示例#1
0
std::array<Eigen::MatrixXi, 4> FillGroup(const Eigen::MatrixXi& m)
{
  std::array<Eigen::MatrixXi, 4> patterns;
  patterns[0] = m;

  // Found in this awesome answer http://stackoverflow.com/a/3488737/505049
  patterns[1] = m.transpose().colwise().reverse().eval();  // Rotate 90 CW
  patterns[2] = m.transpose().colwise().reverse().transpose().colwise().reverse().eval();  // Rotate 180. Not in the S.O. post
  patterns[3] = m.transpose().rowwise().reverse().eval();  // Rotate 270 CW
  return patterns;
}
示例#2
0
// http://www.songho.ca/opengl/gl_vbo.html#create
IGL_INLINE void igl::opengl::create_index_vbo(
  const Eigen::MatrixXi & F,
  GLuint & F_vbo_id)
{
  // Generate Buffers
  glGenBuffers(1,&F_vbo_id);
  // Bind Buffers
  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,F_vbo_id);
  // Copy data to buffers
  // We expect a matrix with each vertex position on a row, we then want to
  // pass this data to OpenGL reading across rows (row-major)
  if(F.Options & Eigen::RowMajor)
  {
    glBufferData(
      GL_ELEMENT_ARRAY_BUFFER,
      sizeof(int)*F.size(),
      F.data(),
      GL_STATIC_DRAW);
  }else
  {
    // Create temporary copy of transpose
    Eigen::MatrixXi FT = F.transpose();
    // If its column major then we need to temporarily store a transpose
    glBufferData(
      GL_ELEMENT_ARRAY_BUFFER,
      sizeof(int)*F.size(),
      FT.data(),
      GL_STATIC_DRAW);
  }
  // bind with 0, so, switch back to normal pointer operation
  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}