git.mutantstargoat.com Git - demo/blob - src/camera.cc

   1 #include <math.h>
   2
   3 #include <gmath/gmath.h>
   4
   5 #include "camera.h"
   6 #include "state_manager.h"
   7
   8 Camera::Camera() {}
   9 Camera::~Camera() {}
  10
  11 void Camera::use() const
  12 {
  13         state_manager.set_state("st_view_matrix", get_view_matrix());
  14 }
  15
  16 OrbitCamera::OrbitCamera()
  17 {
  18         phi = theta = distance = 0;
  19 }
  20
  21 OrbitCamera::~OrbitCamera() {}
  22
  23 void OrbitCamera::set_orbit_params(float phi, float theta, float distance)
  24 {
  25         this->phi = phi;
  26         this->theta = theta;
  27         this->distance = distance;
  28 }
  29
  30 Mat4 OrbitCamera::get_view_matrix() const
  31 {
  32         Mat4 view_matrix;
  33         view_matrix.rotate_y(theta * (float)M_PI / 180);
  34         view_matrix.rotate_x(phi * (float)M_PI / 180);
  35         view_matrix.translate(Vec3(0, 0, -distance));
  36
  37         return view_matrix;
  38 }
  39
  40 Mat4 calc_projection_matrix(float fov_deg, float aspect, float n, float f)
  41 {
  42         float fov = fov_deg / 180 * M_PI;
  43
  44         float tmp;
  45         tmp = 1 / tan(fov / 2.0);
  46
  47         /* near - far clipping planes */
  48         float range = n - f;
  49
  50         Mat4 pmat = Mat4(
  51                         tmp/aspect,     0,              0,                                      0,
  52                         0,                              tmp,    0,                                      0,
  53                         0,                              0,              (f + n) / range,        -1,
  54                         0,                              0,              2 * n * f / range,      0
  55                     );
  56
  57         return pmat;
  58 }