OpenSceneGraph/examples/osgforest/osgforest.cpp
Robert Osfield 4d0a3444be From Christian Buchner, "I am hereby amending the osgforest sample with some code (functionally
equivalent to the GLSL shaders sample) that displays the forest with
shaders on Intel 945 GM hardware. This card supports OpenGL 1.4 and
ARB_fragment/vertex_program only.

I would be pleased if this change made it into the official set of
examples, as it illustrates the use of ARB shaders quite nicely. I did
not find any other example covering this topic."
2009-02-19 16:58:05 +00:00

1178 lines
36 KiB
C++

/* OpenSceneGraph example, osgforest.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <osg/AlphaFunc>
#include <osg/Billboard>
#include <osg/BlendFunc>
#include <osg/Depth>
#include <osg/Geode>
#include <osg/Geometry>
#include <osg/Material>
#include <osg/Math>
#include <osg/MatrixTransform>
#include <osg/PolygonOffset>
#include <osg/Projection>
#include <osg/ShapeDrawable>
#include <osg/StateSet>
#include <osg/Switch>
#include <osg/Texture2D>
#include <osg/TexEnv>
#include <osg/VertexProgram>
#include <osg/FragmentProgram>
#include <osgDB/ReadFile>
#include <osgDB/FileUtils>
#include <osgUtil/LineSegmentIntersector>
#include <osgUtil/IntersectionVisitor>
#include <osgUtil/SmoothingVisitor>
#include <osgText/Text>
#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>
#include <osgGA/StateSetManipulator>
#include <iostream>
#include <sstream>
// for the grid data..
#include "../osghangglide/terrain_coords.h"
// class to create the forest and manage the movement between various techniques.
class ForestTechniqueManager : public osg::Referenced
{
public:
ForestTechniqueManager() {}
class Tree : public osg::Referenced
{
public:
Tree():
_color(255,255,255,255),
_width(1.0f),
_height(1.0f),
_type(0) {}
Tree(const osg::Vec3& position, const osg::Vec4ub& color, float width, float height, unsigned int type):
_position(position),
_color(color),
_width(width),
_height(height),
_type(type) {}
osg::Vec3 _position;
osg::Vec4ub _color;
float _width;
float _height;
unsigned int _type;
};
typedef std::vector< osg::ref_ptr<Tree> > TreeList;
class Cell : public osg::Referenced
{
public:
typedef std::vector< osg::ref_ptr<Cell> > CellList;
Cell():_parent(0) {}
Cell(osg::BoundingBox& bb):_parent(0), _bb(bb) {}
void addCell(Cell* cell) { cell->_parent=this; _cells.push_back(cell); }
void addTree(Tree* tree) { _trees.push_back(tree); }
void addTrees(const TreeList& trees) { _trees.insert(_trees.end(),trees.begin(),trees.end()); }
void computeBound();
bool contains(const osg::Vec3& position) const { return _bb.contains(position); }
bool divide(unsigned int maxNumTreesPerCell=10);
bool divide(bool xAxis, bool yAxis, bool zAxis);
void bin();
Cell* _parent;
osg::BoundingBox _bb;
CellList _cells;
TreeList _trees;
};
float random(float min,float max) { return min + (max-min)*(float)rand()/(float)RAND_MAX; }
int random(int min,int max) { return min + (int)((float)(max-min)*(float)rand()/(float)RAND_MAX); }
osg::Geode* createTerrain(const osg::Vec3& origin, const osg::Vec3& size);
void createTreeList(osg::Node* terrain,const osg::Vec3& origin, const osg::Vec3& size,unsigned int numTreesToCreate,TreeList& trees);
osg::Geometry* createSprite( float w, float h, osg::Vec4ub color );
osg::Geometry* createOrthogonalQuads( const osg::Vec3& pos, float w, float h, osg::Vec4ub color );
osg::Geometry* createOrthogonalQuadsNoColor( const osg::Vec3& pos, float w, float h );
osg::Node* createBillboardGraph(Cell* cell,osg::StateSet* stateset);
osg::Node* createXGraph(Cell* cell,osg::StateSet* stateset);
osg::Node* createTransformGraph(Cell* cell,osg::StateSet* stateset);
osg::Node* createShaderGraph(Cell* cell,osg::StateSet* stateset);
osg::Node* createHUDWithText(const std::string& text);
osg::Node* createScene(unsigned int numTreesToCreates);
void advanceToNextTechnique(int delta=1)
{
if (_techniqueSwitch.valid())
{
_currentTechnique += delta;
if (_currentTechnique<0)
