Viewports¶
-
group
FnViewport
Typedefs
-
typedef FnPlatform::internal::SharedPtr<ViewportWrapper>::type
ViewportWrapperPtr
¶ Pointer to a wrapper of a Viewport.
-
class
ViewportPluginBase
¶ - #include <FnViewport.h>
Interface for the functionality of a single viewport.
A Viewport’s main responsibilities are to draw the contents of a single viewport widget and to handle the UI events of that widget. When the Qt GL Widget for the viewport is created an instance of the Viewport class is also instantiated and associated with it.
Several Viewports can share and access a single ViewerDelegate (see getViewerDelegate()). Some shared data structures can be owned by the ViewerDelegate, so it is convenient to build both plug-ins using the same compiler, so that the result of getViewerDelegate() can be cast into the known subclass of ViewerDelegate, which might contain specific methods and members that can be useful to the plug-in. If that is not possible, then the more generic getOption() / setOption() in both the Viewport and the ViewerDelegate can be used.
By default, the Katana UI will wait for an idle event, and then call the draw() function if the viewport has been marked as dirty via the setDirty() method. It is important to note that prior to draw(), resize() and setup() being called, the OpenGL context of the viewport widget will be made current. The makeGLContextCurrent() / doneGLContextCurrent() functions can also be used to force the GL context to be made current, but this should be used springly, as frequent GL context changes can lead to performance degradation. All of the viewport widgets hosted in a particular Viewer tab will attempt to share Open GL context data with each other. This allows viewports to share certain resources, such as Vertex Buffer Objects, but is subject to the usual limitations of context sharing, such as containers (Vertex Array Objects) not being shared. The default framebuffer in this context is the Qt widget’s framebuffer, so any drawing on it will end up being shown on the widget.
The Viewport can create and own several ViewportLayers. These are independent plug-ins that can potentially be reusable between different Viewports that are responsible for a specific set of drawing and/or event processing activities. The Viewport delegates the draw() function and the event() function on its layers. These layers are organized in a linear sequence, in which the draw(), event() and resize() member functions will be called starting in the layer with the lowest index and ending with the one with the highest index.
The Viewport class is also responsible for activating and deactivating Manipulators on a list of locations (see activateManipulator() and deactivateManipulator()). The compatibility of these Manipulators should be checked previously with the ViewerDelegate.getCompatibleManipulatorsInfo() function, to guarantee that they are compatible with the locations to be manipulated. A ManipulatorLayer can be used then to actually draw and process the events of these manipulators, but the Viewport is responsible for keeping track of which ones are currently activated (see the functions getNumberOfActiveManipulators() and getActiveManipulator()).
A Viewport also allows picking / selection of rendered objects in the scene inside a certain region of the viewport. This can be a deep picking (all objects inside the region, independently if they are occluded or not from the current camera point of view) or it can select only the visible objects. The Viewport provides an optional internal mechanism that makes use of an internal ID pass framebuffer. This can be used by implementing the pickerDraw() virtual function, calling addPickableObject() in it. If the rendering technology provides its own picking mechanism, it can be used by implementing the customPick() function, which will not make use of the internal ID picking, and pickerDraw() will not be called. This mechanism also is present in ViewportLayers.
This is a virtual base class to be extended in your plug-in. In addition to implementing all the pure virtual functions in this class, you must also implement this static method in your derived class:
// Returns a new instance of your derived class. static Viewport* create();
To indicate an error to the caller, your implementation may throw an exception derived from std::exception.
ViewerDelegate is the class that plugins should extend and implement.
ViewerDelegateWrapper is the class that allows other plugin types to access the ViewerDelegate plugin.
ViewerDelegatePluginBase is the base class that provides the common methods between ViewerDelegate and ViewerDelegateWrapper.
Subclassed by Foundry::Katana::ViewerAPI::Viewport, Foundry::Katana::ViewerAPI::ViewportWrapper
Public Functions
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ViewportPluginBase
()¶ Constructor.
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virtual
~ViewportPluginBase
()¶ Destructor.
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std::string
getName
()¶ Gets the Viewport name.
This function is exposed in the Viewport Python class.
- Return
- The name given to the Viewport when it was created.
