source/effects/ambientocclusion.cpp

   1 #include <algorithm>
   2 #include "ambientocclusion.h"
   3 #include "blend.h"
   4 #include "camera.h"
   5 #include "mesh.h"
   6 #include "renderer.h"
   7 #include "resources.h"
   8 #include "texture2d.h"
   9
  10 using namespace std;
  11
  12 namespace Msp {
  13 namespace GL {
  14
  15 AmbientOcclusion::AmbientOcclusion(unsigned w, unsigned h):
  16         rotate_lookup(get_or_create_rotate_lookup()),
  17         occlude_target(w, h, (COLOR_ATTACHMENT,R8)),
  18         occlude_shader(Resources::get_global().get<Program>("_ambientocclusion_occlude.glsl.shader")),
  19         combine_shader(Resources::get_global().get<Program>("_ambientocclusion_combine.glsl.shader")),
  20         quad(Resources::get_global().get<Mesh>("_fullscreen_quad.mesh")),
  21         linear_sampler(Resources::get_global().get<Sampler>("_linear_clamp.samp")),
  22         nearest_clamp_sampler(Resources::get_global().get<Sampler>("_nearest_clamp.samp")),
  23         nearest_sampler(Resources::get_global().get<Sampler>("_nearest.samp"))
  24 {
  25         set_n_samples(16);
  26         set_occlusion_radius(0.5f);
  27         set_darkness(1.0f);
  28         set_edge_depth_threshold(0.1f);
  29 }
  30
  31 const Texture2D &AmbientOcclusion::get_or_create_rotate_lookup()
  32 {
  33         Resources &resources = Resources::get_global();
  34
  35         static const string name = "_ambientocclusion_rotate.tex";
  36         Texture2D *rotate_lookup = resources.find<Texture2D>(name);
  37         if(rotate_lookup)
  38                 return *rotate_lookup;
  39
  40         rotate_lookup = new Texture2D;
  41         rotate_lookup->storage(RGBA8, 4, 4, 1);
  42         resources.add(name, rotate_lookup);
  43
  44         unsigned char data[64];
  45         for(unsigned i=0; i<16; ++i)
  46         {
  47                 Geometry::Angle<float> a = Geometry::Angle<float>::from_turns(i*7/16.0f);
  48                 unsigned char c = (cos(a)*0.5f+0.5f)*255;
  49                 unsigned char s = (sin(a)*0.5f+0.5f)*255;
  50                 data[i*4  ] = c;
  51                 data[i*4+1] = s;
  52                 data[i*4+2] = 255-s;
  53                 data[i*4+3] = ((i+i/4)%2)*255;
  54         }
  55         rotate_lookup->image(0, data);
  56
  57         return *rotate_lookup;
  58 }
  59
  60 float AmbientOcclusion::radical_inverse(unsigned n)
  61 {
  62         unsigned inv = ((n&0x55)<<1) | ((n&0xAA)>>1);
  63         inv = ((inv&0x33)<<2) | ((inv&0xCC)>>2);
  64         inv = ((inv&0x0F)<<4) | ((inv&0xF0)>>4);
  65         return inv/256.0f;
  66 }
  67
  68 void AmbientOcclusion::set_n_samples(unsigned n)
  69 {
  70         if(n<1 || n>128)
  71                 throw out_of_range("AmbientOcclusion::set_n_samples");
  72
  73         vector<Vector3> sample_points(n);
  74         for(unsigned i=0; i<n; ++i)
  75         {
  76                 float r = static_cast<float>(i)/n;
  77                 float z = sqrt(1.0f-r*r);
  78                 float d = radical_inverse(i);
  79                 Geometry::Angle<float> a = Geometry::Angle<float>::from_turns(d);
  80                 sample_points[i] = Vector3(cos(a)*r, sin(a)*r, z)*(0.1f+0.9f*d*d);
  81         }
  82         shdata.uniform3_array("sample_points", n, &sample_points[0][0]);
  83         shdata.uniform("n_samples", static_cast<int>(n));
  84 }
  85
  86 void AmbientOcclusion::set_occlusion_radius(float r)
  87 {
  88         shdata.uniform("occlusion_radius", r);
  89 }
  90
  91 void AmbientOcclusion::set_darkness(float darkness)
  92 {
  93         shdata.uniform("darkness", darkness);
  94 }
  95
  96 void AmbientOcclusion::set_edge_depth_threshold(float edt)
  97 {
  98         shdata.uniform("edge_depth_threshold", edt);
  99 }
 100
 101 void AmbientOcclusion::render(Renderer &renderer, const Texture2D &color, const Texture2D &depth)
 102 {
 103         const Framebuffer *out_fbo = renderer.get_framebuffer();
 104
 105         Renderer::Push push(renderer);
 106         renderer.set_texture("source", &color, &nearest_clamp_sampler);
 107         renderer.set_texture("depth", &depth, &nearest_clamp_sampler);
 108         renderer.set_texture("occlusion", &occlude_target.get_target_texture(COLOR_ATTACHMENT), &linear_sampler);
 109         renderer.set_texture("rotate", &rotate_lookup, &nearest_sampler);
 110         renderer.set_shader_program(&occlude_shader, &shdata);
 111
 112         renderer.set_pipeline_key(this);
 113         renderer.set_framebuffer(&occlude_target.get_framebuffer());
 114         renderer.clear(0);
 115         quad.draw(renderer);
 116
 117         renderer.set_pipeline_key(this, 1);
 118         renderer.set_framebuffer(out_fbo);
 119         renderer.clear(0);
 120         renderer.set_shader_program(&combine_shader);
 121         quad.draw(renderer);
 122 }
 123
 124 void AmbientOcclusion::set_debug_name(const string &name)
 125 {
 126 #ifdef DEBUG
 127         occlude_target.set_debug_name(name+" [RT]");
 128         shdata.set_debug_name(name+" [UBO]");
 129 #else
 130         (void)name;
 131 #endif
 132 }
 133
 134
 135 AmbientOcclusion *AmbientOcclusion::Template::create(unsigned width, unsigned height) const
 136 {
 137         RefPtr<AmbientOcclusion> ao = new AmbientOcclusion(width/size_divisor, height/size_divisor);
 138         ao->set_n_samples(n_samples);
 139         ao->set_occlusion_radius(occlusion_radius);
 140         ao->set_darkness(darkness);
 141         ao->set_edge_depth_threshold(edge_depth_threshold);
 142         return ao.release();
 143 }
 144
 145
 146 AmbientOcclusion::Template::Loader::Loader(Template &t):
 147         DataFile::DerivedObjectLoader<Template, PostProcessor::Template::Loader>(t)
 148 {
 149         add("darkness", &Template::darkness);
 150         add("edge_depth_threshold", &Template::edge_depth_threshold);
 151         add("occlusion_radius", &Template::occlusion_radius);
 152         add("samples", &Template::n_samples);
 153 }
 154
 155 } // namespace GL
 156 } // namespace Msp