Package com.luciad.format.raster

Class TLcdWarpRasterPainter

java.lang.Object
com.luciad.view.gxy.ALcdGXYPainter
com.luciad.format.raster.ALcdRasterPainter
com.luciad.format.raster.TLcdWarpRasterPainter
All Implemented Interfaces:
ILcdRasterPainter, ILcdCloneable, ILcdPropertyChangeSource, ILcdGXYPainter, ILcdGXYPainterProvider, Serializable, Cloneable
public class TLcdWarpRasterPainter extends ALcdRasterPainter implements ILcdRasterPainter, ILcdGXYPainterProvider
This ILcdGXYPainter can paint ILcdRaster instances, warping them between different coordinate systems as required.

It paints the visible portion of the raster if the scale of the ILcdGXYView on which to paint is such that the screen resolution is inside the range defined by the properties startResolutionFactor and stopResolutionFactor. Outside of this range, it paints only the outline of the tiles of the raster The resolution factor defines ratio between the resolution of the raster and the resolution of the screen. For example, a resolution factor of 4 indicates that 4 raster pixels are used to color a single screen pixel. A factor of 0.25 indicates that a single raster pixel will be used to paint four screen pixels. Typical values for startResolutionFactor and stopResolutionFactor are 2 and 0.5, respectively, indicating that as we zoom in, the raster becomes visible at a point where 2 raster pixels are merged into a single screen pixel, and the raster becomes invisible at a point where a single raster pixel is blurred into two screen pixels.

The value of the startResolutionFactor, the dimensions of the tiles and the dimension of the ILcdGXYView on which to paint, determine the maximum number of tiles that need to be loaded in memory, when painting the visible portion of the raster. The minimum value of the maximum number of tiles is always four because the visible portion can always be pointed at the intersection of four tiles. Suppose we have tiles of 1024 by 1024 pixels, and a maximum ILcdGXYView size of 800 by 600. Suppose further that we we choose a startResolutionFactor of 9. Then, there may be a maximum of 3 by 2 tiles needed to paint the 800 by 600 ILcdGXYView, thus requiring 6 tiles to be in memory. This calculation is a rough approximation because of the non-linear transformation between the data reference of the raster and the data reference of the ILcdGXYView. For example, at a small scale, an ILcdGXYView with a data reference based on an Orthographic projection may require more tiles than calculated with the above procedure. Therefore, as a rule of thumb, allocate twice the amount of memory to hold the maximum number of tiles calculated.

It is clear that, if the number of non-empty tiles in the raster is less than four, the value of the startResolutionFactor can be set at any value.

Often times, multiple instances of ILcdRaster with different resolutions are painted in different layers. In that case, the choice of the startResolutionFactor and the stopResolutionFactor of the different TLcdRasterPainters is often chosen such that the stopResolutionFactor of the painter in one layer corresponds to the startResolutionFactor of the next layer holding a raster with a higher resolution. For example, suppose we have two ILcdRaster objects, one that holds 1 degree by 1 degree tiles of 1024 by 1024 pixels and a second raster 30' by 30' of 1024 by 1024 pixels. The resolution of the second raster is four times the resolution of the first raster. Hence, in order to match the stopResolutionFactor of the first raster with the startResolutionFactor of the second raster, they have to be in the proportion of 1 to 4. The symmetrical choice around a ResolutionFactor of 1 is 0.5 for the stopResolutionFactor of the painter of the first raster and 2 for the startResolutionFactor of the painter of the second raster.

See Also:

  • Constructor Details

    • TLcdWarpRasterPainter

      public TLcdWarpRasterPainter()
      Creates a new TLcdWarpRasterPainter, with a default name.

    • TLcdWarpRasterPainter

      public TLcdWarpRasterPainter(String aDisplayName)
      Creates a new TLcdWarpRasterPainter.
      Parameters:
      aDisplayName - the displayName of the painter.

  • Method Details

    • setTraceOn

      public void setTraceOn(boolean aTraceOn)
      Deprecated.
      This method has been deprecated. It is recommended to use the standard Java logging framework directly.
      Enables tracing for this class instance. Calling this method with either true or false as argument automatically turns off tracing for all other class instances for which setTraceOn has not been called. If the argument is false then only the informative, warning and error log messages are recorded.
      Overrides:
      setTraceOn in class ALcdGXYPainter
      Parameters:
      aTraceOn - if true then all log messages are recorded for this instance. If false, then only the informative, warning and error log messages are recorded.

    • isTraceOn

      public boolean isTraceOn()
      Deprecated.
      This method has been deprecated. It is recommended to use the standard Java logging framework directly.
      Returns true if tracing is enabled for this class.
      Overrides:
      isTraceOn in class ALcdGXYPainter
      Returns:
      true if tracing is enabled for this class, false otherwise.

