Implement image-based lighting in PbrMaterial

[libs/gl.git] / source / effects / environmentmap.cpp

diff --git a/source/effects/environmentmap.cpp b/source/effects/environmentmap.cpp
index bd44ae04fecac868c2852534726c3d0b4c58df87..a82731e1e218a1514d9a930a776a2ac08a6a90d1 100644 (file)
--- a/source/effects/environmentmap.cpp
+++ b/source/effects/environmentmap.cpp
@@ -1,6 +1,7 @@
 #include <algorithm>
 #include <cmath>
 #include "environmentmap.h"
+#include "mesh.h"
 #include "renderer.h"
 #include "resources.h"
 #include "texunit.h"
@@ -13,27 +14,50 @@ namespace GL {
 EnvironmentMap::EnvironmentMap(unsigned s, Renderable &r, Renderable &e):
        Effect(r),
        environment(e),
-       sampler(Resources::get_global().get<Sampler>("_linear_clamp.samp"))
+       irradiance_shprog(Resources::get_global().get<Program>("_envmap_irradiance.glsl.shader")),
+       specular_shprog(Resources::get_global().get<Program>("_envmap_specular.glsl.shader")),
+       fullscreen_mesh(Resources::get_global().get<Mesh>("_fullscreen_quad.mesh")),
+       sampler(Resources::get_global().get<Sampler>("_linear_clamp.samp")),
+       mip_sampler(Resources::get_global().get<Sampler>("_mip_clamp.samp"))
 {
-       init(s, RGB8);
+       init(s, RGB8, 1);
 }
 
 EnvironmentMap::EnvironmentMap(unsigned s, PixelFormat f, Renderable &r, Renderable &e):
        Effect(r),
        environment(e),
-       sampler(Resources::get_global().get<Sampler>("_linear_clamp.samp"))
+       irradiance_shprog(Resources::get_global().get<Program>("_envmap_irradiance.glsl.shader")),
+       specular_shprog(Resources::get_global().get<Program>("_envmap_specular.glsl.shader")),
+       fullscreen_mesh(Resources::get_global().get<Mesh>("_fullscreen_quad.mesh")),
+       sampler(Resources::get_global().get<Sampler>("_linear_clamp.samp")),
+       mip_sampler(Resources::get_global().get<Sampler>("_mip_clamp.samp"))
 {
-       init(s, f);
+       init(s, f, 1);
 }
 
-void EnvironmentMap::init(unsigned s, PixelFormat f)
+EnvironmentMap::EnvironmentMap(unsigned s, PixelFormat f, unsigned l, Renderable &r, Renderable &e):
+       Effect(r),
+       environment(e),
+       irradiance_shprog(Resources::get_global().get<Program>("_envmap_irradiance.glsl.shader")),
+       specular_shprog(Resources::get_global().get<Program>("_envmap_specular.glsl.shader")),
+       fullscreen_mesh(Resources::get_global().get<Mesh>("_fullscreen_quad.mesh")),
+       sampler(Resources::get_global().get<Sampler>("_linear_clamp.samp")),
+       mip_sampler(Resources::get_global().get<Sampler>("_mip_clamp.samp"))
+{
+       init(s, f, l);
+}
+
+void EnvironmentMap::init(unsigned s, PixelFormat f, unsigned l)
 {
+       if(!l || (1U<<(l-1))>=s)
+               throw invalid_argument("EnvironmentMap::EnvironmentMap");
+
        size = s;
        rendered = false;
        update_interval = 1;
        update_delay = 0;
 
-       env_tex.storage(f, size);
+       env_tex.storage(f, size, l);
        depth_buf.storage(DEPTH_COMPONENT32F, size, size);
        for(unsigned i=0; i<6; ++i)
        {
@@ -48,6 +72,31 @@ void EnvironmentMap::init(unsigned s, PixelFormat f)
                faces[i].camera.set_depth_clip(0.1, 100);
        }
 
+       irradiance.storage(f, size/4, 1);
+       irradiance_fbo.attach_layered(COLOR_ATTACHMENT0, irradiance);
+
+       if(l>1)
+       {
+               specular_fbos.resize(l-1);
+               for(unsigned i=1; i<l; ++i)
+                       specular_fbos[i-1].attach_layered(COLOR_ATTACHMENT0, env_tex, i);
+
+               LinAl::Matrix<float, 3, 3> face_matrices[6];
+               for(unsigned i=0; i<6; ++i)
+               {
+                       GL::TextureCubeFace face = GL::TextureCube::enumerate_faces(i);
+                       GL::Vector3 columns[3];
+                       columns[0] = GL::TextureCube::get_s_direction(face);
+                       columns[1] = GL::TextureCube::get_t_direction(face);
+                       columns[2] = GL::TextureCube::get_face_direction(face);
+                       face_matrices[i] = LinAl::Matrix<float, 3, 3>::from_columns(columns);
+               }
+
+               prefilter_shdata.uniform_array("faces", 6, &face_matrices[0]);
+               prefilter_shdata.uniform("n_samples", 128);
+               prefilter_shdata.uniform("roughness", 1.0f);
+       }
+
        shdata.uniform("env_world_matrix", LinAl::SquareMatrix<float, 3>::identity());
 }
 
@@ -104,6 +153,19 @@ void EnvironmentMap::setup_frame(Renderer &renderer)
                renderer.set_camera(faces[i].camera);
                renderer.render(environment);
        }
+
+       irradiance_fbo.bind();
+       renderer.set_shader_program(&irradiance_shprog, &prefilter_shdata);
+       renderer.set_texture("environment_map", &env_tex, &sampler);
+       fullscreen_mesh.draw(renderer);
+
+       renderer.set_shader_program(&specular_shprog);
+       for(unsigned i=0; i<specular_fbos.size(); ++i)
+       {
+               prefilter_shdata.uniform("roughness", 1.0f-sqrt(1.0f-static_cast<float>(i+1)/specular_fbos.size()));
+               specular_fbos[i].bind();
+               fullscreen_mesh.draw(renderer);
+       }
 }
 
 void EnvironmentMap::finish_frame()
@@ -123,7 +185,8 @@ void EnvironmentMap::render(Renderer &renderer, Tag tag) const
 
        Renderer::Push _push_rend(renderer);
 
-       renderer.set_texture("environment_map", &env_tex, &sampler);
+       renderer.set_texture("environment_map", &env_tex, &mip_sampler);
+       renderer.set_texture("irradiance_map", &irradiance, &sampler);
        renderer.add_shader_data(shdata);
        renderer.render(renderable, tag);
 }