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## com.trolltech.qt.opengl
Class QGLPixelBuffer

    java.lang.Object
      com.trolltech.qt.internal.QSignalEmitterInternal
          com.trolltech.qt.QSignalEmitter
              com.trolltech.qt.QtJambiObject
                  com.trolltech.qt.opengl.QGLPixelBuffer

All Implemented Interfaces:
  QPaintDeviceInterface, QtJambiInterface

    public class QGLPixelBuffer

extends QtJambiObject
implements QPaintDeviceInterface

The QGLPixelBuffer class encapsulates an OpenGL pbuffer. Rendering into a pbuffer is normally done using full hardware acceleration. This can be significantly faster than rendering into a `QPixmap`.

There are three approaches to using this class:

1. We can draw into the pbuffer and convert it to a `QImage` using `toImage()`. This is normally much faster than calling `QGLWidget::renderPixmap()`.
2. We can draw into the pbuffer and copy the contents into an OpenGL texture using `updateDynamicTexture()`. This allows us to create dynamic textures and works on all systems with pbuffer support.
3. On systems that support it, we can bind the pbuffer to an OpenGL texture. The texture is then updated automatically when the pbuffer contents change, eliminating the need for additional copy operations. This is supported only on Windows and Mac OS X systems that provide the `render_texture` extension.

Pbuffers are provided by the OpenGL `pbuffer` extension; call hasOpenGLPbuffer() to find out if the system provides pbuffers.

See also:
  Pbuffers Example.

Nested Class Summary

Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
`QSignalEmitter.AbstractSignal, QSignalEmitter.Signal0, QSignalEmitter.Signal1, QSignalEmitter.Signal2, QSignalEmitter.Signal3, QSignalEmitter.Signal4, QSignalEmitter.Signal5, QSignalEmitter.Signal6, QSignalEmitter.Signal7, QSignalEmitter.Signal8, QSignalEmitter.Signal9`

Nested classes/interfaces inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
`com.trolltech.qt.internal.QSignalEmitterInternal.AbstractSignalInternal`

Field Summary

Fields inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
`currentSender`

Constructor Summary
`QGLPixelBuffer(int width, int height)` Constructs an OpenGL pbuffer with the `width` and `height`.
`QGLPixelBuffer(int width, int height, QGLFormat format)` Constructs an OpenGL pbuffer with the `width` and `height`.
`QGLPixelBuffer(int width, int height, QGLFormat format, QGLWidget shareWidget)` Constructs an OpenGL pbuffer with the `width` and `height`.
`QGLPixelBuffer(QSize size)` Constructs an OpenGL pbuffer of the given `size`.
`QGLPixelBuffer(QSize size, QGLFormat format)` Constructs an OpenGL pbuffer of the given `size`.
`QGLPixelBuffer(QSize size, QGLFormat format, QGLWidget shareWidget)` Constructs an OpenGL pbuffer of the given `size`.

