vector<Segment> Shape::getCutlines(const Matrix4d &T, double z,
vector<Vector2d> &vertices,
double &max_gradient,
vector<Triangle> &support_triangles,
double supportangle,
double thickness) const
{
Vector2d lineStart;
Vector2d lineEnd;
vector<Segment> lines;
// we know our own tranform:
Matrix4d transform = T * transform3D.transform ;
int count = (int)triangles.size();
// #ifdef _OPENMP
// #pragma omp parallel for schedule(dynamic)
// #endif
for (int i = 0; i < count; i++)
{
Segment line(-1,-1);
int num_cutpoints = triangles[i].CutWithPlane(z, transform, lineStart, lineEnd);
if (num_cutpoints == 0) {
if (supportangle >= 0 && thickness > 0) {
if (triangles[i].isInZrange(z-thickness, z, transform)) {
const double slope = -triangles[i].slopeAngle(transform);
if (slope >= supportangle) {
support_triangles.push_back(triangles[i].transformed(transform));
}
}
}
continue;
}
if (num_cutpoints > 0) {
int havev = find_vertex(vertices, lineStart);
if (havev >= 0)
line.start = havev;
else {
line.start = vertices.size();
vertices.push_back(lineStart);
}
if (abs(triangles[i].Normal.z()) > max_gradient)
max_gradient = abs(triangles[i].Normal.z());
if (supportangle >= 0) {
const double slope = -triangles[i].slopeAngle(transform);
if (slope >= supportangle)
support_triangles.push_back(triangles[i].transformed(transform));
}
}
if (num_cutpoints > 1) {
int havev = find_vertex(vertices, lineEnd);
if (havev >= 0)
line.end = havev;
else {
line.end = vertices.size();
vertices.push_back(lineEnd);
}
}
// Check segment normal against triangle normal. Flip segment, as needed.
if (line.start != -1 && line.end != -1 && line.end != line.start)
{ // if we found a intersecting triangle
Vector3d Norm = triangles[i].transformed(transform).Normal;
Vector2d triangleNormal = Vector2d(Norm.x(), Norm.y());
Vector2d segment = (lineEnd - lineStart);
Vector2d segmentNormal(-segment.y(),segment.x());
triangleNormal.normalize();
segmentNormal.normalize();
if( (triangleNormal-segmentNormal).squared_length() > 0.2){
// if normals do not align, flip the segment
int iswap=line.start;line.start=line.end;line.end=iswap;
}
// cerr << "line "<<line.start << "-"<<line.end << endl;
lines.push_back(line);
}
}
return lines;
}
void UIGeom::render(RenderDevice* rd, float lineScale) {
if (! visible) {
return;
}
if (m_twoSidedPolys) {
rd->setCullFace(RenderDevice::CULL_NONE);
rd->enableTwoSidedLighting();
}
for (int i = 0; i < poly3D.size(); ++i) {
const ConvexPolygon& poly = poly3D[i];
rd->beginPrimitive(RenderDevice::TRIANGLE_FAN);
rd->setNormal(poly.normal());
for (int v = 0; v < poly.numVertices(); ++v) {
rd->sendVertex(poly.vertex(v));
}
rd->endPrimitive();
}
// Per segment normals
Array<Vector3> normal;
const Vector3 eye = computeEye(rd);
for (int i = 0; i < line3D.size(); ++i) {
const PolyLine& line = line3D[i];
// Compute one normal for each segement
normal.resize(line.numSegments(), false);
for (int s = 0; s < line.numSegments(); ++s) {
normal[s] = segmentNormal(line.segment(s), eye);
}
bool closed = line.closed();
// Compute line width
{
Vector4 v = rd->project(line.vertex(0));
float L = 2;
if (v.w > 0) {
L = min(15.0f * v.w, 10.0f);
} else {
L = 10.0f;
}
rd->setLineWidth(L * lineScale);
}
bool colorWrite = rd->colorWrite();
bool depthWrite = rd->depthWrite();
// Draw lines twice. The first time we draw color information
// but do not set the depth buffer. The second time we write
// to the depth buffer; this prevents line strips from
// corrupting their own antialiasing with depth conflicts at
// the line joint points.
if (colorWrite) {
rd->setDepthWrite(false);
rd->beginPrimitive(RenderDevice::LINE_STRIP);
for (int v = 0; v < line.numVertices(); ++v) {
// Compute the smooth normal. If we have a non-closed
// polyline, the ends are special cases.
Vector3 N;
if (! closed && (v == 0)) {
N = normal[0];
} else if (! closed && (v == line.numVertices())) {
N = normal.last();
} else {
// Average two adjacent normals
N = normal[v % normal.size()] + normal[(v - 1) %
normal.size()];
}
if (N.squaredLength() < 0.05) {
// Too small to normalize; revert to the
// nearest segment normal
rd->setNormal(normal[iMin(v, normal.size() - 1)]);
} else {
rd->setNormal(N.direction());
}
rd->sendVertex(line.vertex(v));
}
rd->endPrimitive();
}
if (depthWrite) {
rd->setColorWrite(false);
rd->setDepthWrite(true);
rd->beginPrimitive(RenderDevice::LINE_STRIP);
for (int v = 0; v < line.numVertices(); ++v) {
rd->sendVertex(line.vertex(v));
}
rd->endPrimitive();
}
rd->setColorWrite(colorWrite);
rd->setDepthWrite(depthWrite);
}
}