Unigine::LandscapeFetch Class
| Header: | #include <UnigineObjects.h> |
This class is used to fetch data of the Landscape Terrain Object at a certain point (e.g. a height request) or check for an intersection with a traced line. The following performance optimizations are available:
- For each request you can engage or disengage certain data types (albedo, heights, masks, etc.). When the data type is engaged, you can obtain information via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).
- Both fetch and intersection requests can be performed asynchronously when an instant result is not required.
The workflow is as follows:
- Create a new LandscapeFetch object instance.
- Set necessary parameters (e.g. which data layers are to be used, whether to enable holes or not, etc.).
- To get terrain data for a certain point call the fetchForce() method providing coordinates for the desired point.NoticeYou can also fetch terrain data asynchronously via the fetchAsync() method.
- To find an intersection of a traced line with the terrain call either the intersectionForce() method or the intersectionAsync() method, if you want to perform an asynchronous request.
Usage Example#
Source code (C++)
// creating a fetch object and setting necessary parameters
LandscapeFetchPtr landscape_fetch = LandscapeFetch::create();
landscape_fetch->setUses(0);
landscape_fetch->setUsesHeight(true);
landscape_fetch->setHolesEnabled(true);
// ...
// getting terrain data for a point at (100, 100) and printing the height value
landscape_fetch->setFetchPosition(Vec2(100, 100));
if (landscape_fetch->fetchForce())
Log::message("Terrain height at the specified point is: %f", Scalar(landscape_fetch->getHeight()));Asynchronous Operations Example#
Source code (C++)
// creating a fetch object and setting necessary parameters
LandscapeFetchPtr landscape_fetch = LandscapeFetch::create();
landscape_fetch->setUses(0);
landscape_fetch->setUsesHeight(true);
landscape_fetch->setHolesEnabled(true);
// ...
// making an asynchronous fetch request for a point at (2.05, 2.05)
landscape_fetch->setFetchPosition(Vec2(2.05f, 2.05f));
landscape_fetch->fetchAsync();
// ...
// checking if our asynchronous fetch request is completed and printing the height value
if (landscape_fetch->isAsyncCompleted()) {
Log::message("Terrain height at the specified point is: %f", Scalar(landscape_fetch->getHeight()));
}LandscapeFetch Class
Members
Math::Vec3 getPosition() const#
Returns the current coordinates of the fetch/intersection point.
Return value
Current fetch/intersection point coordinates as a three-component vector.float getHeight() const#
Returns the current height value at the point.
Return value
Current height value at the point.Math::vec3 getNormal() const#
Returns the current normal vector coordinates at the point.
Notice
To get valid normal information via this method, engage normal data for the fetch/intersection request.
Return value
Current normal vector coordinates at the point.Math::vec4 getAlbedo() const#
Returns the current albedo color information at the point.
Notice
To get valid albedo color information via this method, engage albedo data for the fetch/intersection request.
Return value
Current albedo color at the point as a 4 component vector (R, G, B, A).bool isIntersection() const#
Returns the current value indicating if an intersection was detected.
Return value
true if an intersection was detected; otherwise false.void setUses ( int uses ) #
Sets a new flags engaging/disengaging certain data types for the fetch/intersection request.
Arguments
- int uses - The combination of data engagement flags.
int getUses() const#
Returns the current flags engaging/disengaging certain data types for the fetch/intersection request.
Return value
Current combination of data engagement flags.void setUsesHeight ( bool height ) #
Sets a new value indicating if heights data is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point). This option is enabled by default.
Arguments
- bool height - Set true to enable engagement of height data in the fetch/intersection request; false - to disable it.
bool isUsesHeight() const#
Returns the current value indicating if heights data is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point). This option is enabled by default.
Return value
true if engagement of height data in the fetch/intersection request is enabled; otherwise false.void setUsesNormal ( bool normal ) #
Sets a new value indicating if normals data is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).
Notice
Enable this option to get normal information for the point.
Arguments
- bool normal - Set true to enable engagement of normals data in the fetch/intersection request; false - to disable it.
bool isUsesNormal() const#
Returns the current value indicating if normals data is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).
Notice
Enable this option to get normal information for the point.
Return value
true if engagement of normals data in the fetch/intersection request is enabled; otherwise false.void setUsesAlbedo ( bool albedo ) #
Sets a new value indicating if albedo data is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).
Notice
Enable this option to get albedo information for the point.
