自学教程：C++ DrawScene函数代码示例

voidMy_TestGLDrawing::OffscreenTest(){    DrawScene();    WriteToFile("color", "color1_unselected.png");    // select cube0    _picker.Pick(GfVec2i(319,221), GfVec2i(320,222));    DrawScene();    WriteToFile("color", "color2_cube0_pickable.png");    HdSelectionSharedPtr selection = _picker.GetSelection();    HdSelection::HighlightMode mode = HdSelection::HighlightModeSelect;    TF_VERIFY(selection->GetSelectedPrimPaths(mode).size() == 1);    TF_VERIFY(selection->GetSelectedPrimPaths(mode)[0] == SdfPath("/cube0"));    // make cube0 unpickable; it should not let us pick cube1 since it occludes    SdfPathVector excludePaths = {SdfPath("/cube0")};    _pickablesCol.SetExcludePaths(excludePaths);    _picker.SetDoUnpickablesOcclude(true);    _picker.Pick(GfVec2i(319,221), GfVec2i(320,222));    DrawScene();    WriteToFile("color", "color3_cube0_unpickable.png");    selection = _picker.GetSelection();    //TF_VERIFY(selection->GetSelectedPrimPaths(mode).size() == 0);}

static voidEventLoop(WindowData *winData){   while (1) {      static long mask = StructureNotifyMask | ExposureMask | KeyPressMask;      XEvent event;      while (XCheckWindowEvent(winData->display, winData->window,                               mask, &event)) {         if (event.xany.window == winData->window) {            switch (event.type) {            case Expose:               DrawScene(winData);               break;            case ConfigureNotify:               glViewport(0, 0,                          event.xconfigure.width, event.xconfigure.height);               break;            case KeyPress:               {                  char buffer[10];                  int r;                  r = XLookupString(&event.xkey, buffer, sizeof(buffer),                                    NULL, NULL);                  if (buffer[0] == 27) {                     /* escape */                        return;                  }               }            }         }      }      DrawScene(winData);   }}

void GlutDisplay(){    switch ( viewMode ) {        case VIEWMODE_OPENGL:            if ( dofImage ) {                if ( dofDrawCount < MAX_DOF_DRAW ) {                    DrawScene();                    glReadPixels( 0, 0, camera.imgWidth, camera.imgHeight, GL_RGB, GL_UNSIGNED_BYTE, dofBuffer );                    for ( int i=0; i<camera.imgWidth*camera.imgHeight; i++ ) {                        dofImage[i] = (dofImage[i]*dofDrawCount + dofBuffer[i].ToColor())/(dofDrawCount+1);                    }                    dofDrawCount++;                }                glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT );                glDrawPixels( camera.imgWidth, camera.imgHeight, GL_RGB, GL_FLOAT, dofImage );                if ( dofDrawCount < MAX_DOF_DRAW ) {                    DrawProgressBar(float(dofDrawCount)/MAX_DOF_DRAW);                    glutPostRedisplay();                }            } else {                DrawScene();            }            break;        case VIEWMODE_IMAGE:            glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT );            glDrawPixels( renderImage.GetWidth(), renderImage.GetHeight(), GL_RGB, GL_UNSIGNED_BYTE, renderImage.GetPixels() );            DrawRenderProgressBar();            break;        case VIEWMODE_Z:            glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT );            if ( ! renderImage.GetZBufferImage() ) renderImage.ComputeZBufferImage();            glDrawPixels( renderImage.GetWidth(), renderImage.GetHeight(), GL_LUMINANCE, GL_UNSIGNED_BYTE, renderImage.GetZBufferImage() );            break;        case VIEWMODE_SAMPLECOUNT:            glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT );            if ( ! renderImage.GetSampleCountImage() ) renderImage.ComputeSampleCountImage();            glDrawPixels( renderImage.GetWidth(), renderImage.GetHeight(), GL_LUMINANCE, GL_UNSIGNED_BYTE, renderImage.GetSampleCountImage() );            break;        case VIEWMODE_IRRADCOMP:            glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT );            if ( renderImage.GetIrradianceComputationImage() ) {                glDrawPixels( renderImage.GetWidth(), renderImage.GetHeight(), GL_LUMINANCE, GL_UNSIGNED_BYTE, renderImage.GetIrradianceComputationImage() );            }            break;    }        glutSwapBuffers();}