_currentTechnique = _techniqueSwitch->getNumChildren()-1;
if (_currentTechnique>=(int)_techniqueSwitch->getNumChildren())
_currentTechnique = 0;
_techniqueSwitch->setSingleChildOn(_currentTechnique);
}
}
osg::ref_ptr<osg::Switch> _techniqueSwitch;
int _currentTechnique;
};
// event handler to capture keyboard events and use them to advance the technique used for rendering
class TechniqueEventHandler : public osgGA::GUIEventHandler
{
public:
TechniqueEventHandler(ForestTechniqueManager* ttm=0) { _ForestTechniqueManager = ttm; }
META_Object(osgforestApp,TechniqueEventHandler);
virtual bool handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter&, osg::Object*, osg::NodeVisitor*);
virtual void getUsage(osg::ApplicationUsage& usage) const;
protected:
~TechniqueEventHandler() {}
TechniqueEventHandler(const TechniqueEventHandler&,const osg::CopyOp&) {}
osg::ref_ptr<ForestTechniqueManager> _ForestTechniqueManager;
};
bool TechniqueEventHandler::handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter&, osg::Object*, osg::NodeVisitor*)
{
switch(ea.getEventType())
{
case(osgGA::GUIEventAdapter::KEYDOWN):
{
if (ea.getKey()=='n' ||
ea.getKey()==osgGA::GUIEventAdapter::KEY_Right ||
ea.getKey()==osgGA::GUIEventAdapter::KEY_KP_Right)
{
_ForestTechniqueManager->advanceToNextTechnique(1);
return true;
}
else if (ea.getKey()=='p' ||
ea.getKey()==osgGA::GUIEventAdapter::KEY_Left ||
ea.getKey()==osgGA::GUIEventAdapter::KEY_KP_Left)
{
_ForestTechniqueManager->advanceToNextTechnique(-1);
return true;
}
return false;
}
default:
return false;
}
}
void TechniqueEventHandler::getUsage(osg::ApplicationUsage& usage) const
{
usage.addKeyboardMouseBinding("n or Left Arrow","Advance to next technique");
usage.addKeyboardMouseBinding("p or Right Array","Move to previous technique");
}
void ForestTechniqueManager::Cell::computeBound()
{
_bb.init();
for(CellList::iterator citr=_cells.begin();
citr!=_cells.end();
++citr)
{
(*citr)->computeBound();
_bb.expandBy((*citr)->_bb);
}
for(TreeList::iterator titr=_trees.begin();
titr!=_trees.end();
++titr)
{
_bb.expandBy((*titr)->_position);
}
}
bool ForestTechniqueManager::Cell::divide(unsigned int maxNumTreesPerCell)
{
if (_trees.size()<=maxNumTreesPerCell) return false;
computeBound();
float radius = _bb.radius();
float divide_distance = radius*0.7f;
if (divide((_bb.xMax()-_bb.xMin())>divide_distance,(_bb.yMax()-_bb.yMin())>divide_distance,(_bb.zMax()-_bb.zMin())>divide_distance))
{
// recusively divide the new cells till maxNumTreesPerCell is met.
for(CellList::iterator citr=_cells.begin();
citr!=_cells.end();
++citr)
{
(*citr)->divide(maxNumTreesPerCell);
}
return true;
}
else
{
return false;
}
}
bool ForestTechniqueManager::Cell::divide(bool xAxis, bool yAxis, bool zAxis)
{
if (!(xAxis || yAxis || zAxis)) return false;
if (_cells.empty())
_cells.push_back(new Cell(_bb));
if (xAxis)
{
unsigned int numCellsToDivide=_cells.size();
for(unsigned int i=0;i<numCellsToDivide;++i)
{
Cell* orig_cell = _cells[i].get();
Cell* new_cell = new Cell(orig_cell->_bb);
float xCenter = (orig_cell->_bb.xMin()+orig_cell->_bb.xMax())*0.5f;
orig_cell->_bb.xMax() = xCenter;
new_cell->_bb.xMin() = xCenter;
_cells.push_back(new_cell);
}
}
if (yAxis)
{
unsigned int numCellsToDivide=_cells.size();
for(unsigned int i=0;i<numCellsToDivide;++i)
{
Cell* orig_cell = _cells[i].get();
Cell* new_cell = new Cell(orig_cell->_bb);
float yCenter = (orig_cell->_bb.yMin()+orig_cell->_bb.yMax())*0.5f;
orig_cell->_bb.yMax() = yCenter;
new_cell->_bb.yMin() = yCenter;
_cells.push_back(new_cell);
}
}
if (zAxis)
{
unsigned int numCellsToDivide=_cells.size();
for(unsigned int i=0;i<numCellsToDivide;++i)
{
Cell* orig_cell = _cells[i].get();
Cell* new_cell = new Cell(orig_cell->_bb);
float zCenter = (orig_cell->_bb.zMin()+orig_cell->_bb.zMax())*0.5f;
orig_cell->_bb.zMax() = zCenter;
new_cell->_bb.zMin() = zCenter;
_cells.push_back(new_cell);
}
}
bin();
return true;
}
void ForestTechniqueManager::Cell::bin()
{
// put trees in appropriate cells.