Arguments
- bool albedo - Set true to enable engagement of albedo data in the fetch/intersection request; false - to disable it.
bool isUsesAlbedo() const#
Returns the current value indicating if albedo data is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).
Notice
Enable this option to get albedo information for the point.
Return value
true if engagement of albedo data in the fetch/intersection request is enabled; otherwise false.void setIntersectionPrecision ( float precision ) #
Sets a new precision value used for intersection detection requested by intersectionForce() and intersectionAsync() methods.
Arguments
- float precision - The precision for intersection detection as a fraction of maximum precision in the [0; 1] range. The default value is 0.5f. Maximum precision is determined by the Engine on the basis of the data of your Landscape Terrain.
float getIntersectionPrecision() const#
Returns the current precision value used for intersection detection requested by intersectionForce() and intersectionAsync() methods.
Return value
Current precision for intersection detection as a fraction of maximum precision in the [0; 1] range. The default value is 0.5f. Maximum precision is determined by the Engine on the basis of the data of your Landscape Terrain.void setIntersectionPositionBegin ( const Math::Vec3& begin ) #
Sets a new coordinates of the starting point for intersection detection.
Arguments
- const Math::Vec3& begin - The three-component vector specifying starting point coordinates along X, Y, and Z axes.
Math::Vec3 getIntersectionPositionBegin() const#
Returns the current coordinates of the starting point for intersection detection.
Return value
Current three-component vector specifying starting point coordinates along X, Y, and Z axes.void setIntersectionPositionEnd ( const Math::Vec3& end ) #
Sets a new coordinates of the end point for intersection detection.
Arguments
- const Math::Vec3& end - The three-component vector specifying end point coordinates along X, Y, and Z axes.
Math::Vec3 getIntersectionPositionEnd() const#
Returns the current coordinates of the end point for intersection detection.
Return value
Current three-component vector specifying end point coordinates along X, Y, and Z axes.void setFetchPosition ( const Math::Vec2& position ) #
Sets a new point for which terrain data is to be fetched.
Arguments
- const Math::Vec2& position - The two-component vector specifying point coordinates along X and Y axes.
Math::Vec2 getFetchPosition() const#
Returns the current point for which terrain data is to be fetched.
Return value
Current two-component vector specifying point coordinates along X and Y axes.bool isAsyncCompleted() const#
Returns the current value indicating if async operation is completed. As the operation is completed you can obtain necessary data via get*() methods.
Return value
true if async operation is completed; otherwise false.void setHolesEnabled ( bool enabled ) #
Sets a new value indicating if checking for terrain holes in the fetch/intersection request is enabled. This option is enabled by default. When disabled terrain holes created using decals are ignored.
Arguments
- bool enabled - Set true to enable checking for terrain holes in the fetch/intersection request; false - to disable it.
bool isHolesEnabled() const#
Returns the current value indicating if checking for terrain holes in the fetch/intersection request is enabled. This option is enabled by default. When disabled terrain holes created using decals are ignored.
Return value
true if checking for terrain holes in the fetch/intersection request is enabled; otherwise false.Event<> getEventEnd() const#
Event triggered on fetch completion. You can subscribe to events via
connect()
and unsubscribe via
disconnect(). You can also use
EventConnection
and
EventConnections
classes for convenience (see examples below).
The event handler signature is as follows: myhandler(Notice
For more details see the Event Handling article.
Usage Example
Source code (C++)
// implement the End event handler
void end_event_handler()
{
Log::message("\Handling End event\n");
}
//////////////////////////////////////////////////////////////////////////////
// 1. Multiple subscriptions can be linked to an instance of the EventConnections
// class that you can use later to remove all these subscriptions at once
//////////////////////////////////////////////////////////////////////////////
// create an instance of the EventConnections class
EventConnections end_event_connections;
// link to this instance when subscribing to an event (subscription to various events can be linked)
publisher->getEventEnd().connect(end_event_connections, end_event_handler);
// other subscriptions are also linked to this EventConnections instance
// (e.g. you can subscribe using lambdas)
publisher->getEventEnd().connect(end_event_connections, []() {
Log::message("\Handling End event (lambda).\n");
}
);
// ...
// later all of these linked subscriptions can be removed with a single line
end_event_connections.disconnectAll();
//////////////////////////////////////////////////////////////////////////////
// 2. You can subscribe and unsubscribe via an instance of the EventConnection
// class. And toggle this particular connection off and on, when necessary.
