void truncated_cone(const Mat4x4f& m, float l, float w0, float w1, vector<Vec3f>& strip)
{
float len = sqrt(l*l + sqr(w0-w1));
float a = l/len;
float b = (w0-w1)/len;
const int N = 10;
for(int i=0;i<=N;++i)
{
float alpha = 2.0*M_PI*float(i)/N;
Vec3f p0 = m.mul_3D_point(Vec3f(w0*cos(alpha), w0*sin(alpha), 0));
Vec3f p1 = m.mul_3D_point(Vec3f(w1*cos(alpha), w1*sin(alpha), l));
Vec3f n = m.mul_3D_vector(a*Vec3f(cos(alpha), sin(alpha), b));
if(i==0){
strip.push_back(n);
strip.push_back(p0);
}
strip.push_back(n);
strip.push_back(p0);
strip.push_back(n);
strip.push_back(p1);
if(i==N){
strip.push_back(n);
strip.push_back(p1);
}
}
}
// Produce the mesh for a truncated cone
void truncated_cone(const Mat4x4f& m, // transformation matrix used for the points
float l, // length of truncated cone
float w0, // width at base
float w1, // width at top
vector<Vec3f>& triangles, // triangles (out)
vector<Vec3f>& normals) // normals (out)
{
float len = sqrt(l*l + sqr(w0-w1));
float a = l/len;
float b = (w0-w1)/len;
const int N = 10;
for(int i=0;i<=N;++i)
{
float alpha = 2.0*M_PI*float(i)/N;
Vec3f p0 = m.mul_3D_point(Vec3f(w0*cos(alpha), w0*sin(alpha), 0));
Vec3f p1 = m.mul_3D_point(Vec3f(w1*cos(alpha), w1*sin(alpha), l));
Vec3f n0 = m.mul_3D_vector(a*Vec3f(cos(alpha), sin(alpha), b));
Vec3f n1 = n0;
alpha = 2.0*M_PI*float(i+1)/N;
Vec3f p2 = m.mul_3D_point(Vec3f(w0*cos(alpha), w0*sin(alpha), 0));
Vec3f p3 = m.mul_3D_point(Vec3f(w1*cos(alpha), w1*sin(alpha), l));
Vec3f n2 = m.mul_3D_vector(a*Vec3f(cos(alpha), sin(alpha), b));
Vec3f n3 = n2;
normals.push_back(n0);
triangles.push_back(p0);
normals.push_back(n1);
triangles.push_back(p1);
normals.push_back(n3);
triangles.push_back(p3);
normals.push_back(n3);
triangles.push_back(p3);
normals.push_back(n2);
triangles.push_back(p2);
normals.push_back(n0);
triangles.push_back(p0);
}
}