TreeList treesNotAssigned;
for(TreeList::iterator titr=_trees.begin();
titr!=_trees.end();
++titr)
{
Tree* tree = titr->get();
bool assigned = false;
for(CellList::iterator citr=_cells.begin();
citr!=_cells.end() && !assigned;
++citr)
{
if ((*citr)->contains(tree->_position))
{
(*citr)->addTree(tree);
assigned = true;
}
}
if (!assigned) treesNotAssigned.push_back(tree);
}
// put the unassigned trees back into the original local tree list.
_trees.swap(treesNotAssigned);
// prune empty cells.
CellList cellsNotEmpty;
for(CellList::iterator citr=_cells.begin();
citr!=_cells.end();
++citr)
{
if (!((*citr)->_trees.empty()))
{
cellsNotEmpty.push_back(*citr);
}
}
_cells.swap(cellsNotEmpty);
}
osg::Geode* ForestTechniqueManager::createTerrain(const osg::Vec3& origin, const osg::Vec3& size)
{
osg::Geode* geode = new osg::Geode();
// ---------------------------------------
// Set up a StateSet to texture the objects
// ---------------------------------------
osg::StateSet* stateset = new osg::StateSet();
osg::Image* image = osgDB::readImageFile("Images/lz.rgb");
if (image)
{
osg::Texture2D* texture = new osg::Texture2D;
texture->setImage(image);
stateset->setTextureAttributeAndModes(0,texture,osg::StateAttribute::ON);
}
geode->setStateSet( stateset );
unsigned int numColumns = 38;
unsigned int numRows = 39;
unsigned int r;
unsigned int c;
// compute z range of z values of grid data so we can scale it.
float min_z = FLT_MAX;
float max_z = -FLT_MAX;
for(r=0;r<numRows;++r)
{
for(c=0;c<numColumns;++c)
{
min_z = osg::minimum(min_z,vertex[r+c*numRows][2]);
max_z = osg::maximum(max_z,vertex[r+c*numRows][2]);
}
}
float scale_z = size.z()/(max_z-min_z);
bool createGrid = false;
if (createGrid)
{
osg::HeightField* grid = new osg::HeightField;
grid->allocate(numColumns,numRows);
grid->setOrigin(origin);
grid->setXInterval(size.x()/(float)(numColumns-1));
grid->setYInterval(size.y()/(float)(numRows-1));
for(r=0;r<numRows;++r)
{
for(c=0;c<numColumns;++c)
{
grid->setHeight(c,r,(vertex[r+c*numRows][2]-min_z)*scale_z);
}
}
geode->addDrawable(new osg::ShapeDrawable(grid));
}
else
{
osg::Geometry* geometry = new osg::Geometry;
osg::Vec3Array& v = *(new osg::Vec3Array(numColumns*numRows));
osg::Vec2Array& t = *(new osg::Vec2Array(numColumns*numRows));
osg::Vec4ubArray& color = *(new osg::Vec4ubArray(1));
color[0].set(255,255,255,255);
float rowCoordDelta = size.y()/(float)(numRows-1);
float columnCoordDelta = size.x()/(float)(numColumns-1);
float rowTexDelta = 1.0f/(float)(numRows-1);
float columnTexDelta = 1.0f/(float)(numColumns-1);
osg::Vec3 pos = origin;
osg::Vec2 tex(0.0f,0.0f);
int vi=0;
for(r=0;r<numRows;++r)
{
pos.x() = origin.x();
tex.x() = 0.0f;
for(c=0;c<numColumns;++c)
{
v[vi].set(pos.x(),pos.y(),pos.z()+(vertex[r+c*numRows][2]-min_z)*scale_z);
t[vi].set(tex.x(),tex.y());
pos.x()+=columnCoordDelta;
tex.x()+=columnTexDelta;
++vi;
}
pos.y() += rowCoordDelta;
tex.y() += rowTexDelta;
}
geometry->setVertexArray(&v);
geometry->setColorArray(&color);
geometry->setColorBinding(osg::Geometry::BIND_OVERALL);
geometry->setTexCoordArray(0,&t);
for(r=0;r<numRows-1;++r)
{
osg::DrawElementsUShort& drawElements = *(new osg::DrawElementsUShort(GL_QUAD_STRIP,2*numColumns));
geometry->addPrimitiveSet(&drawElements);
int ei=0;
for(c=0;c<numColumns;++c)
{
drawElements[ei++] = (r+1)*numColumns+c;
drawElements[ei++] = (r)*numColumns+c;
}
}
geode->addDrawable(geometry);
osgUtil::SmoothingVisitor sv;
sv.smooth(*geometry);
}
return geode;
}
