OpenSceneGraph/examples/osgdistortion/osgdistortion.cpp
2006-08-02 19:55:03 +00:00

257 lines
8.4 KiB
C++

#include <osg/GLExtensions>
#include <osg/Node>
#include <osg/Geometry>
#include <osg/Notify>
#include <osg/MatrixTransform>
#include <osg/Texture2D>
#include <osg/Stencil>
#include <osg/ColorMask>
#include <osg/Depth>
#include <osg/Billboard>
#include <osg/Material>
#include <osg/Projection>
#include <osgGA/TrackballManipulator>
#include <osgGA/FlightManipulator>
#include <osgGA/DriveManipulator>
#include <osgUtil/SmoothingVisitor>
#include <osgDB/Registry>
#include <osgDB/ReadFile>
#include <osgProducer/Viewer>
using namespace osg;
osg::Node* createDistortionSubgraph(osg::Node* subgraph, const osg::Vec4& clearColour)
{
osg::Group* distortionNode = new osg::Group;
unsigned int tex_width = 1024;
unsigned int tex_height = 1024;
osg::Texture2D* texture = new osg::Texture2D;
texture->setTextureSize(tex_width, tex_height);
texture->setInternalFormat(GL_RGBA);
texture->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
texture->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
// set up the render to texture camera.
{
osg::CameraNode* camera = new osg::CameraNode;
// set clear the color and depth buffer
camera->setClearColor(clearColour);
camera->setClearMask(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
// just inherit the main cameras view
camera->setReferenceFrame(osg::Transform::RELATIVE_RF);
camera->setProjectionMatrix(osg::Matrixd::identity());
camera->setViewMatrix(osg::Matrixd::identity());
// set viewport
camera->setViewport(0,0,tex_width,tex_height);
// set the camera to render before the main camera.
camera->setRenderOrder(osg::CameraNode::PRE_RENDER);
// tell the camera to use OpenGL frame buffer object where supported.
camera->setRenderTargetImplementation(osg::CameraNode::FRAME_BUFFER_OBJECT);
// attach the texture and use it as the color buffer.
camera->attach(osg::CameraNode::COLOR_BUFFER, texture);
// add subgraph to render
camera->addChild(subgraph);
distortionNode->addChild(camera);
}
// set up the render to texture camera.
{
// create the quad to visualize.
osg::Geometry* polyGeom = new osg::Geometry();
polyGeom->setSupportsDisplayList(false);
osg::Vec3 origin(0.0f,0.0f,0.0f);
osg::Vec3 xAxis(1.0f,0.0f,0.0f);
osg::Vec3 yAxis(0.0f,1.0f,0.0f);
osg::Vec3 zAxis(0.0f,0.0f,1.0f);
float height = 1024.0f;
float width = 1280.0f;
int noSteps = 50;
osg::Vec3Array* vertices = new osg::Vec3Array;
osg::Vec2Array* texcoords = new osg::Vec2Array;
osg::Vec4Array* colors = new osg::Vec4Array;
osg::Vec3 bottom = origin;
osg::Vec3 dx = xAxis*(width/((float)(noSteps-1)));
osg::Vec3 dy = yAxis*(height/((float)(noSteps-1)));
osg::Vec2 bottom_texcoord(0.0f,0.0f);
osg::Vec2 dx_texcoord(1.0f/(float)(noSteps-1),0.0f);
osg::Vec2 dy_texcoord(0.0f,1.0f/(float)(noSteps-1));
osg::Vec3 cursor = bottom;
osg::Vec2 texcoord = bottom_texcoord;
int i,j;
for(i=0;i<noSteps;++i)
{
osg::Vec3 cursor = bottom+dy*(float)i;
osg::Vec2 texcoord = bottom_texcoord+dy_texcoord*(float)i;
for(j=0;j<noSteps;++j)
{
vertices->push_back(cursor);
texcoords->push_back(osg::Vec2((sin(texcoord.x()*osg::PI-osg::PI*0.5)+1.0f)*0.5f,(sin(texcoord.y()*osg::PI-osg::PI*0.5)+1.0f)*0.5f));
colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
cursor += dx;
texcoord += dx_texcoord;
}
}
// pass the created vertex array to the points geometry object.