Method Summary
`int` | `bindTexture(QImage image)` Generates and binds a 2D GL texture to the current context, based on `image`.
`int` | `bindTexture(QImage image, int target)` Generates and binds a 2D GL texture to the current context, based on `image`.
`int` | `bindTexture(QPixmap pixmap)` Generates and binds a 2D GL texture based on `pixmap`.
`int` | `bindTexture(QPixmap pixmap, int target)` Generates and binds a 2D GL texture based on `pixmap`.
`int` | `bindTexture(java.lang.String fileName)` Reads the DirectDrawSurface (DDS) compressed file `fileName` and generates a 2D GL texture from it.
`boolean` | `bindToDynamicTexture(int texture)` Binds the texture specified by `texture_id` to this pbuffer.
`void` | `deleteTexture(int texture_id)` Removes the texture identified by `texture_id` from the texture cache.
`int` | `depth()` Returns the bit depth (number of bit planes) of the paint device.
`boolean` | `doneCurrent()` Makes no context the current OpenGL context.
`void` | `drawTexture(QPointF point, int textureId)` Draws the given texture, `textureId`, at the given `point` in OpenGL model space.
`void` | `drawTexture(QPointF point, int textureId, int textureTarget)` Draws the given texture, `textureId`, at the given `point` in OpenGL model space.
`void` | `drawTexture(QRectF target, int textureId)` Draws the given texture, `textureId`, to the given target rectangle, `target`, in OpenGL model space.
`void` | `drawTexture(QRectF target, int textureId, int textureTarget)` Draws the given texture, `textureId`, to the given target rectangle, `target`, in OpenGL model space.
`QGLFormat` | `format()` Returns the format of the pbuffer.
`int` | `generateDynamicTexture()` Generates and binds a 2D GL texture that is the same size as the pbuffer, and returns the texture's ID.
`long` | `handle()` Returns the native pbuffer handle.
`static boolean` | `hasOpenGLPbuffers()` Returns true if the OpenGL `pbuffer` extension is present on this system; otherwise returns false.
`int` | `height()` Returns the height of the paint device in default coordinate system units (e.
`int` | `heightMM()` Returns the height of the paint device in millimeters.
`boolean` | `isValid()` Returns true if this pbuffer is valid; otherwise returns false.
`int` | `logicalDpiX()` Returns the horizontal resolution of the device in dots per inch, which is used when computing font sizes.
`int` | `logicalDpiY()` Returns the vertical resolution of the device in dots per inch, which is used when computing font sizes.
`boolean` | `makeCurrent()` Makes this pbuffer the current OpenGL rendering context.
`int` | `metric(QPaintDevice.PaintDeviceMetric metric)` Returns the metric information for the given paint device `metric`.
`int` | `numColors()` Returns the number of different colors available for the paint device.
`QPaintEngine` | `paintEngine()` Returns a pointer to the paint engine used for drawing on the device.
`boolean` | `paintingActive()` Returns true if the device is currently being painted on, i.
`int` | `physicalDpiX()` Returns the horizontal resolution of the device in dots per inch.
`int` | `physicalDpiY()` Returns the horizontal resolution of the device in dots per inch.
`void` | `releaseFromDynamicTexture()` Releases the pbuffer from any previously bound texture.
`QSize` | `size()` Returns the size of the pbuffer.
`QImage` | `toImage()` Returns the contents of the pbuffer as a `QImage`.
`void` | `updateDynamicTexture(int texture_id)` Copies the pbuffer contents into the texture specified with `texture_id`.
`int` | `width()` Returns the width of the paint device in default coordinate system units (e.
`int` | `widthMM()` Returns the width of the paint device in millimeters.

Methods inherited from class com.trolltech.qt.QtJambiObject
`dispose, disposed, equals, finalize, reassignNativeResources, tr, tr, tr`

Methods inherited from class com.trolltech.qt.QSignalEmitter
`blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread`

Methods inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
`__qt_signalInitialization`

Methods inherited from class java.lang.Object
`clone, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Methods inherited from interface com.trolltech.qt.QtJambiInterface
`disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership`

Constructor Detail

### QGLPixelBuffer

    public QGLPixelBuffer(QSize size,
                          QGLFormat format)

  Constructs an OpenGL pbuffer of the given `size`. If no `format` is specified, the `default format` is used. If the `shareWidget` parameter points to a valid `QGLWidget`, the pbuffer will share its context with `shareWidget`.

  If you intend to bind this pbuffer as a dynamic texture, the width and height components of `size` must be powers of two (e.g., 512 x 128).

See also:
  `size()`, and `format()`.

### QGLPixelBuffer

    public QGLPixelBuffer(QSize size)

  Constructs an OpenGL pbuffer of the given `size`. If no `format` is specified, the `default format` is used. If the `shareWidget` parameter points to a valid `QGLWidget`, the pbuffer will share its context with `shareWidget`.

  If you intend to bind this pbuffer as a dynamic texture, the width and height components of `size` must be powers of two (e.g., 512 x 128).

See also:
  `size()`, and `format()`.

### QGLPixelBuffer

    public QGLPixelBuffer(QSize size,
                          QGLFormat format,
                          QGLWidget shareWidget)

  Constructs an OpenGL pbuffer of the given `size`. If no `format` is specified, the `default format` is used. If the `shareWidget` parameter points to a valid `QGLWidget`, the pbuffer will share its context with `shareWidget`.

