Module javafx.graphics
Package javafx.scene.image

Class PixelBuffer<T extends Buffer>

  • Type Parameters:
    T - the type of Buffer that stores the pixel data. Only ByteBuffer and IntBuffer are supported.
    public class PixelBuffer<T extends Buffer>
extends Object
    The PixelBuffer class represents pixel data that is constructed from a java.nio.Buffer supplied by the application. A WritableImage can use this PixelBuffer directly without copying the pixel data. This PixelBuffer can be shared among multiple WritableImages. Pixel data should be stored either in an IntBuffer using a PixelFormat of type INT_ARGB_PRE or in a ByteBuffer using a PixelFormat of type BYTE_BGRA_PRE. When the Buffer is updated using the PixelBuffer.updateBuffer method, all WritableImages that were created using this PixelBuffer are redrawn.

    Example code that shows how to create a PixelBuffer: 

     // Creating a PixelBuffer using BYTE_BGRA_PRE pixel format.
 ByteBuffer byteBuffer = ByteBuffer.allocateDirect(width * height * 4);
 PixelFormat<ByteBuffer> pixelFormat = PixelFormat.getByteBgraPreInstance();
 PixelBuffer<ByteBuffer> pixelBuffer = new PixelBuffer<>(width, height, byteBuffer, pixelFormat);
 Image img = new WritableImage(pixelBuffer);

 // Creating a PixelBuffer using INT_ARGB_PRE pixel format.
 IntBuffer intBuffer = IntBuffer.allocate(width * height);
 PixelFormat<IntBuffer> pixelFormat = PixelFormat.getIntArgbPreInstance();
 PixelBuffer<IntBuffer> pixelBuffer = new PixelBuffer<>(width, height, intBuffer, pixelFormat);
 Image img = new WritableImage(pixelBuffer);
    Since:
    13
    See Also:
    WritableImage(PixelBuffer)

    • Constructor Detail

      • PixelBuffer

        public PixelBuffer​(int width,
                   int height,
                   T buffer,
                   PixelFormat<T> pixelFormat)
        Constructs a PixelBuffer using the specified Buffer and PixelFormat. The type of the specified PixelFormat must be either PixelFormat.Type.INT_ARGB_PRE or PixelFormat.Type.BYTE_BGRA_PRE.

        The constructor does not allocate memory to store the pixel data. The application must provide a buffer with sufficient memory for the combination of dimensions (width, height) and the type of PixelFormat. The PixelFormat.Type.INT_ARGB_PRE requires an IntBuffer with minimum capacity of width * height, and the PixelFormat.Type.BYTE_BGRA_PRE requires a ByteBuffer with minimum capacity of width * height * 4.

        Parameters:
        width - width in pixels of this PixelBuffer
        height - height in pixels of this PixelBuffer
        buffer - the buffer that stores the pixel data
        pixelFormat - the format of pixels in the buffer
        Throws:
        IllegalArgumentException - if either width or height is negative or zero, or if the type of pixelFormat is unsupported, or if buffer does not have sufficient memory, or if the type of buffer and pixelFormat do not match
        NullPointerException - if buffer or pixelFormat is null

    • Method Detail

      • getBuffer

        public T getBuffer()
        Returns the buffer of this PixelBuffer.
        Returns:
        the buffer of this PixelBuffer

      • getWidth

        public int getWidth()
        Returns the width of this PixelBuffer.
        Returns:
        the width of this PixelBuffer

      • getHeight

        public int getHeight()
        Returns the height of this PixelBuffer.
        Returns:
        the height of this PixelBuffer

      • getPixelFormat

        public PixelFormat<T> getPixelFormat()
        Returns the PixelFormat of this PixelBuffer.
        Returns:
        the PixelFormat of this PixelBuffer

      • updateBuffer

        public void updateBuffer​(Callback<PixelBuffer<T>,​Rectangle2D> callback)
        Invokes the specified Callback method and updates the dirty region of all WritableImages that were created using this PixelBuffer. The Callback method is expected to update the buffer and return a Rectangle2D that encloses the dirty region, or return null to indicate that the entire buffer is dirty.

        This method must be called on the JavaFX Application Thread.

        Example code that shows how to use this method: 

         Callback<PixelBuffer<ByteBuffer>, Rectangle2D> callback = pixelBuffer -> {
     ByteBuffer buffer = pixelBuffer.getBuffer();
     // Update the buffer.
     return new Rectangle2D(x, y, dirtyWidth, dirtyHeight);
 };
 pixelBuffer.updateBuffer(callback);
        Parameters:
        callback - the Callback method that updates the buffer
        Throws:
        IllegalStateException - if this method is called on a thread other than the JavaFX Application Thread.
        NullPointerException - if callback is null