NAME¶

SoGLRenderAction — renders a scene graph using OpenGL

INHERITS FROM¶

SoAction > SoGLRenderAction

SYNOPSIS¶

#include <Inventor/actions/SoGLRenderAction.h>

typedef AbortCode SoGLRenderAbortCB(void *userData)

typedef void SoGLRenderPassCB(void *userData)

enum TransparencyType {

SoGLRenderAction::SCREEN_DOOR Uses stipple patterns for screen-door transparency

SoGLRenderAction::ADD Uses additive alpha blending

SoGLRenderAction::DELAYED_ADD Uses additive blending, rendering all transparent objects after opaque ones

SoGLRenderAction::SORTED_OBJECT_ADD Same as DELAYED_ADD, but sorts transparent objects by distances of bounding boxes from camera

SoGLRenderAction::BLEND Uses multiplicative alpha blending

SoGLRenderAction::DELAYED_BLEND Uses multiplicative alpha blending, rendering all transparent objects after opaque ones

SoGLRenderAction::SORTED_OBJECT_BLEND Same as DELAYED_BLEND, but sorts transparent objects by distances of bounding boxes from camera

}

enum AbortCode {

SoGLRenderAction::CONTINUE Continue traversal as usual

SoGLRenderAction::ABORT Stop traversing the rest of the graph

SoGLRenderAction::PRUNE Do not traverse this node or its children, but continue

SoGLRenderAction::DELAY Delay rendering of this node until the second pass

}

Methods from class SoGLRenderAction:

SoGLRenderAction(const SbViewportRegion &viewportRegion)

void setViewportRegion(const SbViewportRegion &newRegion)

const SbViewportRegion & getViewportRegion() const

void setUpdateArea(const SbVec2f &origin, const SbVec2f &size)

void getUpdateArea(SbVec2f &origin, SbVec2f &size) const

void setAbortCallback(SoGLRenderAbortCB *func, void *userData)

void setTransparencyType(TransparencyType type)

TransparencyType getTransparencyType() const

void setSmoothing(SbBool smooth)

SbBool isSmoothing() const

void setNumPasses(int num)

int getNumPasses() const

void setPassUpdate(SbBool flag)

SbBool isPassUpdate() const

void setPassCallback(SoGLRenderPassCB *func, void *userData)

void setCacheContext(uint32_t context)

uint32_t getCacheContext() const

Methods from class SoAction:

virtual void apply(SoNode *node)

virtual void apply(SoPath *path)

virtual void apply(const SoPathList &pathList, SbBool obeysRules = FALSE)

static SoType getClassTypeId()

virtual SoType getTypeId()

virtual SbBool isOfType(SoType type)

virtual void invalidateState()

DESCRIPTION¶

This class traverses a scene graph and renders it using the OpenGL graphics library. It assumes that a valid window has been created and initialized for proper OpenGL rendering. The SoXtRenderArea class or any of its subclasses may be used to create such a window.

METHODS¶

SoGLRenderAction(const SbViewportRegion &viewportRegion)

Constructor. The parameter defines the viewport region into which rendering will take place.

void setViewportRegion(const SbViewportRegion &newRegion)

const SbViewportRegion & getViewportRegion() const

Changes/returns viewport region to use for rendering.

void setUpdateArea(const SbVec2f &origin, const SbVec2f &size)

void getUpdateArea(SbVec2f &origin, SbVec2f &size) const

Sets/returns the current update area, which is the rectangular area of the viewport region that will actually be rendered into. This can be used for partial updates in applications that can manage them. The update area is specified in normalized viewport coordinates, where (0,0) is the lower left corner of the viewport and (1,1) is the upper right corner. The area is specified or returned as an origin and a size.

void setAbortCallback(SoGLRenderAbortCB *func, void *userData)

Sets callback to call during rendering to test for an abort condition. It will be called for each node that is traversed. This allows applications to terminate rendering prematurely if some condition occurs. The callback function should return one of the AbortCode codes to indicate whether traversal should continue. Use of the various codes in a callback can allow applications to modify Inventor's default order of rendering objects in a scene graph.

void setTransparencyType(TransparencyType type)

TransparencyType getTransparencyType() const

Sets/returns transparency quality level to use when rendering. The default is SCREEN_DOOR. (Note that SCREEN_DOOR transparency does not work in the case where transparency values are specified for each vertex of a shape. If this is the case, use one of the other transparency types.)

void setSmoothing(SbBool smooth)

SbBool isSmoothing() const

Sets/returns smoothing flag. When on, smoothing uses OpenGL's line- and point-smoothing features to provide cheap antialiasing of lines and points. The default is FALSE.

void setNumPasses(int num)

int getNumPasses() const

Sets/returns number of rendering passes for multipass rendering. Specifying more than one pass will result in antialiasing of the rendered scene, using OpenGL's accumulation buffer. (Camera nodes typically move their viewpoints a little bit for each pass to achieve the antialiasing.) Each additional pass provides better antialiasing, but requires more rendering time The default is 1 pass.

void setPassUpdate(SbBool flag)

SbBool isPassUpdate() const

Sets/returns a flag indicating whether intermediate results are displayed after each antialiasing pass for progressive improvement (default is FALSE).

void setPassCallback(SoGLRenderPassCB *func, void *userData)

Sets a callback function to invoke between passes when antialiasing. Passing NULL (which is the default state) will cause a clear of the color and depth buffers to be performed.

void setCacheContext(uint32_t context)

uint32_t getCacheContext() const

Sets/returns the OpenGL cache context. A cache context is just an integer identifying when OpenGL display lists (which are used for render caching) can be shared between render actions; for example, see the documentation on GLX contexts for information on when OpenGL display lists can be shared between GLX windows.

SEE ALSO¶

SoSeparator, SoXtRenderArea