//////////////////////////////////////////////////////////////////////////////
// create an instance of the EventConnection class
EventConnection end_event_connection;
// subscribe to the End event with a handler function keeping the connection
publisher->getEventEnd().connect(end_event_connection, end_event_handler);
// ...
// you can temporarily disable a particular event connection to perform certain actions
end_event_connection.setEnabled(false);
// ... actions to be performed
// and enable it back when necessary
end_event_connection.setEnabled(true);
// ...
// remove subscription to the End event via the connection
end_event_connection.disconnect();
//////////////////////////////////////////////////////////////////////////////
// 3. You can add EventConnection/EventConnections instance as a member of the
// class that handles the event. In this case all linked subscriptions will be
// automatically removed when class destructor is called
//////////////////////////////////////////////////////////////////////////////
// Class handling the event
class SomeClass
{
public:
// instance of the EventConnections class as a class member
EventConnections e_connections;
// A End event handler implemented as a class member
void event_handler()
{
Log::message("\Handling End event\n");
// ...
}
};
SomeClass *sc = new SomeClass();
// ...
// specify a class instance in case a handler method belongs to some class
publisher->getEventEnd().connect(sc->e_connections, sc, &SomeClass::event_handler);
// ...
// handler class instance is deleted with all its subscriptions removed automatically
delete sc;
//////////////////////////////////////////////////////////////////////////////
// 4. You can subscribe and unsubscribe via the handler function directly
//////////////////////////////////////////////////////////////////////////////
// subscribe to the End event with a handler function
publisher->getEventEnd().connect(end_event_handler);
// remove subscription to the End event later by the handler function
publisher->getEventEnd().disconnect(end_event_handler);
//////////////////////////////////////////////////////////////////////////////
// 5. Subscribe to an event saving an ID and unsubscribe later by this ID
//////////////////////////////////////////////////////////////////////////////
// define a connection ID to be used to unsubscribe later
EventConnectionId end_handler_id;
// subscribe to the End event with a lambda handler function and keeping connection ID
end_handler_id = publisher->getEventEnd().connect([]() {
Log::message("\Handling End event (lambda).\n");
}
);
// remove the subscription later using the ID
publisher->getEventEnd().disconnect(end_handler_id);
//////////////////////////////////////////////////////////////////////////////
// 6. Ignoring all End events when necessary
//////////////////////////////////////////////////////////////////////////////
// you can temporarily disable the event to perform certain actions without triggering it
publisher->getEventEnd().setEnabled(false);
// ... actions to be performed
// and enable it back when necessary
publisher->getEventEnd().setEnabled(true);Return value
Event reference.Event<> getEventStart() const#
Event triggered at the beginning of the fetch process. You can subscribe to events via
connect()
and unsubscribe via
disconnect(). You can also use
EventConnection
and
EventConnections
classes for convenience (see examples below).
The event handler signature is as follows: myhandler(Notice
For more details see the Event Handling article.
Usage Example
Source code (C++)
// implement the Start event handler
void start_event_handler()
{
Log::message("\Handling Start event\n");
}
//////////////////////////////////////////////////////////////////////////////
// 1. Multiple subscriptions can be linked to an instance of the EventConnections
// class that you can use later to remove all these subscriptions at once
//////////////////////////////////////////////////////////////////////////////
// create an instance of the EventConnections class
EventConnections start_event_connections;
// link to this instance when subscribing to an event (subscription to various events can be linked)
publisher->getEventStart().connect(start_event_connections, start_event_handler);
// other subscriptions are also linked to this EventConnections instance
// (e.g. you can subscribe using lambdas)
publisher->getEventStart().connect(start_event_connections, []() {
Log::message("\Handling Start event (lambda).\n");
}
);
// ...
// later all of these linked subscriptions can be removed with a single line
start_event_connections.disconnectAll();
//////////////////////////////////////////////////////////////////////////////
// 2. You can subscribe and unsubscribe via an instance of the EventConnection
// class. And toggle this particular connection off and on, when necessary.
//////////////////////////////////////////////////////////////////////////////
// create an instance of the EventConnection class
EventConnection start_event_connection;
// subscribe to the Start event with a handler function keeping the connection
publisher->getEventStart().connect(start_event_connection, start_event_handler);
// ...