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ViewerDelegateWrapperPtr
getViewerDelegate
()¶ Gets the ViewerDelegate of thie Viewport.
- Return
- The ViewerDelegate that serves this Viewport.
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unsigned int
getWidth
()¶ Gets the width in pixels of the Viewport.
- Return
- The width in pixels of 0 if the Viewport hasn’t been initialized.
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unsigned int
getHeight
()¶ Gets the Height in pixels of the Viewport.
- Return
- The height in pixels of 0 if the Viewport hasn’t been initialized.
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ViewportCameraWrapperPtr
getActiveCamera
()¶ Gets the ViewportCamera of the Viewport.
- Return
- The ViewportCamera for this Viewport.
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ViewportCameraWrapperPtr
addCamera
(const std::string &pluginName, const std::string &name)¶ Creates a new ViewportCamera of the passed type.
If a camera of the same name already exists, it will be deleted. If said camera was the active camera, the new camera will become the active camera.
- Return
- The newly created ViewportCamera.
- Parameters
pluginName
-The name of the ViewportCamera plugin.
name
-The name of the new ViewportCamera.
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ViewportCameraWrapperPtr
getCamera
(const std::string &name) const¶ Gets a ViewportCamera by name.
This function is exposed in the Viewport Python class.
- Return
- The ViewportCamera in this Viewport with the given name or 0 if no such layer exists.
- Parameters
name
-The name of the ViewportCamera.
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ViewportCameraWrapperPtr
getCamera
(unsigned int index) const¶ Gets a ViewportCamera by index.
This function is exposed in the Viewport Python class as Viewport.getCameraByIndex().
- Parameters
index
-The position in the list of ViewportLayers on this Viewport.
- Return
- The ViewportCamera in this Viewport with the given index or 0 if no such layer exists.
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void
removeCamera
(const std::string &name)¶ Removes a ViewportCamera by name.
This function is exposed in the Viewport Python class.
- Parameters
name
-The name of the ViewportCamera to be removed.
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void
removeCamera
(unsigned int index)¶ Removes a ViewportCamera by name.
This function is exposed in the Viewport Python class as Viewport.removeCameraByIndex().
- Parameters
index
-The position in the list of ViewportLayers on this Viewport
-
unsigned int
getNumberOfCameras
() const¶ Gets the number of ViewportCameras.
This function is exposed in the Viewport Python class.
- Return
- The number of ViewportCameras added to this Viewport.
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std::string
getCameraName
(unsigned int index)¶ Gets the name of the ViewportCamera on a given index.
- Return
- The name of the ViewportCamera on the given index or empty string if it doesn’t exist.
- Parameters
index
-The position in the list of ViewportLayers on this Viewport.
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std::string
getCameraName
(ViewportCameraWrapperPtr camera)¶ Gets the name of the given camera.
- Return
- The name of the given ViewportCamera or empty string if it doesn’t exist in the viewport.
- Parameters
camera
-ViewportCamera whose name is to be returned.
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int
getCameraIndex
(const std::string &name)¶ Gets the index of the ViewportCamera with a given name.
- Return
- The index of the ViewportCamera with the given name or -1 if it doesn’t exist.
- Parameters
name
-The name of the ViewportCamera.
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void
removeCamera
(ViewportCameraWrapperPtr camera)¶ Destorys the passed ViewportCamera.
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void
setActiveCamera
(ViewportCameraWrapperPtr camera)¶ Makes the passed ViewportCamera active.
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void
setViewFrozen
(bool isViewFrozen)¶ Freezes/thaws the viewport view.
When the view is frozen, viewers are not allowed to make changes in the active camera. However, this is only a soft condition that viewers might decide to ignore.
The viewer delegate will emit an event “__VIEWPORT_VIEW_FROZEN_STATE_CHANGED” containing the viewport’s name and the new state.
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bool
isViewFrozen
() const¶ Returns whether the viewport view is currently frozen.
When the view is frozen, viewers are not allowed to make changes in the active camera. However, this is only a soft condition that viewers might decide to ignore.
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const double *
getViewMatrix
()¶ Gets the View Matrix for this Viewport.
- Return
- The 4x4 Viewer Matrix represented by 16 doubles.