void CMemoryCardView::CRender::ThreadProc(){	unsigned int nPixelFormat = ChoosePixelFormat(m_deviceContext, &m_PFD);	SetPixelFormat(m_deviceContext, nPixelFormat, &m_PFD);	m_hRC = wglCreateContext(m_deviceContext);	wglMakeCurrent(m_deviceContext, m_hRC);	glEnable(GL_TEXTURE_2D);	glClearColor(1.0, 1.0, 1.0, 1.0);	while(!m_threadOver)	{		while(m_mailBox.IsPending())		{			m_mailBox.ReceiveCall();		}		Animate();		DrawScene();		Sleep(16);	}	m_icons.clear();	wglMakeCurrent(NULL, NULL);	wglDeleteContext(m_hRC);}

void rwxGLView::DrawReconditeScene(){    PrepareToDraw();    DrawScene();    SwapBuffers();}

void OVRScene::RenderForOneEye(const float* pMview, const float* pPersp) const{    printf("Rendering in OVRScene!/n");    if (m_bDraw == false)        return;    if (pMview == false)        return;    if (pPersp == false)        return;    const glm::mat4 modelview = glm::make_mat4(pMview);    const glm::mat4 projection = glm::make_mat4(pPersp);    // Assemble modelview matrix to lock camera in with real world geometry:    // We still have to use the assembled HMD stereo modelview matrices from OVRSDK05AppSkeleton,    // but we undo the effects of chassis yaw and position so the frustum follows the viewer.    if (m_pHmd != NULL)    {        const ovrTrackingState ts = ovrHmd_GetTrackingState(m_pHmd, ovr_GetTimeInSeconds());        const ovrPosef& cp = ts.CameraPose;        OVR::Matrix4f camMtx = OVR::Matrix4f();        camMtx *= OVR::Matrix4f::Translation(cp.Position)            * OVR::Matrix4f(OVR::Quatf(cp.Orientation));        glm::mat4 ogmat = glm::make_mat4(&camMtx.Transposed().M[0][0]);        DrawScene(modelview * ogmat, projection);    }}

int DemoBase::RunDemo(){	MSG msg = { 0 };	mTimer.Reset();	while (msg.message != WM_QUIT)	{		if (PeekMessage(&msg, 0, 0, 0, PM_REMOVE))		{			TranslateMessage(&msg);			DispatchMessage(&msg);		}		else		{			mTimer.Tick();			if (!mAppPaused)			{				CalculateFrameStats();				UpdateScene(mTimer.DeltaTime());				DrawScene();			}			else			{				Sleep(100);			}		}	}	return (int)msg.wParam;}

void RENDERING_PASS (){	glViewport(0, 0, windowWidth, windowHeight);	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	// textureMatrix=biasMatrix*lightProjectionMatrix*lightViewMatrix*cameraViewInverse	// store the coordinate conversion matrix to texture matrix[3]	// to be used in shader	glActiveTexture (GL_TEXTURE3);  // use the last texture unit	glBindTexture (GL_TEXTURE_2D, depthTextureId);	glMatrixMode (GL_TEXTURE);	glLoadIdentity();	static float b[16] = {.5, 0,0,0, 0,.5,0,0, 0,0,.5,0, .5,.5,.5,1};	glMultMatrixf (b);  // scale and bias	MULT_LIGHT_PROJECTION();	MULT_LIGHT_MODELVIEW();	apply_modelview_inverse ();  // camera view inverse 	glMatrixMode (GL_MODELVIEW);		// three important settings to use depth texture (see notes)	glUseProgram (program);	DrawScene();}

