LLPointer<LLModel> LLMeshReduction::reduce(LLModel* in_model, F32 limit, S32 mode)
{
LLVertexBuffer::unbind();
// create vertex buffers from model
std::vector<LLPointer<LLVertexBuffer> > in_vertex_buffers;
create_vertex_buffers_from_model(in_model, in_vertex_buffers);
// create glod object from vertex buffers
stop_gloderror();
S32 glod_group = mCounter++;
S32 glod_object = mCounter++;
create_glod_object_from_vertex_buffers(glod_object, glod_group, in_vertex_buffers);
// set reduction parameters
stop_gloderror();
if (mode == TRIANGLE_BUDGET)
{
// triangle budget mode
glodGroupParameteri(glod_group, GLOD_ADAPT_MODE, GLOD_TRIANGLE_BUDGET);
stop_gloderror();
glodGroupParameteri(glod_group, GLOD_ERROR_MODE, GLOD_OBJECT_SPACE_ERROR);
stop_gloderror();
S32 triangle_count = (S32)limit;
glodGroupParameteri(glod_group, GLOD_MAX_TRIANGLES, triangle_count);
stop_gloderror();
}
else if (mode == ERROR_THRESHOLD)
{
// error threshold mode
glodGroupParameteri(glod_group, GLOD_ADAPT_MODE, GLOD_ERROR_THRESHOLD);
glodGroupParameteri(glod_group, GLOD_ERROR_MODE, GLOD_OBJECT_SPACE_ERROR);
F32 error_threshold = limit;
glodGroupParameterf(glod_group, GLOD_OBJECT_SPACE_ERROR_THRESHOLD, error_threshold);
stop_gloderror();
}
else
{
// not a legal mode
return NULL;
}
// do the reduction
glodAdaptGroup(glod_group);
stop_gloderror();
// convert glod object into vertex buffers
std::vector<LLPointer<LLVertexBuffer> > out_vertex_buffers;
create_vertex_buffers_from_glod_object(glod_object, glod_group, out_vertex_buffers);
// convert vertex buffers into a model
LLPointer<LLModel> out_model = create_model_from_vertex_buffers(out_vertex_buffers);
return out_model;
}
void LODDrawCallback::drawImplementation( osg::State& state, const osg::Drawable* p_drawable ) const
{
assert( _p_lodMesh && "lod mesh data not available!" );
const GLuint groupname = _p_lodMesh->getGroupName();
const GLuint objectname = _p_lodMesh->getObjectName();
const GLuint numpatches = _p_lodMesh->getNumPatches();
// need for LOD adaptation?
if ( _p_lodMesh->adaptLOD() )
{
glodBindObjectXform( objectname, GL_PROJECTION_MATRIX | GL_MODELVIEW_MATRIX );
glodAdaptGroup( groupname );
// reset the adaptation flag after every adaptation
// the adaptation is triggered by update callback
_p_lodMesh->setAdaptLOD( false );
}
// apply drawable's state
state.apply( p_drawable->getStateSet() );
// draw the object patches
for( GLuint patch = 0; patch < numpatches; ++patch )
glodDrawPatch( objectname, patch );
}