  If you intend to bind this pbuffer as a dynamic texture, the width and height components of `size` must be powers of two (e.g., 512 x 128).

See also:
  `size()`, and `format()`.

### QGLPixelBuffer

    public QGLPixelBuffer(int width,
                          int height,
                          QGLFormat format)

  Constructs an OpenGL pbuffer with the `width` and `height`. If no `format` is specified, the `default format` is used. If the `shareWidget` parameter points to a valid `QGLWidget`, the pbuffer will share its context with `shareWidget`.

  If you intend to bind this pbuffer as a dynamic texture, the width and height components of `size` must be powers of two (e.g., 512 x 128).

See also:
  `size()`, and `format()`.

### QGLPixelBuffer

    public QGLPixelBuffer(int width,
                          int height)

  Constructs an OpenGL pbuffer with the `width` and `height`. If no `format` is specified, the `default format` is used. If the `shareWidget` parameter points to a valid `QGLWidget`, the pbuffer will share its context with `shareWidget`.

  If you intend to bind this pbuffer as a dynamic texture, the width and height components of `size` must be powers of two (e.g., 512 x 128).

See also:
  `size()`, and `format()`.

### QGLPixelBuffer

    public QGLPixelBuffer(int width,
                          int height,
                          QGLFormat format,
                          QGLWidget shareWidget)

  Constructs an OpenGL pbuffer with the `width` and `height`. If no `format` is specified, the `default format` is used. If the `shareWidget` parameter points to a valid `QGLWidget`, the pbuffer will share its context with `shareWidget`.

  If you intend to bind this pbuffer as a dynamic texture, the width and height components of `size` must be powers of two (e.g., 512 x 128).

See also:
  `size()`, and `format()`.

Method Detail

### bindTexture

    public final int bindTexture(QImage image)

  Generates and binds a 2D GL texture to the current context, based on `image`. The generated texture id is returned and can be used in later glBindTexture() calls.

  The `target` parameter specifies the texture target.

  Equivalent to calling `QGLContext::bindTexture()`.

See also:
  `deleteTexture()`.

### bindTexture

    public final int bindTexture(QImage image,
                                 int target)

  Generates and binds a 2D GL texture to the current context, based on `image`. The generated texture id is returned and can be used in later glBindTexture() calls.

  The `target` parameter specifies the texture target.

  Equivalent to calling `QGLContext::bindTexture()`.

See also:
  `deleteTexture()`.

### bindTexture

    public final int bindTexture(QPixmap pixmap)

  Generates and binds a 2D GL texture based on `pixmap`.

  Equivalent to calling `QGLContext::bindTexture()`.

See also:
  `deleteTexture()`.

### bindTexture

    public final int bindTexture(QPixmap pixmap,
                                 int target)

  Generates and binds a 2D GL texture based on `pixmap`.

  Equivalent to calling `QGLContext::bindTexture()`.

See also:
  `deleteTexture()`.

### bindTexture

    public final int bindTexture(java.lang.String fileName)

  Reads the DirectDrawSurface (DDS) compressed file `fileName` and generates a 2D GL texture from it.

  Equivalent to calling `QGLContext::bindTexture()`.

See also:
  `deleteTexture()`.

### bindToDynamicTexture

    public final boolean bindToDynamicTexture(int texture)

  Binds the texture specified by `texture_id` to this pbuffer. Returns true on success; otherwise returns false.

  The texture must be of the same size and format as the pbuffer.

  To unbind the texture, call `releaseFromDynamicTexture()`. While the texture is bound, it is updated automatically when the pbuffer contents change, eliminating the need for additional copy operations.

  Example:

              QGLPixelBuffer pbuffer = new QGLPixelBuffer(256, 256);
              //...
              pbuffer.makeCurrent();
              int dynamicTexture = pbuffer.generateDynamicTexture();
              pbuffer.bindToDynamicTexture(dynamicTexture);
              //...
              pbuffer.releaseFromDynamicTexture();

  Warning: This function uses the `render_texture` extension, which is currently not supported under X11. An alternative that works on all systems (including X11) is to manually copy the pbuffer contents to a texture using `updateDynamicTexture()`.

