source/effects/sky.h

   1 #ifndef MSP_GL_SKY_H_
   2 #define MSP_GL_SKY_H_
   3
   4 #include "effect.h"
   5 #include "framebuffer.h"
   6 #include "programdata.h"
   7 #include "rendertarget.h"
   8
   9 namespace Msp {
  10 namespace GL {
  11
  12 class Mesh;
  13 class Light;
  14 class Program;
  15
  16 /**
  17 Renders a procedurally generated sky at the background.  Based on the paper
  18 "A Scalable and Production Ready Sky and Atmosphere Rendering Technique" by
  19 Sébastien Hillaire (https://sebh.github.io/publications/egsr2020.pdf).
  20 */
  21 class Sky: public Effect
  22 {
  23 public:
  24         struct Planet
  25         {
  26                 Color rayleigh_scatter;
  27                 Color mie_scatter;
  28                 Color mie_absorb;
  29                 Color ozone_absorb;
  30                 float rayleigh_density_decay;
  31                 float mie_density_decay;
  32                 float ozone_band_center;
  33                 float ozone_band_extent;
  34                 float atmosphere_thickness;
  35                 float planet_radius;
  36                 Color ground_albedo;
  37
  38                 Planet();
  39
  40                 static Planet earth();
  41         };
  42
  43 private:
  44         Planet planet;
  45         Light &sun;
  46         RenderTarget transmittance_lookup;
  47         const Program &transmittance_shprog;
  48         bool transmittance_lookup_dirty;
  49         RenderTarget distant;
  50         const Program &distant_shprog;
  51         const Mesh &fullscreen_mesh;
  52         const Program &backdrop_shprog;
  53         const Sampler &sampler;
  54         const Sampler &wrap_sampler;
  55         mutable ProgramData shdata;
  56         float view_height;
  57         bool rendered;
  58
  59 public:
  60         Sky(Renderable &, Light &);
  61
  62         void set_planet(const Planet &);
  63         void set_view_height(float);
  64
  65         Color get_transmittance(const Vector3 &);
  66
  67         virtual void setup_frame(Renderer &);
  68         virtual void finish_frame();
  69         virtual void render(Renderer &, Tag = Tag()) const;
  70 };
  71
  72 } // namespace GL
  73 } // namespace Msp
  74
  75 #endif