OpenSceneGraph实现的NeHe OpenGL教程 - 第三十五课_附录1

简介

在OSG中支持动态纹理，因此不需要我们对视频文件进行大量的解析工作，这些内容都已经在osgPlugins中完成了，在OSG中通过纹理osg::Image的派生类支持这一特性



有了以上内容，在OSG中实现就十分简单了，使用过程类似于我们常见的添加osgTexture2D的过程：

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osg::Texture2D *texture2D = new osg::Texture2D;

texture2D = new osg::Texture2D;

texture2D->setFilter(osg::Texture::MAG_FILTER, osg::Texture::NEAREST);

texture2D->setFilter(osg::Texture::MIN_FILTER, osg::Texture::NEAREST);

osg::ImageStream *imageStream = dynamic_cast<osg::ImageStream*>(osgDB::readImageFile("Data/Child.gif"));

if(imageStream)

imageStream->play();

texture2D->setImage(imageStream);

root->getOrCreateStateSet()->setTextureAttributeAndModes(0, texture2D);

其他部分与之前的课程介绍中一样。

由于我并没有编译支持AVI的插件，因此此处以已经编译好的GIF插件做参考，读者可以自行编译AVI的插件来支持AVI格式的文件。

编译运行程序：



附：本课源码(源码中可能存在错误和不足，仅供参考)

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#include "../osgNeHe.h"

#include <QtCore/QTimer>

#include <QtGui/QApplication>

#include <QtGui/QVBoxLayout>

#include <osgViewer/Viewer>

#include <osgDB/ReadFile>

#include <osgQt/GraphicsWindowQt>

#include <osg/MatrixTransform>

#include <osg/Texture2D>

#include <osg/ImageStream>

#include <osg/ShapeDrawable>

#include <osg/Switch>

#include <osg/AnimationPath>

#include <osg/TexGen>

#include <osg/TexGenNode>

osg::Switch *g_SwitchNode = NULL;

//////////////////////////////////////////////////////////////////////////

///////////////////////绘制几何体/////////////////////////////////

//////////////////////////////////////////////////////////////////////////

osg::Geode* createBackGroundGeode()

{

osg::Geode *geode = new osg::Geode;

osg::Geometry *geometry = new osg::Geometry;

osg::Vec3Array *vertexArray = new osg::Vec3Array;

osg::Vec2Array *textureArray = new osg::Vec2Array;

vertexArray->push_back(osg::Vec3(11.0f, 8.3f, -20.0f));

vertexArray->push_back(osg::Vec3(-11.0f, 8.3f, -20.0f));

vertexArray->push_back(osg::Vec3(-11.0f, -8.3f, -20.0f));

vertexArray->push_back(osg::Vec3(11.0f, -8.3f, -20.0f));

textureArray->push_back(osg::Vec2(1.0f, 1.0f));

textureArray->push_back(osg::Vec2(0.0f, 1.0f));

textureArray->push_back(osg::Vec2(0.0f, 0.0f));

textureArray->push_back(osg::Vec2(1.0f, 0.0f));

geometry->setVertexArray(vertexArray);

geometry->setTexCoordArray(0, textureArray, osg::Array::BIND_PER_VERTEX);

geometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, vertexArray->size()));

geometry->getOrCreateStateSet()->setMode(GL_LIGHTING, false);

geode->addDrawable(geometry);

return geode;

}

osg::Node* createBox()

{

osg::MatrixTransform *mtX = new osg::MatrixTransform;

mtX->addUpdateCallback(new osg::AnimationPathCallback(osg::Vec3(), osg::X_AXIS, 1.5));

osg::MatrixTransform *mtY = new osg::MatrixTransform;

mtY->addUpdateCallback(new osg::AnimationPathCallback(osg::Vec3(), osg::Y_AXIS, 2.5));

osg::MatrixTransform *mtZ = new osg::MatrixTransform;

mtZ->addUpdateCallback(new osg::AnimationPathCallback(osg::Vec3(), osg::Z_AXIS, 3.5));

osg::Geode *geode = new osg::Geode;

osg::Geometry *geometry = new osg::Geometry;

osg::Vec3Array *vertexArray = new osg::Vec3Array;

osg::Vec2Array *textureArray = new osg::Vec2Array;

osg::Vec3Array *normalArray = new osg::Vec3Array;

for (int i = 0; i < 4; ++i)

