程序的开始并无任何特别。我们包含了需要的头文件和创建一个事件接收器(译注:原文是event listener 事件监听器?看代码就是event receiver嘛,为了统一故译作事件接收器)用于响应用户的按键,如果用户按下‘w’则变成线框模式,而按下‘d’则决定材质在普通贴图和详细贴图之间变换。(译注:在新版本的sdk添加响应‘p’键,则变成只显示顶点)
#include <irrlicht.h> #include <iostream> using namespace irr;
#pragma comment(lib, "Irrlicht.lib")
class MyEventReceiver : public IEventReceiver { public: MyEventReceiver(scene::ISceneNode* terrain) { // store pointer to terrain so we can change its drawing mode Terrain = terrain; }
bool OnEvent(SEvent event) { // check if user presses the key 'W' or 'D' if (event.EventType == irr::EET_KEY_INPUT_EVENT && !event.KeyInput.PressedDown) { switch (event.KeyInput.Key) { case irr::KEY_KEY_W: // switch wire frame mode Terrain->setMaterialFlag(video::EMF_WIREFRAME, !Terrain->getMaterial(0).Wireframe); return true; case irr::KEY_KEY_D: // toggle detail map Terrain->setMaterialType( Terrain->getMaterial(0).MaterialType == video::EMT_SOLID ? video::EMT_DETAIL_MAP : video::EMT_SOLID); return true; } } return false; }
private: scene::ISceneNode* Terrain; };
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就如其它例子那样,使用main函数作为开始。接着询问用户希望使用的渲染器,并启动。
int main() { // let user select driver type
video::E_DRIVER_TYPE driverType = video::EDT_DIRECT3D9;
printf("Please select the driver you want for this example:\n"\ " (a) Direct3D 9.0c\n (b) Direct3D 8.1\n (c) OpenGL 1.5\n"\ " (d) Software Renderer\n (e) Apfelbaum Software Renderer\n"\ " (f) NullDevice\n (otherKey) exit\n\n");
char i; std::cin >> i;
switch(i) { case 'a': driverType = video::EDT_DIRECT3D9;break; case 'b': driverType = video::EDT_DIRECT3D8;break; case 'c': driverType = video::EDT_OPENGL; break; case 'd': driverType = video::EDT_SOFTWARE; break; case 'e': driverType = video::EDT_SOFTWARE2;break; case 'f': driverType = video::EDT_NULL; break; default: return 1; }
// create device IrrlichtDevice* device = createDevice(driverType, core::dimension2d<s32>(640, 480));
if (device == 0) return 1; // could not create selected driver.
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首先,我们添加标准部件到场景:一个漂亮的IrrLicht引擎标志,一个细小的帮助文本,一个用户可控的摄像机,并取消鼠标光标。
video::IVideoDriver* driver = device->getVideoDriver(); scene::ISceneManager* smgr = device->getSceneManager(); gui::IGUIEnvironment* env = device->getGUIEnvironment();
driver->setTextureCreationFlag(video::ETCF_ALWAYS_32_BIT, true);
// add irrlicht logo env->addImage(driver->getTexture("../../media/irrlichtlogoalpha.tga"), core::position2d<s32>(10,10));
// add some help text gui::IGUIStaticText* text = env->addStaticText( L"Press 'W' to change wireframe mode\nPress 'D' to toggle detail map", core::rect<s32>(10,453,200,475), true, true, 0, -1, true);
// add camera scene::ICameraSceneNode* camera = smgr->addCameraSceneNodeFPS(0,100.0f,1200.0f); camera->setPosition(core::vector3df(1900*2,255*2,3700*2)); camera->setTarget(core::vector3df(2397*2,343*2,2700*2)); camera->setFarValue(12000.0f);
// disable mouse cursor device->getCursorControl()->setVisible(false);
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这里来到了地形渲染器场景节点:我们就像添加其它场景节点一样使用ISceneManager::addTerrainSceneNode()方法添加它。只需要一个高度图文件名的参数。高度图是一个简单的灰度纹理。地形渲染器加载这个纹理并根据它创建3D地形。 为了使地形看起来更大,我们使用ISceneManager::setScale()方法设置比例为(40, 4.4, 40)(译注:在新版本的sdk中修改了ISceneManager::addTerrainSceneNode()方法的参数表,可以在这个方法中设置比例而不用setScale()了)。因为在这个场景中没有灯光,所以我们关闭了灯光效果,并设置文件terrain-texture.jpg 作为地形的纹理而文件detailmap3.jpg作为第二层纹理,称为详细贴图。最后,我们设置纹理的比例:第一个纹理只需一次就能覆盖整个地形,而第二个纹理就需要20次。
// add terrain scene node scene::ITerrainSceneNode* terrain = smgr->addTerrainSceneNode( "../../media/terrain-heightmap.bmp");
terrain->setScale(core::vector3df(40, 4.4f, 40)); terrain->setMaterialFlag(video::EMF_LIGHTING, false);
terrain->setMaterialTexture(0, driver->getTexture( "../../media/terrain-texture.jpg")); terrain->setMaterialTexture(1, driver->getTexture( "../../media/detailmap3.jpg")); terrain->setMaterialType(video::EMT_DETAIL_MAP); terrain->scaleTexture(1.0f, 20.0f);
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为了能与地形进行碰撞,我们创建一个三角形选择器。如果你想了解三角形选择器,可以浏览collision教程。这个三角形选择器根据地形工作的。为了演示它,我们创建一个碰撞响应动作器并附到摄像机上,于是摄像机就不能穿过地形了。
// create triangle selector for the terrain scene::ITriangleSelector* selector = smgr->createTerrainTriangleSelector(terrain, 0); terrain->setTriangleSelector(selector); selector->drop();
// create collision response animator and attach it to the camera scene::ISceneNodeAnimator* anim = smgr->createCollisionResponseAnimator( selector, camera, core::vector3df(60,100,60), core::vector3df(0,0,0), core::vector3df(0,50,0)); camera->addAnimator(anim); anim->drop();
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为了使用户能在普通模式和线框模式之间转换,我们根据上面定义的事件接收器类创建一个事件接收器并告诉IrrLicht引擎。另外,我们还添加一个已经在其它例子(译注:mesh viewer)中使用过的天空盒。In addition, we add the skybox which we already used in lots of Irrlicht examples.
// create event receiver MyEventReceiver receiver(terrain); device->setEventReceiver(&receiver);
// create skybox driver->setTextureCreationFlag(video::ETCF_CREATE_MIP_MAPS, false);
smgr->addSkyBoxSceneNode( driver->getTexture("../../media/irrlicht2_up.jpg"), driver->getTexture("../../media/irrlicht2_dn.jpg"), driver->getTexture("../../media/irrlicht2_lf.jpg"), driver->getTexture("../../media/irrlicht2_rt.jpg"), driver->getTexture("../../media/irrlicht2_ft.jpg"), driver->getTexture("../../media/irrlicht2_bk.jpg"));
driver->setTextureCreationFlag(video::ETCF_CREATE_MIP_MAPS, true);
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就是这样,绘制出全部。现在你知道如何在IrrLicht引擎中使用地形了吧。
int lastFPS = -1;
while(device->run()) if (device->isWindowActive()) { driver->beginScene(true, true, 0 );
smgr->drawAll(); env->drawAll();
driver->endScene();
// display frames per second in window title
int fps = driver->getFPS();
if (lastFPS != fps) { core::stringw str = L"Terrain Renderer - Irrlicht Engine ["; str += driver->getName(); str += "] FPS:"; str += fps; device->setWindowCaption(str.c_str()); lastFPS = fps; } }
device->drop(); return 0; }
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