source/render/occludedscene.cpp

   1 #include <algorithm>
   2 #include "camera.h"
   3 #include "occludedscene.h"
   4 #include "renderer.h"
   5 #include "resources.h"
   6 #include "sphere.h"
   7
   8 using namespace std;
   9
  10 namespace Msp {
  11 namespace GL {
  12
  13 OccludedScene::OccludedScene():
  14         bounding_mesh(Resources::get_global().get<Mesh>("_occluder.mesh")),
  15         bounding_shader(Resources::get_global().get<Program>("_occluder.glsl.shader")),
  16         no_depth_write(LEQUAL, false),
  17         occluder_min_size(0.25f),
  18         queries(OCCLUSION_QUERY, 0),
  19         cache_dirty(false)
  20 {
  21         no_color_write.write_mask = WRITE_NONE;
  22 }
  23
  24 void OccludedScene::add(Renderable &r)
  25 {
  26         renderables.insert(&r);
  27         cache_dirty = true;
  28 }
  29
  30 void OccludedScene::remove(Renderable &r)
  31 {
  32         renderables.erase(&r);
  33         cache_dirty = true;
  34 }
  35
  36 void OccludedScene::populate_cache() const
  37 {
  38         if(!cache_dirty)
  39                 return;
  40
  41         if(queries.get_size()<renderables.size())
  42                 queries.resize(renderables.size());
  43         if(occluded_cache.size()<renderables.size())
  44                 occluded_cache.resize(renderables.size());
  45
  46         auto j = occluded_cache.begin();
  47         for(Renderable *r: renderables)
  48                 j++->renderable = r;
  49         for(; j!=occluded_cache.end(); ++j)
  50         {
  51                 j->renderable = 0;
  52                 j->in_frustum = false;
  53         }
  54
  55         cache_dirty = false;
  56 }
  57
  58 void OccludedScene::setup_frame(Renderer &renderer)
  59 {
  60         populate_cache();
  61         for(const OccludedRenderable &o: occluded_cache)
  62                 o.renderable->setup_frame(renderer);
  63 }
  64
  65 void OccludedScene::finish_frame()
  66 {
  67         for(const OccludedRenderable &o: occluded_cache)
  68                 o.renderable->finish_frame();
  69 }
  70
  71 void OccludedScene::render(Renderer &renderer, Tag tag) const
  72 {
  73         if(renderables.empty())
  74                 return;
  75
  76         populate_cache();
  77
  78         const Camera *camera = renderer.get_camera();
  79         if(!camera)
  80         {
  81                 for(const OccludedRenderable &o: occluded_cache)
  82                         renderer.render(*o.renderable, tag);
  83                 return;
  84         }
  85
  86         const Vector3 &camera_pos = camera->get_position();
  87         const Vector3 &look_dir = camera->get_look_direction();
  88         float near_clip = camera->get_near_clip();
  89         float frustum_h = tan(camera->get_field_of_view()/2.0f)*2.0f;
  90
  91         // Perform frustum culling and render any major occluders
  92         bool use_frustum = setup_frustum(renderer);
  93         for(auto i=occluded_cache.begin(); (i!=occluded_cache.end() && i->renderable); ++i)
  94         {
  95                 i->in_frustum = (!use_frustum || !frustum_cull(*i->renderable));
  96                 if(!i->in_frustum)
  97                         continue;
  98
  99                 const Matrix *matrix = i->renderable->get_matrix();
 100                 i->bounding_sphere = i->renderable->get_bounding_sphere();
 101                 if(matrix && i->bounding_sphere)
 102                 {
 103                         float depth = dot(*matrix*i->bounding_sphere->get_center()-camera_pos, look_dir);
 104                         float size = i->bounding_sphere->get_radius()*2/max(depth, near_clip);
 105                         i->occluder = (size>frustum_h*occluder_min_size);
 106                 }
 107                 else
 108                         // If the size can't be calculated, treat it as occluder
 109                         i->occluder = true;
 110
 111                 if(i->occluder)
 112                         renderer.render(*i->renderable, tag);
 113         }
 114
 115         // Move all objects within the frustum to the beginning of the array
 116         for(auto i=occluded_cache.begin(), j=i+renderables.size()-1; i!=j; )
 117         {
 118                 if(i->in_frustum)
 119                         ++i;
 120                 else if(j->in_frustum)
 121                         swap(*i, *j);
 122                 else
 123                         --j;
 124         }
 125
 126         {
 127                 Renderer::Push push(renderer);
 128                 renderer.set_shader_program(&bounding_shader);
 129
 130                 renderer.set_blend(&no_color_write);
 131                 // XXX Preserve existing depth test predicate
 132                 renderer.set_depth_test(&no_depth_write);
 133
 134                 // Fire off the occlusion queries
 135                 for(auto i=occluded_cache.begin(); (i!=occluded_cache.end() && i->in_frustum); ++i)
 136                         if(!i->occluder)
 137                         {
 138                                 QueryPool::Activate activate_query(renderer, queries, i-occluded_cache.begin());
 139                                 Renderer::Push push2(renderer);
 140                                 renderer.transform(Matrix(*i->renderable->get_matrix())
 141                                         .translate(i->bounding_sphere->get_center())
 142                                         .scale(i->bounding_sphere->get_radius()));
 143                                 bounding_mesh.draw(renderer);
 144                         }
 145         }
 146
 147         // Render anything that has a chance of being visible
 148         for(auto i=occluded_cache.begin(); (i!=occluded_cache.end() && i->in_frustum); ++i)
 149                 if(!i->occluder && queries.get_result(i-occluded_cache.begin()))
 150                         renderer.render(*i->renderable, tag);
 151 }
 152
 153
 154 OccludedScene::OccludedRenderable::OccludedRenderable():
 155         renderable(0),
 156         bounding_sphere(0),
 157         in_frustum(false),
 158         occluder(false)
 159 { }
 160
 161 } // namespace GL
 162 } // namespace Msp