source/effects/ambientocclusion.cpp

   1 #include <algorithm>
   2 #include "ambientocclusion.h"
   3 #include "blend.h"
   4 #include "camera.h"
   5 #include "renderer.h"
   6 #include "resources.h"
   7 #include "shader.h"
   8 #include "tests.h"
   9
  10 using namespace std;
  11
  12 namespace Msp {
  13 namespace GL {
  14
  15 AmbientOcclusion::AmbientOcclusion(unsigned w, unsigned h, float):
  16         rotate_lookup(get_or_create_rotate_lookup()),
  17         occlude_target(w, h, (RENDER_COLOR,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.tex2d";
  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 seed = 1;
  45         unsigned char data[64];
  46         for(unsigned i=0; i<16; ++i)
  47         {
  48                 Geometry::Angle<float> a = Geometry::Angle<float>::from_turns(random(seed));
  49                 unsigned char c = (cos(a)*0.5f+0.5f)*255;
  50                 unsigned char s = (sin(a)*0.5f+0.5f)*255;
  51                 data[i*4  ] = c;
  52                 data[i*4+1] = s;
  53                 data[i*4+2] = 255-s;
  54                 data[i*4+3] = ((i+i/4)%2)*255;
  55         }
  56         rotate_lookup->image(0, data);
  57
  58         return *rotate_lookup;
  59 }
  60
  61 float AmbientOcclusion::random(unsigned &seed)
  62 {
  63         static const unsigned modulus = (1U<<31)-1;
  64         seed = (static_cast<UInt64>(seed)*48271)%modulus;  // minstd
  65         return static_cast<float>(seed)/(modulus-1);
  66 }
  67
  68 void AmbientOcclusion::set_n_samples(unsigned n)
  69 {
  70         if(n<1 || n>32)
  71                 throw out_of_range("AmbientOcclusion::set_n_samples");
  72
  73         unsigned seed = 1;
  74         float radius_divisor = (n-1)*(n-1);
  75         Vector3 sample_points[32];
  76         for(unsigned i=0; i<n; ++i)
  77         {
  78                 Vector3 v(random(seed)-0.5f, random(seed)-0.5f, random(seed)-0.5f);
  79                 sample_points[i] = normalize(v)*(0.1f+0.9f*i*i/radius_divisor);
  80         }
  81         shdata.uniform3_array("sample_points", n, &sample_points[0].x);
  82         shdata.uniform("n_samples", static_cast<int>(n));
  83 }
  84
  85 void AmbientOcclusion::set_occlusion_radius(float r)
  86 {
  87         shdata.uniform("occlusion_radius", r);
  88 }
  89
  90 void AmbientOcclusion::set_darkness(float darkness)
  91 {
  92         shdata.uniform("darkness", darkness);
  93 }
  94
  95 void AmbientOcclusion::set_edge_depth_threshold(float edt)
  96 {
  97         shdata.uniform("edge_depth_threshold", edt);
  98 }
  99
 100 void AmbientOcclusion::render(Renderer &renderer, const Texture2D &color, const Texture2D &depth)
 101 {
 102         Renderer::Push push(renderer);
 103         renderer.set_texture("source", &color, &nearest_clamp_sampler);
 104         renderer.set_texture("depth", &depth, &nearest_clamp_sampler);
 105         renderer.set_texture("occlusion", &occlude_target.get_target_texture(RENDER_COLOR), &linear_sampler);
 106         renderer.set_texture("rotate", &rotate_lookup, &nearest_sampler);
 107         renderer.set_shader_program(&occlude_shader, &shdata);
 108
 109         {
 110                 BindRestore bind_fbo(occlude_target.get_framebuffer());
 111                 quad.draw(renderer);
 112         }
 113
 114         renderer.set_shader_program(&combine_shader);
 115         quad.draw(renderer);
 116 }
 117
 118
 119 AmbientOcclusion::Template::Template():
 120         n_samples(16),
 121         occlusion_radius(0.5f),
 122         darkness(1.0f),
 123         edge_depth_threshold(0.1f)
 124 { }
 125
 126 AmbientOcclusion *AmbientOcclusion::Template::create(unsigned width, unsigned height) const
 127 {
 128         RefPtr<AmbientOcclusion> ao = new AmbientOcclusion(width/size_divisor, height/size_divisor);
 129         ao->set_n_samples(n_samples);
 130         ao->set_occlusion_radius(occlusion_radius);
 131         ao->set_darkness(darkness);
 132         ao->set_edge_depth_threshold(edge_depth_threshold);
 133         return ao.release();
 134 }
 135
 136
 137 AmbientOcclusion::Template::Loader::Loader(Template &t):
 138         DataFile::DerivedObjectLoader<Template, PostProcessor::Template::Loader>(t)
 139 {
 140         add("darkness", &Template::darkness);
 141         add("edge_depth_threshold", &Template::edge_depth_threshold);
 142         add("occlusion_radius", &Template::occlusion_radius);
 143         add("samples", &Template::n_samples);
 144 }
 145
 146 } // namespace GL
 147 } // namespace Msp