source/bloom.cpp

   1 #include <cmath>
   2 #include <msp/strings/format.h>
   3 #include "blend.h"
   4 #include "bloom.h"
   5 #include "misc.h"
   6 #include "shader.h"
   7 #include "tests.h"
   8 #include "texunit.h"
   9
  10 using namespace std;
  11
  12 namespace Msp {
  13 namespace GL {
  14
  15 Bloom::Bloom(unsigned w, unsigned h):
  16         blur_shader("bloom_blur.glsl"),
  17         combine_shader("bloom_combine.glsl"),
  18         quad(get_fullscreen_quad())
  19 {
  20         blur_shdata[0].uniform("delta", 1.0f/w, 0.0f);
  21         blur_shdata[1].uniform("delta", 0.0f, 1.0f/h);
  22
  23         blur_shdata_common.uniform("source", 0);
  24         for(unsigned i=0; i<2; ++i)
  25         {
  26                 tex[i].set_min_filter(NEAREST);
  27                 tex[i].set_wrap(CLAMP_TO_EDGE);
  28                 tex[i].storage(RGB16F, w, h);
  29                 fbo[i].attach(COLOR_ATTACHMENT0, tex[i], 0);
  30                 fbo[i].require_complete();
  31         }
  32
  33         combine_shdata.uniform("source", 1);
  34         combine_shdata.uniform("blurred", 0);
  35
  36         combine_texturing.attach(0, tex[1]);
  37
  38         set_radius(2.0f);
  39         set_strength(0.2f);
  40 }
  41
  42 void Bloom::set_radius(float r)
  43 {
  44         if(r<=0.0f)
  45                 throw invalid_argument("Bloom::set_radius");
  46
  47         int size = min(static_cast<int>(r*3.0f), 9);
  48         blur_shdata_common.uniform("size", size);
  49
  50         vector<float> factors(size*2+1);
  51         float sum = 0.0f;
  52         r = 2*r*r;
  53         for(int i=-size; i<=size; ++i)
  54                 sum += (factors[size+i] = exp(-i*i/r));
  55         for(int i=0; i<=size*2; ++i)
  56                 factors[i] /= sum;
  57
  58         blur_shdata_common.uniform1_array("factors", size*2+1, &factors.front());
  59 }
  60
  61 void Bloom::set_strength(float s)
  62 {
  63         if(s<0.0f || s>1.0f)
  64                 throw invalid_argument("Bloom::set_strength");
  65         combine_shdata.uniform("strength", s);
  66 }
  67
  68 void Bloom::render(const Texture2D &src, const Texture2D &)
  69 {
  70         BindRestore unbind_dtest(static_cast<DepthTest *>(0));
  71         BindRestore unbind_blend(static_cast<Blend *>(0));
  72         Bind bind_mesh(quad);
  73
  74         {
  75                 Bind bind_shader(blur_shader);
  76                 blur_shdata_common.apply();
  77                 for(unsigned i=0; i<2; ++i)
  78                 {
  79                         BindRestore bind_fbo(fbo[i]);
  80                         Bind bind_tex(i ? tex[0] : src);
  81                         blur_shdata[i].apply();
  82                         quad.draw();
  83                 }
  84         }
  85
  86         combine_texturing.attach(1, src);
  87         Bind bind_texturing(combine_texturing);
  88         Bind bind_shader(combine_shader);
  89         combine_shdata.apply();
  90         quad.draw();
  91 }
  92
  93 } // namespace GL
  94 } // namespace Msp