SoOffscreenRenderer(3IV)

NAME
     SoOffscreenRenderer - renders to an off-screen buffer for printing or
     generating textures

INHERITS FROM
     SoOffscreenRenderer

SYNOPSIS
     #include <Inventor/SoOffscreenRenderer.h>

     enum Components {
          SoOffscreenRenderer::LUMINANCE

          SoOffscreenRenderer::LUMINANCE_TRANSPARENCY

          SoOffscreenRenderer::RGB
          SoOffscreenRenderer::RGB_TRANSPARENCY

     }

          Methods from class SoOffscreenRenderer:

                               SoOffscreenRenderer(const SbViewportRegion
                                    &viewportRegion)
                               SoOffscreenRenderer(SoGLRenderAction *ra)
                               ~SoOffscreenRenderer()
     static float              getScreenPixelsPerInch()
     static SbVec2s            getMaximumResolution()
     void                      setComponents(Components components)
     Components                getComponents() const
     void                      setViewportRegion(const SbViewportRegion
                                    &region)
     const SbViewportRegion &  getViewportRegion() const
     void                      setBackgroundColor(const SbColor &c)
     const SbColor &           getBackgroundColor() const
     void                      setGLRenderAction(const SoGLRenderAction *ra)
     SoGLRenderAction *        getGLRenderAction() const
     SbBool                    render(SoNode *scene)
     SbBool                    render(SoPath *scene)
     unsigned char *           getBuffer() const
     SbBool                    writeToRGB(FILE *fp) const
     SbBool                    writeToPostScript(FILE *fp) const
     SbBool                    writeToPostScript(FILE *fp, const SbVec2f
                                    &printSize) const


DESCRIPTION
     This class is used to render into an off-screen buffer to create a
     printable image or to generate a texture image. It uses X Pixmaps for
     rendering. Methods are provided to write the buffer to a file, either as
     an RGB image or an encapsulated PostScript description.

METHODS
                               SoOffscreenRenderer(const SbViewportRegion
                                    &viewportRegion)
                               SoOffscreenRenderer(SoGLRenderAction *ra)
                               ~SoOffscreenRenderer()
          Constructors and destructor. If a render action is passed to the
          contructor, that action will be used in all subsequent offscreen
          renderings. Otherwise, an internal instance of an SoGLRenderAction
          will be maintained with a viewport region set to the on passed in by
          the constructor.

     static float              getScreenPixelsPerInch()
          Returns the number of pixels per inch (in the horizontal direction)
          of the current X device screen.

     static SbVec2s            getMaximumResolution()
          Get the maximum supported resolution of the viewport.

     void                      setComponents(Components components)
     Components                getComponents() const
          Sets or returns the components to be rendered.

     void                      setViewportRegion(const SbViewportRegion
                                    &region)
     const SbViewportRegion &  getViewportRegion() const
          Sets or returns the viewport region used for rendering. This will
          NOT be applied to the viewport region of any render action passed
          in.

     void                      setBackgroundColor(const SbColor &c)
     const SbColor &           getBackgroundColor() const
          Sets or returns the background color for rendering.

     void                      setGLRenderAction(const SoGLRenderAction *ra)
     SoGLRenderAction *        getGLRenderAction() const
          Set and get the render action to use for rendering. This will return
          any render action passed in by the caller.

     SbBool                    render(SoNode *scene)
     SbBool                    render(SoPath *scene)
          Renders the given scene, specified as a node or a path, into an
          off-screen buffer.

     unsigned char *           getBuffer() const
          Returns the buffer containing the rendered image. The buffer is an
          array of unsigned characters. Each pixel is stored sequentially by
          scanline, starting with the lower left corner. The data stored for
          each pixel is determined by the Components set before rendering.
          Pixels are stored in RGBA order and are packed without any padding
          between pixels or scanlines. The buffer is allocated by the
          offscreen renderer class and the space is deleted when the instance
          is destructed.
     SbBool                    writeToRGB(FILE *fp) const
          Writes the buffer as a .rgb file to the given file pointer.

     SbBool                    writeToPostScript(FILE *fp) const
     SbBool                    writeToPostScript(FILE *fp, const SbVec2f
                                    &printSize) const
          Writes the buffer as encapsulated PostScript. If a print size is not
          given, the size of the image in the buffer is adjusted so it is the
          same as the apparent size of the viewport region on the current
          device.