事件处理回调

WorldTriggerPtr trigger;
int enter_callback_id;
				
// implement the enter callback
void AppWorldLogic::enter_callback(NodePtr node){
	Log::message("\nA node named %s has entered the trigger\n", node->getName());
}
				
// implement the leave callback
void AppWorldLogic::leave_callback(NodePtr node){
	Log::message("\nA node named %s has left the trigger\n", node->getName());
}
				
int AppWorldLogic::init() {
	// create a world trigger node
	trigger = WorldTrigger::create(Math::vec3(3.0f));
				
	// add the enter callback to be fired when a node enters the world trigger
	//and keep its id to be used to remove the callback when necessary
	enter_callback_id = trigger->addEnterCallback(MakeCallback(this, &AppWorldLogic::enter_callback));
	// add the leave callback to be fired when a node leaves the world trigger
	trigger->addLeaveCallback(MakeCallback(this, &AppWorldLogic::leave_callback));

	return 1;
}

// remove the callback by using its id
trigger->removeEnterCallback(enter_callback_id);
// clear all leave callbacks
trigger->clearLeaveCallbacks();

/* .. */

// event handler function
int onButtonClicked()
{
	/* .. */
	
	return 1;
}

/* .. */

// getting a pointer to the system GUI
GuiPtr gui = Gui::get();

// creating a button widget and setting its caption
WidgetButtonPtr widget_button = WidgetButton::create(gui, "Press me");

// setting a tooltip
widget_button->setToolTip("Click this button");

// rearranging button size
widget_button->arrange();

// setting button position
widget_button->setPosition(10, 10);

// setting onButtonClicked function to handle CLICKED event
widget_button->addCallback(Gui::CLICKED, MakeCallback(onButtonClicked));

// adding the created button widget to the system GUI
gui->addChild(widget_button, Gui::ALIGN_OVERLAP | Gui::ALIGN_FIXED);

/* .. */

// set the node's albedo color to red on freezing event
int AppWorldLogic::frozen_callback(BodyPtr body)
{
	body->getObject()->setMaterialParameterFloat4("albedo_color", vec4(1.0f, 0.0f, 0.0f, 1.0f), 0);
	return 1;
}

// set the node's albedo color to blue on position change event
int AppWorldLogic::position_callback(BodyPtr body)
{
	body->getObject()->setMaterialParameterFloat4("albedo_color", vec4(0.0f, 0.0f, 1.0f, 1.0f), 0);
	return 1;
}

// set the node's albedo color to yellow on each contact
int AppWorldLogic::contact_enter_callback(BodyPtr body, int num)
{
	body->getObject()->setMaterialParameterFloat4("albedo_color", vec4(1.0f, 1.0f, 0.0f, 1.0f), 0);
	return 1;
}

int AppWorldLogic::init() {
	// create a box
	MeshPtr mesh = Mesh::create();
	mesh->addBoxSurface("box", vec3(1.0f));
	ObjectMeshStaticPtr node = ObjectMeshStatic::create(mesh);
	node->setMaterial("mesh_base", "*");
	node->setPosition(Vec3(0, 0, 5.0f));
	// add a rigid body to the box
	BodyRigidPtr body = BodyRigid::create(node);
	// register callbacks for events
	body->addFrozenCallback(MakeCallback(this, &AppWorldLogic::frozen_callback));
	body->addPositionCallback(MakeCallback(this, &AppWorldLogic::position_callback));
	body->addContactEnterCallback(MakeCallback(this, &AppWorldLogic::contact_enter_callback));
	// add a shape to the body
	ShapeBoxPtr shape = ShapeBox::create(body, vec3(1.0f));

	return 1;
}
/* .. */

NodePtr node;

void node_property_added(NodePtr node, PropertyPtr property)
{
	Log::message("Property \"%s\" was added to the node named \"%s\".\n", property->getName(), node->getName());
    // ...
}

// somewhere in the code

// inheriting a new property named "my_prop" from the base property "node_base"
Properties::findManualProperty("node_base")->inherit("my_prop");

// setting our callback function on adding a node property
node->addCallback(Node::CALLBACK_PROPERTY_NODE_ADD, MakeCallback(node_property_added));

// adding the property named "my_prop" to the node
node->addProperty("my_prop");

void parameter_changed(PropertyPtr property, int num)
{
	Log::message("Parameter \"%s\" of the property \"%s\" has changed its value.\n", property->getParameterName(num), property->getName());
    // ...
}

// somewhere in the code

// getting a manual property named "my_prop" via the Property Manager
PropertyPtr property = Properties::findManualProperty("my_prop");

// setting our callback function on parameter change
property->addCallback(Property::CALLBACK_PARAMETER_CHANGED, MakeCallback(parameter_changed));

// changing the value of the "my_int_param" parameter
property->setParameterInt(property->findParameter("my_int_param"), 3);

void property_removed(PropertyPtr property)
{
	Log::message("Property \"%s\" was removed.\n", property->getName());
    // ...
}

// somewhere in the code

// inheriting a new property named "my_prop" from the base property "surface_base"
PropertyPtr property = Properties::findManualProperty("surface_base")->inherit("my_prop");

// setting our callback function on property removal
Properties::addCallback(Property::CALLBACK_REMOVED, MakeCallback(property_removed));

// removing the property named "my_prop"
Properties::removeProperty(Properties::findProperty("my_prop")->getGUID());