double TileSetLLByPixelArea::calcTriangleNDCAreaVisible(Plane const &clip_plane,
osg::Matrixd const &mvp,
std::vector<osg::Vec3d> const &tri,
std::vector<osg::Vec2d> const &tri_ndc) const
{
bool ok;
double area=0.0;
// NDC bounding rectangle
static const std::vector<osg::Vec2d> ndc_rect = {
osg::Vec2d(-1.0,-1.0), // bl
osg::Vec2d( 1.0,-1.0), // br
osg::Vec2d( 1.0, 1.0), // tr
osg::Vec2d(-1.0, 1.0) // tl
};
std::vector<osg::Vec3d> inside;
std::vector<osg::Vec3d> outside;
GeometryResult const result =
CalcTrianglePlaneClip(tri,
clip_plane,
inside,
outside);
if(result == GeometryResult::CLIP_OUTSIDE) {
// Completely outside the near plane
if(CalcTriangleAARectIntersection(tri_ndc,ndc_rect)) {
area += CalcTriangleArea(tri_ndc[0],tri_ndc[1],tri_ndc[2]);
}
}
else if(result == GeometryResult::CLIP_XSEC) {
// Triangle was clipped against the clip plane.
// Use the outside tri or quad to calculate area
std::vector<osg::Vec2d> list_ndc;
for(auto const & vx : outside) {
list_ndc.push_back(ConvWorldToNDC(mvp,vx,ok));
}
if(list_ndc.size() > 3) { // outside is a quad
if(CalcQuadAARectIntersection(list_ndc,ndc_rect)) {
area += CalcTriangleArea(list_ndc[0],list_ndc[1],list_ndc[2]);
area += CalcTriangleArea(list_ndc[0],list_ndc[2],list_ndc[3]);
}
}
else { // outside is a tri
if(CalcTriangleAARectIntersection(list_ndc,ndc_rect)) {
area += CalcTriangleArea(list_ndc[0],list_ndc[1],list_ndc[2]);
}
}
}
return area;
}
double TileSetLLByPixelArea::calcTriangleNDCAreaFull(Plane const &clip_plane,
osg::Matrixd const &mvp,
std::vector<osg::Vec3d> const &tri,
std::vector<osg::Vec2d> const &tri_ndc) const
{
bool ok;
double area=0.0;
std::vector<osg::Vec3d> inside;
std::vector<osg::Vec3d> outside;
GeometryResult const result =
CalcTrianglePlaneClip(tri,
clip_plane,
inside,
outside);
if(result == GeometryResult::CLIP_OUTSIDE) {
// Completely outside the near plane
area += CalcTriangleArea(tri_ndc[0],tri_ndc[1],tri_ndc[2]);
}
else if(result == GeometryResult::CLIP_XSEC) {
// Triangle was clipped against the clip plane.
// Use the outside tri or quad to calculate area
std::vector<osg::Vec2d> list_ndc;
for(auto const & vx : outside) {
list_ndc.push_back(ConvWorldToNDC(mvp,vx,ok));
}
if(list_ndc.size() > 3) { // outside is a quad
area += CalcTriangleArea(list_ndc[0],list_ndc[1],list_ndc[2]);
area += CalcTriangleArea(list_ndc[0],list_ndc[2],list_ndc[3]);
}
else { // outside is a tri
area += CalcTriangleArea(list_ndc[0],list_ndc[1],list_ndc[2]);
}
}
return area;
}
double CalcFaceArea (FacePtr pFace)
{ SidePtr pS; // to loop over a Face's Sides
double Area; // Face area
Loc3DTD FC; // Face centroid
CalcFaceCentroidFromNodes ( pFace );
FC = pFace->Centroid;
Area = 0.0;
pS = pFace->p1stSide;
while (pS != NULL)
{
Area = Area + CalcTriangleArea (FC, pS->pNode1->Loc3D, pS->pNode2->Loc3D);
pS = pS->pFsNextS;
}
return (Area);
}
/**
* 多角形の面積を計算.
*/
double MathUtil::CalcPolygonArea (sxsdk::shade_interface& shade, std::vector<sxsdk::vec3>& polygon)
{
if (polygon.size() < 3) return 0.0;
// 三角形分割を行う.
