Package org.eclipse.swt.graphics
Class PaletteData
- java.lang.Object
-
- org.eclipse.swt.graphics.PaletteData
-
public final class PaletteData extends Object
Instances of this class describe the color data used by an image.Depending on the depth of the image, the PaletteData can take one of two forms, indicated by the isDirect field:
- isDirect is false
-
If isDirect is
false
, this palette is an indexed palette which maps pixel values to RGBs. The actual RGB values may be retrieved by using the getRGBs() method. - isDirect is true
-
If isDirect is
true
, this palette is a direct color palette. Instead of containing RGB values, it contains red, green and blue mask and shift information which indicates how the color components may be extracted from a given pixel. This means that the RGB value is actually encoded in the pixel value.In this case, the shift data is the number of bits required to shift the RGB value to the left in order to align the high bit of the corresponding mask with the high bit of the first byte. This number may be negative, so care must be taken when shifting. For example, with a red mask of 0xFF0000, the red shift would be -16. With a red mask of 0x1F, the red shift would be 3.
- See Also:
Image
,RGB
, Sample code and further information
-
-
Field Summary
Fields Modifier and Type Field Description int
blueMask
the blue mask for a direct paletteint
blueShift
the blue shift for a direct paletteRGB[]
colors
the RGB values for an indexed palette, where the indices of the array correspond to pixel valuesint
greenMask
the green mask for a direct paletteint
greenShift
the green shift for a direct paletteboolean
isDirect
true if the receiver is a direct palette, and false otherwiseint
redMask
the red mask for a direct paletteint
redShift
the red shift for a direct palette
-
Constructor Summary
Constructors Constructor Description PaletteData(int redMask, int greenMask, int blueMask)
Constructs a new direct palette given the red, green and blue masks.PaletteData(RGB... colors)
Constructs a new indexed palette given an array of RGB values.
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description int
getPixel(RGB rgb)
Returns the pixel value corresponding to the givenRGB
.RGB
getRGB(int pixel)
Returns anRGB
corresponding to the given pixel value.RGB[]
getRGBs()
Returns all the RGB values in the receiver if it is an indexed palette, or null if it is a direct palette.
-
-
-
Field Detail
-
isDirect
public boolean isDirect
true if the receiver is a direct palette, and false otherwise
-
colors
public RGB[] colors
the RGB values for an indexed palette, where the indices of the array correspond to pixel values
-
redMask
public int redMask
the red mask for a direct palette
-
greenMask
public int greenMask
the green mask for a direct palette
-
blueMask
public int blueMask
the blue mask for a direct palette
-
redShift
public int redShift
the red shift for a direct palette
-
greenShift
public int greenShift
the green shift for a direct palette
-
blueShift
public int blueShift
the blue shift for a direct palette
-
-
Constructor Detail
-
PaletteData
public PaletteData(RGB... colors)
Constructs a new indexed palette given an array of RGB values.- Parameters:
colors
- the array ofRGB
s for the palette- Throws:
IllegalArgumentException
-- ERROR_NULL_ARGUMENT - if the argument is null
-
PaletteData
public PaletteData(int redMask, int greenMask, int blueMask)
Constructs a new direct palette given the red, green and blue masks.- Parameters:
redMask
- the red maskgreenMask
- the green maskblueMask
- the blue mask
-
-
Method Detail
-
getPixel
public int getPixel(RGB rgb)
Returns the pixel value corresponding to the givenRGB
.- Parameters:
rgb
- the RGB to get the pixel value for- Returns:
- the pixel value for the given RGB
- Throws:
IllegalArgumentException
-- ERROR_NULL_ARGUMENT - if the argument is null
- ERROR_INVALID_ARGUMENT - if the RGB is not found in the palette
-
getRGB
public RGB getRGB(int pixel)
Returns anRGB
corresponding to the given pixel value.- Parameters:
pixel
- the pixel to get the RGB value for- Returns:
- the RGB value for the given pixel
- Throws:
IllegalArgumentException
-- ERROR_NULL_ARGUMENT - if the argument is null
- ERROR_INVALID_ARGUMENT - if the pixel does not exist in the palette
-
getRGBs
public RGB[] getRGBs()
Returns all the RGB values in the receiver if it is an indexed palette, or null if it is a direct palette.- Returns:
- the
RGB
s for the receiver or null
-
-