    • setPaintCache

      public void setPaintCache(boolean aCache)
      Specifies whether this painter should cache the warped raster images it has painted. A warped raster image has the same size as the view for which it was created. Caching it may improve performance if it can be reused, and it can generally avoid repeated allocation of large image objects on the heap. The default is true.
      See Also:

    • getPaintCache

      public boolean getPaintCache()
      Returns whether this painter caches the warped raster images it has painted.
      See Also:

    • setReuseInternalBuffer

      public void setReuseInternalBuffer(boolean aReuseInternalBuffer)
      Specifies whether this painter should cache a single warped raster image with this raster painter, or whether it should cache a warped raster image with each raster that is painted. Caching a single image with this painter and reusing it is generally more memory-efficient. Caching images with the painted rasters can improve performance, but it may also waste a a lot of memory. The default is false.

      This property is only relevant if setPaintCache(boolean) is true.

    • isReuseInternalBuffer

      public boolean isReuseInternalBuffer()
      Returns whether this painter caches a single warped raster image with this raster painter.
      See Also:

    • setAvoidOpaqueBorder

      public void setAvoidOpaqueBorder(boolean aAvoidOpaqueBorder)
      Specifies whether the painter should avoid drawing opaque borders around transformed rasters.

      The painter normally uses the default pixel of a raster when painting the border around a transformed raster. If the default pixel is transparent, the border is invisible. Otherwise, the border is opaque. This typically occurs if a raster has an IndexColorModel without a transparent color index.

      Setting this property activates some additional processing to avoid the opaque border anyway. The processing overhead can run up to 50% when painting described rasters. Leaving the property unset is therefore preferable, for instance when the area around painted rasters is not relevant for the application. The default is false.

    • isAvoidOpaqueBorder

      public boolean isAvoidOpaqueBorder()
      See Also:

    • setBorder

      public void setBorder(int aBorder)
      Sets an additional border around all sides of the view, defining a region in which a painted raster is transformed and cached. A full repaint will be slower, but subsequent panning over the cached region will then be faster. For instance, a border of 200 pixels around a view of 800 by 600 pixels defines a cache region of 1200 by 1000 pixels. The default border is 0 pixels.
      Parameters:
      aBorder - the border, expressed in pixels.

    • getBorder

      public int getBorder()
      Returns the additional border around all sides of the view.
      See Also:

    • setOversamplingRate

      public void setOversamplingRate(int aOverSamplingRate)
      Sets the number of samples used per pixel when transforming a raster. The default is 1. The total number of samples used per pixel equals (aOverSamplingRate * aOverSamplingRate). For instance, if the oversampling rate is set to 2, the painter will take 4 samples per pixel and average their values. This increases the image quality, especially if the raster contains sharp edges, but it also increases the computational cost.
      Parameters:
      aOverSamplingRate - the number of samples used per pixel in one direction.

    • getOversamplingRate

      public int getOversamplingRate()
      Returns the sampling rate used when transforming the raster. This is the number of samples used per pixel in one direction.
      See Also:

    • setWarpBlockSize

      public void setWarpBlockSize(int aWarpBlockSize)
      Sets the width and height of the block in which the raster transformation is approximated using bilinear interpolation. Smaller values result in more accurate results, but also larger computation times. The default is 64. With a value of 1, every pixel is transformed without approximation.
      Parameters:
      aWarpBlockSize - the width and height, expressed in pixels.

    • getWarpBlockSize

      public int getWarpBlockSize()
      Returns the width and height of the block in which the raster transformation is approximated using bilinear interpolation.
      See Also:

    • setObject

      public void setObject(Object aObject)
      Description copied from interface: ILcdGXYPainter
      Sets the Object for which the representation shall be handled by this painter.

      Setting the object on the painter may have an effect on the internal state of the painter, for example, the color to use.

      When the object is set to a painter, the context parameter in subsequent calls to methods in this class must contain a layer that contains this object and for which the painter for this object is this painter.

      Specified by:
      setObject in interface ILcdGXYPainter
      Parameters:
      aObject - the object for which the representation shall be handled by this painter.
      See Also:

    • getObject

      public Object getObject()
      Description copied from interface: ILcdGXYPainter
      Returns the Object for which the representation is currently being handled by this painter.
      Specified by:
      getObject in interface ILcdGXYPainter
      Returns:
      the Object for which the representation is currently being handled by this painter.
      See Also:

    • paint

      public void paint(Graphics aGraphics, int aMode, ILcdGXYContext aGXYContext)
      Description copied from interface: ILcdGXYPainter
      Displays the representation of the object in the given mode on the Graphics passed, taking into account the supplied context.

      The visual representation of an object depends on the context. Depending on the context (e.g. is the location covered by the view), an object may or may not have a representation. The context contains:

      • transformations which allow to compute the location in view space of points and bounds given in model, space
      • a pen which can connect points with a line or create arcs around a point,
      • the view for which the object's representation must be painted. This can be useful when the painted object depends on the scale of the view, or the presence of other layers in the view.
      • the current location(s) of the mouse or input device and the last location(s) the mouse or input device was pressed.