-
const double *
getProjectionMatrix
()¶ Gets the Projection Matrix for this Viewport.
- Return
- The 4x4 Projection Matrix represented by 16 doubles.
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Matrix44d
getProjectionMatrix44d
()¶ Gets the Projection Matrix for this camera.
- Return
- The 4x4 Projection Matrix.
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bool
isDirty
()¶ Returns whether the viewer state is dirty.
Returns whether the viewport state is dirty, if so it will be re-drawn.
This function is exposed in the Viewport Python class.
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void
setDirty
(bool dirty)¶ Sets the viewer state of the Viewport.
Sets whether the viewport state is dirty (due to something that happened that led to the need or re-drawing the scene).
This function is exposed in the Viewport Python class.
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ViewportLayerWrapperPtr
addLayer
(const std::string &pluginName, const std::string &name)¶ Adds a ViewportLayer.
Instantiates a ViewportLayer and adds it to the end of the list of layers on this Viewport.
- Return
- The newly created ViewportLayer.
- Parameters
pluginName
-The name of the ViewportLayer plugin.
name
-The name for the new ViewportLayer.
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ViewportLayerWrapperPtr
insertLayer
(const std::string &pluginName, const std::string &name, unsigned int index)¶ Inserts a ViewportLayer.
Instantiates a ViewportLayer and adds it a specified index on the list of layers on this Viewport.
This function is exposed in the Viewport Python class.
- Return
- The newly created ViewportLayer.
- Parameters
pluginName
-The name of the ViewportLayer plugin.
name
-The name for the new ViewportLayer.
index
-The index of the parameter
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ViewportLayerWrapperPtr
getLayer
(const std::string &name) const¶ Gets a ViewportLayer by name.
This function is exposed in the Viewport Python class.
- Return
- The ViewportLayer in this Viewport with the given name or 0 if no such layer exists.
- Parameters
name
-The name of the ViewportLayer.
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ViewportLayerWrapperPtr
getLayer
(unsigned int index) const¶ Gets a ViewportLayer by index.
This function is exposed in the Viewport Python class as Viewport.getLayerByIndex().
- Parameters
index
-The position in the list of ViewportLayers on this Viewport.
- Return
- The ViewportLayer in this Viewport with the given index or 0 if no such layer exists.
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void
removeLayer
(const std::string &name)¶ Removes a ViewportLayer by name.
This function is exposed in the Viewport Python class.
- Parameters
name
-The name of the ViewportLayer to be removed.
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void
removeLayer
(unsigned int index)¶ Removes a ViewportLayer by name.
This function is exposed in the Viewport Python class as Viewport.removeLayerByIndex().
- Parameters
index
-The position in the list of ViewportLayers on this Viewport
-
unsigned int
getNumberOfLayers
() const¶ Gets the number of ViewportLayers.
This function is exposed in the Viewport Python class.
- Return
- The number of ViewportLayers added to this Viewport.
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std::string
getLayerName
(unsigned int index)¶ Gets the name of the ViewportLayer on a given index.
- Return
- The name of the ViewportLayer on the given index or empty string if it doesn’t exist.
- Parameters
index
-The position in the list of ViewportLayers on this Viewport.
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int
getLayerIndex
(const std::string &name)¶ Gets the index of the ViewportLayer on a given name.
- Return
- The index of the ViewportLayer with the given name or -1 if it doesn’t exist.
- Parameters
name
-The name of the ViewportLayer.
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void
activateManipulator
(const std::string &pluginName, const std::vector<std::string> &locationPaths)¶ Activates a Manipulator on the Viewport.
Activates a Manipulator with the given plugin name for the specified locations. This will instantiate a Manipulator plugin on this Viewport that manipulates those locations. After this the manipulator will be ready to be drawn and interacted with, which can either be implemented directly on the Viewport or in a ViewportLayer dedicated to manipulators. Only one Manipulator instance of the given type can be active at once.
This function is exposed in the Viewport Python class.
- Parameters
pluginName
-The name of the Manipulator plugin.
locationPaths
-The locations to be manipulated.
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void
deactivateManipulator
(const std::string &pluginName)¶ Deactivates a Manipulator on the Viewport.
Deactivates a Manipulator with the given plugin name that has been previously activated in this Viewport.
