Files
OpenSceneGraph/src/osgPlugins/lwo/Tessellator.cpp
2012-03-21 17:36:20 +00:00

122 lines
3.4 KiB
C++

/*******************************************************
Lightwave Object Loader for OSG
Copyright (C) 2004 Marco Jez <marco.jez@poste.it>
OpenSceneGraph is (C) 2004 Robert Osfield
********************************************************/
#include "Tessellator.h"
using namespace lwosg;
namespace lwosg
{
void CALLBACK cb_begin_data(GLenum type, void *data)
{
Tessellator *tess = static_cast<Tessellator *>(data);
tess->prim_type_ = type;
tess->incoming_.clear();
}
void CALLBACK cb_vertex_data(void *vertex_data, void *data)
{
Tessellator *tess = static_cast<Tessellator *>(data);
tess->incoming_.push_back(*static_cast<int *>(vertex_data));
}
void CALLBACK cb_end_data(void *data)
{
Tessellator *tess = static_cast<Tessellator *>(data);
tess->finalize_primitive();
}
void CALLBACK cb_error_data(GLenum error, void *data)
{
Tessellator *tess = static_cast<Tessellator *>(data);
tess->last_error_ = error;
}
}
bool Tessellator::tessellate(const Polygon &poly, const osg::Vec3Array *points, osg::DrawElementsUInt *out, const std::vector<int> *remap)
{
out_ = out;
last_error_ = 0;
osg::GLUtesselator *tess = osg::gluNewTess();
osg::gluTessCallback(tess, GLU_TESS_BEGIN_DATA, (osg::GLU_TESS_CALLBACK) (cb_begin_data));
osg::gluTessCallback(tess, GLU_TESS_VERTEX_DATA, (osg::GLU_TESS_CALLBACK) (cb_vertex_data));
osg::gluTessCallback(tess, GLU_TESS_END_DATA, (osg::GLU_TESS_CALLBACK) (cb_end_data));
osg::gluTessCallback(tess, GLU_TESS_ERROR_DATA, (osg::GLU_TESS_CALLBACK) (cb_error_data));
osg::gluTessBeginPolygon(tess, this);
osg::gluTessBeginContour(tess);
double *vertices = new double[poly.indices().size() * 3];
int *indices = new int[poly.indices().size()];
double *v = vertices;
int *x = indices;
for (Polygon::Index_list::const_iterator i=poly.indices().begin(); i!=poly.indices().end(); ++i, v+=3, ++x) {
const osg::Vec3 &P = (*points)[*i];
v[0] = P.x();
v[1] = P.y();
v[2] = P.z();
if (remap) {
*x = (*remap)[*i];
} else {
*x = *i;
}
gluTessVertex(tess, v, x);
}
osg::gluTessEndContour(tess);
osg::gluTessEndPolygon(tess);
osg::gluDeleteTess(tess);
delete[] vertices;
delete[] indices;
return last_error_ == 0;
}
Tessellator::~Tessellator()
{
}
void Tessellator::finalize_primitive()
{
if (incoming_.size() < 3) return;
if (prim_type_ == GL_TRIANGLES) {
for (Index_list::const_iterator i=incoming_.begin(); i!=incoming_.end(); ++i) {
out_->push_back(*i);
}
}
if (prim_type_ == GL_TRIANGLE_FAN) {
for (Index_list::const_iterator i=incoming_.begin()+1; (i+1)!=incoming_.end(); ++i) {
out_->push_back(incoming_.front());
out_->push_back(*i);
out_->push_back(*(i+1));
}
}
if (prim_type_ == GL_TRIANGLE_STRIP) {
int j = 0;
for (Index_list::const_iterator i=incoming_.begin(); (i+2)!=incoming_.end(); ++i, ++j) {
if ((j % 2) == 0) {
out_->push_back(*i);
out_->push_back(*(i+1));
out_->push_back(*(i+2));
} else {
out_->push_back(*i);
out_->push_back(*(i+2));
out_->push_back(*(i+1));
}
}
}
}