org.geotools.coverage
Class AbstractCoverage.Renderable

Object
  PropertySourceImpl
      AbstractCoverage.Renderable

All Implemented Interfaces:

RenderableImage, Serializable, ImageFunction, PropertySource

Direct Known Subclasses:

GridCoverage2D.Renderable

Enclosing class:

AbstractCoverage

protected class AbstractCoverage.Renderable
extends PropertySourceImpl
implements RenderableImage, ImageFunction

A view of a coverage as a renderable image. Renderable images allow interoperability with Java2D for a two-dimensional slice of a coverage (which may or may not be a grid coverage).

Author:

Martin Desruisseaux

See Also:

AbstractCoverage.getRenderableImage(int, int), Serialized Form

Field Summary

protected GeneralDirectPosition	coordinate A coordinate point where to evaluate the function.
protected int	xAxis Dimension to use for x axis.
protected int	yAxis Dimension to use for y axis.

Fields inherited from class PropertySourceImpl

cachedPropertyNames, properties, propertySources

Fields inherited from interface RenderableImage

HINTS_OBSERVED

Constructor Summary

AbstractCoverage.Renderable(int xAxis, int yAxis)
Constructs a renderable image.

Method Summary

RenderedImage	createDefaultRendering() Returns a rendered image with a default width and height in pixels.
protected RenderContext	createRenderContext(Rectangle2D gridBounds, RenderingHints hints) Initializes a render context with an affine transform that maps the coverage envelope to the specified destination rectangle.
RenderedImage	createRendering(RenderContext context) Creates a rendered image using a given render context.
RenderedImage	createScaledRendering(int width, int height, RenderingHints hints) Creates a rendered image with width width and height height in pixels.
void	getElements(double startX, double startY, double deltaX, double deltaY, int countX, int countY, int element, double[] real, double[] imag) Returns all values of a given element for a specified set of coordinates.
void	getElements(float startX, float startY, float deltaX, float deltaY, int countX, int countY, int element, float[] real, float[] imag) Returns all values of a given element for a specified set of coordinates.
float	getHeight() Gets the height in coverage coordinate space.
float	getMinX() Gets the minimum X coordinate of the rendering-independent image data.
float	getMinY() Gets the minimum Y coordinate of the rendering-independent image data.
int	getNumElements() Returns the number of elements per value at each position.
Vector	getSources() Returns null to indicate that no source information is available.
float	getWidth() Gets the width in coverage coordinate space.
boolean	isComplex() Returns false since values are not complex.
boolean	isDynamic() Returns true if successive renderings with the same arguments may produce different results.

Methods inherited from class PropertySourceImpl

getProperties, getProperty, getPropertyClass, getPropertyNames, getPropertyNames

Methods inherited from class Object

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

Methods inherited from interface RenderableImage

getProperty, getPropertyNames

Field Detail

xAxis

protected final int xAxis

Dimension to use for x axis.

yAxis

protected final int yAxis

Dimension to use for y axis.

coordinate

protected final GeneralDirectPosition coordinate

A coordinate point where to evaluate the function. The point dimension is equals to the coverage's dimension. The x and y ordinates will be ignored, since they will vary for each pixel to be evaluated. Other ordinates, if any, should be set to a fixed value. For example a coverage may be three-dimensional, where the third dimension is the time axis. In such case, coordinate.ord[2] should be set to the point in time where to evaluate the coverage. By default, all ordinates are initialized to 0. Subclasses should set the desired values in their constructor if needed.

Constructor Detail

AbstractCoverage.Renderable

public AbstractCoverage.Renderable(int xAxis,
                                   int yAxis)

Constructs a renderable image.

Parameters:

xAxis - Dimension to use for x axis.

yAxis - Dimension to use for y axis.

Method Detail

getSources

public Vector getSources()

Returns null to indicate that no source information is available.

Specified by:

getSources in interface RenderableImage

isDynamic

public boolean isDynamic()

Returns true if successive renderings with the same arguments may produce different results. The default implementation returns false.

Specified by:

isDynamic in interface RenderableImage

See Also:

GridCoverage2D.isDataEditable()

isComplex

public boolean isComplex()

Returns false since values are not complex.

Specified by:

isComplex in interface ImageFunction

getWidth

public float getWidth()

Gets the width in coverage coordinate space.

