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