void ms_tick(void){	DrawScene();	draw_banner();		if (ms.state == MS_EXPANDING)	{		ms.expandframe++;				if (ms.expandframe > EXPAND_LENGTH)			ms.state = MS_DISPLAYED;		else			draw_expand();	}		if (ms.state == MS_DISPLAYED)	{		// scan down effect		if (ms.current_row < map.ysize)		{			draw_row(ms.current_row++);						if (ms.current_row < map.ysize)				draw_row(ms.current_row++);		}				// draw map		DrawRect(ms.x - 1, ms.y - 1, ms.x + ms.w, ms.y + ms.h, DK_BLUE);		DrawSurface(ms.sfc, ms.x, ms.y);				// you-are-here dot		if (++ms.timer & 8)			draw_sprite(ms.px, ms.py, SPR_MAP_PIXELS, 4);				// dismissal		if (ms.lastbuttondown)		{			if (!buttondown())				ms.lastbuttondown = false;		}		else if (buttondown())		{			ms.state = MS_CONTRACTING;		}	}	else if (ms.state == MS_CONTRACTING)	{		ms.expandframe--;				if (ms.expandframe <= 0)		{			int param = (ms.return_gm == GM_INVENTORY) ? 1 : 0;			game.setmode(ms.return_gm, param);		}		else		{			draw_expand();		}	}}

void SceneManager::Draw(){    if (MainEngine::_enableShadows)    {        DrawShadowMapping();    }    else    {        glUseProgram(MainEngine::shaders["MainShader"]);        glUniform1i(glGetUniformLocation(MainEngine::shaders["MainShader"], "bEnableShadowMapping"), 0);        DrawScene();        glUseProgram(0);    }    // ---- Debug Show Depth Texture    //glPushMatrix();    //glOrtho(-int(MainEngine::_mainWindow->getSize().x) / 2, MainEngine::_mainWindow->getSize().x / 2,    //        -int(MainEngine::_mainWindow->getSize().y) / 2, MainEngine::_mainWindow->getSize().y / 2, 1, 2000);    //glActiveTexture(GL_TEXTURE0);    //glBindTexture(GL_TEXTURE_2D, MainEngine::m_shadowMapFBO.GetShadowMap());    //glEnable(GL_TEXTURE_2D);    //glTranslated(0, 0, - 1);    //glBegin(GL_QUADS);    //glTexCoord2d(0, 0); glVertex3f(0, 0, 0);    //glTexCoord2d(1, 0); glVertex3f(MainEngine::_mainWindow->getSize().x / 2, 0, 0);    //glTexCoord2d(1, 1); glVertex3f(MainEngine::_mainWindow->getSize().x / 2, MainEngine::_mainWindow->getSize().y / 2, 0);    //glTexCoord2d(0, 1); glVertex3f(0, MainEngine::_mainWindow->getSize().y / 2, 0);    //glEnd();    //glDisable(GL_TEXTURE_2D);    //glPopMatrix();}

void SHADOW_MAP_PASS()   // NON-FBO Version{	glClear(GL_DEPTH_BUFFER_BIT);  // no output to colorbuffer	glViewport(0, 0, shadowMapSize, shadowMapSize);	glMatrixMode(GL_PROJECTION); glPushMatrix();   glLoadIdentity();// save current projection	MULT_LIGHT_PROJECTION();  // light projection	glMatrixMode(GL_MODELVIEW);	glPushMatrix();  glLoadIdentity(); // viewer: save current modelview (containing Viewing of camera)	MULT_LIGHT_MODELVIEW();   // light view	// disable texturing in the first pass (if any)	// disable lighting too	glPushAttrib (GL_ENABLE_BIT | GL_LIGHTING_BIT | GL_COLOR_BUFFER_BIT);		//Disable color writes, and use flat shading for speed		glColorMask(0, 0, 0, 0);  // color buffer bit		glShadeModel(GL_FLAT);    // lighting bit		glDisable (GL_LIGHTING);		glDisable (GL_TEXTURE_2D);		glPolygonOffset (8.0, 4.0); // IMPORTANT: to remove moire pattern (from z-fighting)		glEnable (GL_POLYGON_OFFSET_FILL);				glUseProgram(0);		DrawScene(); // Draw the scene (fixed function)	glPopAttrib();	glMatrixMode(GL_PROJECTION); glPopMatrix();  // restore current projection	glMatrixMode(GL_MODELVIEW); glPopMatrix();  // restore Modelview to Vcamera	//Read the depth buffer into the shadow map texture	glActiveTexture (GL_TEXTURE3);	glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, shadowMapSize, shadowMapSize);}