Specified by:

getWidth in interface RenderableImage

See Also:

AbstractCoverage.getEnvelope(), AbstractCoverage.getCoordinateReferenceSystem()

getHeight

public float getHeight()

Gets the height in coverage coordinate space.

Specified by:

getHeight in interface RenderableImage

See Also:

AbstractCoverage.getEnvelope(), AbstractCoverage.getCoordinateReferenceSystem()

getMinX

public float getMinX()

Gets the minimum X coordinate of the rendering-independent image data. This is the coverage's envelope minimal value for the x axis.

Specified by:

getMinX in interface RenderableImage

See Also:

AbstractCoverage.getEnvelope(), AbstractCoverage.getCoordinateReferenceSystem()

getMinY

public float getMinY()

Gets the minimum Y coordinate of the rendering-independent image data. This is the coverage's envelope minimal value for the y axis.

Specified by:

getMinY in interface RenderableImage

See Also:

AbstractCoverage.getEnvelope(), AbstractCoverage.getCoordinateReferenceSystem()

createDefaultRendering

public RenderedImage createDefaultRendering()

Returns a rendered image with a default width and height in pixels.

Specified by:

createDefaultRendering in interface RenderableImage

Returns:

A rendered image containing the rendered data

createScaledRendering

public RenderedImage createScaledRendering(int width,
                                           int height,
                                           RenderingHints hints)

Creates a rendered image with width width and height height in pixels. If width is 0, it will be computed automatically from height. Conversely, if height is 0, il will be computed automatically from width.

The default implementation creates a render context with createRenderContext(java.awt.geom.Rectangle2D, java.awt.RenderingHints) and invokes createRendering(RenderContext).

Specified by:

createScaledRendering in interface RenderableImage

Parameters:

width - The width of rendered image in pixels, or 0.

height - The height of rendered image in pixels, or 0.

hints - Rendering hints, or null.

Returns:

A rendered image containing the rendered data

createRendering

public RenderedImage createRendering(RenderContext context)

Creates a rendered image using a given render context. This method will uses an "ImageFunction" operation if possible (i.e. if the area of interect is rectangular and the affine transform contains only translation and scale coefficients).

Specified by:

createRendering in interface RenderableImage

Parameters:

context - The render context to use to produce the rendering.

Returns:

A rendered image containing the rendered data

createRenderContext

protected RenderContext createRenderContext(Rectangle2D gridBounds,
                                            RenderingHints hints)

Initializes a render context with an affine transform that maps the coverage envelope to the specified destination rectangle. The affine transform mays swap axis in order to normalize their order (i.e. make them appear in the (x,y) order), so that the image appears properly oriented when rendered.

Parameters:

gridBounds - The two-dimensional destination rectangle.

hints - The rendering hints, or null if none.

Returns:

A render context initialized with an affine transform from the coverage to the grid coordinate system. This transform is the inverse of GridGeometry2D.getGridToCRS2D().

See Also:

GridGeometry2D.getGridToCRS2D()

getNumElements

public int getNumElements()

Returns the number of elements per value at each position. This is the maximum value plus 1 allowed in getElements(...) methods invocation. The default implementation returns the number of sample dimensions in the coverage.

Specified by:

getNumElements in interface ImageFunction

getElements

public void getElements(float startX,
                        float startY,
                        float deltaX,
                        float deltaY,
                        int countX,
                        int countY,
                        int element,
                        float[] real,
                        float[] imag)

Returns all values of a given element for a specified set of coordinates. This method is automatically invoked at rendering time for populating an image tile, providing that the rendered image is created using the "ImageFunction" operator and the image type is not double. The default implementation invokes AbstractCoverage.evaluate(DirectPosition,float[]) recursively.

Specified by:

getElements in interface ImageFunction

getElements

public void getElements(double startX,
                        double startY,
                        double deltaX,
                        double deltaY,
                        int countX,
                        int countY,
                        int element,
                        double[] real,
                        double[] imag)

Returns all values of a given element for a specified set of coordinates. This method is automatically invoked at rendering time for populating an image tile, providing that the rendered image is created using the "ImageFunction" operator and the image type is double. The default implementation invokes AbstractCoverage.evaluate(DirectPosition,double[]) recursively.

Specified by:

getElements in interface ImageFunction