source/render/camera.cpp

   1 #include <cmath>
   2 #include "camera.h"
   3 #include "matrix.h"
   4
   5 using namespace std;
   6
   7 namespace Msp {
   8 namespace GL {
   9
  10 Camera::Camera()
  11 {
  12         update_projection_matrix();
  13         update_object_matrix();
  14 }
  15
  16 void Camera::copy_parameters(const Camera &source)
  17 {
  18         fov = source.fov;
  19         height = source.height;
  20         aspect = source.aspect;
  21         clip_near = source.clip_near;
  22         clip_far = source.clip_far;
  23         frustum_x = source.frustum_x;
  24         frustum_y = source.frustum_y;
  25         rotate = source.rotate;
  26         position = source.position;
  27         look_dir = source.look_dir;
  28         up_dir = source.up_dir;
  29         update_projection_matrix();
  30         update_object_matrix();
  31 }
  32
  33 void Camera::set_field_of_view(const Geometry::Angle<float> &f)
  34 {
  35         fov = f;
  36         update_projection_matrix();
  37 }
  38
  39 void Camera::set_orthographic(float w, float h)
  40 {
  41         fov = Geometry::Angle<float>::zero();
  42         height = h;
  43         if(w)
  44                 aspect = w/h;
  45         update_projection_matrix();
  46 }
  47
  48 void Camera::set_aspect_ratio(float a)
  49 {
  50         aspect = a;
  51         update_projection_matrix();
  52 }
  53
  54 void Camera::set_depth_clip(float n, float f)
  55 {
  56         clip_near = n;
  57         clip_far = f;
  58         update_projection_matrix();
  59 }
  60
  61 void Camera::set_frustum_axis(float x, float y)
  62 {
  63         frustum_x = x;
  64         frustum_y = y;
  65         update_projection_matrix();
  66 }
  67
  68 void Camera::set_frustum_rotation(const Geometry::Angle<float> &r)
  69 {
  70         rotate = r;
  71         update_projection_matrix();
  72 }
  73
  74 void Camera::set_position(const Vector3 &p)
  75 {
  76         position = p;
  77         update_object_matrix();
  78 }
  79
  80 void Camera::set_look_direction(const Vector3 &l)
  81 {
  82         look_dir = normalize(l);
  83         update_object_matrix();
  84 }
  85
  86 void Camera::look_at(const Vector3 &p)
  87 {
  88         set_look_direction(p-position);
  89 }
  90
  91 void Camera::set_up_direction(const Vector3 &u)
  92 {
  93         up_dir = normalize(u);
  94         update_object_matrix();
  95 }
  96
  97 void Camera::set_object_matrix(const Matrix &m)
  98 {
  99         position = m.column(3).slice<3>(0);
 100         look_dir = normalize(-m.column(2).slice<3>(0));
 101         up_dir = normalize(m.column(1).slice<3>(0));
 102         update_object_matrix();
 103 }
 104
 105 Vector3 Camera::project(const Vector4 &p) const
 106 {
 107         Vector4 r = proj_matrix*(view_matrix*p);
 108         return r.slice<3>(0)/r.w;
 109 }
 110
 111 Vector3 Camera::project(const Vector3 &p) const
 112 {
 113         return project(compose(p, 1.0f));
 114 }
 115
 116 Vector4 Camera::unproject(const Vector4 &p) const
 117 {
 118         Vector4 r = invert(proj_matrix)*Vector4(p.x, p.y, p.z, 1.0f);
 119         r = matrix*Vector4(r.x/r.w, r.y/r.w, r.z/r.w, p.w);
 120         return r;
 121 }
 122
 123 Vector3 Camera::unproject(const Vector3 &p) const
 124 {
 125         return unproject(compose(p, 1.0f)).slice<3>(0);
 126 }
 127
 128 bool Camera::is_in_frustum(const Renderable &renderable) const
 129 {
 130         const Matrix *rmatrix = renderable.get_matrix();
 131         const Geometry::BoundingSphere<float, 3> *bsphere = renderable.get_bounding_sphere();
 132         if(!rmatrix || !bsphere)
 133                 return true;
 134
 135         Vector4 center = *rmatrix*compose(bsphere->get_center(), 1.0f);
 136         Vector3 x_axis = (rmatrix->column(0)*bsphere->get_radius()).slice<3>(0);
 137         float radius_sq = inner_product(x_axis, x_axis);
 138
 139         for(unsigned i=0; i<6; ++i)
 140         {
 141                 float distance = inner_product(center, frustum_planes[i]);
 142                 if(distance<0 && distance*distance>radius_sq)
 143                         return false;
 144         }
 145
 146         return true;
 147 }
 148
 149 void Camera::update_projection_matrix()
 150 {
 151         float frustum_h = (is_orthographic() ? height/2 : tan(fov/2.0f)*clip_near);
 152         float frustum_w = frustum_h*aspect;
 153         float left = frustum_w*(frustum_x-1.0f);
 154         float right = frustum_w*(frustum_x+1.0f);
