source/vignette.cpp

   1 #include <algorithm>
   2 #include <msp/gl/mesh.h>
   3 #include <msp/gl/renderer.h>
   4 #include <msp/gl/texture2d.h>
   5 #include "resources.h"
   6 #include "vignette.h"
   7
   8 using namespace std;
   9
  10 namespace Msp {
  11 namespace DemoScene {
  12
  13 Vignette::Vignette(float aspect):
  14         mesh(get_fullscreen_quad()),
  15         shprog(Resources::get_builtins().get<GL::Program>("vignette.glsl"))
  16 {
  17         shdata.uniform("coord_scale", min(aspect, 1.0f), min(1.0f/aspect, 1.0f));
  18         set_optical(1.0f, 0.5f);
  19         set_natural(1.0f, 1.0f);
  20 }
  21
  22 void Vignette::set_optical(float pupil, float aperture)
  23 {
  24         if(pupil<0.0f || aperture<0.0f || aperture>pupil)
  25                 throw std::invalid_argument("Vignette::set_optical");
  26
  27         float p_sq = pupil*pupil;
  28         float a_sq = aperture*aperture;
  29         float two_ap = 2*pupil*aperture;
  30         static const float pi = Geometry::Angle<float>::straight().radians();
  31         shdata.uniform("optical", pupil, aperture, a_sq, a_sq*pi);
  32         shdata.uniform("optical_range", p_sq-two_ap+a_sq, p_sq+two_ap+a_sq);
  33 }
  34
  35 void Vignette::set_natural(float radius, float darkening)
  36 {
  37         if(radius<=0.0f || darkening<0.0f)
  38                 throw std::invalid_argument("Vignette::set_natural");
  39
  40         float v = pow(2.0f, -darkening);
  41         float t_sq = 1/sqrt(v)-1;
  42         shdata.uniform("natural", t_sq/(radius*radius));
  43 }
  44
  45 void Vignette::render(GL::Renderer &renderer, const GL::Texture2D &color, const GL::Texture2D &)
  46 {
  47         renderer.set_texture(&color);
  48         renderer.set_shader_program(&shprog, &shdata);
  49         mesh.draw(renderer);
  50 }
  51
  52
  53 Vignette::Template::Template():
  54         pupil(1.0f),
  55         aperture(0.5f),
  56         radius(1.0f),
  57         darkening(1.0f)
  58 { }
  59
  60 Vignette *Vignette::Template::create(unsigned w, unsigned h) const
  61 {
  62         Vignette *vign = new Vignette(static_cast<float>(w)/h);
  63         vign->set_optical(pupil, aperture);
  64         vign->set_natural(radius, darkening);
  65         return vign;
  66 }
  67
  68
  69 Vignette::Template::Loader::Loader(Template &t):
  70         DerivedObjectLoader<Template, PostProcessor::Template::Loader>(t)
  71 {
  72         add("optical", &Template::pupil, &Template::aperture);
  73         add("natural", &Template::radius, &Template::darkening);
  74 }
  75
  76 } // namespace DemoScene
  77 } // namespace Msp