void ForestTechniqueManager::createTreeList(osg::Node* terrain,const osg::Vec3& origin, const osg::Vec3& size,unsigned int numTreesToCreate,TreeList& trees)
{
float max_TreeHeight = sqrtf(size.length2()/(float)numTreesToCreate);
float max_TreeWidth = max_TreeHeight*0.5f;
float min_TreeHeight = max_TreeHeight*0.3f;
float min_TreeWidth = min_TreeHeight*0.5f;
trees.reserve(trees.size()+numTreesToCreate);
for(unsigned int i=0;i<numTreesToCreate;++i)
{
Tree* tree = new Tree;
tree->_position.set(random(origin.x(),origin.x()+size.x()),random(origin.y(),origin.y()+size.y()),origin.z());
tree->_color.set(random(128,255),random(128,255),random(128,255),255);
tree->_width = random(min_TreeWidth,max_TreeWidth);
tree->_height = random(min_TreeHeight,max_TreeHeight);
tree->_type = 0;
if (terrain)
{
osg::ref_ptr<osgUtil::LineSegmentIntersector> intersector =
new osgUtil::LineSegmentIntersector(tree->_position,tree->_position+osg::Vec3(0.0f,0.0f,size.z()));
osgUtil::IntersectionVisitor iv(intersector.get());
terrain->accept(iv);
if (intersector->containsIntersections())
{
osgUtil::LineSegmentIntersector::Intersections& intersections = intersector->getIntersections();
for(osgUtil::LineSegmentIntersector::Intersections::iterator itr = intersections.begin();
itr != intersections.end();
++itr)
{
const osgUtil::LineSegmentIntersector::Intersection& intersection = *itr;
tree->_position = intersection.getWorldIntersectPoint();
}
}
}
trees.push_back(tree);
}
}
osg::Geometry* ForestTechniqueManager::createSprite( float w, float h, osg::Vec4ub color )
{
// set up the coords
osg::Vec3Array& v = *(new osg::Vec3Array(4));
osg::Vec2Array& t = *(new osg::Vec2Array(4));
osg::Vec4ubArray& c = *(new osg::Vec4ubArray(1));
v[0].set(-w*0.5f,0.0f,0.0f);
v[1].set( w*0.5f,0.0f,0.0f);
v[2].set( w*0.5f,0.0f,h);
v[3].set(-w*0.5f,0.0f,h);
c[0] = color;
t[0].set(0.0f,0.0f);
t[1].set(1.0f,0.0f);
t[2].set(1.0f,1.0f);
t[3].set(0.0f,1.0f);
osg::Geometry *geom = new osg::Geometry;
geom->setVertexArray( &v );
geom->setTexCoordArray( 0, &t );
geom->setColorArray( &c );
geom->setColorBinding( osg::Geometry::BIND_OVERALL );
geom->addPrimitiveSet( new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,4) );
return geom;
}
osg::Geometry* ForestTechniqueManager::createOrthogonalQuads( const osg::Vec3& pos, float w, float h, osg::Vec4ub color )
{
// set up the coords
osg::Vec3Array& v = *(new osg::Vec3Array(8));
osg::Vec2Array& t = *(new osg::Vec2Array(8));
osg::Vec4ubArray& c = *(new osg::Vec4ubArray(1));
float rotation = random(0.0f,osg::PI/2.0f);
float sw = sinf(rotation)*w*0.5f;
float cw = cosf(rotation)*w*0.5f;
v[0].set(pos.x()-sw,pos.y()-cw,pos.z()+0.0f);
v[1].set(pos.x()+sw,pos.y()+cw,pos.z()+0.0f);
v[2].set(pos.x()+sw,pos.y()+cw,pos.z()+h);
v[3].set(pos.x()-sw,pos.y()-cw,pos.z()+h);
v[4].set(pos.x()-cw,pos.y()+sw,pos.z()+0.0f);
v[5].set(pos.x()+cw,pos.y()-sw,pos.z()+0.0f);
v[6].set(pos.x()+cw,pos.y()-sw,pos.z()+h);
v[7].set(pos.x()-cw,pos.y()+sw,pos.z()+h);
c[0] = color;
t[0].set(0.0f,0.0f);
t[1].set(1.0f,0.0f);
t[2].set(1.0f,1.0f);
t[3].set(0.0f,1.0f);
t[4].set(0.0f,0.0f);
t[5].set(1.0f,0.0f);
t[6].set(1.0f,1.0f);
t[7].set(0.0f,1.0f);
osg::Geometry *geom = new osg::Geometry;
geom->setVertexArray( &v );
geom->setTexCoordArray( 0, &t );
geom->setColorArray( &c );
geom->setColorBinding( osg::Geometry::BIND_OVERALL );
geom->addPrimitiveSet( new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,8) );
return geom;
}
osg::Node* ForestTechniqueManager::createBillboardGraph(Cell* cell,osg::StateSet* stateset)
