source/effects/sky.cpp

   1 #include "light.h"
   2 #include "mesh.h"
   3 #include "renderer.h"
   4 #include "resources.h"
   5 #include "sky.h"
   6
   7 using namespace std;
   8
   9 namespace Msp {
  10 namespace GL {
  11
  12 Sky::Sky(Resources &resources, Renderable &r, const Light &s):
  13         Effect(r),
  14         sun(s),
  15         transmittance_shprog(resources.get<Program>("_sky_transmittance.glsl.shader")),
  16         transmittance_lookup_dirty(true),
  17         distant_shprog(resources.get<Program>("_sky_distant.glsl.shader")),
  18         fullscreen_mesh(resources.get<Mesh>("_fullscreen_quad.mesh")),
  19         backdrop_shprog(resources.get<Program>("_sky_backdrop.glsl.shader")),
  20         sampler(resources.get<Sampler>("_linear_clamp.samp")),
  21         wrap_sampler(resources.get<Sampler>("_linear_clamp_v.samp")),
  22         rendered(false)
  23 {
  24         transmittance_lookup.storage(RGB16F, 128, 64, 1);
  25         transmittance_fbo.attach(COLOR_ATTACHMENT0, transmittance_lookup);
  26
  27         distant.storage(RGB16F, 256, 128, 1);
  28         distant_fbo.attach(COLOR_ATTACHMENT0, distant);
  29
  30         shdata.uniform("n_steps", 50);
  31
  32         set_planet(Planet::earth());
  33         set_view_height(5.0f);
  34 }
  35
  36 void Sky::set_planet(const Planet &planet)
  37 {
  38         shdata.uniform("events.rayleigh_scatter", planet.rayleigh_scatter.r, planet.rayleigh_scatter.g, planet.rayleigh_scatter.b);
  39         shdata.uniform("events.mie_scatter", planet.mie_scatter.r, planet.mie_scatter.g, planet.mie_scatter.b);
  40         shdata.uniform("events.mie_absorb", planet.mie_absorb.r, planet.mie_absorb.g, planet.mie_absorb.b);
  41         shdata.uniform("events.ozone_absorb", planet.ozone_absorb.r, planet.ozone_absorb.g, planet.ozone_absorb.b);
  42         shdata.uniform("rayleigh_density_decay", planet.rayleigh_density_decay);
  43         shdata.uniform("mie_density_decay", planet.mie_density_decay);
  44         shdata.uniform("ozone_band_center", planet.ozone_band_center);
  45         shdata.uniform("ozone_band_extent", planet.ozone_band_extent);
  46         shdata.uniform("atmosphere_thickness", planet.atmosphere_thickness);
  47         shdata.uniform("planet_radius", planet.planet_radius);
  48         shdata.uniform("ground_albedo", planet.ground_albedo.r, planet.ground_albedo.g, planet.ground_albedo.b);
  49 }
  50
  51 void Sky::set_view_height(float h)
  52 {
  53         shdata.uniform("view_height", h);
  54 }
  55
  56 void Sky::setup_frame(Renderer &renderer)
  57 {
  58         if(rendered)
  59                 return;
  60
  61         rendered = true;
  62
  63         shdata.uniform("light_color", sun.get_color());
  64         shdata.uniform("light_dir", sun.get_position().slice<3>(0));
  65
  66         Renderer::Push push(renderer);
  67
  68         if(transmittance_lookup_dirty)
  69         {
  70                 transmittance_lookup_dirty = false;
  71                 Bind bind_fbo(transmittance_fbo);
  72                 renderer.set_shader_program(&transmittance_shprog, &shdata);
  73                 fullscreen_mesh.draw(renderer);
  74         }
  75
  76         Bind bind_fbo(distant_fbo);
  77         renderer.set_shader_program(&distant_shprog, &shdata);
  78         renderer.set_texture("transmittance_lookup", &transmittance_lookup, &sampler);
  79         fullscreen_mesh.draw(renderer);
  80
  81         renderable.setup_frame(renderer);
  82 }
  83
  84 void Sky::finish_frame()
  85 {
  86         if(rendered)
  87         {
  88                 rendered = false;
  89                 renderable.finish_frame();
  90         }
  91 }
  92
  93 void Sky::render(Renderer &renderer, Tag tag) const
  94 {
  95         renderable.render(renderer, tag);
  96
  97         Renderer::Push push(renderer);
  98
  99         renderer.set_shader_program(&backdrop_shprog, &shdata);
 100         renderer.set_texture("distant", &distant, &wrap_sampler);
 101         fullscreen_mesh.draw(renderer);
 102 }
 103
 104
 105 Sky::Planet::Planet():
 106         rayleigh_scatter(0.0f),
 107         mie_scatter(0.0f),
 108         mie_absorb(0.0f),
 109         ozone_absorb(0.0f),
 110         rayleigh_density_decay(1e3f),
 111         mie_density_decay(1e3f),
 112         ozone_band_center(1e4f),
 113         ozone_band_extent(1e2f),
 114         atmosphere_thickness(2e4f),
 115         planet_radius(1e6f)
 116 { }
 117
 118 Sky::Planet Sky::Planet::earth()
 119 {
 120         Planet planet;
 121         planet.rayleigh_scatter = Color(5.802e-6f, 13.558e-6f, 33.1e-6f);
 122         planet.mie_scatter = Color(3.996e-6f, 3.996e-6f, 3.996e-6f);
 123         planet.mie_absorb = Color(4.4e-6f, 4.4e-6f, 4.4e-6f);
 124         planet.ozone_absorb = Color(0.65e-6f, 1.881e-6f, 0.085e-6f);
 125         planet.rayleigh_density_decay = -8e3f;
 126         planet.mie_density_decay = -1.2e3f;
 127         planet.ozone_band_center = 25e3f;
 128         planet.ozone_band_extent = 15e3f;
 129         planet.atmosphere_thickness = 1e5f;
 130         planet.planet_radius = 6.36e6f;
 131         return planet;
 132 }
 133
 134 } // namespace GL
 135 } // namespace Msp