegmentDetails>	computeContourLines(double[][] X, double[][] Y, double[][] Z, double isoValue, int color)	Computes the contour lines from the grid samples of a bivariate function z(x,y).
static List<ContourPlot.SegmentDetails>	computeContourLines(double[][] uniformGridSamples, double isoValue, int color)	Computes the contour lines from the grid samples of a bivariate function z(x,y) with implicit integer valued (x,y) = (i,j). The resulting line segments are solutions to the equation { (x,y) | z(x,y)=iso } within the grid.
static final int	g(int color)
static final double	g_normalized(int color)
static int	interpolateColor(int c1, int c2, double m)	Linearly interpolates between the two specified colors. c = c1*(1-m) + c2*m
(package private) static double	interpolateToValue(double lower, double upper, double iso)	Returns m of the equation: iso = lower*(1-m) + upper*m which is: m = (iso-lower)/(upper-lower)
static final int	r(int color)
static final double	r_normalized(int color)
static void	requireAreaInImageBounds(int xStart, int yStart, int width, int height, ContourPlot.ImgBase<?> img)	Throws an IllegalArgumentException when the specified area is not within the bounds of the specified image, or if the area is not positive.
static final int	rgb_bounded(int r, int g, int b)	Packs 8bit RGB color components into a single 32bit ARGB integer value with alpha=255 (opaque).
static final int	rgb_fast(int r, int g, int b)	Packs 8bit RGB color components into a single 32bit ARGB integer value with alpha=255 (opaque).
static final int	rgb_fromNormalized(double r, double g, double b)	Packs normalized ARGB color components (values in [0.0 .. 1.0]) into a single 32bit integer value with alpha=255 (opaque).
void	runAlgorithm()	Actually runs the algorithm.
void	testContourPlot()
void	testIsolinesViz()

Methods inherited from class gov.nih.mipav.model.algorithms.AlgorithmBase

actionPerformed, addListener, addProgressChangeListener, calculateImageSize, calculatePrincipleAxis, computeElapsedTime, computeElapsedTime, convertIntoFloat, delinkProgressToAlgorithm, delinkProgressToAlgorithmMulti, displayError, errorCleanUp, finalize, fireProgressStateChanged, fireProgressStateChanged, fireProgressStateChanged, fireProgressStateChanged, fireProgressStateChanged, generateProgressValues, getDestImage, getElapsedTime, getMask, getMaxProgressValue, getMinProgressValue, getNumberOfThreads, getProgress, getProgressChangeListener, getProgressChangeListeners, getProgressModulus, getProgressStep, getProgressValues, getSrcImage, isCompleted, isImage25D, isMultiThreadingEnabled, isRunningInSeparateThread, isThreadStopped, linkProgressToAlgorithm, linkProgressToAlgorithm, makeProgress, notifyListeners, removeListener, removeProgressChangeListener, run, setCompleted, setImage25D, setMask, setMaxProgressValue, setMinProgressValue, setMultiThreadingEnabled, setNumberOfThreads, setProgress, setProgressModulus, setProgressStep, setProgressValues, setProgressValues, setRunningInSeparateThread, setSrcImage, setStartTime, setThreadStopped, startMethod, windowActivated, windowClosed, windowClosing, windowDeactivated, windowDeiconified, windowIconified, windowOpened

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, isVirtual, join, join, join, join, ofPlatform, ofVirtual, onSpinWait, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, sleep, start, startVirtualThread, stop, suspend, threadId, toString, yield

Methods inherited from class java.lang.Object

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

Field Details

cp

private static ContourPlot cp

Example from source ContourPlot.java draws contour plot of function surface correctly. Need to work on example in IsolinesViz.java.

Constructor Details

ContourPlot

public ContourPlot()

Method Details

testIsolinesViz

public void testIsolinesViz()

testContourPlot

public void testContourPlot()

runAlgorithm

public void runAlgorithm()

Description copied from class: AlgorithmBase

Actually runs the algorithm. Implemented by inheriting algorithms.

Specified by:

runAlgorithm in class AlgorithmBase

b

public static final int b(int color)

Parameters:

color - ARGB(32bit) or RGB(24bit) value

Returns:

blue component(8bit) of specified color.