  Warning: For the `bindToDynamicTexture()` call to succeed on the Mac OS X, the pbuffer needs a shared context, i.e. the QGLPixelBuffer must be created with a share widget.

See also:
  `generateDynamicTexture()`, and `releaseFromDynamicTexture()`.

### deleteTexture

    public final void deleteTexture(int texture_id)

  Removes the texture identified by `texture_id` from the texture cache.

  Equivalent to calling `QGLContext::deleteTexture()`.

### depth

    public final int depth()

  Returns the bit depth (number of bit planes) of the paint device.

  Specified by:
    `depth` in interface `QPaintDeviceInterface`

### doneCurrent

    public final boolean doneCurrent()

  Makes no context the current OpenGL context. Returns true on success; otherwise returns false.

### drawTexture

    public final void drawTexture(QPointF point,
                                  int textureId)

  Draws the given texture, `textureId`, at the given `point` in OpenGL model space. The textureTarget parameter should be a 2D texture target.

  Equivalent to the corresponding `QGLContext::drawTexture()`.

### drawTexture

    public final void drawTexture(QPointF point,
                                  int textureId,
                                  int textureTarget)

  Draws the given texture, `textureId`, at the given `point` in OpenGL model space. The textureTarget parameter should be a 2D texture target.

  Equivalent to the corresponding `QGLContext::drawTexture()`.

### drawTexture

    public final void drawTexture(QRectF target,
                                  int textureId)

  Draws the given texture, `textureId`, to the given target rectangle, `target`, in OpenGL model space. The `textureTarget` should be a 2D texture target.

  Equivalent to the corresponding `QGLContext::drawTexture()`.

### drawTexture

    public final void drawTexture(QRectF target,
                                  int textureId,
                                  int textureTarget)

  Draws the given texture, `textureId`, to the given target rectangle, `target`, in OpenGL model space. The `textureTarget` should be a 2D texture target.

  Equivalent to the corresponding `QGLContext::drawTexture()`.

### format

    public final QGLFormat format()

  Returns the format of the pbuffer. The format may be different from the one that was requested.

### generateDynamicTexture

    public final int generateDynamicTexture()

  Generates and binds a 2D GL texture that is the same size as the pbuffer, and returns the texture's ID. This can be used in conjunction with `bindToDynamicTexture()` and `updateDynamicTexture()`.

See also:
  `size()`.

### handle

    public final long handle()

  Returns the native pbuffer handle.

### height

    public final int height()

  Returns the height of the paint device in default coordinate system units (e. . pixels for `QPixmap` and `QWidget`).

See also:
  `heightMM()`.

  Specified by:
    `height` in interface `QPaintDeviceInterface`

### heightMM

    public final int heightMM()

  Returns the height of the paint device in millimeters.

See also:
  `height()`.

  Specified by:
    `heightMM` in interface `QPaintDeviceInterface`

### isValid

    public final boolean isValid()

  Returns true if this pbuffer is valid; otherwise returns false.

### logicalDpiX

    public final int logicalDpiX()

  Returns the horizontal resolution of the device in dots per inch, which is used when computing font sizes. For X11, this is usually the same as could be computed from `widthMM()`.

  Note that if the `logicalDpiX()` doesn't equal the `physicalDpiX()`, the corresponding `QPaintEngine` must handle the resolution mapping.

See also:
  `logicalDpiY()`, and `physicalDpiX()`.

  Specified by:
    `logicalDpiX` in interface `QPaintDeviceInterface`

### logicalDpiY

    public final int logicalDpiY()

  Returns the vertical resolution of the device in dots per inch, which is used when computing font sizes. For X11, this is usually the same as could be computed from `heightMM()`.

  Note that if the `logicalDpiY()` doesn't equal the `physicalDpiY()`, the corresponding `QPaintEngine` must handle the resolution mapping.

See also:
  `logicalDpiX()`, and `physicalDpiY()`.