int messageloop(){	MSG msg;	ZeroMemory(&msg, sizeof(MSG));	while(true)	{		BOOL PeekMessageL( 			LPMSG lpMsg,			HWND hWnd,			UINT wMsgFilterMin,			UINT wMsgFilterMax,			UINT wRemoveMsg			);		if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))		{			if (msg.message == WM_QUIT)				break;			TranslateMessage(&msg);				DispatchMessage(&msg);		}		else{			// run game code            			UpdateScene();			DrawScene();		}	}	return msg.wParam;}

void CCg3DTransView::OnTimer(UINT nIDEvent) {	// TODO: Add your message handler code here and/or call default	DrawScene();	CView::OnTimer(nIDEvent);}

void Test3(){	LoadBCP("data.bcp");	ReadLanguageFile();	InitWindow();	//InitRectDrawing();	//IDirect3DTexture9 *mytex = GetTexture("Interface//LOADING SCREEN 1.tga");	//IDirect3DPixelShader9 *psh = LoadPixelShader("test.psh");	InitScene(); LoadMap("testmap.bcm");	while(!appexit)	{		BeginDrawing();		//ddev->SetRenderState(D3DRS_ZENABLE, FALSE);		//ddev->SetRenderState(D3DRS_CULLMODE, D3DCULL_NONE);		//ddev->SetPixelShader(psh);		//ddev->SetTexture(0, mytex);		//DrawRect(0, 0, 640, 480, -1);		DrawScene();		EndDrawing();		HandleWindow();		if(keyheld[VK_UP]) camerapos += Vector3(0.0f, 0.0f, walkstep);		if(keyheld[VK_DOWN]) camerapos -= Vector3(0.0f, 0.0f, walkstep);		if(keyheld[VK_LEFT]) camerapos -= Vector3(walkstep, 0.0f, 0.0f);		if(keyheld[VK_RIGHT]) camerapos += Vector3(walkstep, 0.0f, 0.0f);		if(keyheld['E']) camerapos += Vector3(0.0f, walkstep, 0.0f);		if(keyheld['D']) camerapos -= Vector3(0.0f, walkstep, 0.0f);	}}

void ViewWindow::draw (){	//bool use_solid = false; // unused	if(!valid ())		InitGL ();	glClearColor(backgroundColor.x,backgroundColor.y,backgroundColor.z,0.0f);	glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	glMatrixMode(GL_PROJECTION);	glLoadIdentity ();	SetupProjectionMatrix ();	bSelecting=false;	selector_count=0;	DrawScene ();	SetRasterMatrix ();	Draw2D ();	if (bBoxSelect)	{		fltk::glsetcolor(fltk::WHITE);		fltk::glstrokerect(click.x,click.y,last.x-click.x, last.y-click.y);	}}

int D3DApplication::Run(){	MSG message = {0};	m_GameTimer.Reset();	while (message.message != WM_QUIT)	{		// If there are Window messages then process them.		if (PeekMessage(&message, nullptr, 0, 0, PM_REMOVE))		{			TranslateMessage(&message);			DispatchMessage(&message);		}		// Otherwise, do animation/game stuff.		else		{			m_GameTimer.Tick();			if(!m_IsPaused)			{				UpdateScene(m_GameTimer.GetDeltaTime());				}			else			{				Sleep(50);			}			DrawScene();		}	}	return int(message.wParam);}