// you can temporarily disable a particular event connection to perform certain actions
start_event_connection.setEnabled(false);
// ... actions to be performed
// and enable it back when necessary
start_event_connection.setEnabled(true);
// ...
// remove subscription to the Start event via the connection
start_event_connection.disconnect();
//////////////////////////////////////////////////////////////////////////////
// 3. You can add EventConnection/EventConnections instance as a member of the
// class that handles the event. In this case all linked subscriptions will be
// automatically removed when class destructor is called
//////////////////////////////////////////////////////////////////////////////
// Class handling the event
class SomeClass
{
public:
// instance of the EventConnections class as a class member
EventConnections e_connections;
// A Start event handler implemented as a class member
void event_handler()
{
Log::message("\Handling Start event\n");
// ...
}
};
SomeClass *sc = new SomeClass();
// ...
// specify a class instance in case a handler method belongs to some class
publisher->getEventStart().connect(sc->e_connections, sc, &SomeClass::event_handler);
// ...
// handler class instance is deleted with all its subscriptions removed automatically
delete sc;
//////////////////////////////////////////////////////////////////////////////
// 4. You can subscribe and unsubscribe via the handler function directly
//////////////////////////////////////////////////////////////////////////////
// subscribe to the Start event with a handler function
publisher->getEventStart().connect(start_event_handler);
// remove subscription to the Start event later by the handler function
publisher->getEventStart().disconnect(start_event_handler);
//////////////////////////////////////////////////////////////////////////////
// 5. Subscribe to an event saving an ID and unsubscribe later by this ID
//////////////////////////////////////////////////////////////////////////////
// define a connection ID to be used to unsubscribe later
EventConnectionId start_handler_id;
// subscribe to the Start event with a lambda handler function and keeping connection ID
start_handler_id = publisher->getEventStart().connect([]() {
Log::message("\Handling Start event (lambda).\n");
}
);
// remove the subscription later using the ID
publisher->getEventStart().disconnect(start_handler_id);
//////////////////////////////////////////////////////////////////////////////
// 6. Ignoring all Start events when necessary
//////////////////////////////////////////////////////////////////////////////
// you can temporarily disable the event to perform certain actions without triggering it
publisher->getEventStart().setEnabled(false);
// ... actions to be performed
// and enable it back when necessary
publisher->getEventStart().setEnabled(true);Return value
Event reference.static LandscapeFetchPtr create ( ) #
The LandscapeFetch constructor.float getMask ( int num ) const#
Returns information stored for the point in the detail mask with the specified number.Notice
To get valid detail mask information via this method, engage mask data for the fetch/intersection request.
Arguments
- int num - Number of the detail mask in the [0; 19] range.
Return value
Value for the point stored in the detail mask with the specified number.void setUsesMask ( int num, bool value ) #
Sets a value indicating if data of the specified detail mask is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).Notice
Enable this option to get detail mask data for the point.
Arguments
- int num - Detail mask number in the [0; 19] range.
- bool value - true to engage data of the specified detail mask in the fetch/intersection request, false - to disengage.
bool isUsesMask ( int num ) const#
Returns a value indicating if data of the specified detail mask is engaged in the fetch/intersection request. When the data type is engaged, you can obtain it via the corresponding get() method. Disengaging unnecessary data when performing requests saves some performance (e.g., you can engage albedo data only if you need only color information at a certain point).Notice
Enable this option to get detail mask data for the point.
Arguments
- int num - Detail mask number in the [0; 19] range.
Return value
true if data of the specified detail mask is engaged in the fetch/intersection request; otherwise, false.bool fetchForce ( ) #
Fetches terrain data in forced mode for the point specified by the setFetchPosition(). You can use the fetchAsync() method to reduce load, when an instant result is not required.Return value
true if terrain data was successfully obtained for the specified point; otherwise, false.bool fetchForce ( const Math::Vec2 & position ) #
Fetches terrain data in forced mode for the specified point. You can use the fetchAsync() method to reduce load, when an instant result is not required.Arguments
- const Math::Vec2 & position - Coordinates of the point.