This function is exposed in the Viewport Python class.
- Parameters
pluginName
-The name of the Manipulator plugin.
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void
deactivateAllManipulators
()¶ Deactivates all Manipulators on the Viewport.
This function is exposed in the Viewport Python class.
Deactivates all Manipulators that have been previously activated in this Viewport.
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unsigned int
getNumberOfActiveManipulators
()¶ Gets the number of active Manipulators on the Viewport.
This function is exposed in the Viewport Python class.
Deactivates all Manipulators that have been previously activated in this Viewport.
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ManipulatorWrapperPtr
getActiveManipulator
(unsigned int index)¶ Gets an active Manipulator by index.
Get the active Manipulator on the given index. Each active Manipulator has an associated index internally. The indices are always sequential, so this can be used to iterate through all the active Manipulators, using getNumberOfActiveManipulators() to know how many there are.
- Note
- An index might not refer to the same Manipulator on consecutive calls.
- Return
- The active Manipulator with the given index or 0 if no Manipulator has that index.
- Parameters
index
-The index of the Manipulator.
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ManipulatorWrapperPtr
getActiveManipulator
(const std::string &pluginName)¶ Gets an active Manipulator by plugin name.
- Return
- The active Manipulator with the given plugin name or 0 if there no active Manipulators with that pluginName.
- Parameters
pluginName
-The name of the Manipulator plugin.
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bool
makeGLContextCurrent
()¶ Makes the Viewport OpenGL context current.
- Return
- true if successful or false on failure.
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bool
doneGLContextCurrent
()¶ Makes the Viewport OpenGL context no longer current.
- Return
- true if successful or false on failure.
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bool
detectGLContext
()¶ Associates the current OpenGL context with the Viewport’s makeGLContextCurrent() function.
- Return
- true if successful or false on failure.
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bool
isGLContextCurrent
()¶ Determines if the Viewport’s OpenGL context is the current context.
- Return
- true if the Viewport’s OpenGL context is current; false otherwise.
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void
enableCap
(uint32_t cap)¶ Enables a server-side OpenGL capability.
- Note
- To temporarily change the OpenGL state, please use
GLStateRestore
. - Parameters
cap
-Specifies a symbolic constant indicating a OpenGL capability.
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void
disableCap
(uint32_t cap)¶ Disables a server-side OpenGL capability.
- Note
- To temporarily change the OpenGL state, please use
GLStateRestore
. - Parameters
cap
-Specifies a symbolic constant indicating a OpenGL capability.
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void
pick
(unsigned int x, unsigned int y, unsigned int w, unsigned int h, bool deepPicking, PickedAttrsMap &pickedAttrs, float *singlePointDepth = NULL)¶ Picks the objects that are inside a given viewport region.
Allows to query the scene for objects that are visible inside a given rectangular region in the viewport. This region can be a single pixel on the screen, by setting both its width and height to 1.
The object picking can optionally be deep, meaning that all the objects viewed inside the region will be picked even if they are currently occluded by other objects. A non-deep picking means that only currently visible objects inside the region will be picked.
Picking can be implemented in two ways:
- Using the internal ID framebuffer based technique implemented via
pickerDraw()
andaddPickableObject()
- Implementing a custom picking implemented using some third party technology via
customPick()
.
This function makes use of whatever picking technique is implemented in this Viewport.
This function returns a map of picking IDs to Attributes that represent the picked objects and, optionally a depth value for when the picked region is one single pixel. If
pickerDraw()
is used, as opposed tocustomPick()
, then the IDs are returned by theaddPickableObject()
calls insidepickerDraw()
and the Attributes are the ones passed to it. They can be used to identify what objects have been picked.- Parameters
x
-The region origin X component in viewport pixels.
y
-The region origin Y component in viewport pixels.
w
-The region width in viewport pixels.
h
-The region height in viewport pixels.
deepPicking
-Specifies if all objects inside the region, including occluded ones, will be picked. If set to false, only the visible objects should be picked.
pickedAttrs
-A map top be filled with
FnPickId
(key) toAttribute
(value) pairs that represent the picked objects. Internally, this will be either populated bycustomPick()
or byaddPickableObject()
calls insidepickerDraw()
.PickedAttrsMap
has the same public interface as:std::map<FnPickId, FnAttributes::Attribute>
.singlePointDepth
-The value pointed by this will be set with the GL depth of a single pixel when the region with and height are both 1 and this pointer is set to something other than NULL. This can be used to solve occlusion between picked objects from the Viewport and different ViewportLayers when, for example, the user clicks on a single pixel when selecting something.
