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
   8 using namespace std;
   9
  10 namespace Msp {
  11 namespace GL {
  12
  13 AmbientOcclusion::AmbientOcclusion(unsigned w, unsigned h, float):
  14         rotate_lookup(get_or_create_rotate_lookup()),
  15         occlude_target(w, h, (COLOR_ATTACHMENT,R8)),
  16         occlude_shader(Resources::get_global().get<Program>("_ambientocclusion_occlude.glsl.shader")),
  17         combine_shader(Resources::get_global().get<Program>("_ambientocclusion_combine.glsl.shader")),
  18         quad(Resources::get_global().get<Mesh>("_fullscreen_quad.mesh")),
  19         linear_sampler(Resources::get_global().get<Sampler>("_linear_clamp.samp")),
  20         nearest_clamp_sampler(Resources::get_global().get<Sampler>("_nearest_clamp.samp")),
  21         nearest_sampler(Resources::get_global().get<Sampler>("_nearest.samp"))
  22 {
  23         set_n_samples(16);
  24         set_occlusion_radius(0.5f);
  25         set_darkness(1.0f);
  26         set_edge_depth_threshold(0.1f);
  27 }
  28
  29 const Texture2D &AmbientOcclusion::get_or_create_rotate_lookup()
  30 {
  31         Resources &resources = Resources::get_global();
  32
  33         static const string name = "_ambientocclusion_rotate.tex2d";
  34         Texture2D *rotate_lookup = resources.find<Texture2D>(name);
  35         if(rotate_lookup)
  36                 return *rotate_lookup;
  37
  38         rotate_lookup = new Texture2D;
  39         rotate_lookup->storage(RGBA8, 4, 4, 1);
  40         resources.add(name, rotate_lookup);
  41
  42         unsigned char data[64];
  43         for(unsigned i=0; i<16; ++i)
  44         {
  45                 Geometry::Angle<float> a = Geometry::Angle<float>::from_turns(i*7/16.0f);
  46                 unsigned char c = (cos(a)*0.5f+0.5f)*255;
  47                 unsigned char s = (sin(a)*0.5f+0.5f)*255;
  48                 data[i*4  ] = c;
  49                 data[i*4+1] = s;
  50                 data[i*4+2] = 255-s;
  51                 data[i*4+3] = ((i+i/4)%2)*255;
  52         }
  53         rotate_lookup->image(0, data);
  54
  55         return *rotate_lookup;
  56 }
  57
  58 float AmbientOcclusion::radical_inverse(unsigned n)
  59 {
  60         unsigned inv = ((n&0x55)<<1) | ((n&0xAA)>>1);
  61         inv = ((inv&0x33)<<2) | ((inv&0xCC)>>2);
  62         inv = ((inv&0x0F)<<4) | ((inv&0xF0)>>4);
  63         return inv/256.0f;
  64 }
  65
  66 void AmbientOcclusion::set_n_samples(unsigned n)
  67 {
  68         if(n<1 || n>128)
  69                 throw out_of_range("AmbientOcclusion::set_n_samples");
  70
  71         vector<Vector3> sample_points(n);
  72         for(unsigned i=0; i<n; ++i)
  73         {
  74                 float r = static_cast<float>(i)/n;
  75                 float z = sqrt(1.0f-r*r);
  76                 float d = radical_inverse(i);
  77                 Geometry::Angle<float> a = Geometry::Angle<float>::from_turns(d);
  78                 sample_points[i] = Vector3(cos(a)*r, sin(a)*r, z)*(0.1f+0.9f*d*d);
  79         }
  80         shdata.uniform3_array("sample_points", n, &sample_points[0].x);
  81         shdata.uniform("n_samples", static_cast<int>(n));
  82 }
  83
  84 void AmbientOcclusion::set_occlusion_radius(float r)
  85 {
  86         shdata.uniform("occlusion_radius", r);
  87 }
  88
  89 void AmbientOcclusion::set_darkness(float darkness)
  90 {
  91         shdata.uniform("darkness", darkness);
  92 }
  93
  94 void AmbientOcclusion::set_edge_depth_threshold(float edt)
  95 {
  96         shdata.uniform("edge_depth_threshold", edt);
  97 }
  98
  99 void AmbientOcclusion::render(Renderer &renderer, const Texture2D &color, const Texture2D &depth)
 100 {
 101         const Framebuffer *out_fbo = renderer.get_framebuffer();
 102
 103         Renderer::Push push(renderer);
 104         renderer.set_texture("source", &color, &nearest_clamp_sampler);
 105         renderer.set_texture("depth", &depth, &nearest_clamp_sampler);
 106         renderer.set_texture("occlusion", &occlude_target.get_target_texture(COLOR_ATTACHMENT), &linear_sampler);
 107         renderer.set_texture("rotate", &rotate_lookup, &nearest_sampler);
 108         renderer.set_shader_program(&occlude_shader, &shdata);
 109
 110         renderer.set_framebuffer(&occlude_target.get_framebuffer());
 111         quad.draw(renderer);
 112
 113         renderer.set_framebuffer(out_fbo);
 114         renderer.set_shader_program(&combine_shader);
 115         quad.draw(renderer);
 116 }
 117
 118 void AmbientOcclusion::set_debug_name(const string &name)
 119 {
 120 #ifdef DEBUG
 121         occlude_target.set_debug_name(name+" [RT]");
 122         shdata.set_debug_name(name+" [UBO]");
 123 #else
 124         (void)name;
 125 #endif
 126 }
 127
 128
 129 AmbientOcclusion::Template::Template():
 130         n_samples(16),
 131         occlusion_radius(0.5f),
 132         darkness(1.0f),
 133         edge_depth_threshold(0.1f)
 134 { }
 135
 136 AmbientOcclusion *AmbientOcclusion::Template::create(unsigned width, unsigned height) const
 137 {
 138         RefPtr<AmbientOcclusion> ao = new AmbientOcclusion(width/size_divisor, height/size_divisor);
 139         ao->set_n_samples(n_samples);
 140         ao->set_occlusion_radius(occlusion_radius);
 141         ao->set_darkness(darkness);
 142         ao->set_edge_depth_threshold(edge_depth_threshold);
 143         return ao.release();
 144 }
 145
 146
 147 AmbientOcclusion::Template::Loader::Loader(Template &t):
 148         DataFile::DerivedObjectLoader<Template, PostProcessor::Template::Loader>(t)
 149 {
 150         add("darkness", &Template::darkness);
 151         add("edge_depth_threshold", &Template::edge_depth_threshold);
 152         add("occlusion_radius", &Template::occlusion_radius);
 153         add("samples", &Template::n_samples);
 154 }
 155
 156 } // namespace GL
 157 } // namespace Msp