Class PaintAlpha


  • public class PaintAlpha
    extends java.lang.Object
    This class contains static methods for the manipulation of objects of type Paint

    The intention is to honour the alpha-channel in the process. PaintAlpha was originally conceived to improve the rendering of 3D Shapes with transparent colours and to allow invisible bars by making them completely transparent.

    In, for example StackedBarRenderer3D, bars are rendered with 6 faces. The front face is rendered with the Paint requested. The other 5 faces are rendered darker to achieve the 3D effect.

    Previously Color.darker() was used for this, which always returns an opaque colour.

    Additionally there are methods to control the behaviour and in particular a cloneImage(..) method which is needed to darken objects of type TexturePaint.

    Since:
    1.0.15
    Author:
    DaveLaw
    • Constructor Summary

      Constructors 
      Constructor Description
      PaintAlpha()  
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static java.awt.image.BufferedImage cloneImage​(java.awt.image.BufferedImage image)
      Clone a BufferedImage.
      static java.awt.Paint darker​(java.awt.Paint paint)
      Create a new (if possible, darker) Paint of the same Type.
      static boolean setLegacyAlpha​(boolean legacyAlpha)
      Per default PaintAlpha will try to honour alpha-channel information.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Method Detail

      • setLegacyAlpha

        public static boolean setLegacyAlpha​(boolean legacyAlpha)
        Per default PaintAlpha will try to honour alpha-channel information. In the past this was not the case. If you wish legacy functionality for your application you can request this here.
        Parameters:
        legacyAlpha - boolean
        Returns:
        the previous setting
      • darker

        public static java.awt.Paint darker​(java.awt.Paint paint)
        Create a new (if possible, darker) Paint of the same Type. If the Type is not supported, the original Paint is returned.

        Parameters:
        paint - a Paint implementation (e.g. Color, GradientPaint, TexturePaint,..)

        Returns:
        a (usually new, see above) Paint
      • cloneImage

        public static java.awt.image.BufferedImage cloneImage​(java.awt.image.BufferedImage image)
        Clone a BufferedImage.

        Note: when constructing the clone, the original Color Model Object is reused.
        That keeps things simple and should not be a problem, as all known Color Models
        (IndexColorModel, DirectColorModel, ComponentColorModel) are immutable.

        Parameters:
        image - original BufferedImage to clone
        Returns:
        a new BufferedImage reusing the original's Color Model and containing a clone of its pixels