- Using the internal ID framebuffer based technique implemented via
-
void
setPanAndZoomActive
(bool active)¶ Sets the pan and zoom active state.
-
bool
isPanAndZoomActive
()¶ Returns whether the pan and zoom is active.
-
-
class
Viewport
¶ - #include <FnViewport.h>
The Viewport class to be extended by plugins.
Inherits from Foundry::Katana::ViewerAPI::ViewportPluginBase
Public Functions
-
Viewport
()¶ Constructor.
-
virtual
~Viewport
()¶ Destructor.
-
virtual void
setup
() = 0¶ Initializes the GL components of the Viewport.
Called when a Viewport is created. It runs inside the correct GL context. Can be used to initialize anything GL related. For example, in the case of an OpenGL renderer this function should set up any required OpenGL context rendering flags, defining display lists, etc.
This function is exposed in the Viewport Python class.
-
virtual void
cleanup
() = 0¶ Cleans up the Viewport resources.
Called when a Viewport is removed by the ViewerDelegate.
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virtual bool
event
(const FnEventWrapper &eventData)¶ Processes UI events.
Called whenever a user interaction event occurs. This will be also propagated through the ViewerLayers of this Viewport.
This function is exposed in the Viewport Python class.
- Return
- true if the event has been handled, false otherwise.
- Parameters
eventData
-The event data (see FnEventWrapper).
-
virtual void
draw
()¶ Draws the scene.
Called when the scene needs to be drawn in the correct GL context. In a non-GL renderer the generated image should be drawn in the GL framebuffer in order to be displayed. This will be also propagated through the ViewerLayers of this Viewport.
This function is exposed in the Viewport Python class.
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virtual void
resize
(unsigned int width, unsigned int height)¶ Processes Viewport resizing.
Called when the Viewport widget is resized. This can be extended by sub-clases to accomodate viewport size changes in the renderer.
This function is exposed in the Viewport Python class.
- Parameters
width
-The viewport width in pixels.
height
-The viewport height in pixels.
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virtual void
hover
(bool isHovering, int x, int y)¶ Called when the mouse hovers the Viewport.
The Viewport can detect when the mouse is hovering it so that, for example, objects under the mouse pointer can be highlighted. This is called with the correct GL context so that GL based picking can be executed.
This function is exposed in the Viewport Python class.
- Parameters
isHovering
-Flag that specifies if the mouse is hovering the viewport. If false, then the mouse left the viewport. In this case x and y should be ignored.
x
-The horizontal pixel coordinate of the mouse pointer in the Viewport’s local coordinate system.
y
-The vertical pixel coordinate of the mouse pointer in the Viewport’s local coordinate system.
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virtual void
setOption
(OptionIdGenerator::value_type optionId, FnAttribute::Attribute attr)¶ Sets a generic option.
Optional. Reacts to a generic option being set from Python or called directly by other C++ Viewer plugin classes. This can be used as a message passing mechanism from the outside into the Viewport.
This function is exposed in the Viewport Python class.
- Parameters
optionId
-The ID of the option created from OptionIdGenerator or manually defined by users.
attr
-Attribute with the value being set.
-
virtual FnAttribute::Attribute
getOption
(OptionIdGenerator::value_type optionId)¶ Gets the value of a generic option.
Optional. Returns the value of a generic option being requested from Python or from other C++ Viewer plugin classes.
This function is exposed in the Viewport Python class.
- Return
- Attribute with the value of the option.
- Parameters
optionId
-The ID of the option created from OptionIdGenerator or manually defined by users.
-
void
setOption
(const std::string &name, FnAttribute::Attribute attr)¶ Sets a generic option by generating an option ID from the passed name.
This generates an Option ID from the passed string and passes it to setOption(OptionIdGenerator::value_type optionId, FnAttribute::Attribute attr). Since the ID is generated on every call, it is more efficient to generate the ID once, and store it for future use.
