vtkOpenGLRenderUtilities Class Reference

OpenGL rendering utility functions. More...

#include <vtkOpenGLRenderUtilities.h>

Inheritance diagram for vtkOpenGLRenderUtilities:

Collaboration diagram for vtkOpenGLRenderUtilities:

Public Types
typedef vtkObject	Superclass

Public Member Functions
virtual vtkTypeBool	IsA (const char *type)
	Return 1 if this class is the same type of (or a subclass of) the named class.
vtkOpenGLRenderUtilities *	NewInstance () const
void	PrintSelf (ostream &os, vtkIndent indent) override
	Methods invoked by print to print information about the object including superclasses.
Public Member Functions inherited from vtkObject
	vtkBaseTypeMacro (vtkObject, vtkObjectBase)
virtual void	DebugOn ()
	Turn debugging output on.
virtual void	DebugOff ()
	Turn debugging output off.
bool	GetDebug ()
	Get the value of the debug flag.
void	SetDebug (bool debugFlag)
	Set the value of the debug flag.
virtual void	Modified ()
	Update the modification time for this object.
virtual vtkMTimeType	GetMTime ()
	Return this object's modified time.
void	PrintSelf (ostream &os, vtkIndent indent) override
	Methods invoked by print to print information about the object including superclasses.
void	RemoveObserver (unsigned long tag)
void	RemoveObservers (unsigned long event)
void	RemoveObservers (const char *event)
void	RemoveAllObservers ()
vtkTypeBool	HasObserver (unsigned long event)
vtkTypeBool	HasObserver (const char *event)
vtkTypeBool	InvokeEvent (unsigned long event)
vtkTypeBool	InvokeEvent (const char *event)
std::string	GetObjectDescription () const override
	The object description printed in messages and PrintSelf output.
unsigned long	AddObserver (unsigned long event, vtkCommand *, float priority=0.0f)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.
unsigned long	AddObserver (const char *event, vtkCommand *, float priority=0.0f)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.
vtkCommand *	GetCommand (unsigned long tag)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.
void	RemoveObserver (vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.
void	RemoveObservers (unsigned long event, vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.
void	RemoveObservers (const char *event, vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.
vtkTypeBool	HasObserver (unsigned long event, vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.
vtkTypeBool	HasObserver (const char *event, vtkCommand *)
	Allow people to add/remove/invoke observers (callbacks) to any VTK object.
template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, void(T::*callback)(), float priority=0.0f)
	Overloads to AddObserver that allow developers to add class member functions as callbacks for events.
template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, void(T::*callback)(vtkObject *, unsigned long, void *), float priority=0.0f)
	Overloads to AddObserver that allow developers to add class member functions as callbacks for events.
template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, bool(T::*callback)(vtkObject *, unsigned long, void *), float priority=0.0f)
	Allow user to set the AbortFlagOn() with the return value of the callback method.
vtkTypeBool	InvokeEvent (unsigned long event, void *callData)
	This method invokes an event and return whether the event was aborted or not.
vtkTypeBool	InvokeEvent (const char *event, void *callData)
	This method invokes an event and return whether the event was aborted or not.
virtual void	SetObjectName (const std::string &objectName)
	Set/get the name of this object for reporting purposes.
virtual std::string	GetObjectName () const
	Set/get the name of this object for reporting purposes.
Public Member Functions inherited from vtkObjectBase
const char *	GetClassName () const
	Return the class name as a string.
virtual std::string	GetObjectDescription () const
	The object description printed in messages and PrintSelf output.
virtual vtkTypeBool	IsA (const char *name)
	Return 1 if this class is the same type of (or a subclass of) the named class.
virtual vtkIdType	GetNumberOfGenerationsFromBase (const char *name)
	Given the name of a base class of this class type, return the distance of inheritance between this class type and the named class (how many generations of inheritance are there between this class and the named class).
virtual void	Delete ()
	Delete a VTK object.
virtual void	FastDelete ()
	Delete a reference to this object.
void	InitializeObjectBase ()
void	Print (ostream &os)
	Print an object to an ostream.
void	Register (vtkObjectBase *o)
	Increase the reference count (mark as used by another object).
virtual void	UnRegister (vtkObjectBase *o)
	Decrease the reference count (release by another object).
int	GetReferenceCount ()
	Return the current reference count of this object.
void	SetReferenceCount (int)
	Sets the reference count.
bool	GetIsInMemkind () const
	A local state flag that remembers whether this object lives in the normal or extended memory space.
virtual void	PrintHeader (ostream &os, vtkIndent indent)
	Methods invoked by print to print information about the object including superclasses.
virtual void	PrintTrailer (ostream &os, vtkIndent indent)
	Methods invoked by print to print information about the object including superclasses.
virtual bool	UsesGarbageCollector () const
	Indicate whether the class uses vtkGarbageCollector or not.