Since:

1.0

See Also:

• a(int)
• r(int)
• g(int)
• invalid reference

  #argb(int, int, int, int)

• invalid reference

  #rgb(int, int, int)

g

public static final int g(int color)

Parameters:

color - ARGB(32bit) or RGB(24bit) value

Returns:

green component(8bit) of specified color.

Since:

1.0

See Also:

• a(int)
• r(int)
• b(int)
• invalid reference

  #argb(int, int, int, int)

• invalid reference

  #rgb(int, int, int)

r

public static final int r(int color)

Parameters:

color - ARGB(32bit) or RGB(24bit) value

Returns:

red component(8bit) of specified color.

Since:

1.0

See Also:

• a(int)
• g(int)
• b(int)
• invalid reference

  #argb(int, int, int, int)

• invalid reference

  #rgb(int, int, int)

a

public static final int a(int color)

Parameters:

color - ARGB(32bit) value

Returns:

alpha component(8bit) of specified color.

Since:

1.0

See Also:

• r(int)
• g(int)
• b(int)
• invalid reference

  #argb(int, int, int, int)

• invalid reference

  #rgb(int, int, int)

b_normalized

public static final double b_normalized(int color)

Parameters:

color - ARGB(32bit) or RGB(24bit) value

Returns:

normalized blue component of specified color
(value in [0.0 .. 1.0]).

Since:

1.2

See Also:

• invalid reference

  #b()

• r_normalized(int)
• g_normalized(int)
• a_normalized(int)

g_normalized

public static final double g_normalized(int color)

Parameters:

color - ARGB(32bit) or RGB(24bit) value

Returns:

normalized green component of specified color
(value in [0.0 .. 1.0]).

Since:

1.2

See Also:

• invalid reference

  #g()

• r_normalized(int)
• b_normalized(int)
• a_normalized(int)

r_normalized

public static final double r_normalized(int color)

Parameters:

color - ARGB(32bit) or RGB(24bit) value

Returns:

normalized red component of specified color
(value in [0.0 .. 1.0]).

Since:

1.2

See Also:

• invalid reference

  #r()

• b_normalized(int)
• g_normalized(int)
• a_normalized(int)

a_normalized

public static final double a_normalized(int color)

Parameters:

color - ARGB(32bit) value

Returns:

normalized alpha component of specified color
(value in [0.0 .. 1.0]).

Since:

1.2

See Also:

• invalid reference

  #a()

• r_normalized(int)
• g_normalized(int)
• a_normalized(int)

argb_fast

public static final int argb_fast(int a,
 int r,
 int g,
 int b)

Packs 8bit ARGB color components into a single 32bit integer value. Components larger than 8bit are NOT truncated and will result in a broken, malformed value.

Parameters:

a - alpha

r - red

g - green

b - blue

Returns:

packed ARGB value

Since:

1.0

See Also:

• invalid reference

  #argb(int, int, int, int)

• argb_bounded(int, int, int, int)
• rgb_bounded(int, int, int)
• invalid reference

  #rgb(int, int, int)

• rgb_fast(int, int, int)
• a(int)
• r(int)
• g(int)
• b(int)

argb_bounded

public static final int argb_bounded(int a,
 int r,
 int g,
 int b)

Packs 8bit ARGB color components into a single 32bit integer value. Components are clamped to [0,255].

Parameters:

a - alpha

r - red

g - green

b - blue

Returns:

packed ARGB value

Since:

1.0

See Also:

• invalid reference

  #argb(int, int, int, int)

• argb_fast(int, int, int, int)
• rgb_bounded(int, int, int)
• invalid reference

  #rgb(int, int, int)

• rgb_fast(int, int, int)
• a(int)
• r(int)
• g(int)
• b(int)

argb_fromNormalized

public static final int argb_fromNormalized(double a,
 double r,
 double g,
 double b)

Packs normalized ARGB color components (values in [0.0 .. 1.0]) into a single 32bit integer value. Component values less than 0 or greater than 1 are clamped to fit the range.

Parameters:

a - alpha

r - red

g - green

b - blue

Returns:

packed ARGB value

Since:

1.2

See Also:

• rgb_fromNormalized(double, double, double)
• invalid reference

  #argb(int, int, int, int)

• a_normalized(int)
• r_normalized(int)
• g_normalized(int)
• b_normalized(int)

rgb_fast

public static final int rgb_fast(int r,
 int g,
 int b)

Packs 8bit RGB color components into a single 32bit ARGB integer value with alpha=255 (opaque). Components larger than 8bit are NOT truncated and will result in a broken, malformed value.

