source/ambientocclusion.cpp

   1 #define _USE_MATH_DEFINES
   2 #include <cmath>
   3 #include "ambientocclusion.h"
   4 #include "blend.h"
   5 #include "shader.h"
   6 #include "tests.h"
   7
   8 namespace Msp {
   9 namespace GL {
  10
  11 AmbientOcclusion::AmbientOcclusion(unsigned w, unsigned h, float depth_ratio):
  12         occlude_shader("ambientocclusion_occlude.glsl"),
  13         combine_shader("ambientocclusion_combine.glsl"),
  14         quad(get_fullscreen_quad())
  15 {
  16         occlusion.storage(RGB, w, h);
  17         occlusion.set_min_filter(NEAREST);
  18         occlusion.set_mag_filter(NEAREST);
  19         occlusion.set_wrap(CLAMP_TO_EDGE);
  20         fbo.attach(COLOR_ATTACHMENT0, occlusion, 0);
  21         fbo.require_complete();
  22
  23         combine_texturing.attach(2, occlusion);
  24
  25         rotate_lookup.storage(RGBA, 4, 4);
  26         rotate_lookup.set_min_filter(NEAREST);
  27         rotate_lookup.set_mag_filter(NEAREST);
  28         unsigned char data[64];
  29         for(unsigned i=0; i<16; ++i)
  30         {
  31                 float a = ((i*541)%16)*M_PI/32;
  32                 float c = cos(a);
  33                 float s = sin(a);
  34                 data[i*3  ] = static_cast<unsigned char>(127+c*127);
  35                 data[i*3+1] = static_cast<unsigned char>(127+s*127);
  36                 data[i*3+2] = static_cast<unsigned char>(127-s*127);
  37                 data[i*3+4] = static_cast<unsigned char>(127+c*127);
  38         }
  39         rotate_lookup.image(0, RGBA, UNSIGNED_BYTE, data);
  40
  41         occlude_texturing.attach(1, rotate_lookup);
  42
  43         occlude_shdata.uniform("depth", 0);
  44         occlude_shdata.uniform("rotate", 1);
  45         occlude_shdata.uniform("screen_size", static_cast<float>(w), static_cast<float>(h));
  46
  47         combine_shdata.uniform("source", 1);
  48         combine_shdata.uniform("depth", 0);
  49         combine_shdata.uniform("occlusion", 2);
  50         combine_shdata.uniform("screen_size", static_cast<float>(w), static_cast<float>(h));
  51
  52         set_depth_ratio(depth_ratio);
  53         set_darkness(1.5);
  54 }
  55
  56 void AmbientOcclusion::set_depth_ratio(float depth_ratio)
  57 {
  58         depth_ratio = 1/depth_ratio;
  59
  60         occlude_shdata.uniform("depth_ratio", depth_ratio, 1+depth_ratio);
  61         combine_shdata.uniform("depth_ratio", depth_ratio, 1+depth_ratio);
  62 }
  63
  64 void AmbientOcclusion::set_darkness(float darkness)
  65 {
  66         occlude_shdata.uniform("darkness", darkness);
  67 }
  68
  69 void AmbientOcclusion::render(const Texture2D &color, const Texture2D &depth)
  70 {
  71         occlude_texturing.attach(0, depth);
  72         combine_texturing.attach(0, depth);
  73         combine_texturing.attach(1, color);
  74
  75         BindRestore unbind_dtest(static_cast<DepthTest *>(0));
  76         BindRestore unbind_blend(static_cast<Blend *>(0));
  77         Bind bind_mesh(quad);
  78
  79         {
  80                 BindRestore bind_fbo(fbo);
  81                 Bind bind_tex(occlude_texturing);
  82                 Bind bind_shader(occlude_shader);
  83                 occlude_shdata.apply();
  84                 quad.draw();
  85         }
  86
  87         Bind bind_tex(combine_texturing);
  88         Bind bind_shader(combine_shader);
  89         combine_shdata.apply();
  90         quad.draw();
  91 }
  92
  93 } // namespace GL
  94 } // namespace Msp