source/render/occludedscene.cpp

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