Static Public Member Functions
static vtkTypeBool	IsTypeOf (const char *type)
static vtkOpenGLRenderUtilities *	SafeDownCast (vtkObjectBase *o)
static bool	PrepFullScreenVAO (vtkOpenGLBufferObject *vertBuf, vtkOpenGLVertexArrayObject *vao, vtkShaderProgram *prog)
static void	MarkDebugEvent (const std::string &event)
	Pass a debugging mark to the render engine to assist development via tools like apitrace.
static void	RenderQuad (float *verts, float *tcoords, vtkShaderProgram *program, vtkOpenGLVertexArrayObject *vao)
	Helper function that draws a quad on the screen at the specified vertex coordinates and if tcoords are not NULL with the specified texture coordinates.
static void	RenderTriangles (float *verts, unsigned int numVerts, GLuint *iboData, unsigned int numIndices, float *tcoords, vtkShaderProgram *program, vtkOpenGLVertexArrayObject *vao)
	Helper function that draws a quad on the screen at the specified vertex coordinates and if tcoords are not NULL with the specified texture coordinates.
static std::string	GetFullScreenQuadVertexShader ()
	Draw a full-screen quad:
static std::string	GetFullScreenQuadFragmentShaderTemplate ()
	Draw a full-screen quad:
static std::string	GetFullScreenQuadGeometryShader ()
	Draw a full-screen quad:
static bool	PrepFullScreenVAO (vtkOpenGLRenderWindow *renWin, vtkOpenGLVertexArrayObject *vao, vtkShaderProgram *prog)
	Draw a full-screen quad:
static void	DrawFullScreenQuad ()
	Draw a full-screen quad:
Static Public Member Functions inherited from vtkObject
static vtkObject *	New ()
	Create an object with Debug turned off, modified time initialized to zero, and reference counting on.
static void	BreakOnError ()
	This method is called when vtkErrorMacro executes.
static void	SetGlobalWarningDisplay (vtkTypeBool val)
	This is a global flag that controls whether any debug, warning or error messages are displayed.
static void	GlobalWarningDisplayOn ()
	This is a global flag that controls whether any debug, warning or error messages are displayed.
static void	GlobalWarningDisplayOff ()
	This is a global flag that controls whether any debug, warning or error messages are displayed.
static vtkTypeBool	GetGlobalWarningDisplay ()
	This is a global flag that controls whether any debug, warning or error messages are displayed.
Static Public Member Functions inherited from vtkObjectBase
static vtkTypeBool	IsTypeOf (const char *name)
	Return 1 if this class type is the same type of (or a subclass of) the named class.
static vtkIdType	GetNumberOfGenerationsFromBaseType (const char *name)
	Given a the name of a base class of this class type, return the distance of inheritance between this class type and the named class (how many generations of inheritance are there between this class and the named class).
static vtkObjectBase *	New ()
	Create an object with Debug turned off, modified time initialized to zero, and reference counting on.
static void	SetMemkindDirectory (const char *directoryname)
	The name of a directory, ideally mounted -o dax, to memory map an extended memory space within.
static bool	GetUsingMemkind ()
	A global state flag that controls whether vtkObjects are constructed in the usual way (the default) or within the extended memory space.

