#include "Scene.hpp"
namespace Scene {

glm::vec3 OrbitCamera::eye() const {
  const float ce = std::cos(elevation), se = std::sin(elevation);
  const float ca = std::cos(azimuth), sa = std::sin(azimuth);
  return target + radius * glm::vec3(ce * ca, ce * sa, se);
}
glm::mat4 OrbitCamera::view() const {
  return glm::lookAt(eye(), target, glm::vec3(0, 0, 1));  // Z-up
}

glm::mat4 OrbitCamera::proj() const {
  return glm::perspective(glm::radians(fov_deg), aspect, nearZ, farZ);
}


// controls (delta-based, feed from input)
void OrbitCamera::dolly(float dr) {
  radius = std::max(0.05f, radius * std::exp(-dr));
}
void OrbitCamera::rotate(float dAzim, float dElev) {
  azimuth += dAzim;
  elevation = std::clamp(elevation + dElev, -1.55f, +1.55f);
}
void OrbitCamera::pan_world(const glm::vec2& d) {
  const float ce = std::cos(elevation), se = std::sin(elevation);
  const float ca = std::cos(azimuth), sa = std::sin(azimuth);
  glm::vec3 right = glm::normalize(glm::vec3(-sa, ca, 0.0f));
  glm::vec3 up = glm::normalize(glm::vec3(-ca * se, -sa * se, ce));
  target += (-d.x * right + d.y * up);
}
// keep aspect updated on resize
void OrbitCamera::set_aspect_from_pixels(int W, int H) {
  aspect = (H > 0) ? float(W) / float(H) : 1.0f;
}

}  // namespace Scene