{
bool needGroup = !(cell->_cells.empty());
bool needBillboard = !(cell->_trees.empty());
osg::Billboard* billboard = 0;
osg::Group* group = 0;
if (needBillboard)
{
billboard = new osg::Billboard;
billboard->setStateSet(stateset);
for(TreeList::iterator itr=cell->_trees.begin();
itr!=cell->_trees.end();
++itr)
{
Tree& tree = **itr;
billboard->addDrawable(createSprite(tree._width,tree._height,tree._color),tree._position);
}
}
if (needGroup)
{
group = new osg::Group;
for(Cell::CellList::iterator itr=cell->_cells.begin();
itr!=cell->_cells.end();
++itr)
{
group->addChild(createBillboardGraph(itr->get(),stateset));
}
if (billboard) group->addChild(billboard);
}
if (group) return group;
else return billboard;
}
osg::Node* ForestTechniqueManager::createXGraph(Cell* cell,osg::StateSet* stateset)
{
bool needGroup = !(cell->_cells.empty());
bool needTrees = !(cell->_trees.empty());
osg::Geode* geode = 0;
osg::Group* group = 0;
if (needTrees)
{
geode = new osg::Geode;
geode->setStateSet(stateset);
for(TreeList::iterator itr=cell->_trees.begin();
itr!=cell->_trees.end();
++itr)
{
Tree& tree = **itr;
geode->addDrawable(createOrthogonalQuads(tree._position,tree._width,tree._height,tree._color));
}
}
if (needGroup)
{
group = new osg::Group;
for(Cell::CellList::iterator itr=cell->_cells.begin();
itr!=cell->_cells.end();
++itr)
{
group->addChild(createXGraph(itr->get(),stateset));
}
if (geode) group->addChild(geode);
}
if (group) return group;
else return geode;
}
osg::Node* ForestTechniqueManager::createTransformGraph(Cell* cell,osg::StateSet* stateset)
{
bool needGroup = !(cell->_cells.empty());
bool needTrees = !(cell->_trees.empty());
osg::Group* transform_group = 0;
osg::Group* group = 0;
if (needTrees)
{
transform_group = new osg::Group;
osg::Geometry* geometry = createOrthogonalQuads(osg::Vec3(0.0f,0.0f,0.0f),1.0f,1.0f,osg::Vec4ub(255,255,255,255));
for(TreeList::iterator itr=cell->_trees.begin();
itr!=cell->_trees.end();
++itr)
{
Tree& tree = **itr;
osg::MatrixTransform* transform = new osg::MatrixTransform;
transform->setMatrix(osg::Matrix::scale(tree._width,tree._width,tree._height)*osg::Matrix::translate(tree._position));
osg::Geode* geode = new osg::Geode;
geode->setStateSet(stateset);
geode->addDrawable(geometry);
transform->addChild(geode);
transform_group->addChild(transform);
}
}
if (needGroup)
{
group = new osg::Group;
for(Cell::CellList::iterator itr=cell->_cells.begin();
itr!=cell->_cells.end();
++itr)
{
group->addChild(createTransformGraph(itr->get(),stateset));
}
if (transform_group) group->addChild(transform_group);
}
if (group) return group;
else return transform_group;
}
osg::Geometry* ForestTechniqueManager::createOrthogonalQuadsNoColor( const osg::Vec3& pos, float w, float h)
{
// set up the coords
osg::Vec3Array& v = *(new osg::Vec3Array(8));
osg::Vec2Array& t = *(new osg::Vec2Array(8));
float rotation = random(0.0f,osg::PI/2.0f);
float sw = sinf(rotation)*w*0.5f;
float cw = cosf(rotation)*w*0.5f;
v[0].set(pos.x()-sw,pos.y()-cw,pos.z()+0.0f);
v[1].set(pos.x()+sw,pos.y()+cw,pos.z()+0.0f);
v[2].set(pos.x()+sw,pos.y()+cw,pos.z()+h);
v[3].set(pos.x()-sw,pos.y()-cw,pos.z()+h);
v[4].set(pos.x()-cw,pos.y()+sw,pos.z()+0.0f);
v[5].set(pos.x()+cw,pos.y()-sw,pos.z()+0.0f);
v[6].set(pos.x()+cw,pos.y()-sw,pos.z()+h);
v[7].set(pos.x()-cw,pos.y()+sw,pos.z()+h);
t[0].set(0.0f,0.0f);
t[1].set(1.0f,0.0f);
t[2].set(1.0f,1.0f);
t[3].set(0.0f,1.0f);
t[4].set(0.0f,0.0f);
t[5].set(1.0f,0.0f);