normalArray->push_back(osg::Vec3(0.0f, 0.0f, 0.5f));

textureArray->push_back(osg::Vec2(0.0f, 0.0f));

textureArray->push_back(osg::Vec2(1.0f, 0.0f));

textureArray->push_back(osg::Vec2(1.0f, 1.0f));

textureArray->push_back(osg::Vec2(0.0f, 1.0f));

vertexArray->push_back(osg::Vec3(-1.0f, -1.0f, 1.0f));

vertexArray->push_back(osg::Vec3(1.0f, -1.0f, 1.0f));

vertexArray->push_back(osg::Vec3(1.0f, 1.0f, 1.0f));

vertexArray->push_back(osg::Vec3(-1.0f, 1.0f, 1.0f));

for (int i = 0; i < 4; ++i)

normalArray->push_back(osg::Vec3(0.0f, 0.0f,-0.5f));

textureArray->push_back(osg::Vec2(1.0f, 0.0f));

textureArray->push_back(osg::Vec2(1.0f, 1.0f));

textureArray->push_back(osg::Vec2(0.0f, 1.0f));

textureArray->push_back(osg::Vec2(0.0f, 0.0f));

vertexArray->push_back(osg::Vec3(-1.0f, -1.0f, -1.0f));

vertexArray->push_back(osg::Vec3(-1.0f, 1.0f, -1.0f));

vertexArray->push_back(osg::Vec3(1.0f, 1.0f, - 1.0f));

vertexArray->push_back(osg::Vec3(1.0f, -1.0f, -1.0f));

for (int i = 0; i < 4; ++i)

normalArray->push_back(osg::Vec3(0.0f, 0.5f,0.0f));

textureArray->push_back(osg::Vec2(0.0f, 1.0f));

textureArray->push_back(osg::Vec2(0.0f, 0.0f));

textureArray->push_back(osg::Vec2(1.0f, 0.0f));

textureArray->push_back(osg::Vec2(1.0f, 1.0f));

vertexArray->push_back(osg::Vec3(-1.0f, 1.0f, -1.0f));

vertexArray->push_back(osg::Vec3(-1.0f, 1.0f, 1.0f));

vertexArray->push_back(osg::Vec3(1.0f, 1.0f, 1.0f));

vertexArray->push_back(osg::Vec3(1.0f, 1.0f, -1.0f));

for (int i = 0; i < 4; ++i)

normalArray->push_back(osg::Vec3(0.0f, -0.5f,0.0f));

textureArray->push_back(osg::Vec2(1.0f, 1.0f));

textureArray->push_back(osg::Vec2(0.0f, 1.0f));

textureArray->push_back(osg::Vec2(0.0f, 0.0f));

textureArray->push_back(osg::Vec2(1.0f, 0.0f));

vertexArray->push_back(osg::Vec3(-1.0f, -1.0f, -1.0f));

vertexArray->push_back(osg::Vec3(1.0f, -1.0f, -1.0f));

vertexArray->push_back(osg::Vec3(1.0f, -1.0f, 1.0f));

vertexArray->push_back(osg::Vec3(-1.0f, -1.0f, 1.0f));

for (int i = 0; i < 4; ++i)

normalArray->push_back(osg::Vec3(0.5f, 0.0f,0.0f));

textureArray->push_back(osg::Vec2(1.0f, 0.0f));

textureArray->push_back(osg::Vec2(1.0f, 1.0f));

textureArray->push_back(osg::Vec2(0.0f, 1.0f));

textureArray->push_back(osg::Vec2(0.0f, 0.0f));

vertexArray->push_back(osg::Vec3(1.0f, -1.0f, -1.0f));

vertexArray->push_back(osg::Vec3(1.0f, 1.0f, -1.0f));

vertexArray->push_back(osg::Vec3(1.0f, 1.0f, 1.0f));

vertexArray->push_back(osg::Vec3(1.0f, -1.0f, 1.0f));

for (int i = 0; i < 4; ++i)

normalArray->push_back(osg::Vec3(-0.5f, 0.0f,0.0f));

textureArray->push_back(osg::Vec2(0.0f, 0.0f));

textureArray->push_back(osg::Vec2(1.0f, 0.0f));

textureArray->push_back(osg::Vec2(1.0f, 1.0f));

textureArray->push_back(osg::Vec2(0.0f, 1.0f));

vertexArray->push_back(osg::Vec3(-1.0f, -1.0f, -1.0f));