Return value
true if terrain data was successfully obtained for the specified point; otherwise, false.bool intersectionForce ( ) #
Performs tracing along the line from the p0 point specified by the setIntersectionPositionBegin() to the p1 point specified by the setIntersectionPositionEnd() to find an intersection with the terrain in forced mode. You can use the intersectionAsync() method to reduce load, when an instant result is not required.Return value
true if an intersection with the terrain was found; otherwise, false.bool intersectionForce ( const Math::Vec3 & p0, const Math::Vec3 & p1 ) #
Performs tracing along the line from the p0 point to the p1 point to find an intersection with the terrain in forced mode. You can use the intersectionAsync() method to reduce load, when an instant result is not required.Arguments
- const Math::Vec3 & p0 - Coordinates of the p0 point.
- const Math::Vec3 & p1 - Coordinates of the p1 point.
Return value
true if an intersection with the terrain was found; otherwise, false.void fetchAsync ( bool critical = false ) #
Fetches terrain data for the point specified by the setFetchPosition() in asynchronous mode (the corresponding task shall be put to the queue, to wait until the result is obtained use the wait() method). For an instant result use the fetchForce() method.Arguments
- bool critical - true to set high priority for the fetch task, false - to set normal priority.
void fetchAsync ( const Math::Vec2 & position, bool critical = false ) #
Fetches terrain data for the specified point in asynchronous mode (the corresponding task shall be put to the queue, to wait until the result is obtained use the wait() method). For an instant result use the fetchForce() method.Arguments
- const Math::Vec2 & position - Coordinates of the point.
- bool critical - true to set high priority for the fetch task, false - to set normal priority.
void intersectionAsync ( bool critical = false ) #
Performs tracing along the line from the p0 point specified by the setIntersectionPositionBegin() to the p1 point specified by the setIntersectionPositionEnd() to find an intersection with the terrain in asynchronous mode (the corresponding task shall be put to the queue, to wait until the result is obtained use the wait() method). For an instant result use the intersectionForce() method.Arguments
- bool critical - true to set high priority for the intersection task, false - to set normal priority.
void intersectionAsync ( const Math::Vec3 & p0, const Math::Vec3 & p1, bool critical = false ) #
Performs tracing along the line from the p0 point to the p1 point to find an intersection with the terrain in asynchronous mode (the corresponding task shall be put to the queue, to wait until the result is obtained use the wait() method). For an instant result use the intersectionForce() method.Arguments
- const Math::Vec3 & p0 - Coordinates of the p0 point.
- const Math::Vec3 & p1 - Coordinates of the p1 point.
- bool critical - true to set high priority for the intersection task, false - to set normal priority.
void fetchForce ( const Vector<Ptr<LandscapeFetch>> & fetches ) #
Fetches (batch) terrain data in forced mode for the point specified by the setFetchPosition(). You can use the fetchAsync() method to reduce load, when an instant result is not required.Arguments
void intersectionForce ( const Vector<Ptr<LandscapeFetch>> & fetches ) #
Performs tracing (batch) along the line from the p0 point specified by the setIntersectionPositionBegin() to the p1 point specified by the setIntersectionPositionEnd() to find an intersection with the terrain in forced mode. You can use the intersectionAsync() method to reduce load, when an instant result is not required.Arguments
void fetchAsync ( const Vector<Ptr<LandscapeFetch>> & fetches, bool critical = false ) #
Fetches (batch) terrain data for the point specified by the setFetchPosition() in asynchronous mode (the corresponding task shall be put to the queue, to wait until the result is obtained use the wait() method). For an instant result use the fetchForce() method.Arguments
- const Vector<Ptr<LandscapeFetch>> & fetches - List of fetch requests to be completed.
- bool critical - true to set high priority for the fetch task, false - to set normal priority.
void intersectionAsync ( const Vector<Ptr<LandscapeFetch>> & fetches, bool critical = false ) #
Performs tracing (batch) along the line from the p0 point specified by the setIntersectionPositionBegin() to the p1 point specified by the setIntersectionPositionEnd() to find an intersection with the terrain in asynchronous mode (the corresponding task shall be put to the queue, to wait until the result is obtained use the wait() method). For an instant result use the intersectionForce() method.Arguments
- const Vector<Ptr<LandscapeFetch>> & fetches - List of fetch requests to be completed.
- bool critical - true to set high priority for the intersection task, false - to set normal priority.
void wait ( ) #
Waits for completion of the fetch operation. As the operation is completed you can obtain necessary data via get*() methods.void wait ( const Vector<Ptr<LandscapeFetch>> & fetches ) #
Waits for completion of the specified fetch operations. As the operations are completed you can obtain necessary data via get*() methods.Arguments
Last update:
19.04.2024
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