- Parameters
name
-The name of the option whose value to set.
attr
-Attribute with the value to set for the option.
-
FnAttribute::Attribute
getOption
(const std::string &name)¶ Gets a generic option by generating an option ID from the passed name.
This generates an Option ID from the passed string and passes it to getOption(OptionIdGenerator::value_type optionId). Since the ID is generated on every call, it is more efficient to generate the ID once, and store it for future use.
- Return
- The value of the option with the given name.
- Parameters
name
-The name of the option whose value to retrieve.
-
virtual void
freeze
() = 0¶ Freezes the Viewport when the Viewer is hidden.
Allows the Viewport to freeze its activities when the Viewer is not visible. This allows the ViewerDelegate to stop any kind of unecessary processing that might happen durging that time.
This function is exposed in the Viewport Python class.
-
virtual void
thaw
() = 0¶ Thaws the Viewport when the Viewer is shown.
Allows the Viewport to restart its activities when the Viewer becomes visible. This restarts the activities paused by freeze().
This function is exposed in the Viewport Python class.
-
virtual void *
getPrivateData
(void *inputData)¶ Returns some arbitrary data.
This can be used by other plugins to access some data that is specific to this object after it is compiled, allowing built-in parts of existing Viewers to be extendable by other plugins like ViewerDelegateComponents, Viewports and ViewportLayers.
This function should be called by other plugins after getting a ManipulatorWrapperPtr and converting it into a concrete instance via ManipulatorWrapper::getPluginInstance(). These other plugins will have to be built with the same compiler and using the same compiler flags as the ViewerDelegate so that this data can be cast and used without running into C++ name mangling issues.
- Return
- The arbitrary private data. A void pointer that can be cast into specific object types by other plugins.
- Parameters
inputData
-A pointer to some input data that can be used to produce the returned data.
-
virtual void
pickerDraw
(unsigned int x, unsigned int y, unsigned int w, unsigned int h, const PickedAttrsMap &ignoreAttrs)¶ Draws an ID pass to be used by the optional internal picking.
This allows this Viewport to make use of the internal ID framebuffer pass technique provided to the Viewport and ViewportLayers. This function should draw all the pickable objects into the current GL framebuffer using an ID color. Inside this function each pickable object has to be registered using
addPickableObject()
, which will return a FnPickId. This id can be converted into a color usingpickIdToColor()
(see FnPickingTypes.h), the objects should be rendered without any kind of antialiasing and with that flat color, so that they cover their pickable pixels.This will be called by Katana if customPick() returns false or if it is not implemented.
This function receives a list of Attributes that refer to pickable objects to be ignored in this render. This is internally used to do a multi-pass id render for deep picking, in which an onion peeling technique is used to detect all the occluded objects. On each iteration this function should not render the objects that were detected in previous iterations. These Attributes correspond to the ones passed previously to
addPickableObject()
.- Parameters
x
-The region origin X component in viewport pixels.
y
-The region origin Y component in viewport pixels.
w
-The region width in viewport pixels.
h
-The region height in viewport pixels.
ignoreAttrs
-Contains information about the objects that should not be rendered here.
PickedAttrsMap
has the same public interface asstd::map<FnPickId, FnAttributes::Attribute>
.
-
virtual bool
customPick
(unsigned int x, unsigned int y, unsigned int w, unsigned int h, bool deepPicking, PickedAttrsMap &pickedAttrs, float *singlePointDepth = NULL)¶ Overrides the internal ID picking using a third party technique.
If the technology used in the Viewport implements its own picking, or if a GL ID pass is not feasible, then this function allows to override the internal ID picking and to implement the picking of what is present in the scene. If this is implemented and returns true, then
pickerDraw()
will never be called by Katana. This is called internally bypick()
, which will return the returned values of this function.An example of the use of this function is when using a non-realtime renderer that is able to produce its own ID pass or when the renderer data structures allows to query the geometry present inside the frustrum defined by the picking area.
There is no need to call
addPickableObject()
inside this function.This should return a map of
FnPickId
to Attributes, similar to the one returned bypickerDraw()
, which can identify or contain information about each picked objects. TheThis can optionally return a depth value for when the picked region is one single pixel.