vertexArray->push_back(osg::Vec3(-1.0f, -1.0f, 1.0f));

vertexArray->push_back(osg::Vec3(-1.0f, 1.0f, 1.0f));

vertexArray->push_back(osg::Vec3(-1.0f, 1.0f, -1.0f));

geometry->setVertexArray(vertexArray);

geometry->setNormalArray(normalArray, osg::Array::BIND_PER_VERTEX);

geometry->setTexCoordArray(0, textureArray, osg::Array::BIND_PER_VERTEX);

geometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, vertexArray->size()));

geometry->getOrCreateStateSet()->setMode(GL_LIGHTING, false);

geode->addDrawable(geometry);

mtX->addChild(mtY);

mtY->addChild(mtZ);

mtZ->addChild(geode);

return mtX;

}

osg::Node* createSphere()

{

osg::MatrixTransform *mtX = new osg::MatrixTransform;

mtX->addUpdateCallback(new osg::AnimationPathCallback(osg::Vec3(), osg::X_AXIS, 1.5));

osg::MatrixTransform *mtY = new osg::MatrixTransform;

mtY->addUpdateCallback(new osg::AnimationPathCallback(osg::Vec3(), osg::Y_AXIS, 2.5));

osg::MatrixTransform *mtZ = new osg::MatrixTransform;

mtZ->addUpdateCallback(new osg::AnimationPathCallback(osg::Vec3(), osg::Z_AXIS, 3.5));

osg::Geode *sphere = new osg::Geode;

osg::ShapeDrawable *sphereDrawable = new osg::ShapeDrawable(new osg::Sphere(osg::Vec3(0,0,0), 1.3));

sphere->addDrawable(sphereDrawable);

mtX->addChild(mtY);

mtY->addChild(mtZ);

mtZ->addChild(sphere);

return mtX;

}

osg::Node* createCylinder()

{

osg::MatrixTransform *mtX = new osg::MatrixTransform;

mtX->addUpdateCallback(new osg::AnimationPathCallback(osg::Vec3(), osg::X_AXIS, 1.5));

osg::MatrixTransform *mtY = new osg::MatrixTransform;

mtY->addUpdateCallback(new osg::AnimationPathCallback(osg::Vec3(), osg::Y_AXIS, 2.5));

osg::MatrixTransform *mtZ = new osg::MatrixTransform;

mtZ->addUpdateCallback(new osg::AnimationPathCallback(osg::Vec3(), osg::Z_AXIS, 3.5));

osg::Geode *cylinder = new osg::Geode;

osg::ShapeDrawable *cylinderDrawable = new osg::ShapeDrawable(new osg::Cylinder(osg::Vec3(0,0,0), 0.5, 2.0));

cylinder->addDrawable(cylinderDrawable);

mtX->addChild(mtY);

mtY->addChild(mtZ);

mtZ->addChild(cylinder);

return mtX;

}

//////////////////////////////////////////////////////////////////////////

/////////////////////////////场景交互//////////////////////////////

//////////////////////////////////////////////////////////////////////////

class ManipulatorSceneHandler : public osgGA::GUIEventHandler

{

public:

ManipulatorSceneHandler()

{

}

virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa)

{

osgViewer::Viewer *viewer = dynamic_cast<osgViewer::Viewer*>(&aa);

if (!viewer)

return false;

if (!viewer->getSceneData())

return false;

if (ea.getHandled())

return false;

switch(ea.getEventType())

{

case(osgGA::GUIEventAdapter::KEYDOWN):

{

if (ea.getKey() == osgGA::GUIEventAdapter::KEY_Space)

{

if (!g_SwitchNode)

return false;

static int i = 0;

++i;

if (i > 2)

i = 0;

g_SwitchNode->setSingleChildOn(i);

}

if (ea.getKey() == osgGA::GUIEventAdapter::KEY_E)

{

static bool flag = true;

if(flag){

g_SwitchNode->getOrCreateStateSet()->setTextureMode(0, GL_TEXTURE_GEN_S, osg::StateAttribute::OFF);

g_SwitchNode->getOrCreateStateSet()->setTextureMode(0, GL_TEXTURE_GEN_T, osg::StateAttribute::OFF);

}else{

g_SwitchNode->getOrCreateStateSet()->setTextureMode(0, GL_TEXTURE_GEN_S, osg::StateAttribute::ON);

g_SwitchNode->getOrCreateStateSet()->setTextureMode(0, GL_TEXTURE_GEN_T, osg::StateAttribute::ON);