 155         float bottom = frustum_h*(frustum_y-1.0f);
 156         float top = frustum_h*(frustum_y+1.0f);
 157         if(is_orthographic())
 158                 proj_matrix = Matrix::ortho(left, right, bottom, top, clip_near, clip_far);
 159         else
 160                 proj_matrix = Matrix::frustum(left, right, bottom, top, clip_near, clip_far);
 161         proj_matrix = Matrix::rotation(rotate, Vector3(0, 0, 1))*proj_matrix;
 162
 163         shdata.uniform("clip_eye_matrix", proj_matrix);
 164         shdata.uniform("eye_clip_matrix", invert(proj_matrix));
 165
 166         update_frustum_planes();
 167 }
 168
 169 void Camera::update_object_matrix()
 170 {
 171         Vector3 right_dir = normalize(cross(look_dir, up_dir));
 172         Vector4 columns[4];
 173         columns[0] = compose(right_dir, 0.0f);
 174         columns[1] = compose(cross(right_dir, look_dir), 0.0f);
 175         columns[2] = compose(-look_dir, 0.0f);
 176         columns[3] = compose(position, 1.0f);
 177         matrix = Matrix::from_columns(columns);
 178         view_matrix = invert(matrix);
 179
 180         shdata.uniform("world_eye_matrix", matrix);
 181         shdata.uniform("eye_world_matrix", view_matrix);
 182
 183         update_frustum_planes();
 184 }
 185
 186 void Camera::update_frustum_planes()
 187 {
 188         // TODO Handle off-center and rotated frustums
 189         if(is_orthographic())
 190         {
 191                 frustum_planes[0] = Vector4(0, 1, 0, height);
 192                 frustum_planes[1] = Vector4(0, -1, 0, height);
 193
 194                 frustum_planes[2] = Vector4(1, 0, 0, height*aspect);
 195                 frustum_planes[3] = Vector4(-1, 0, 0, height*aspect);
 196         }
 197         else
 198         {
 199                 float y = tan(fov/2.0f);
 200                 float s = sqrt(y*y+1);
 201                 frustum_planes[0] = Vector4(0, 1/s, -y/s, 0);
 202                 frustum_planes[1] = Vector4(0, -1/s, -y/s, 0);
 203
 204                 float x = y*aspect;
 205                 s = sqrt(x*x+1);
 206                 frustum_planes[2] = Vector4(1/s, 0, -x/s, 0);
 207                 frustum_planes[3] = Vector4(-1/s, 0, -x/s, 0);
 208         }
 209
 210         frustum_planes[4] = Vector4(0, 0, 1, clip_far);
 211         frustum_planes[5] = Vector4(0, 0, -1, -clip_near);
 212
 213         for(unsigned i=0; i<6; ++i)
 214         {
 215                 Vector3 normal = frustum_planes[i].slice<3>(0);
 216                 normal = (matrix*compose(normal, 0.0f)).slice<3>(0);
 217                 frustum_planes[i] = compose(normal, frustum_planes[i].w-dot(normal, matrix.column(3).slice<3>(0)));
 218         }
 219 }
 220
 221 void Camera::set_debug_name(const string &name)
 222 {
 223 #ifdef DEBUG
 224         shdata.set_debug_name(name+" [UBO]");
 225 #else
 226         (void)name;
 227 #endif
 228 }
 229
 230
 231 Camera::Loader::Loader(Camera &c):
 232         DataFile::ObjectLoader<Camera>(c)
 233 {
 234         add("aspect_ratio", &Loader::aspect_ratio);
 235         add("depth_clip", &Loader::depth_clip);
 236         add("field_of_view", &Loader::field_of_view);
 237         add("look_at", &Loader::look_at);
 238         add("look_direction", &Loader::look_direction);
 239         add("orthographic", &Loader::orthographic);
 240         add("position", &Loader::position);
 241         add("up_direction", &Loader::up_direction);
 242 }
 243
 244 void Camera::Loader::aspect_ratio(float a)
 245 {
 246         obj.set_aspect_ratio(a);
 247 }
 248
 249 void Camera::Loader::depth_clip(float n, float f)
 250 {
 251         obj.set_depth_clip(n, f);
 252 }
 253
 254 void Camera::Loader::field_of_view(float a)
 255 {
 256         obj.set_field_of_view(Geometry::Angle<float>::from_degrees(a));
 257 }
 258
 259 void Camera::Loader::look_at(float x, float y, float z)
 260 {
 261         obj.look_at(Vector3(x, y, z));
 262 }
 263
 264 void Camera::Loader::look_direction(float x, float y, float z)
 265 {
 266         obj.set_look_direction(Vector3(x, y, z));
 267 }
 268
 269 void Camera::Loader::orthographic(float w, float h)
 270 {
 271         obj.set_orthographic(w, h);
 272 }
 273
 274 void Camera::Loader::position(float x, float y, float z)
 275 {
 276         obj.set_position(Vector3(x, y, z));
 277 }
 278
 279 void Camera::Loader::up_direction(float x, float y, float z)
 280 {
 281         obj.set_up_direction(Vector3(x, y, z));
 282 }
 283
 284 } // namespace GL
 285 } // namespace Msp