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
   9 using namespace std;
  10
  11 namespace Msp {
  12 namespace GL {
  13
  14 AmbientOcclusion::AmbientOcclusion(unsigned w, unsigned h, float):
  15         rotate_lookup(get_or_create_rotate_lookup()),
  16         occlude_target(w, h, (RENDER_COLOR,R8)),
  17         occlude_shader(Resources::get_global().get<Program>("_ambientocclusion_occlude.glsl.shader")),
  18         combine_shader(Resources::get_global().get<Program>("_ambientocclusion_combine.glsl.shader")),
  19         quad(Resources::get_global().get<Mesh>("_fullscreen_quad.mesh")),
  20         linear_sampler(Resources::get_global().get<Sampler>("_linear_clamp.samp")),
  21         nearest_clamp_sampler(Resources::get_global().get<Sampler>("_nearest_clamp.samp")),
  22         nearest_sampler(Resources::get_global().get<Sampler>("_nearest.samp"))
  23 {
  24         set_n_samples(16);
  25         set_occlusion_radius(0.5f);
  26         set_darkness(1.0f);
  27         set_edge_depth_threshold(0.1f);
  28 }
  29
  30 const Texture2D &AmbientOcclusion::get_or_create_rotate_lookup()
  31 {
  32         Resources &resources = Resources::get_global();
  33
  34         static const string name = "_ambientocclusion_rotate.tex2d";
  35         Texture2D *rotate_lookup = resources.find<Texture2D>(name);
  36         if(rotate_lookup)
  37                 return *rotate_lookup;
  38
  39         rotate_lookup = new Texture2D;
  40         rotate_lookup->storage(RGBA8, 4, 4, 1);
  41         resources.add(name, rotate_lookup);
  42
  43         unsigned char data[64];
  44         for(unsigned i=0; i<16; ++i)
  45         {
  46                 Geometry::Angle<float> a = Geometry::Angle<float>::from_turns(i*7/16.0f);
  47                 unsigned char c = (cos(a)*0.5f+0.5f)*255;
  48                 unsigned char s = (sin(a)*0.5f+0.5f)*255;
  49                 data[i*4  ] = c;
  50                 data[i*4+1] = s;
  51                 data[i*4+2] = 255-s;
  52                 data[i*4+3] = ((i+i/4)%2)*255;
  53         }
  54         rotate_lookup->image(0, data);
  55
  56         return *rotate_lookup;
  57 }
  58
  59 float AmbientOcclusion::radical_inverse(unsigned n)
  60 {
  61         unsigned inv = ((n&0x55)<<1) | ((n&0xAA)>>1);
  62         inv = ((inv&0x33)<<2) | ((inv&0xCC)>>2);
  63         inv = ((inv&0x0F)<<4) | ((inv&0xF0)>>4);
  64         return inv/256.0f;
  65 }
  66
  67 void AmbientOcclusion::set_n_samples(unsigned n)
  68 {
  69         if(n<1 || n>128)
  70                 throw out_of_range("AmbientOcclusion::set_n_samples");
  71
  72         vector<Vector3> sample_points(n);
  73         for(unsigned i=0; i<n; ++i)
  74         {
  75                 float r = static_cast<float>(i)/n;
  76                 float z = sqrt(1.0f-r*r);
  77                 float d = radical_inverse(i);
  78                 Geometry::Angle<float> a = Geometry::Angle<float>::from_turns(d);
  79                 sample_points[i] = Vector3(cos(a)*r, sin(a)*r, z)*(0.1f+0.9f*d*d);
  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         const Framebuffer *out_fbo = renderer.get_framebuffer();
 103
 104         Renderer::Push push(renderer);
 105         renderer.set_texture("source", &color, &nearest_clamp_sampler);
 106         renderer.set_texture("depth", &depth, &nearest_clamp_sampler);
 107         renderer.set_texture("occlusion", &occlude_target.get_target_texture(RENDER_COLOR), &linear_sampler);
 108         renderer.set_texture("rotate", &rotate_lookup, &nearest_sampler);
 109         renderer.set_shader_program(&occlude_shader, &shdata);
 110
 111         renderer.set_framebuffer(&occlude_target.get_framebuffer());
 112         quad.draw(renderer);
 113
 114         renderer.set_framebuffer(out_fbo);
 115         renderer.set_shader_program(&combine_shader);
 116         quad.draw(renderer);
 117 }
 118
 119 void AmbientOcclusion::set_debug_name(const string &name)
 120 {
 121 #ifdef DEBUG
 122         occlude_target.set_debug_name(name+" [RT]");
 123         shdata.set_debug_name(name+" [UBO]");
 124 #else
 125         (void)name;
 126 #endif
 127 }
 128
 129
 130 AmbientOcclusion::Template::Template():
 131         n_samples(16),
 132         occlusion_radius(0.5f),
 133         darkness(1.0f),
 134         edge_depth_threshold(0.1f)
 135 { }
 136
 137 AmbientOcclusion *AmbientOcclusion::Template::create(unsigned width, unsigned height) const
 138 {
 139         RefPtr<AmbientOcclusion> ao = new AmbientOcclusion(width/size_divisor, height/size_divisor);
 140         ao->set_n_samples(n_samples);
 141         ao->set_occlusion_radius(occlusion_radius);
 142         ao->set_darkness(darkness);
 143         ao->set_edge_depth_threshold(edge_depth_threshold);
 144         return ao.release();
 145 }
 146
 147
 148 AmbientOcclusion::Template::Loader::Loader(Template &t):
 149         DataFile::DerivedObjectLoader<Template, PostProcessor::Template::Loader>(t)
 150 {
 151         add("darkness", &Template::darkness);
 152         add("edge_depth_threshold", &Template::edge_depth_threshold);
 153         add("occlusion_radius", &Template::occlusion_radius);
 154         add("samples", &Template::n_samples);
 155 }
 156
 157 } // namespace GL
 158 } // namespace Msp