t[6].set(1.0f,1.0f);
t[7].set(0.0f,1.0f);
osg::Geometry *geom = new osg::Geometry;
geom->setVertexArray( &v );
geom->setTexCoordArray( 0, &t );
geom->addPrimitiveSet( new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,8) );
return geom;
}
class ShaderGeometry : public osg::Drawable
{
public:
ShaderGeometry() { setUseDisplayList(false); }
/** Copy constructor using CopyOp to manage deep vs shallow copy.*/
ShaderGeometry(const ShaderGeometry& ShaderGeometry,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY):
osg::Drawable(ShaderGeometry,copyop) {}
META_Object(osg,ShaderGeometry)
typedef std::vector<osg::Vec4> PositionSizeList;
virtual void drawImplementation(osg::RenderInfo& renderInfo) const
{
for(PositionSizeList::const_iterator itr = _trees.begin();
itr != _trees.end();
++itr)
{
glColor4fv(itr->ptr());
_geometry->draw(renderInfo);
}
}
virtual osg::BoundingBox computeBound() const
{
osg::BoundingBox geom_box = _geometry->getBound();
osg::BoundingBox bb;
for(PositionSizeList::const_iterator itr = _trees.begin();
itr != _trees.end();
++itr)
{
bb.expandBy(geom_box.corner(0)*(*itr)[3] +
osg::Vec3( (*itr)[0], (*itr)[1], (*itr)[2] ));
bb.expandBy(geom_box.corner(7)*(*itr)[3] +
osg::Vec3( (*itr)[0], (*itr)[1], (*itr)[2] ));
}
return bb;
}
void setGeometry(osg::Geometry* geometry)
{
_geometry = geometry;
}
void addTree(ForestTechniqueManager::Tree& tree)
{
_trees.push_back(osg::Vec4(tree._position.x(), tree._position.y(), tree._position.z(), tree._height));
}
osg::ref_ptr<osg::Geometry> _geometry;
PositionSizeList _trees;
protected:
virtual ~ShaderGeometry() {}
};
osg::Geometry* shared_geometry = 0;
osg::Node* ForestTechniqueManager::createShaderGraph(Cell* cell,osg::StateSet* stateset)
{
if (shared_geometry==0)
{
shared_geometry = createOrthogonalQuadsNoColor(osg::Vec3(0.0f,0.0f,0.0f),1.0f,1.0f);
//shared_geometry->setUseDisplayList(false);
}
bool needGroup = !(cell->_cells.empty());
bool needTrees = !(cell->_trees.empty());
osg::Geode* geode = 0;
osg::Group* group = 0;
if (needTrees)
{
geode = new osg::Geode;
ShaderGeometry* shader_geometry = new ShaderGeometry;
shader_geometry->setGeometry(shared_geometry);
for(TreeList::iterator itr=cell->_trees.begin();
itr!=cell->_trees.end();
++itr)
{
Tree& tree = **itr;
shader_geometry->addTree(tree);
}
geode->setStateSet(stateset);
geode->addDrawable(shader_geometry);
}
if (needGroup)
{
group = new osg::Group;
for(Cell::CellList::iterator itr=cell->_cells.begin();
itr!=cell->_cells.end();
++itr)
{
group->addChild(createShaderGraph(itr->get(),stateset));
}
if (geode) group->addChild(geode);
}
if (group) return group;
else return geode;
}
osg::Node* ForestTechniqueManager::createHUDWithText(const std::string& str)
{
osg::Geode* geode = new osg::Geode();
std::string timesFont("fonts/arial.ttf");
// turn lighting off for the text and disable depth test to ensure its always ontop.
osg::StateSet* stateset = geode->getOrCreateStateSet();
stateset->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
// or disable depth test, and make sure that the hud is drawn after everything
// else so that it always appears ontop.
stateset->setMode(GL_DEPTH_TEST,osg::StateAttribute::OFF);
stateset->setRenderBinDetails(11,"RenderBin");
osg::Vec3 position(150.0f,800.0f,0.0f);
osg::Vec3 delta(0.0f,-120.0f,0.0f);
{
osgText::Text* text = new osgText::Text;
geode->addDrawable( text );
text->setFont(timesFont);
text->setPosition(position);
text->setText(str);
position += delta;
}
// create the hud.