      The mode passed in this method indicates what part of the object must be painted, whether it should be painted as selected or not, and whether user interaction (via mouse movements) must be taken into account.

      When the mode passed contains either TRANSLATING, RESHAPING or CREATING, this method is also responsible for interpreting interaction on the representation of an object and modifying the representation of the object accordingly. The painter is not responsible for modifying the object itself, this is done by a corresponding ILcdGXYEditor . Implementations of ILcdGXYPainter and ILcdGXYEditor interfaces must be consistent for an object: the painter must display the result of the user interaction on the object, while the editor is responsible for modifying the object as a result of the user interaction. A good practice to ensure a consistent implementation is to implement both the ILcdGXYPainter and ILcdGXYEditor interfaces in a single class.

      When the mode passed includes SNAPS, the part of the representation which corresponds to the object returned as snap target by the method snapTarget must be painted in order to provide the user with a visual indication of the snap target.

      The Graphics passed in this method can be different from the Graphics returned by a view due to techniques such as double buffering (as applied in Swing). Basic drawing operations must always be performed on the Graphics passed as an argument in this method.

      Specified by:
      paint in interface ILcdGXYPainter
      Overrides:
      paint in class ALcdRasterPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aMode - the mode the object is represented in (see class documentation).
      aGXYContext - the ILcdGXYContext the drawing depends on.

    • createTransformedImage

      protected Image createTransformedImage(ILcdGXYContext aGXYContext, Rectangle aClip, ILcdRaster aRaster, RGBImageFilter aRGBImageFilter, float aTransparency, float aBrightness, float aContrast, ColorModel aColorModel)
      Creates the warped image that can be painted onto the view.

      This method is subject to change.

      See Also:

    • boundsSFCT

      public void boundsSFCT(Graphics aGraphics, int aMode, ILcdGXYContext aGXYContext, ILcd2DEditableBounds aBoundsSFCT) throws TLcdNoBoundsException
      Description copied from interface: ILcdGXYPainter
      Sets the supplied bounds (in view coordinates, pixels) so that it encompasses the representation of the object in the given mode taking into account the given context.

      If this method returns without exception the bounds argument must encompass the representation of the object. A point outside the bounds will not be contained within the painted object.

      The bounds returned in this method can be seen as the equivalent in the view space of the bounds in the model space for ILcdBounded objects.

      Specified by:
      boundsSFCT in interface ILcdGXYPainter
      Parameters:
      aGraphics - the Graphics on which the representation of the object is painted
      aMode - the mode the object is represented in (see class documentation). For example, an object may be represented differently in SELECTED mode compared to DEFAULT mode. The returned bounds of the representation must take this different representation into account.
      aGXYContext - the context for which the representation of the object is painted. It contains amongst others the transformations from model to world and world to view.
      aBoundsSFCT - the bounds that must be adapted to encompass the representation of the object in the given mode and context. These bounds must not be taken into account when the method has thrown an exception.
      Throws:
      TLcdNoBoundsException - if no bounds can be determined for the representation of the object. This can happen when the object does not have a representation in the given context, for example when it is located in a part of the world which is not visible in the current view.
      See Also:

    • getGXYPainter

      public ILcdGXYPainter getGXYPainter(Object aObject)
      Description copied from interface: ILcdGXYPainterProvider
      Finds an ILcdGXYPainter that can be used to paint or locate the object passed.

      The painter provider is responsible for setting the object to the painter before returning the painter. An implementation should therefore have the following structure: 

      
 public ILcdGXYPainter getGXYPainter(Object aObject) {
   ILcdGXYPainter painter = ... // find the painter for the object
   if (painter != null) {
    painter.setObject(aObject);
   }
   return painter;
 }

      Specified by:
      getGXYPainter in interface ILcdGXYPainterProvider
      Overrides:
      getGXYPainter in class ALcdGXYPainter
      Parameters:
      aObject - the object to find a painter for
      Returns:
      a painter that can be used to paint or locate the object; or null if no painter could be found for the given object, or the object could not be set on the retrieved painter.

    • clone

      public Object clone()
      Description copied from interface: ILcdCloneable

      Makes Object.clone() public.

      When for example extending from java.lang.Object, it can be implemented like this: 
      
 public Object clone() {
   try {
     return super.clone();
   } catch ( CloneNotSupportedException e ) {
     // Cannot happen: extends from Object and implements Cloneable (see also Object.clone)
     throw new RuntimeException( e );
   }
 }
      Specified by:
      clone in interface ILcdCloneable
      Specified by:
      clone in interface ILcdGXYPainterProvider
      Overrides:
      clone in class ALcdRasterPainter
      Returns:
      a clone of this painter provider.
      See Also: