基於OGRE所實現的高層遊戲引擎架構（3）

  附錄

　　Terrain Example

　　/*

　　This source file is part of OGRE

　　(Object-oriented Graphics Rendering Engine)

　　For the latest info, see http://www.ogre3d.org/

　　Copyright ?2000-2003 The OGRE Team

　　Also see acknowledgements in Readme.html

　　You may use this sample code for anything you like, it is not covered by the

　　LGPL like the rest of the engine.

　　*/

　　/**

　　/file

　　Terrain.h

　　/brief

　　Specialisation of OGRE's framework application to show the

　　terrain rendering plugin

　　*/

　　#include "ExampleApplication.h"

　　#include "OgreStringConverter.h"

　　#define FLOW_SPEED 0.2

　　#define FLOW_HEIGHT 0.8

　　class TerrainListener : public ExampleFrameListener

　　{

　　public:

　　TerrainListener(RenderWindow* win, Camera* cam) :ExampleFrameListener(win, cam) { };

　　// Override frameStarted event to process that (don't care about frameEnded)

　　bool frameStarted(const FrameEvent& evt)

　　{

　　float moveScale;

　　float rotScale;

　　float waterFlow;

　　static float flowAmount = 0.0f;

　　static bool flowUp = true;

　　// local just to stop toggles flipping too fast

　　static Real timeUntilNextToggle = 0;

　　if (timeUntilNextToggle >= 0)

　　timeUntilNextToggle -= evt.timeSinceLastFrame;

　　// If this is the first frame, pick a speed

　　if (evt.timeSinceLastFrame == 0)

　　{

　　moveScale = 1;

　　rotScale = 0.1;

　　waterFlow = 0.0f;

　　}

　　// Otherwise scale movement units by time passed since last frame

　　else

　　{

　　// Move about 100 units per second,

　　moveScale = 10.0 * evt.timeSinceLastFrame;

　　// Take about 10 seconds for full rotation

　　rotScale = 36 * evt.timeSinceLastFrame;

　　// set a nice waterflow rate

　　waterFlow = FLOW_SPEED * evt.timeSinceLastFrame;

　　}

　　// Grab input device state

　　mInputDevice->capture();

　　SceneNode *waterNode = static_cast<SceneNode*>(

　　mCamera->getSceneManager()->getRootSceneNode()->getChild("WaterNode"));

　　if(waterNode)

　　{

　　if(flowUp)

　　flowAmount += waterFlow;

　　else

　　flowAmount -= waterFlow;

　　if(flowAmount >= FLOW_HEIGHT)

　　flowUp = false;

　　else if(flowAmount <= 0.0f)

　　flowUp = true;

　　waterNode->translate(0, (flowUp ? waterFlow : -waterFlow), 0);

　　}

　　static Vector3 vec;

　　vec = Vector3::ZERO;

　　if (mInputDevice->isKeyDown(KC_A))

　　{

　　// Move camera left

　　vec.x = -moveScale;

　　}

　　if (mInputDevice->isKeyDown(KC_D))

　　{

　　// Move camera RIGHT

　　vec.x = moveScale;

　　}

　　if (mInputDevice->isKeyDown(KC_UP) || mInputDevice->isKeyDown(KC_W))

　　{

　　// Move camera forward

　　vec.z = -moveScale;

　　}

　　if (mInputDevice->isKeyDown(KC_DOWN) || mInputDevice->isKeyDown(KC_S))

　　{

　　// Move camera backward

　　vec.z = moveScale;

　　}

　　if (mInputDevice->isKeyDown(KC_PGUP))

　　{

　　// Move camera up

　　vec.y = moveScale;

　　}

　　if (mInputDevice->isKeyDown(KC_PGDOWN))

　　{

　　// Move camera down

　　vec.y = -moveScale;

　　}

　　if (mInputDevice->isKeyDown(KC_RIGHT))

　　{

　　mCamera->yaw(-rotScale);

　　}

　　if (mInputDevice->isKeyDown(KC_LEFT))

　　{

　　mCamera->yaw(rotScale);

　　}

　　if( mInputDevice->isKeyDown( KC_ESCAPE) )

　　{

　　return false;

　　}

　　// Rotate view by mouse relative position

　　float rotX, rotY;

　　rotX = -mInputDevice->getMouseRelativeX() * 0.13;

　　rotY = -mInputDevice->getMouseRelativeY() * 0.13;

　　// Make all the changes to the camera

　　// Note that YAW direction is around a fixed axis (freelook stylee) rather than a natural YAW (e.g. airplane)

　　mCamera->yaw(rotX);

　　mCamera->pitch(rotY);

　　mCamera->moveRelative(vec);

　　// Rotate scene node if required

　　SceneNode* node = mCamera->getSceneManager()->getRootSceneNode();

　　if (mInputDevice->isKeyDown(KC_O))

　　{

　　node->yaw(rotScale);

　　}

　　if (mInputDevice->isKeyDown(KC_P))

　　{

　　node->yaw(-rotScale);

　　}

　　if (mInputDevice->isKeyDown(KC_I))

　　{

　　node->pitch(rotScale);

　　}

　　if (mInputDevice->isKeyDown(KC_K))

　　{

　　node->pitch(-rotScale);

　　}

　　if (mInputDevice->isKeyDown(KC_F) && timeUntilNextToggle <= 0)

　　{

　　mStatsOn = !mStatsOn;

　　//Root::getSingleton().showDebugOverlay(mStatsOn);

　　showDebugOverlay(mStatsOn);

　　timeUntilNextToggle = 1;

　　}

　　// Return true to continue rendering

　　return true;

　　}

　　};

　　class TerrainApplication : public ExampleApplication

　　{

　　public:

　　TerrainApplication() {}

　　protected:

　　virtual void createFrameListener(void)

　　{

　　mFrameListener= new TerrainListener(mWindow, mCamera);

　　mFrameListener->showDebugOverlay(true);

　　mRoot->addFrameListener(mFrameListener);

　　}

　　virtual void chooseSceneManager(void)

　　{

　　// Get the SceneManager, in this case a generic one

　　mSceneMgr = mRoot->getSceneManager( ST_EXTERIOR_CLOSE );