osg::MatrixTransform* modelview_abs = new osg::MatrixTransform;
modelview_abs->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
modelview_abs->setMatrix(osg::Matrix::identity());
modelview_abs->addChild(geode);
osg::Projection* projection = new osg::Projection;
projection->setMatrix(osg::Matrix::ortho2D(0,1280,0,1024));
projection->addChild(modelview_abs);
return projection;
}
osg::Node* ForestTechniqueManager::createScene(unsigned int numTreesToCreates)
{
osg::Vec3 origin(0.0f,0.0f,0.0f);
osg::Vec3 size(1000.0f,1000.0f,200.0f);
std::cout<<"Creating terrain...";
osg::ref_ptr<osg::Node> terrain = createTerrain(origin,size);
std::cout<<"done."<<std::endl;
std::cout<<"Creating tree locations...";std::cout.flush();
TreeList trees;
createTreeList(terrain.get(),origin,size,numTreesToCreates,trees);
std::cout<<"done."<<std::endl;
std::cout<<"Creating cell subdivision...";
osg::ref_ptr<Cell> cell = new Cell;
cell->addTrees(trees);
cell->divide();
std::cout<<"done."<<std::endl;
osg::Texture2D *tex = new osg::Texture2D;
tex->setWrap( osg::Texture2D::WRAP_S, osg::Texture2D::CLAMP );
tex->setWrap( osg::Texture2D::WRAP_T, osg::Texture2D::CLAMP );
tex->setImage(osgDB::readImageFile("Images/tree0.rgba"));
osg::StateSet *dstate = new osg::StateSet;
{
dstate->setTextureAttributeAndModes(0, tex, osg::StateAttribute::ON );
dstate->setTextureAttribute(0, new osg::TexEnv );
dstate->setAttributeAndModes( new osg::BlendFunc, osg::StateAttribute::ON );
osg::AlphaFunc* alphaFunc = new osg::AlphaFunc;
alphaFunc->setFunction(osg::AlphaFunc::GEQUAL,0.05f);
dstate->setAttributeAndModes( alphaFunc, osg::StateAttribute::ON );
dstate->setMode( GL_LIGHTING, osg::StateAttribute::OFF );
dstate->setRenderingHint( osg::StateSet::TRANSPARENT_BIN );
}
_techniqueSwitch = new osg::Switch;
{
std::cout<<"Creating osg::Billboard based forest...";
osg::Group* group = new osg::Group;
group->addChild(createBillboardGraph(cell.get(),dstate));
group->addChild(createHUDWithText("Using osg::Billboard's to create a forest\n\nPress left cursor key to select OpenGL shader based forest\nPress right cursor key to select double quad based forest"));
_techniqueSwitch->addChild(group);
std::cout<<"done."<<std::endl;
}
{
std::cout<<"Creating double quad based forest...";
osg::Group* group = new osg::Group;
group->addChild(createXGraph(cell.get(),dstate));
group->addChild(createHUDWithText("Using double quads to create a forest\n\nPress left cursor key to select osg::Billboard based forest\nPress right cursor key to select osg::MatrixTransform based forest\n"));
_techniqueSwitch->addChild(group);
std::cout<<"done."<<std::endl;
}
{
std::cout<<"Creating osg::MatrixTransform based forest...";
osg::Group* group = new osg::Group;
group->addChild(createTransformGraph(cell.get(),dstate));
group->addChild(createHUDWithText("Using osg::MatrixTransform's to create a forest\n\nPress left cursor key to select double quad based forest\nPress right cursor key to select osg::Vertex/FragmentProgram based forest"));
_techniqueSwitch->addChild(group);
std::cout<<"done."<<std::endl;
}
{
std::cout<<"Creating osg::Vertex/FragmentProgram based forest...";
osg::Group* group = new osg::Group;
osg::StateSet* stateset = new osg::StateSet(*dstate, osg::CopyOp::DEEP_COPY_ALL);
{
// vertex program
std::ostringstream vp_oss;
vp_oss <<
"!!ARBvp1.0\n"
"ATTRIB vpos = vertex.position;\n"
"ATTRIB vcol = vertex.color;\n"
"ATTRIB tc = vertex.texcoord[" << 0 << "];"
"PARAM mvp[4] = { state.matrix.mvp };\n"
"PARAM one = { 1.0, 1.0, 1.0, 1.0 };"
"TEMP position;\n"
// vec3 position = gl_Vertex.xyz * gl_Color.w + gl_Color.xyz;
"MAD position, vpos, vcol.w, vcol;\n"
// gl_Position = gl_ModelViewProjectionMatrix * vec4(position,1.0);
"MOV position.w, one;\n"
"DP4 result.position.x, mvp[0], position;\n"
"DP4 result.position.y, mvp[1], position;\n"
"DP4 result.position.z, mvp[2], position;\n"
"DP4 result.position.w, mvp[3], position;\n"
// gl_FrontColor = vec4(1.0,1.0,1.0,1.0);
"MOV result.color.front.primary, one;\n"
// texcoord = gl_MultiTexCoord0.st;
"MOV result.texcoord, tc;\n"
"END\n";
// fragment program
std::ostringstream fp_oss;
fp_oss <<
"!!ARBfp1.0\n"
"TEX result.color, fragment.texcoord[" << 0 << "], texture[" << 0 << "], 2D;"
"END\n";
osg::ref_ptr<osg::VertexProgram> vp = new osg::VertexProgram;
vp->setVertexProgram(vp_oss.str());
stateset->setAttributeAndModes(vp.get(), osg::StateAttribute::OVERRIDE|osg::StateAttribute::ON);
osg::ref_ptr<osg::FragmentProgram> fp = new osg::FragmentProgram;
fp->setFragmentProgram(fp_oss.str());
stateset->setAttributeAndModes(fp.get(), osg::StateAttribute::OVERRIDE|osg::StateAttribute::ON);
}
group->addChild(createShaderGraph(cell.get(),stateset));
group->addChild(createHUDWithText("Using osg::Vertex/FragmentProgram to create a forest\n\nPress left cursor key to select osg::MatrixTransform's based forest\nPress right cursor key to select OpenGL shader based forest"));
_techniqueSwitch->addChild(group);
std::cout<<"done."<<std::endl;
}
{
std::cout<<"Creating OpenGL shader based forest...";
osg::Group* group = new osg::Group;
osg::StateSet* stateset = new osg::StateSet(*dstate, osg::CopyOp::DEEP_COPY_ALL);
{
osg::Program* program = new osg::Program;
stateset->setAttribute(program);
#if 1
// use inline shaders
///////////////////////////////////////////////////////////////////
// vertex shader using just Vec4 coefficients
char vertexShaderSource[] =
"varying vec2 texcoord;\n"
"\n"
"void main(void)\n"
"{\n"
" vec3 position = gl_Vertex.xyz * gl_Color.w + gl_Color.xyz;\n"
" gl_Position = gl_ModelViewProjectionMatrix * vec4(position,1.0);\n"
" gl_FrontColor = vec4(1.0,1.0,1.0,1.0);\n"
" texcoord = gl_MultiTexCoord0.st;\n"
"}\n";
//////////////////////////////////////////////////////////////////
// fragment shader
//
char fragmentShaderSource[] =
"uniform sampler2D baseTexture; \n"
"varying vec2 texcoord; \n"
"\n"
"void main(void) \n"
"{ \n"
" gl_FragColor = texture2D( baseTexture, texcoord); \n"
"}\n";
osg::Shader* vertex_shader = new osg::Shader(osg::Shader::VERTEX, vertexShaderSource);
program->addShader(vertex_shader);
osg::Shader* fragment_shader = new osg::Shader(osg::Shader::FRAGMENT, fragmentShaderSource);
program->addShader(fragment_shader);
#else
// get shaders from source
program->addShader(osg::Shader::readShaderFile(osg::Shader::VERTEX, osgDB::findDataFile("shaders/forest.vert")));
program->addShader(osg::Shader::readShaderFile(osg::Shader::FRAGMENT, osgDB::findDataFile("shaders/forest.frag")));
#endif
osg::Uniform* baseTextureSampler = new osg::Uniform("baseTexture",0);
stateset->addUniform(baseTextureSampler);
}
group->addChild(createShaderGraph(cell.get(),stateset));
group->addChild(createHUDWithText("Using OpenGL Shader to create a forest\n\nPress left cursor key to select osg::Vertex/FragmentProgram based forest\nPress right cursor key to select osg::Billboard based forest"));
_techniqueSwitch->addChild(group);
std::cout<<"done."<<std::endl;
}
_currentTechnique = 0;
_techniqueSwitch->setSingleChildOn(_currentTechnique);
osg::Group* scene = new osg::Group;
scene->addChild(terrain.get());
scene->addChild(_techniqueSwitch.get());
return scene;
}
int main( int argc, char **argv )
{
// use an ArgumentParser object to manage the program arguments.
osg::ArgumentParser arguments(&argc,argv);
// construct the viewer.
osgViewer::Viewer viewer(arguments);
float numTreesToCreates = 10000;
arguments.read("--trees",numTreesToCreates);
osg::ref_ptr<ForestTechniqueManager> ttm = new ForestTechniqueManager;
// add the stats handler
viewer.addEventHandler(new osgViewer::StatsHandler);
viewer.addEventHandler(new TechniqueEventHandler(ttm.get()));
viewer.addEventHandler(new osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()));
// add model to viewer.
viewer.setSceneData( ttm->createScene((unsigned int)numTreesToCreates) );
return viewer.run();
}