Protected Member Functions
virtual vtkObjectBase *	NewInstanceInternal () const
	vtkOpenGLRenderUtilities ()
	~vtkOpenGLRenderUtilities () override
Protected Member Functions inherited from vtkObject
	vtkObject ()
	~vtkObject () override
void	RegisterInternal (vtkObjectBase *, vtkTypeBool check) override
void	UnRegisterInternal (vtkObjectBase *, vtkTypeBool check) override
void	InternalGrabFocus (vtkCommand *mouseEvents, vtkCommand *keypressEvents=nullptr)
	These methods allow a command to exclusively grab all events.
void	InternalReleaseFocus ()
	These methods allow a command to exclusively grab all events.
Protected Member Functions inherited from vtkObjectBase
	vtkObjectBase ()
virtual	~vtkObjectBase ()
virtual void	RegisterInternal (vtkObjectBase *, vtkTypeBool check)
virtual void	UnRegisterInternal (vtkObjectBase *, vtkTypeBool check)
virtual void	ReportReferences (vtkGarbageCollector *)
virtual void	ObjectFinalize ()
	vtkObjectBase (const vtkObjectBase &)
void	operator= (const vtkObjectBase &)

Additional Inherited Members
Static Protected Member Functions inherited from vtkObjectBase
static vtkMallocingFunction	GetCurrentMallocFunction ()
static vtkReallocingFunction	GetCurrentReallocFunction ()
static vtkFreeingFunction	GetCurrentFreeFunction ()
static vtkFreeingFunction	GetAlternateFreeFunction ()
Protected Attributes inherited from vtkObject
bool	Debug
vtkTimeStamp	MTime
vtkSubjectHelper *	SubjectHelper
std::string	ObjectName
Protected Attributes inherited from vtkObjectBase
std::atomic< int32_t >	ReferenceCount
vtkWeakPointerBase **	WeakPointers

Detailed Description

OpenGL rendering utility functions.

vtkOpenGLRenderUtilities provides functions to help render primitives.

See also the vtkOpenGLQuadHelper class which may be easier to use.

Tests:

vtkOpenGLRenderUtilities (Tests)

Definition at line 31 of file vtkOpenGLRenderUtilities.h.

Member Typedef Documentation

Superclass

typedef vtkObject vtkOpenGLRenderUtilities::Superclass

Definition at line 34 of file vtkOpenGLRenderUtilities.h.

Constructor & Destructor Documentation

vtkOpenGLRenderUtilities()

vtkOpenGLRenderUtilities::vtkOpenGLRenderUtilities ( )

protected

~vtkOpenGLRenderUtilities()

vtkOpenGLRenderUtilities::~vtkOpenGLRenderUtilities ( )

overrideprotected

Member Function Documentation

IsTypeOf()

static vtkTypeBool vtkOpenGLRenderUtilities::IsTypeOf ( const char *  type )

static

IsA()

virtual vtkTypeBool vtkOpenGLRenderUtilities::IsA ( const char *  name )

virtual

Return 1 if this class is the same type of (or a subclass of) the named class.

Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h.

Reimplemented from vtkObjectBase.

SafeDownCast()

static vtkOpenGLRenderUtilities * vtkOpenGLRenderUtilities::SafeDownCast ( vtkObjectBase *  o )

static

NewInstanceInternal()

virtual vtkObjectBase * vtkOpenGLRenderUtilities::NewInstanceInternal ( ) const

protectedvirtual

NewInstance()

vtkOpenGLRenderUtilities * vtkOpenGLRenderUtilities::NewInstance

(

)

const

PrintSelf()

void vtkOpenGLRenderUtilities::PrintSelf ( ostream &  os, vtkIndent  indent  )

overridevirtual

Methods invoked by print to print information about the object including superclasses.

Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.

Reimplemented from vtkObject.

RenderQuad()

static void vtkOpenGLRenderUtilities::RenderQuad ( float *  verts, float *  tcoords, vtkShaderProgram *  program, vtkOpenGLVertexArrayObject *  vao  )

static

Helper function that draws a quad on the screen at the specified vertex coordinates and if tcoords are not NULL with the specified texture coordinates.

RenderTriangles()

static void vtkOpenGLRenderUtilities::RenderTriangles ( float *  verts, unsigned int  numVerts, GLuint *  iboData, unsigned int  numIndices, float *  tcoords, vtkShaderProgram *  program, vtkOpenGLVertexArrayObject *  vao  )

static

Helper function that draws a quad on the screen at the specified vertex coordinates and if tcoords are not NULL with the specified texture coordinates.

GetFullScreenQuadVertexShader()

static std::string vtkOpenGLRenderUtilities::GetFullScreenQuadVertexShader ( )

static

Draw a full-screen quad:

• VertexShader and GeometryShader should be used as-is when building the ShaderProgram.
• FragmentShaderTemplate supports the replacements

  //VTK::FSQ::Decl 

  and

  //VTK::FSQ::Impl 

  for declaring variables and the shader body, respectively.
• The varying texCoord is available to the fragment shader for texture lookups into full-screen textures, ie. texture2D(textureName, texCoord).
• PrepFullScreenVAO initializes a new VAO for drawing a quad.
• DrawFullScreenQuad actually draws the quad.

Example usage:

typedef vtkOpenGLRenderUtilities GLUtil;
 
// Prep fragment shader source:
std::string fragShader = GLUtil::GetFullScreenQuadFragmentShaderTemplate();
vtkShaderProgram::Substitute(fragShader, "//VTK::FSQ::Decl",
"uniform sampler2D aTexture;");
vtkShaderProgram::Substitute(fragShader, "//VTK::FSQ::Impl",
"gl_FragData[0] = texture2D(aTexture, texCoord);");
 
// Create shader program:
vtkShaderProgram *prog = shaderCache->ReadyShaderProgram(
GLUtil::GetFullScreenQuadVertexShader().c_str(),
fragShader.c_str(),
GLUtil::GetFullScreenQuadGeometryShader().c_str());
 
// Initialize new VAO/vertex buffer. This is only done once:
vtkNew<vtkOpenGLVertexArrayObject> vao;
GLUtil::PrepFullScreenVAO(renWin, vao.Get(), prog);
 
// Setup shader program to sample vtkTextureObject aTexture:
aTexture->Activate();
prog->SetUniformi("aTexture", aTexture->GetTextureUnit());
 
// Render the full-screen quad:
vao->Bind();
GLUtil::DrawFullScreenQuad();
vao->Release();
aTexture->Deactivate();

GetFullScreenQuadFragmentShaderTemplate()

static std::string vtkOpenGLRenderUtilities::GetFullScreenQuadFragmentShaderTemplate ( )

static

Draw a full-screen quad:

• VertexShader and GeometryShader should be used as-is when building the ShaderProgram.
• FragmentShaderTemplate supports the replacements

  //VTK::FSQ::Decl 

  and

  //VTK::FSQ::Impl 

  for declaring variables and the shader body, respectively.
• The varying texCoord is available to the fragment shader for texture lookups into full-screen textures, ie. texture2D(textureName, texCoord).
• PrepFullScreenVAO initializes a new VAO for drawing a quad.
• DrawFullScreenQuad actually draws the quad.

