Classes

struct AccelState

Public Member Functions

CameraNavigator (const string &name, int, const RefPtr< VCreationPreferences > &VP)
override RefPtr< State > newState () const
create a new state object. Child classes might deliver child states.
override bool request (VRequest &R, double precision, const WeakVObjectPtr &ImmediateRequestor, const WeakVObjectPtr &RootRequestor)
Request an action, to be performed with a certain precision.
RefPtr< VScriptValue > setup (const RefPtr< VScriptParameters > &V, const RefPtr< ValuePool > &)
override bool update (VRequest &R, double precision)
Virtual update function that implements some heavy action on the object.
override const char *const * xpm_icon () const
If this object provides an icon in XPM source format, return it here.

Detailed Description

Implementation of a camera which interacts with the mouse.

It is a VEnvironmentRenderObject, i.e. its settings of the OpenGL state influences all consecutive layers.

Three functions need to be overloaded:

must_update() Determine when a mouse action is eligble to change the camera settings. Note that a mouse MOTION does not induce a new input, but a mouse CLICK does.
update() Change the camera settings on behalf of the input parameters.
environment_render() Translate the camera parameters into OpenGL.

A fourth function is optional:

request() This function is ALWAYS called, while update() is not. Thus, if in this function the camera object is touched, then it will always be new and update() is going to be called. This mechanism defines auto-update, i.e. an object which defines a loop.

Note that environment_render() may be called any time and more often than update(), in any case independently. It may even be called in a thread simulateneously, so it must be thread safe. In no case the render() function may change the object or static variables. All state variables that need to be transported from one render to the next call need to be placed in the local context state.

Member Function Documentation

bool CameraNavigator::request	(	VRequest &	request,
		double	precision,
		const WeakVObjectPtr &	ImmediateRequestor,
		const WeakVObjectPtr &	RootRequestor
	)		`[virtual]`

Request an action, to be performed with a certain precision.

Its main purpose is to iterate all parameters and forward the request to them. If this all parameters have fullfilled their request(), then the virtual update() function is called.

In rare case, an object might want to overload this function, for instance when request shall be forwarded to input objects only under certain circumstances (e.g. an Viewer object that is not visible at the moment).

Returns:: true if the object was changed

Exceptions:

VRequest::Incomplete might occur if a synchroneous request is issued but some operations are still in asynchroneous construction. This is the case when a synchroneous request is issued after an asynchroneous one that has not yet been completed. In such a case, the caller may just repeat the same request. The caller may and should do something else in the meantime, as the async request may still take a while to finish.

Note:: Requests are only processed if enableRequestProcessing() has been called for this object. By default, processing of requests is disabled to avoid requests() to be processed when an object is yet incomplete during construction which may happen in a multithreading environment. This flag must be set after an object is completely constructed.

Check the age of the local state

Some parameter has changed, so call object's update().

Reimplemented from Wizt::VObject.

bool CameraNavigator::update	(	VRequest &	,
		double	precision
	)		`[virtual]`

Virtual update function that implements some heavy action on the object.

Update function.

It is called only if any input object is newer than the current object. It must return true on successful completion. However, the object may touch() itself in the update() routine. Then, it will get a newer time than all input objects, which will trigger all dependent objects as well.

Returns:: Must return true to indicate that the object was successfully updated and may now get the age of the most recent parameter.

Reimplemented from Wizt::VObject.

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

ocean/vcamera/VCameraNavigator.hpp
ocean/vcamera/VCameraNavigator.cpp