Parameters:

r - red

g - green

b - blue

Returns:

packed ARGB value

Since:

1.0

See Also:

• invalid reference

  #argb(int, int, int, int)

• argb_bounded(int, int, int, int)
• argb_fast(int, int, int, int)
• rgb_bounded(int, int, int)
• invalid reference

  #rgb(int, int, int)

• a(int)
• r(int)
• g(int)
• b(int)

rgb_bounded

public static final int rgb_bounded(int r,
 int g,
 int b)

Packs 8bit RGB color components into a single 32bit ARGB integer value with alpha=255 (opaque). Components are clamped to [0,255].

Parameters:

r - red

g - green

b - blue

Returns:

packed ARGB value

Since:

1.0

See Also:

• invalid reference

  #argb(int, int, int, int)

• argb_bounded(int, int, int, int)
• argb_fast(int, int, int, int)
• invalid reference

  #rgb(int, int, int)

• rgb_fast(int, int, int)
• a(int)
• r(int)
• g(int)
• b(int)

rgb_fromNormalized

public static final int rgb_fromNormalized(double r,
 double g,
 double b)

Packs normalized ARGB color components (values in [0.0 .. 1.0]) into a single 32bit integer value with alpha=255 (opaque). Component values less than 0 or greater than 1 clamped to fit the range.

Parameters:

r - red

g - green

b - blue

Returns:

packed ARGB value

Since:

1.2

See Also:

• argb_fromNormalized(double, double, double, double)
• invalid reference

  #rgb(int, int, int)

• a_normalized(int)
• r_normalized(int)
• g_normalized(int)
• b_normalized(int)

interpolateColor

public static int interpolateColor(int c1,
 int c2,
 double m)

Linearly interpolates between the two specified colors.
c = c1*(1-m) + c2*m

Parameters:

c1 - integer packed ARGB color value

c2 - integer packed ARGB color value, e.g. 0xff00ff00 for opaque green

m - in [0,1]

Returns:

interpolated color

computeContourLines

public static List<ContourPlot.SegmentDetails> computeContourLines(double[][] X,
 double[][] Y,
 double[][] Z,
 double isoValue,
 int color)

Computes the contour lines from the grid samples of a bivariate function z(x,y). The resulting line segments are solutions to the equation { (x,y) | z(x,y)=iso } within the grid.

About indices For cartesian or rectilinear grids, x varies with the inner index of the 2D array, y with the outer index:
X_ij=X[i][j]=X[?][j].
Y_ij=Y[i][j]=Y[i][?]

Parameters:

X - x-coordinates of the grid points ( (x,y,z)_ij = (X_ij,Y_ij,Z_ij) )

Y - y-coordinates of the grid points ( (x,y,z)_ij = (X_ij,Y_ij,Z_ij) )

Z - z-coordinates of the grid points ( (x,y,z)_ij = (X_ij,Y_ij,Z_ij) )

isoValue - the iso value for which the contour (iso) lines should be computed

color - integer packed ARGB color value the returned line segments should have, e.g. 0xff00ff00 for opaque green.

Returns:

list of line segments that form the contour lines. There is no particular order so subsequent segments are not necessarily adjacent.

computeContourBands

public static List<ContourPlot.TriangleDetails> computeContourBands(double[][] X,
 double[][] Y,
 double[][] Z,
 double isoValue1,
 double isoValue2,
 int c1,
 int c2)

Computes the contour bands from the grid samples of a bivariate function z(x,y). The resulting triangles are solutions to the equation { (x,y) | iso1 < z(x,y) < iso2 } within the grid.

About indices For cartesian or rectilinear grids, x varies with the inner index of the 2D array, y with the outer index:
X_ij=X[i][j]=X[?][j].
Y_ij=Y[i][j]=Y[i][?]