}

flag = !flag;

}

}

default: break;

}

return false;

}

};

//////////////////////////////////////////////////////////////////////////

//////////////////////////////////////////////////////////////////////////

//////////////////////////osgNeHe框架////////////////////////////

//////////////////////////////////////////////////////////////////////////

class ViewerWidget : public QWidget, public osgViewer::Viewer

{

public:

ViewerWidget(osg::Node *scene = NULL)

{

QWidget* renderWidget = getRenderWidget( createGraphicsWindow(0,0,100,100), scene);

QVBoxLayout* layout = new QVBoxLayout;

layout->addWidget(renderWidget);

layout->setContentsMargins(0, 0, 0, 1);

setLayout( layout );

connect( &_timer, SIGNAL(timeout()), this, SLOT(update()) );

_timer.start( 10 );

}

QWidget* getRenderWidget( osgQt::GraphicsWindowQt* gw, osg::Node* scene )

{

osg::Camera* camera = this->getCamera();

camera->setGraphicsContext( gw );

const osg::GraphicsContext::Traits* traits = gw->getTraits();

camera->setClearColor( osg::Vec4(0.0, 0.0, 0.0, 1.0) );

camera->setViewport( new osg::Viewport(0, 0, traits->width, traits->height) );

camera->setProjectionMatrixAsPerspective(45.0f, static_cast<double>(traits->width)/static_cast<double>(traits->height), 0.1f, 100.0f );

camera->setViewMatrixAsLookAt(osg::Vec3d(0, 0, 0), osg::Vec3d(0, 0, -1), osg::Vec3d(0, 1, 0));

this->setSceneData( scene );

this->addEventHandler(new ManipulatorSceneHandler);

return gw->getGLWidget();

}

osgQt::GraphicsWindowQt* createGraphicsWindow( int x, int y, int w, int h, const std::string& name="", bool windowDecoration=false )

{

osg::DisplaySettings* ds = osg::DisplaySettings::instance().get();

osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;

traits->windowName = name;

traits->windowDecoration = windowDecoration;

traits->x = x;

traits->y = y;

traits->width = w;

traits->height = h;

traits->doubleBuffer = true;

traits->alpha = ds->getMinimumNumAlphaBits();

traits->stencil = ds->getMinimumNumStencilBits();

traits->sampleBuffers = ds->getMultiSamples();

traits->samples = ds->getNumMultiSamples();

return new osgQt::GraphicsWindowQt(traits.get());

}

virtual void paintEvent( QPaintEvent* event )

{

frame();

}

protected:

QTimer _timer;

};

osg::Node* buildScene()

{

osg::Group *root = new osg::Group;

osg::Texture2D *texture2D = new osg::Texture2D;

texture2D = new osg::Texture2D;

texture2D->setFilter(osg::Texture::MAG_FILTER, osg::Texture::NEAREST);

texture2D->setFilter(osg::Texture::MIN_FILTER, osg::Texture::NEAREST);

osg::ImageStream *imageStream = dynamic_cast<osg::ImageStream*>(osgDB::readImageFile("Data/Child.gif"));

if(imageStream)

imageStream->play();

texture2D->setImage(imageStream);

root->getOrCreateStateSet()->setTextureAttributeAndModes(0, texture2D);

osg::Switch *switchNode = new osg::Switch;

g_SwitchNode = switchNode;

switchNode->addChild(createBox());

switchNode->addChild(createCylinder());

switchNode->addChild(createSphere());

switchNode->setSingleChildOn(0);

osg::TexGen *texGen = new osg::TexGen;

texGen->setMode(osg::TexGen::SPHERE_MAP);

switchNode->getOrCreateStateSet()->setTextureAttributeAndModes(0, texGen);

osg::MatrixTransform *zoomMT = new osg::MatrixTransform;

zoomMT->setMatrix(osg::Matrix::translate(0.0f, 0.0f, -10.0f));

zoomMT->addChild(switchNode);

root->addChild(createBackGroundGeode());

root->addChild(zoomMT);

return root;

}

int main( int argc, char** argv )

{

QApplication app(argc, argv);

ViewerWidget* viewWidget = new ViewerWidget(buildScene());

viewWidget->setGeometry( 100, 100, 640, 480 );

viewWidget->show();

return app.exec();

}