::m_triangleIndex.clear();
::CDivideTrianglesOutput divC;
shade.divide_polygon(divC, polygon.size(), &(polygon[0]), true);
const int triCou = ::m_triangleIndex.size() / 3;
double area = 0.0;
int iPos = 0;
for (int i = 0; i < triCou; i++, iPos += 3) {
const int i0 = ::m_triangleIndex[iPos + 0];
const int i1 = ::m_triangleIndex[iPos + 1];
const int i2 = ::m_triangleIndex[iPos + 2];
area += CalcTriangleArea(polygon[i0], polygon[i1], polygon[i2]);
}
return area;
}
void TileSetLLByPixelArea::calcTileNDCArea(Eval const &eval,
double &ndc_area,
double &surf_area_m2) const
{
// Find a quads that are completely visible
// (not clipped) and calculate both its pixel
// and surface areas
ndc_area = 0.0;
surf_area_m2 = 0.0;
// For each quad
for(size_t i=0; i < eval.list_ix.size(); i+=6) {
// Ignore quads that face away from the camera
if((eval.list_quad_nx[i/6]*m_view_dirn) >= -0.01) { // TODO experiment adjusting threshold
continue;
}
bool bad_tri=false;
// Try converting first tri to NDC
std::vector<osg::Vec3d> const tri0 = {
eval.list_vx[eval.list_ix[i+0]],
eval.list_vx[eval.list_ix[i+1]],
eval.list_vx[eval.list_ix[i+2]]
};
std::vector<osg::Vec2d> tri0_ndc(3);
for(size_t j=0; j < 3; j++) {
if(!ConvWorldToNDC(m_mvp,tri0[j],tri0_ndc[j])) {
bad_tri=true;
break;
}
}
if(bad_tri) {
continue;
}
// Try converting second tri to NDC
std::vector<osg::Vec3d> const tri1 = {
eval.list_vx[eval.list_ix[i+3]],
eval.list_vx[eval.list_ix[i+4]],
eval.list_vx[eval.list_ix[i+5]]
};
std::vector<osg::Vec2d> tri1_ndc(3);
for(size_t j=0; j < 3; j++) {
if(!ConvWorldToNDC(m_mvp,tri1[j],tri1_ndc[j])) {
bad_tri=true;
break;
}
}
if(bad_tri) {
continue;
}
// Add NDC area
double tri0_area = CalcTriangleArea(tri0_ndc[0],tri0_ndc[1],tri0_ndc[2]);
double tri1_area = CalcTriangleArea(tri1_ndc[0],tri1_ndc[1],tri1_ndc[2]);
ndc_area += tri0_area;
ndc_area += tri1_area;
// Add surface area
std::vector<LLA> const tri0_lla = {
eval.list_lla[eval.list_ix[i+0]],
eval.list_lla[eval.list_ix[i+1]],
eval.list_lla[eval.list_ix[i+2]]
};
// lon range for surface area
auto list_lon_ranges = CalcLonRange(tri0_lla);
if(list_lon_ranges.size() > 1) {
// We might get two ranges due to numerical
// precision issues near the antemeridian;
// discard the smaller range
double range0 =
list_lon_ranges[0].second-
list_lon_ranges[0].first;
double range1 =
list_lon_ranges[1].second-
list_lon_ranges[1].first;
if(range0 > range1) {
list_lon_ranges.pop_back();
}
else {
list_lon_ranges.erase(list_lon_ranges.begin());
}
}
// lat range for surface area
std::pair<double,double> lat_range(90.0,-90.0);
for(auto const &lla : tri0_lla) {
lat_range.first = std::min(lat_range.first,lla.lat);
lat_range.second = std::max(lat_range.second,lla.lat);
}
GeoBounds const bounds(list_lon_ranges[0].first,
list_lon_ranges[0].second,
lat_range.first,
lat_range.second);
// std::cout << "####: ndirn: " << (eval.list_quad_nx[i/6]*m_view_dirn) << std::endl;
// std::cout << "####: tri0_area: " << tri0_area << ", tri1_area: " << tri1_area << std::endl;
// std::cout << "####: bounds.lon [" << bounds.minLon << "," << bounds.maxLon << "]" << std::endl;
// std::cout << "####: bounds.lat [" << bounds.minLat << "," << bounds.maxLat << "]" << std::endl;
// std::cout << "####: bounds.area: " << CalcGeoBoundsArea(bounds) << std::endl;
surf_area_m2 += CalcGeoBoundsArea(bounds);
}
}