int main(int argc, char* argv[]){	//初始化NGE分为VIDEO,AUDIO，这里是只初始化VIDEO，如果初始化所有用INIT_VIDEO|INIT_AUDIO,或者INIT_ALL	NGE_Init(INIT_VIDEO);	//初始化按键处理btn_down是按下响应,后面是弹起时的响应，0是让nge处理home消息(直接退出),填1就是让PSP系统处理	//home消息,通常填1正常退出（1.50版的自制程序需要填0）	InitInput(btn_down,NULL,1);	//最后一个参数是psp swizzle优化，通常填1	p_bg = image_load("images/demo0.jpg",DISPLAY_PIXEL_FORMAT_8888,1);	if(p_bg == NULL) {		printf("can not open file/n");	}	p_logo = image_load("images/nge2logo.png",DISPLAY_PIXEL_FORMAT_4444,1);	if(p_logo == NULL) {		printf("can not open file/n");	}	//创建一个半透明的图片遮罩color	logomask1 = CreateColor(255,255,255,128,p_logo->dtype);	//随便创建一个图片遮罩color	logomask2 = CreateColor(100,100,100,255,p_logo->dtype);	while ( !game_quit )	{		ShowFps();		InputProc();		DrawScene();	}	image_free(p_bg);	image_free(p_logo);	NGE_Quit();	return 0;}

// рисуем сцену в соответствии со стерео-режимомvoid FullDraw(){	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	DrawScene();}

void Renderer::RenderScene() {	DrawScene();	DrawPostProcess();	PresentScene();DrawDebugTexture();	SwapBuffers();}

TesseractWidget::TesseractWidget(Socket *_TheSocket,int PlayerNum,QString PlayerName,QGLWidget *parent) : QGLWidget(parent), ui(new Ui::TesseractWidget) {    ui->setupUi(this);    TheSocket=_TheSocket;    QThread *tt=new QThread(TheSocket);    TheSocket->moveToThread(tt);    tt->start();    connect(TheSocket,SIGNAL(readVariantMap(int,QString,quint16,const QVariantMap&)),this,SLOT(recvVariantMap(int,QString,quint16,const QVariantMap&)));    connect(TheSocket,SIGNAL(sockDisconnect(int,QString,quint16)),this,SLOT(sockDisconnect(int,QString,quint16)));    memset(KeyStatus,0,sizeof(KeyStatus));    creatingblock=0;    mousetracked=1;    TheWorld=new World;    connect(TheWorld,SIGNAL(log(const QString&)),this,SLOT(Log(const QString&)));    connect(TheWorld,SIGNAL(releaseMouse()),this,SLOT(releaseMouse()));    connect(TheWorld,SIGNAL(trackMouse()),this,SLOT(trackMouse()));    connect(TheWorld,SIGNAL(renderText2D(Coordinate,const QString&)),this,SLOT(renderText2D(Coordinate,const QString&)));    connect(TheWorld,SIGNAL(renderText3D(Coordinate,const QString&,int)),this,SLOT(renderText3D(Coordinate,const QString&,int)));    Player tp;    tp.Name=PlayerName;    TheWorld->Players.insert(PlayerNum,tp);    TheWorld->Myself=TheWorld->Players.find(PlayerNum);    PM=new PluginManager;    PM->ClientLoadFolder("plugins",TheWorld,TheSocket);    QApplication::setOverrideCursor(Qt::BlankCursor);    gt=new GameThread(TheWorld,KeyStatus,TheSocket);    gt->start();    GLTimer=new QTimer;    GLTimer->start(16);    connect(GLTimer,SIGNAL(timeout()),this,SLOT(DrawScene()));    TheWorld->RegisterBlock(Block("Stone",Coordinate(.2,.2,.2),""));    currentblocktype="Stone";    QVariantMap qvm;    qvm.insert("type","getbasic");    emit TheSocket->sendVariantMap(qvm,-1);}

int Draw(Screen *screen){//   メイン描画
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