FGFS-4.1/OpenSceneGraph
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Implemented more code for the new osgprerender demo.

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This commit is contained in:
Robert Osfield
2002-07-09 19:23:53 +00:00
parent 68540f5fb1
commit 842eb59e1f
3 changed files with 335 additions and 8 deletions
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333
src/Demos/osgprerender/osgprerender.cpp
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@@ -7,12 +7,15 @@
#include <osg/Stencil>
#include <osg/ColorMask>
#include <osg/Depth>
#include <osg/ClipPlane>
#include <osg/Billboard>
#include <osg/Material>
#include <osgGA/TrackballManipulator>
#include <osgGA/FlightManipulator>
#include <osgGA/DriveManipulator>
#include <osgUtil/TransformCallback>
#include <osgUtil/RenderToTextureStage>
#include <osgDB/Registry>
#include <osgDB/ReadFile>
@@ -20,11 +23,333 @@
#include <osgGLUT/glut>
#include <osgGLUT/Viewer>
class MyCullCallback : public osg::NodeCallback
{
public:
MyCullCallback(osg::Node* subgraph,osg::Texture* texture):
_subgraph(subgraph),
_texture(texture) {}
virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
{
osgUtil::CullVisitor* cullVisitor = dynamic_cast<osgUtil::CullVisitor*>(nv);
if (cullVisitor && _texture.valid() && _subgraph.valid())
{
doPreRender(*node,*cullVisitor);
// must traverse the subgraph
traverse(node,nv);
}
else
{
// must traverse the subgraph
traverse(node,nv);
}
}
void doPreRender(osg::Node& node, osgUtil::CullVisitor& cv);
osg::ref_ptr<osg::Node> _subgraph;
osg::ref_ptr<osg::Texture> _texture;
};
void MyCullCallback::doPreRender(osg::Node& node, osgUtil::CullVisitor& cv)
{
// default to true right now, will dertermine if perspective from the
// projection matrix...
bool isPerspectiveProjection = true;
const osg::Matrix& matrix = cv.getModelViewMatrix();
const osg::BoundingSphere& bs = _subgraph->getBound();
osg::Vec3 eye_local = cv.getEyeLocal();
if (!bs.valid())
{
osg::notify(osg::WARN) << "bb invalid"<<_subgraph.get()<<std::endl;
return;
}
osg::Vec3 eye_world(0.0,0.0,0.0);
osg::Vec3 center_world = bs.center()*matrix;
// no appropriate sprite has been found therefore need to create
// one for use.
// create the render to texture stage.
osg::ref_ptr<osgUtil::RenderToTextureStage> rtts = osgNew osgUtil::RenderToTextureStage;
// set up lighting.
// currently ignore lights in the scene graph itself..
// will do later.
osgUtil::RenderStage* previous_stage = cv.getCurrentRenderBin()->_stage;
// set up the background color and clear mask.
osg::Vec4 clear_color = previous_stage->getClearColor();
clear_color[3] = 0.0f; // set the alpha to zero.
rtts->setClearColor(clear_color);
rtts->setClearMask(previous_stage->getClearMask());
// set up to charge the same RenderStageLighting is the parent previous stage.
rtts->setRenderStageLighting(previous_stage->getRenderStageLighting());
// record the render bin, to be restored after creation
// of the render to text
osgUtil::RenderBin* previousRenderBin = cv.getCurrentRenderBin();
// set the current renderbin to be the newly created stage.
cv.setCurrentRenderBin(rtts.get());
// create quad coords (in local coords)
osg::Vec3 center_local = bs.center();
osg::Vec3 camera_up_local = cv.getUpLocal();
osg::Vec3 lv_local = center_local-eye_local;
float distance_local = lv_local.length();
lv_local /= distance_local;
osg::Vec3 sv_local = lv_local^camera_up_local;
sv_local.normalize();
osg::Vec3 up_local = sv_local^lv_local;
float width = bs.radius();
if (isPerspectiveProjection)
{
// expand the width to account for projection onto sprite.
width *= (distance_local/sqrtf(distance_local*distance_local-bs.radius2()));
}
// scale up and side vectors to sprite width.
up_local *= width;
sv_local *= width;
// create the corners of the sprite.
osg::Vec3 c00(center_local - sv_local - up_local);
osg::Vec3 c11(center_local + sv_local + up_local);
// adjust camera left,right,up,down to fit (in world coords)
osg::Vec3 near_local ( center_local-lv_local*width );
osg::Vec3 far_local ( center_local+lv_local*width );
osg::Vec3 top_local ( center_local+up_local);
osg::Vec3 right_local ( center_local+sv_local);
osg::Vec3 near_world = near_local * matrix;
osg::Vec3 far_world = far_local * matrix;
osg::Vec3 top_world = top_local * matrix;
osg::Vec3 right_world = right_local * matrix;
float znear = (near_world-eye_world).length();
float zfar = (far_world-eye_world).length();
float top = (top_world-center_world).length();
float right = (right_world-center_world).length();
znear *= 0.9f;
zfar *= 1.1f;
// set up projection.
osg::Matrix* projection = osgNew osg::Matrix;
if (isPerspectiveProjection)
{
// deal with projection issue move the top and right points
// onto the near plane.
float ratio = znear/(center_world-eye_world).length();
top *= ratio;
right *= ratio;
projection->makeFrustum(-right,right,-top,top,znear,zfar);
}
else
{
projection->makeOrtho(-right,right,-top,top,znear,zfar);
}
cv.pushProjectionMatrix(projection);
osg::Vec3 rotate_from = bs.center()-eye_local;
osg::Vec3 rotate_to = cv.getLookVectorLocal();
osg::Matrix* rotate_matrix = osgNew osg::Matrix(
osg::Matrix::translate(-eye_local)*
osg::Matrix::rotate(rotate_from,rotate_to)*
osg::Matrix::translate(eye_local)*
cv.getModelViewMatrix());
// pushing the cull view state will update it so it takes
// into account the new camera orientation.
cv.pushModelViewMatrix(rotate_matrix);
osg::ref_ptr<osg::StateSet> dummyState = osgNew osg::StateSet;
cv.pushStateSet(dummyState.get());
{
// traverse the subgraph
_subgraph->accept(cv);
}
cv.popStateSet();
// restore the previous model view matrix.
cv.popModelViewMatrix();
// restore the previous model view matrix.
cv.popProjectionMatrix();
// restore the previous renderbin.
cv.setCurrentRenderBin(previousRenderBin);
if (rtts->_renderGraphList.size()==0 && rtts->_bins.size()==0)
{
// getting to this point means that all the subgraph has been
// culled by small feature culling or is beyond LOD ranges.
return;
}
const osg::Viewport& viewport = *cv.getViewport();
// calc texture size for eye, bs.
// convert the corners of the sprite (in world coords) into their
// equivilant window coordinates by using the camera's project method.
const osg::Matrix& MVPW = cv.getMVPW();
osg::Vec3 c00_win = c00 * MVPW;
osg::Vec3 c11_win = c11 * MVPW;
// adjust texture size to be nearest power of 2.
float s = c11_win.x()-c00_win.x();
float t = c11_win.y()-c00_win.y();
// may need to reverse sign of width or height if a matrix has
// been applied which flips the orientation of this subgraph.
if (s<0.0f) s = -s;
if (t<0.0f) t = -t;
// bias value used to assist the rounding up or down of
// the texture dimensions to the nearest power of two.
// bias near 0.0 will almost always round down.
// bias near 1.0 will almost always round up.
float bias = 0.7f;
float sp2 = logf((float)s)/logf(2.0f);
float rounded_sp2 = floorf(sp2+bias);
int new_s = (int)(powf(2.0f,rounded_sp2));
float tp2 = logf((float)t)/logf(2.0f);
float rounded_tp2 = floorf(tp2+bias);
int new_t = (int)(powf(2.0f,rounded_tp2));
// if dimension is bigger than window divide it down.
while (new_s>viewport.width()) new_s /= 2;
// if dimension is bigger than window divide it down.
while (new_t>viewport.height()) new_t /= 2;
// offset the impostor viewport from the center of the main window
// viewport as often the edges of the viewport might be obscured by
// other windows, which can cause image/reading writing problems.
int center_x = viewport.x()+viewport.width()/2;
int center_y = viewport.y()+viewport.height()/2;
osg::Viewport* new_viewport = new osg::Viewport;
new_viewport->setViewport(center_x-new_s/2,center_y-new_t/2,new_s,new_t);
rtts->setViewport(new_viewport);
dummyState->setAttribute(new_viewport);
// and the render to texture stage to the current stages
// dependancy list.
cv.getCurrentRenderBin()->_stage->addToDependencyList(rtts.get());
// attach texture to the RenderToTextureStage.
rtts->setTexture(_texture.get());
}
osg::Node* createPreRenderSubGraph(osg::Node* subgraph)
{
// ok we havn't done anything yet, but this is where the funky code
// will go :)
return NULL;
if (!subgraph) return 0;
const osg::BoundingSphere& bs = subgraph->getBound();
// create the quad to visualize.
osg::Geometry* polyGeom = new osg::Geometry();
float radius = bs.radius()*1.5f;
osg::Vec3Array* vertices = new osg::Vec3Array;
vertices->push_back(osg::Vec3(-radius,0.0f,radius));
vertices->push_back(osg::Vec3(-radius,0.0f,-radius));
vertices->push_back(osg::Vec3(radius,0.0f,-radius));
vertices->push_back(osg::Vec3(radius,0.0f,radius));
// pass the created vertex array to the points geometry object.
polyGeom->setVertexArray(vertices);
osg::Vec3Array* normals = new osg::Vec3Array;
normals->push_back(osg::Vec3(0.0f,-1.0f,0.0f));
polyGeom->setNormalArray(normals);
polyGeom->setNormalBinding(osg::Geometry::BIND_OVERALL);
osg::Vec4Array* colors = new osg::Vec4Array;
colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
polyGeom->setColorArray(colors);
polyGeom->setColorBinding(osg::Geometry::BIND_OVERALL);
osg::Vec2 myTexCoords[] =
{
osg::Vec2(0,1),
osg::Vec2(0,0),
osg::Vec2(1,0),
osg::Vec2(1,1)
};
int numTexCoords = sizeof(myTexCoords)/sizeof(osg::Vec2);
polyGeom->setTexCoordArray(0,new osg::Vec2Array(numTexCoords,myTexCoords));
polyGeom->addPrimitive(new osg::DrawArrays(osg::Primitive::QUADS,0,4));
// 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 = new osg::StateSet;
// set up the texture.
osg::Texture* texture = new osg::Texture;
stateset->setTextureAttributeAndModes(0, texture,osg::StateAttribute::ON);
stateset->setMode(GL_LIGHTING,osg::StateAttribute::OVERRIDE_OFF);
polyGeom->setStateSet(stateset);
osg::Billboard* billboard = osgNew osg::Billboard();
billboard->setMode(osg::Billboard::POINT_ROT_EYE);
billboard->addDrawable(polyGeom,bs.center());
osg::Group* parent = new osg::Group;
parent->setCullCallback(new MyCullCallback(subgraph,texture));
parent->addChild(billboard);
return parent;
}
void write_usage(std::ostream& out,const std::string& name)