Parameters:

X - x-coordinates of the grid points ( (x,y,z)_ij = (X_ij,Y_ij,Z_ij) )

Y - y-coordinates of the grid points ( (x,y,z)_ij = (X_ij,Y_ij,Z_ij) )

Z - z-coordinates of the grid points ( (x,y,z)_ij = (X_ij,Y_ij,Z_ij) )

isoValue1 - the lower bound for values of the iso bands

isoValue2 - the upper bound for values of the iso bands

c1 - color for the isoValue1

c2 - color for the isoValue2, values in between iso1 and iso2 will have their color linearly interpolated

Returns:

list of triangles that form the iso bands. The order of triangles does NOT imply any adjacency between them.

computeContourLines

public static List<ContourPlot.SegmentDetails> computeContourLines(double[][] uniformGridSamples,
 double isoValue,
 int color)

Computes the contour lines from the grid samples of a bivariate function z(x,y)
with implicit integer valued (x,y) = (i,j).
The resulting line segments are solutions to the equation { (x,y) | z(x,y)=iso } within the grid.

The lines are computed using the Meandering Triangles algorithm which divides each square cell of the grid into 2 triangle cells first before computing isovalue intersections on the triangle sides. The more well known Marching Squares algorithm has significantly more cell cases to check, which is why Meandering Triangles was preferred here.

Parameters:

uniformGridSamples - z-coordinates of the grid points ( (x,y,z)_ij = (i,j,Z_ij) )

isoValue - the iso value for which the contour (iso) lines should be computed

color - integer packed ARGB color value the returned line segments should have, e.g. 0xff00ff00 for opaque green.

Returns:

list of line segments that form the contour lines. There is no particular order so subsequent segments are not necessarily adjacent.

computeContourBands

public static List<ContourPlot.TriangleDetails> computeContourBands(double[][] uniformGridSamples,
 double isoValue1,
 double isoValue2,
 int c1,
 int c2)

Computes the contour bands from the grid samples of a bivariate function z(x,y)
with implicit integer valued (x,y) = (i,j).
The resulting triangles are solutions to the equation { (x,y) | iso1 < z(x,y) < iso2 } within the grid.

The triangles are computed using the Meandering Triangles algorithm which divides each square cell of the grid into 2 triangle cells first before computing isovalue intersections on the triangle sides. The more well known Marching Squares algorithm has significantly more cell cases to check, which is why Meandering Triangles was preferred here.

Parameters:

uniformGridSamples - z-coordinates of the grid points ( (x,y,z)_ij = (i,j,Z_ij) )

isoValue1 - the lower bound for values of the iso bands

isoValue2 - the upper bound for values of the iso bands

c1 - color for the isoValue1

c2 - color for the isoValue2, values in between iso1 and iso2 will have their color linearly interpolated

Returns:

list of triangles that form the iso bands. The order of triangles does NOT imply any adjacency between them.

celltype

static int celltype(boolean v1,
 boolean v2,
 boolean v3)

celltype

static int celltype(boolean v11,
 boolean v21,
 boolean v31,
 boolean v12,
 boolean v22,
 boolean v32)

interpolateToValue

static double interpolateToValue(double lower,
 double upper,
 double iso)

Returns m of the equation: iso = lower*(1-m) + upper*m
which is: m = (iso-lower)/(upper-lower)

Parameters:

lower - value

upper - value

iso - value in between lower and upper

Returns:

m

clamp_0_255

public final int clamp_0_255(int val)

Clamps a value to the range [0,255]. Returns 0 for values less than 0, 255 for values greater than 255, and the value it self when in range.

Parameters:

val - value to be clamped

Returns:

value clamped to [0,255]

clamp_0_1

public static double clamp_0_1(double val)

Clamps a value to the range [0.0, 1.0]. Returns 0.0 for values less than 0, 1.0 for values greater than 1.0, and the value it self when in range.

Parameters:

val - value to be clamped

Returns:

value clamped to [0.0, 1.0]

requireAreaInImageBounds

public static void requireAreaInImageBounds(int xStart,
 int yStart,
 int width,
 int height,
 ContourPlot.ImgBase<?> img)

Throws an IllegalArgumentException when the specified area is not within the bounds of the specified image, or if the area is not positive. This is used for parameter evaluation.

Parameters:

xStart - left boundary of the area

yStart - top boundary of the area

width - of the area

height - of the area

img - the area has to fit in.

Throws:

IllegalArgumentException - when area not in image bounds or not area not positive