VRS::OcclusionQueryGL Class Reference
Class for testing the visibility of shapes rendered by OpenGL. More...
#include <vrs/opengl/occlusionquerygl.h>
Public Types | |
| enum | QueryMode { QM_ImmediateMode, QM_DelayedMode } |
| enum | SupportedVersion { SV_OGL15, SV_ARB, SV_NV, SV_NotSupported } |
Public Member Functions | |
| VRS_SERIALIZABLE_CLASS_ENUM (QueryMode) | |
| OcclusionQueryGL (QueryMode mode=OcclusionQueryGL::QM_ImmediateMode) | |
| virtual | ~OcclusionQueryGL () |
| bool | isSupported () const |
| bool | isAvailable () const |
| unsigned int | fragmentCount () const |
| unsigned int | getQueryID (void) const |
| VRS_TYPEINFO (OcclusionQueryGL, MonoAttribute) | |
Friends | |
| class | OcclusionQueryPainterGL |
Detailed Description
Class for testing the visibility of shapes rendered by OpenGL.Member Enumeration Documentation
Constructor & Destructor Documentation
| VRS::OcclusionQueryGL::OcclusionQueryGL | ( | QueryMode | mode = OcclusionQueryGL::QM_ImmediateMode |
) |
An OcclusionQuery object can be used to count the number of fragments that pass the z-test during the application of this attribute (i.e. between pushing and popping to/from the rendering engine). This attribute relies on the OpenGL extension GL_ARB_occlusion_query or the older GL_NV_occlusion_query. If one of these extension is available at runtime or not can be queried by the method isSupported() *after* the application of the attribute. If the needed extension is not available at runtime it is always indicated that a z-test has been passed successfully and the fragment count will be UINT_MAX. If the query mode is QM_ImmediateMode, the result will be available directly after popping the attribute, which may lead to a stall in the OpenGL command pipeline. The QM_DelayedMode allows to query the result at a later time, but you should be sure, that the current OpenGL rendering context is the same, when querying the result!
| virtual VRS::OcclusionQueryGL::~OcclusionQueryGL | ( | ) | [virtual] |
Member Function Documentation
| VRS::OcclusionQueryGL::VRS_SERIALIZABLE_CLASS_ENUM | ( | QueryMode | ) |
| bool VRS::OcclusionQueryGL::isSupported | ( | ) | const |
Returns true if the needed OpenGL extension GL_ARB_occlusion_query or GL_NV_occlusion_query was available (which can be queried after pushing the attribute to the engine).
| bool VRS::OcclusionQueryGL::isAvailable | ( | ) | const |
Returns true if the result of the occlusion query is already available (always the case for QM_ImmediateMode or when the GL_ARB_occlusion_query or GL_NV_occlusion_query extension is not supported).
| unsigned int VRS::OcclusionQueryGL::fragmentCount | ( | ) | const |
Return the number of fragments for that the z-test has been passed. If the GL_ARB_occlusion_query extension is not supported, the returned value is UINT_MAX. For the QM_DelayedMode you must ensure that the correct OpenGL rendering context is current!
| unsigned int VRS::OcclusionQueryGL::getQueryID | ( | void | ) | const [inline] |
| VRS::OcclusionQueryGL::VRS_TYPEINFO | ( | OcclusionQueryGL | , | |
| MonoAttribute | ||||
| ) |
Friends And Related Function Documentation
friend class OcclusionQueryPainterGL [friend] |
The documentation for this class was generated from the following file: