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From Trajce Nikolov, "Here is extended version of the osgforest example - technique with geometry shader added, was doing it for a project so I thought might be useful to update the example as well

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"
This commit is contained in:
Robert Osfield
2011-11-18 08:20:04 +00:00
parent c7542d5cd8
commit 116b9a978c
1 changed files with 184 additions and 9 deletions
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193
examples/osgforest/osgforest.cpp
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@@ -140,6 +140,9 @@ public:
osg::Node* createShaderGraph(Cell* cell,osg::StateSet* stateset);
osg::Node* createGeometryShaderGraph(Cell* cell, osg::StateSet* stateset);
void CollectTreePositions(Cell* cell, std::vector< osg::Vec3 >& positions);
osg::Node* createHUDWithText(const std::string& text);
osg::Node* createScene(unsigned int numTreesToCreates);
@@ -201,8 +204,8 @@ bool TechniqueEventHandler::handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIAc
return true;
}
else if (ea.getKey()=='p' ||
ea.getKey()==osgGA::GUIEventAdapter::KEY_Left ||
ea.getKey()==osgGA::GUIEventAdapter::KEY_KP_Left)
ea.getKey()==osgGA::GUIEventAdapter::KEY_Left ||
ea.getKey()==osgGA::GUIEventAdapter::KEY_KP_Left)
{
_ForestTechniqueManager->advanceToNextTechnique(-1);
return true;
@@ -260,11 +263,11 @@ bool ForestTechniqueManager::Cell::divide(unsigned int maxNumTreesPerCell)
(*citr)->divide(maxNumTreesPerCell);
}
return true;
}
else
{
return false;
}
}
else
{
return false;
}
}
bool ForestTechniqueManager::Cell::divide(bool xAxis, bool yAxis, bool zAxis)
@@ -845,6 +848,165 @@ class ShaderGeometry : public osg::Drawable
osg::Geometry* shared_geometry = 0;
osg::Program* createGeometryShader()
{
static const char* vertSource = {
"#version 120\n"
"#extension GL_EXT_geometry_shader4 : enable\n"
"varying vec2 texcoord;\n"
"void main(void)\n"
"{\n"
" gl_Position = gl_Vertex;\n"
" texcoord = gl_MultiTexCoord0.st;\n"
"}\n"
};
static const char* geomSource = {
"#version 120\n"
"#extension GL_EXT_geometry_shader4 : enable\n"
"varying vec2 texcoord;\n"
"varying float intensity; \n"
"varying float red_intensity; \n"
"void main(void)\n"
"{\n"
" vec4 v = gl_PositionIn[0];\n"
" vec4 info = gl_PositionIn[1];\n"
" intensity = info.y;\n"
" red_intensity = info.z;\n"
"\n"
" float h = info.x;\n"
" float w = h*0.35;\n"
" vec4 e;\n"
" e = v + vec4(-w,0.0,0.0,0.0); gl_Position = gl_ModelViewProjectionMatrix * e; texcoord = vec2(0.0,0.0); EmitVertex();\n"
" e = v + vec4(w,0.0,0.0,0.0); gl_Position = gl_ModelViewProjectionMatrix * e; texcoord = vec2(1.0,0.0); EmitVertex();\n"
" e = v + vec4(-w,0.0,h,0.0); gl_Position = gl_ModelViewProjectionMatrix * e; texcoord = vec2(0.0,1.0); EmitVertex();\n"
" e = v + vec4(w,0.0,h,0.0); gl_Position = gl_ModelViewProjectionMatrix * e; texcoord = vec2(1.0,1.0); EmitVertex();\n"
" EndPrimitive();\n"
" e = v + vec4(0.0,-w,0.0,0.0); gl_Position = gl_ModelViewProjectionMatrix * e; texcoord = vec2(0.0,0.0); EmitVertex();\n"
" e = v + vec4(0.0,w,0.0,0.0); gl_Position = gl_ModelViewProjectionMatrix * e; texcoord = vec2(1.0,0.0); EmitVertex();\n"
" e = v + vec4(0.0,-w,h,0.0); gl_Position = gl_ModelViewProjectionMatrix * e; texcoord = vec2(0.0,1.0); EmitVertex();\n"
" e = v + vec4(0.0,w,h,0.0); gl_Position = gl_ModelViewProjectionMatrix * e; texcoord = vec2(1.0,1.0); EmitVertex();\n"
" EndPrimitive();\n"
"}\n"
};
static const char* fragSource = {
"uniform sampler2D baseTexture; \n"
"varying vec2 texcoord; \n"
"varying float intensity; \n"
"varying float red_intensity; \n"
"\n"
"void main(void) \n"
"{ \n"
" vec4 finalColor = texture2D( baseTexture, texcoord); \n"
" vec4 color = finalColor * intensity;\n"
" color.w = finalColor.w;\n"
" color.x *= red_intensity;\n"
" gl_FragColor = color;\n"
"}\n"
};
osg::Program* pgm = new osg::Program;
pgm->setName( "osgshader2 demo" );
pgm->addShader( new osg::Shader( osg::Shader::VERTEX, vertSource ) );
pgm->addShader( new osg::Shader( osg::Shader::FRAGMENT, fragSource ) );
pgm->addShader( new osg::Shader( osg::Shader::GEOMETRY, geomSource ) );
pgm->setParameter( GL_GEOMETRY_VERTICES_OUT_EXT, 8 );
pgm->setParameter( GL_GEOMETRY_INPUT_TYPE_EXT, GL_LINES );
pgm->setParameter( GL_GEOMETRY_OUTPUT_TYPE_EXT, GL_TRIANGLE_STRIP);
return pgm;
}
void ForestTechniqueManager::CollectTreePositions(Cell* cell, std::vector< osg::Vec3 >& positions)
{
bool needGroup = !(cell->_cells.empty());
bool needTrees = !(cell->_trees.empty());
if (needTrees)
{
for(TreeList::iterator itr=cell->_trees.begin();
itr!=cell->_trees.end();
++itr)
{
Tree& tree = **itr;
positions.push_back(tree._position);
}
}
if (needGroup)
{
for(Cell::CellList::iterator itr=cell->_cells.begin();
itr!=cell->_cells.end();
++itr)
{
CollectTreePositions(itr->get(),positions);
}
}
}
osg::Node* ForestTechniqueManager::createGeometryShaderGraph(Cell* cell, osg::StateSet* dstate)
{
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(dstate);
osg::Geometry* geometry = new osg::Geometry;
geode->addDrawable(geometry);
osg::Vec3Array* v = new osg::Vec3Array;
for(TreeList::iterator itr=cell->_trees.begin();
itr!=cell->_trees.end();
++itr)
{
Tree& tree = **itr;
v->push_back(tree._position);
v->push_back(osg::Vec3(/*tree._height*/30.0,(double)random(0.75f,1.15f),(double)random(1.0f,1.250f)));
}
geometry->setVertexArray( v );
geometry->addPrimitiveSet( new osg::DrawArrays( GL_LINES, 0, v->size() ) );
osg::StateSet* sset = geode->getOrCreateStateSet();
sset->setMode( GL_LIGHTING, osg::StateAttribute::OFF );
sset->setAttribute( createGeometryShader() );
osg::Uniform* baseTextureSampler = new osg::Uniform("baseTexture",0);
sset->addUniform(baseTextureSampler);
}
if (needGroup)
{
group = new osg::Group;
for(Cell::CellList::iterator itr=cell->_cells.begin();
itr!=cell->_cells.end();
++itr)
{
group->addChild(createGeometryShaderGraph(itr->get(),dstate));
}
if (geode) group->addChild(geode);
}
if (group) return group;
else return geode;
}
osg::Node* ForestTechniqueManager::createShaderGraph(Cell* cell,osg::StateSet* stateset)
{
if (shared_geometry==0)
@@ -991,7 +1153,7 @@ osg::Node* ForestTechniqueManager::createScene(unsigned int numTreesToCreates)
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"));
group->addChild(createHUDWithText("Using osg::Billboard's to create a forest\n\nPress left cursor key to select osg::Vertex/Geometry/FragmentProgram shader based forest\nPress right cursor key to select double quad based forest"));
_techniqueSwitch->addChild(group);
std::cout<<"done."<<std::endl;
}
@@ -1132,7 +1294,20 @@ osg::Node* ForestTechniqueManager::createScene(unsigned int numTreesToCreates)
}
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"));
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::Vertex/Geometry/FragmentProgram based forest"));
_techniqueSwitch->addChild(group);
std::cout<<"done."<<std::endl;
}
{
std::cout<<"Creating Geometry Shader based forest...";
osg::StateSet* stateset = new osg::StateSet(*dstate, osg::CopyOp::DEEP_COPY_ALL);
osg::Group* group = new osg::Group;
group->addChild(createGeometryShaderGraph(cell.get(), stateset));
group->addChild(createHUDWithText("Using osg::Vertex/Geometry/FragmentProgram to create a forest\n\nPress left cursor key to select OpenGL Shader based forest\nPress right cursor key to select osg::Billboard based forest"));
_techniqueSwitch->addChild(group);
std::cout<<"done."<<std::endl;
}