  Specified by:
    `logicalDpiY` in interface `QPaintDeviceInterface`

### makeCurrent

    public final boolean makeCurrent()

  Makes this pbuffer the current OpenGL rendering context. Returns true on success; otherwise returns false.

See also:
  `QGLContext::makeCurrent()`, and `doneCurrent()`.

### numColors

    public final int numColors()

  Returns the number of different colors available for the paint device. Since this value is an int, it will not be sufficient to represent the number of colors on 32 bit displays, in this case INT_MAX is returned instead.

  Specified by:
    `numColors` in interface `QPaintDeviceInterface`

### paintingActive

    public final boolean paintingActive()

  Returns true if the device is currently being painted on, i. . someone has called `QPainter::begin()` but not yet called `QPainter::end()` for this device; otherwise returns false.

See also:
  `QPainter::isActive()`.

  Specified by:
    `paintingActive` in interface `QPaintDeviceInterface`

### physicalDpiX

    public final int physicalDpiX()

  Returns the horizontal resolution of the device in dots per inch. For example, when printing, this resolution refers to the physical printer's resolution. The logical DPI on the other hand, refers to the resolution used by the actual paint engine.

  Note that if the `physicalDpiX()` doesn't equal the `logicalDpiX()`, the corresponding `QPaintEngine` must handle the resolution mapping.

See also:
  `physicalDpiY()`, and `logicalDpiX()`.

  Specified by:
    `physicalDpiX` in interface `QPaintDeviceInterface`

### physicalDpiY

    public final int physicalDpiY()

  Returns the horizontal resolution of the device in dots per inch. For example, when printing, this resolution refers to the physical printer's resolution. The logical DPI on the other hand, refers to the resolution used by the actual paint engine.

  Note that if the `physicalDpiY()` doesn't equal the `logicalDpiY()`, the corresponding `QPaintEngine` must handle the resolution mapping.

See also:
  `physicalDpiX()`, and `logicalDpiY()`.

  Specified by:
    `physicalDpiY` in interface `QPaintDeviceInterface`

### releaseFromDynamicTexture

    public final void releaseFromDynamicTexture()

  Releases the pbuffer from any previously bound texture.

See also:
  `bindToDynamicTexture()`.

### size

    public final QSize size()

  Returns the size of the pbuffer.

### toImage

    public final QImage toImage()

  Returns the contents of the pbuffer as a `QImage`.

### updateDynamicTexture

    public final void updateDynamicTexture(int texture_id)

  Copies the pbuffer contents into the texture specified with `texture_id`.

  The texture must be of the same size and format as the pbuffer.

  Example:

              QGLPixelBuffer pbuffer = new QGLPixelBuffer(256, 256);
              // ...
              pbuffer.makeCurrent();
              int dynamicTexture = pbuffer.generateDynamicTexture();
              // ...
              pbuffer.updateDynamicTexture(dynamicTexture);

  An alternative on Windows and Mac OS X systems that support the `render_texture` extension is to use `bindToDynamicTexture()` to get dynamic updates of the texture.

See also:
  `generateDynamicTexture()`, and `bindToDynamicTexture()`.

### width

    public final int width()

  Returns the width of the paint device in default coordinate system units (e. . pixels for `QPixmap` and `QWidget`).

See also:
  `widthMM()`.

  Specified by:
    `width` in interface `QPaintDeviceInterface`

### widthMM

    public final int widthMM()

  Returns the width of the paint device in millimeters.

See also:
  `width()`.

  Specified by:
    `widthMM` in interface `QPaintDeviceInterface`

### metric

    public int metric(QPaintDevice.PaintDeviceMetric metric)

  Returns the metric information for the given paint device `metric`.

See also:
  `PaintDeviceMetric` .

  Specified by:
    `metric` in interface `QPaintDeviceInterface`

### paintEngine

    public QPaintEngine paintEngine()

  Returns a pointer to the paint engine used for drawing on the device.

  Specified by:
    `paintEngine` in interface `QPaintDeviceInterface`

### hasOpenGLPbuffers

    public static boolean hasOpenGLPbuffers()

  Returns true if the OpenGL `pbuffer` extension is present on this system; otherwise returns false.

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