Function positionFromView

Cesium3DTilesSelection/src/ViewState.cpp:50–58

namespace {
glm::dvec3 positionFromView(const glm::dmat4& viewMatrix) {
  // Back out the world position by multiplying the view matrix translation by
  // the rotation transpose (inverse) and negating.
  glm::dvec3 position(0.0);
  position.x = -glm::dot(glm::dvec3(viewMatrix[0]), glm::dvec3(viewMatrix[3]));
  position.y = -glm::dot(glm::dvec3(viewMatrix[1]), glm::dvec3(viewMatrix[3]));
  position.z = -glm::dot(glm::dvec3(viewMatrix[2]), glm::dvec3(viewMatrix[3]));
  return position;
}

glm::dvec3 directionFromView(const glm::dmat4& viewMatrix) {
  return glm::dvec3(viewMatrix[0][2], viewMatrix[1][2], viewMatrix[2][2]) *