Example usage:

typedef vtkOpenGLRenderUtilities GLUtil;
 
// Prep fragment shader source:
std::string fragShader = GLUtil::GetFullScreenQuadFragmentShaderTemplate();
vtkShaderProgram::Substitute(fragShader, "//VTK::FSQ::Decl",
"uniform sampler2D aTexture;");
vtkShaderProgram::Substitute(fragShader, "//VTK::FSQ::Impl",
"gl_FragData[0] = texture2D(aTexture, texCoord);");
 
// Create shader program:
vtkShaderProgram *prog = shaderCache->ReadyShaderProgram(
GLUtil::GetFullScreenQuadVertexShader().c_str(),
fragShader.c_str(),
GLUtil::GetFullScreenQuadGeometryShader().c_str());
 
// Initialize new VAO/vertex buffer. This is only done once:
vtkNew<vtkOpenGLVertexArrayObject> vao;
GLUtil::PrepFullScreenVAO(renWin, vao.Get(), prog);
 
// Setup shader program to sample vtkTextureObject aTexture:
aTexture->Activate();
prog->SetUniformi("aTexture", aTexture->GetTextureUnit());
 
// Render the full-screen quad:
vao->Bind();
GLUtil::DrawFullScreenQuad();
vao->Release();
aTexture->Deactivate();

GetFullScreenQuadGeometryShader()

static std::string vtkOpenGLRenderUtilities::GetFullScreenQuadGeometryShader ( )

static

Draw a full-screen quad:

• VertexShader and GeometryShader should be used as-is when building the ShaderProgram.
• FragmentShaderTemplate supports the replacements

  //VTK::FSQ::Decl 

  and

  //VTK::FSQ::Impl 

  for declaring variables and the shader body, respectively.
• The varying texCoord is available to the fragment shader for texture lookups into full-screen textures, ie. texture2D(textureName, texCoord).
• PrepFullScreenVAO initializes a new VAO for drawing a quad.
• DrawFullScreenQuad actually draws the quad.

Example usage:

typedef vtkOpenGLRenderUtilities GLUtil;
 
// Prep fragment shader source:
std::string fragShader = GLUtil::GetFullScreenQuadFragmentShaderTemplate();
vtkShaderProgram::Substitute(fragShader, "//VTK::FSQ::Decl",
"uniform sampler2D aTexture;");
vtkShaderProgram::Substitute(fragShader, "//VTK::FSQ::Impl",
"gl_FragData[0] = texture2D(aTexture, texCoord);");
 
// Create shader program:
vtkShaderProgram *prog = shaderCache->ReadyShaderProgram(
GLUtil::GetFullScreenQuadVertexShader().c_str(),
fragShader.c_str(),
GLUtil::GetFullScreenQuadGeometryShader().c_str());
 
// Initialize new VAO/vertex buffer. This is only done once:
vtkNew<vtkOpenGLVertexArrayObject> vao;
GLUtil::PrepFullScreenVAO(renWin, vao.Get(), prog);
 
// Setup shader program to sample vtkTextureObject aTexture:
aTexture->Activate();
prog->SetUniformi("aTexture", aTexture->GetTextureUnit());
 
// Render the full-screen quad:
vao->Bind();
GLUtil::DrawFullScreenQuad();
vao->Release();
aTexture->Deactivate();

PrepFullScreenVAO() [1/2]

static bool vtkOpenGLRenderUtilities::PrepFullScreenVAO ( vtkOpenGLRenderWindow *  renWin, vtkOpenGLVertexArrayObject *  vao, vtkShaderProgram *  prog  )

static

Draw a full-screen quad:

• VertexShader and GeometryShader should be used as-is when building the ShaderProgram.
• FragmentShaderTemplate supports the replacements

  //VTK::FSQ::Decl 

  and

  //VTK::FSQ::Impl 

  for declaring variables and the shader body, respectively.
• The varying texCoord is available to the fragment shader for texture lookups into full-screen textures, ie. texture2D(textureName, texCoord).
• PrepFullScreenVAO initializes a new VAO for drawing a quad.
• DrawFullScreenQuad actually draws the quad.