- Parameters
x
-The region origin X component in viewport pixels.
y
-The region origin Y component in viewport pixels.
w
-The region width in viewport pixels.
h
-The region height in viewport pixels.
deepPicking
-Specifies if all objects inside the region, including occluded ones, will be picked. If set to false, only the visible objects should be picked.
pickedAttrs
-A map top be filled with
FnPickId
(key) toAttribute
(value) pairs that represent the picked objects. Internally, this will be either populated bycustomPick()
or byaddPickableObject()
calls insidepickerDraw()
.PickedAttrsMap
has the same public interface as:std::map<FnPickId, FnAttributes::Attribute>
.singlePointDepth
-The value pointed by this will be set with the GL depth of a single pixel when the region with and height are both 1 and this pointer is set to something other than NULL. This can be used to solve occlusion between picked objects from the Viewport and different ViewportLayers when, for example, the user clicks on a single pixel when selecting something.
-
FnPickId
addPickableObject
(FnAttribute::Attribute attr)¶ Registers a pickable object during
pickerDraw()
.This should be called inside
pickerDraw()
in order to let the internal ID picking system know about each pickable object.The ID returned by this function can be used to both identify an object in some data structure implemented inside this plugin and to define the color to be used by the object when rendering itself in the current ID framebuffer in
pickerDraw()
, via thepickIdToColor()
function (see FnPickingTypes.h). Also see FnGLShaderProgram.h, which implements a way of loading GLSL shaders.The Attribute passed to this function can contain further information about the pickable object. For some generic cases there will be Attribute conventions that prescribe how this Attribute should be structured in order to be recognized as some typical objects. This allows some out-of-the-box or third party plugins, like other ViewportLayer plugins, to identify objects like, for example, a location:
- A location should be identified using a GroupAttribute containing at least a child StringAttribute named “location” and with a single value containing the full location path. This will be recognized by the ViewportLayer plugin “SelectionLayer” shipped with Katana, which is responsible for dealing with locations selection in the Viewer.
Any kind of rendered object, other than locations, can be pickable. For example, a handle of some overlay widget that can be manipulated using the mouse. For this, each Viewport will make use of some Attribute convention that is suitable to identify its own pickable objects.
The
pick()
function will return theFnPickID
/Attribute
pairs of all picked objects inside its region.- Return
- A picking ID assigned to the pickable object.
- Parameters
attr
-The Attribute that describes the pickable object.
Public Static Functions
-
static void
flush
()¶ Flush plugin Caches.
Allows to discard any cache for this plugin when a Flush Caches event occurs.
-
-
class
ViewportWrapper
¶ - #include <FnViewport.h>
The Viewport class accessed by other plugins.
Inherits from Foundry::Katana::ViewerAPI::ViewportPluginBase
Public Functions
-
ViewportWrapper
(FnPluginHost *host, FnViewportHostHandle hostHandle, FnViewportPluginHandle pluginHandle, FnViewportPluginSuite_v2 *pluginSuite)¶
-
~ViewportWrapper
()¶
- template <class T>
-
T *
getPluginInstance
()¶ Gets a pointer to the real plugin instance.
WARNING: This function purposely breaks the compiler agnostic pattern of the Katana plugin API, so it needs to be used with care. This performs a dynamic cast to the real type so the implications of what that means in different circumstances should be understood. If the caller and plugin instance are not contained in the same shared library the RTTI check may fail.
This function allows a plugin wrapper to return the actual plugin class. The plugin is returned as a pointer to a child class of Viewport that is a registerd plugin. The type of that child class needs to be specified in the template, so that it can be properly cast. If the specified type doesn’t match the plugin type then NULL is returned.
-
bool
event
(const FnEventWrapper &eventData)¶ Processes UI events.
- Return
- true if the event has been handled, false if not.
-
void
setOption
(OptionIdGenerator::value_type optionId, FnAttribute::Attribute attr)¶ Sets a Viewport option.
-
FnAttribute::Attribute
getOption
(OptionIdGenerator::value_type optionId)¶ Gets a Viewport option.
-
-
typedef FnPlatform::internal::SharedPtr<ViewportWrapper>::type