polyGeom->setVertexArray(vertices);
polyGeom->setColorArray(colors);
polyGeom->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
polyGeom->setTexCoordArray(0,texcoords);
for(i=0;i<noSteps-1;++i)
{
osg::DrawElementsUShort* elements = new osg::DrawElementsUShort(osg::PrimitiveSet::QUAD_STRIP);
for(j=0;j<noSteps;++j)
{
elements->push_back(j+(i+1)*noSteps);
elements->push_back(j+(i)*noSteps);
}
polyGeom->addPrimitiveSet(elements);
}
// new we need to add the texture to the Drawable, we do so by creating a
// StateSet to contain the Texture StateAttribute.
osg::StateSet* stateset = polyGeom->getOrCreateStateSet();
stateset->setTextureAttributeAndModes(0, texture,osg::StateAttribute::ON);
stateset->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
osg::Geode* geode = new osg::Geode();
geode->addDrawable(polyGeom);
// set up the camera to render the textured quad
osg::CameraNode* camera = new osg::CameraNode;
// just inherit the main cameras view
camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
camera->setViewMatrix(osg::Matrix::identity());
camera->setProjectionMatrixAsOrtho2D(0,1280,0,1024);
// set the camera to render before the main camera.
camera->setRenderOrder(osg::CameraNode::NESTED_RENDER);
// tell the camera to use OpenGL frame buffer object where supported.
camera->setRenderTargetImplementation(osg::CameraNode::FRAME_BUFFER_OBJECT);
// attach the texture and use it as the color buffer.
camera->attach(osg::CameraNode::COLOR_BUFFER, texture);
// add subgraph to render
camera->addChild(geode);
distortionNode->addChild(camera);
}
return distortionNode;
}
int main( int argc, char **argv )
{
// use an ArgumentParser object to manage the program arguments.
osg::ArgumentParser arguments(&argc,argv);
// set up the usage document, in case we need to print out how to use this program.
arguments.getApplicationUsage()->setDescription(arguments.getApplicationName()+" is the example which demonstrates pre rendering of scene to a texture, and then apply this texture to geometry.");
arguments.getApplicationUsage()->setCommandLineUsage(arguments.getApplicationName()+" [options] filename ...");
arguments.getApplicationUsage()->addCommandLineOption("-h or --help","Display this information");
// construct the viewer.
osgProducer::Viewer viewer(arguments);
// set up the value with sensible default event handlers.
viewer.setUpViewer(osgProducer::Viewer::STANDARD_SETTINGS);
// get details on keyboard and mouse bindings used by the viewer.
viewer.getUsage(*arguments.getApplicationUsage());
// if user request help write it out to cout.
if (arguments.read("-h") || arguments.read("--help"))
{
arguments.getApplicationUsage()->write(std::cout);
return 1;
}
// any option left unread are converted into errors to write out later.
arguments.reportRemainingOptionsAsUnrecognized();
// report any errors if they have occured when parsing the program aguments.
if (arguments.errors())
{
arguments.writeErrorMessages(std::cout);
return 1;
}
if (arguments.argc()<=1)
{
arguments.getApplicationUsage()->write(std::cout,osg::ApplicationUsage::COMMAND_LINE_OPTION);
return 1;
}
// load the nodes from the commandline arguments.
osg::Node* loadedModel = osgDB::readNodeFiles(arguments);
if (!loadedModel)
{
// write_usage(osg::notify(osg::NOTICE),argv[0]);
return 1;
}
osg::Node* distortionNode = createDistortionSubgraph(loadedModel, viewer.getClearColor());
// add model to the viewer.
viewer.setSceneData( distortionNode );
// create the windows and run the threads.
viewer.realize();
while( !viewer.done() )
{
// wait for all cull and draw threads to complete.
viewer.sync();
// update the scene by traversing it with the the update visitor which will
// call all node update callbacks and animations.
viewer.update();
// fire off the cull and draw traversals of the scene.
viewer.frame();
}
// wait for all cull and draw threads to complete.
viewer.sync();
// run a clean up frame to delete all OpenGL objects.
viewer.cleanup_frame();
// wait for all the clean up frame to complete.
viewer.sync();
return 0;
}