Example usage:

typedef vtkOpenGLRenderUtilities GLUtil;
 
// Prep fragment shader source:
std::string fragShader = GLUtil::GetFullScreenQuadFragmentShaderTemplate();
vtkShaderProgram::Substitute(fragShader, "//VTK::FSQ::Decl",
"uniform sampler2D aTexture;");
vtkShaderProgram::Substitute(fragShader, "//VTK::FSQ::Impl",
"gl_FragData[0] = texture2D(aTexture, texCoord);");
 
// Create shader program:
vtkShaderProgram *prog = shaderCache->ReadyShaderProgram(
GLUtil::GetFullScreenQuadVertexShader().c_str(),
fragShader.c_str(),
GLUtil::GetFullScreenQuadGeometryShader().c_str());
 
// Initialize new VAO/vertex buffer. This is only done once:
vtkNew<vtkOpenGLVertexArrayObject> vao;
GLUtil::PrepFullScreenVAO(renWin, vao.Get(), prog);
 
// Setup shader program to sample vtkTextureObject aTexture:
aTexture->Activate();
prog->SetUniformi("aTexture", aTexture->GetTextureUnit());
 
// Render the full-screen quad:
vao->Bind();
GLUtil::DrawFullScreenQuad();
vao->Release();
aTexture->Deactivate();

DrawFullScreenQuad()

static void vtkOpenGLRenderUtilities::DrawFullScreenQuad ( )

static

Draw a full-screen quad:

• VertexShader and GeometryShader should be used as-is when building the ShaderProgram.
• FragmentShaderTemplate supports the replacements

  //VTK::FSQ::Decl 

  and

  //VTK::FSQ::Impl 

  for declaring variables and the shader body, respectively.
• The varying texCoord is available to the fragment shader for texture lookups into full-screen textures, ie. texture2D(textureName, texCoord).
• PrepFullScreenVAO initializes a new VAO for drawing a quad.
• DrawFullScreenQuad actually draws the quad.

Example usage:

typedef vtkOpenGLRenderUtilities GLUtil;
 
// Prep fragment shader source:
std::string fragShader = GLUtil::GetFullScreenQuadFragmentShaderTemplate();
vtkShaderProgram::Substitute(fragShader, "//VTK::FSQ::Decl",
"uniform sampler2D aTexture;");
vtkShaderProgram::Substitute(fragShader, "//VTK::FSQ::Impl",
"gl_FragData[0] = texture2D(aTexture, texCoord);");
 
// Create shader program:
vtkShaderProgram *prog = shaderCache->ReadyShaderProgram(
GLUtil::GetFullScreenQuadVertexShader().c_str(),
fragShader.c_str(),
GLUtil::GetFullScreenQuadGeometryShader().c_str());
 
// Initialize new VAO/vertex buffer. This is only done once:
vtkNew<vtkOpenGLVertexArrayObject> vao;
GLUtil::PrepFullScreenVAO(renWin, vao.Get(), prog);
 
// Setup shader program to sample vtkTextureObject aTexture:
aTexture->Activate();
prog->SetUniformi("aTexture", aTexture->GetTextureUnit());
 
// Render the full-screen quad:
vao->Bind();
GLUtil::DrawFullScreenQuad();
vao->Release();
aTexture->Deactivate();

PrepFullScreenVAO() [2/2]

static bool vtkOpenGLRenderUtilities::PrepFullScreenVAO ( vtkOpenGLBufferObject *  vertBuf, vtkOpenGLVertexArrayObject *  vao, vtkShaderProgram *  prog  )

static

MarkDebugEvent()

static void vtkOpenGLRenderUtilities::MarkDebugEvent ( const std::string &  event )

static

Pass a debugging mark to the render engine to assist development via tools like apitrace.

This calls glDebugMessageInsert to insert the event string into the OpenGL command stream.

Note that this method only works when glDebugMessageInsert is bound, which it may not be on certain platforms.

---

The documentation for this class was generated from the following file:

• Rendering/OpenGL2/vtkOpenGLRenderUtilities.h