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 {
  13
  14 static const char blur_fs[]=
  15         "uniform sampler2D source;\n"
  16         "uniform vec2 delta;\n"
  17         "uniform float factors[19];\n"
  18         "uniform int size;\n"
  19         "varying vec2 texcoord;\n"
  20         "void main()\n"
  21         "{\n"
  22         "       gl_FragColor = vec4(0.0, 0.0, 0.0, 0.0);\n"
  23         "       for(int i=0; i<=size*2; ++i)\n"
  24         "               gl_FragColor += texture2D(source, texcoord+delta*float(i-size))*factors[i];\n"
  25         "}";
  26
  27 static const char combine_fs[]=
  28         "uniform sampler2D source;\n"
  29         "uniform sampler2D blurred;\n"
  30         "uniform float strength;\n"
  31         "varying vec2 texcoord;\n"
  32         "void main()\n"
  33         "{\n"
  34         "       gl_FragColor = mix(texture2D(source, texcoord), texture2D(blurred, texcoord), strength);\n"
  35         "}";
  36
  37 }
  38
  39 namespace Msp {
  40 namespace GL {
  41
  42 Bloom::Bloom(unsigned w, unsigned h):
  43         quad(get_fullscreen_quad())
  44 {
  45         blur_shader.attach_shader(get_fullscreen_vertex_shader());
  46         blur_shader.attach_shader_owned(new FragmentShader(blur_fs));
  47         blur_shader.link();
  48
  49         combine_shader.attach_shader(get_fullscreen_vertex_shader());
  50         combine_shader.attach_shader_owned(new FragmentShader(combine_fs));
  51         combine_shader.link();
  52
  53         blur_shdata[0].uniform("delta", 1.0f/w, 0.0f);
  54         blur_shdata[1].uniform("delta", 0.0f, 1.0f/h);
  55
  56         blur_shdata_common.uniform("source", 0);
  57         for(unsigned i=0; i<2; ++i)
  58         {
  59                 tex[i].set_min_filter(NEAREST);
  60                 tex[i].set_wrap(CLAMP_TO_EDGE);
  61                 tex[i].storage(RGB16F, w, h);
  62         }
  63
  64         combine_shdata.uniform("source", 1);
  65         combine_shdata.uniform("blurred", 0);
  66
  67         combine_texturing.attach(0, tex[1]);
  68
  69         set_radius(2.0f);
  70         set_strength(0.2f);
  71 }
  72
  73 void Bloom::set_radius(float r)
  74 {
  75         if(r<=0.0f)
  76                 throw invalid_argument("Bloom::set_radius");
  77
  78         int size = min(static_cast<int>(r*3.0f), 9);
  79         blur_shdata_common.uniform("size", size);
  80
  81         vector<float> factors(size*2+1);
  82         float sum = 0.0f;
  83         r = 2*r*r;
  84         for(int i=-size; i<=size; ++i)
  85                 sum += (factors[size+i] = exp(-i*i/r));
  86         for(int i=0; i<=size*2; ++i)
  87                 factors[i] /= sum;
  88
  89         blur_shdata_common.uniform1_array("factors[0]", size*2+1, &factors.front());
  90 }
  91
  92 void Bloom::set_strength(float s)
  93 {
  94         if(s<0.0f || s>1.0f)
  95                 throw invalid_argument("Bloom::set_strength");
  96         combine_shdata.uniform("strength", s);
  97 }
  98
  99 void Bloom::render(const Texture2D &src, const Texture2D &)
 100 {
 101         Bind unbind_dtest(static_cast<DepthTest *>(0), true);
 102         Bind unbind_blend(static_cast<Blend *>(0), true);
 103
 104         {
 105                 Bind bind_shader(blur_shader);
 106                 blur_shdata_common.apply();
 107                 Bind bind_fbo(fbo, true);
 108                 for(unsigned i=0; i<2; ++i)
 109                 {
 110                         Bind bind_tex(i ? tex[0] : src);
 111                         fbo.attach(COLOR_ATTACHMENT0, tex[i], 0);
 112                         blur_shdata[i].apply();
 113                         quad.draw();
 114                 }
 115         }
 116
 117         combine_texturing.attach(1, src);
 118         Bind bind_texturing(combine_texturing);
 119         Bind bind_shader(combine_shader);
 120         combine_shdata.apply();
 121         quad.draw();
 122 }
 123
 124 } // namespace GL
 125 } // namespace Msp