feat: add HDRI

1 files changed, 161 insertions, 1 deletions

diff --git a/src/states/world_builder_state.cpp b/src/states/world_builder_state.cpp
index f28f70a..c0999d4 100644
--- a/src/states/world_builder_state.cpp
+++ b/src/states/world_builder_state.cpp
@@ -2,6 +2,7 @@
 
 #include "core/application.h"
 #include "core/window.h"
+#include "core/hdri_manager.h"
 
 #include "rendering/renderer.h"
 #include "rendering/shader.h"
@@ -23,6 +24,7 @@
 #include <fstream>
 #include <sstream>
 #include <limits>
+#include <vector>
 
 namespace Donut
 {
@@ -43,7 +45,25 @@ namespace Donut
         m_camera.update_orbital();
         
         m_sphere_shader = Ref<Shader>(Shader::create("assets/shaders/sphere.glsl"));
+        m_skybox_shader = Ref<Shader>(Shader::create("assets/shaders/skybox.glsl"));
+        
+        if (!m_sphere_shader)
+            DONUT_ERROR("Failed to create sphere shader");
+        if (!m_skybox_shader)
+            DONUT_ERROR("Failed to create skybox shader");
+        
         initialize_sphere_geometry();
+        initialize_skybox_geometry();
+        
+        auto& hdri_manager = HDRIManager::get();
+        m_hdri_environment = hdri_manager.get_current_hdri();
+        if (!m_hdri_environment)
+        {
+            hdri_manager.set_current_hdri("assets/hdri/hdr_blue_nebulae_1.hdr");
+            m_hdri_environment = hdri_manager.get_current_hdri();
+            if (!m_hdri_environment)
+                DONUT_WARN("Failed to load default HDRI for WorldBuilder, using fallback");
+        }
         
         Material black_hole_material(glm::vec3(0.0f, 0.0f, 0.0f), 0.0f, 0.0f);
         m_black_hole = Object(glm::vec3(0.0f, 0.0f, 0.0f), 2.0f, black_hole_material);
@@ -88,8 +108,15 @@ namespace Donut
     
     void WorldBuilderState::on_render()
     {
+        auto& hdri_manager = HDRIManager::get();
+        m_hdri_environment = hdri_manager.get_current_hdri();
+        
         RenderCommand::set_clear_color(glm::vec4(0.1f, 0.1f, 0.1f, 1.0f));
         RenderCommand::clear();
+        
+        if (m_hdri_environment)
+            render_skybox();
+        
         render_scene();
     }
     
@@ -464,6 +491,44 @@ namespace Donut
             ImGui::Spacing();
             ImGui::TextColored(ImVec4(0.7f, 0.7f, 0.7f, 1.0f), "White rim around sphere silhouette");
         }
+
+        ImGui::Spacing();
+
+        if (ImGui::CollapsingHeader("HDRI Environment", nullptr))
+        {
+            ImGui::TextColored(ImVec4(0.9f, 0.9f, 1.0f, 1.0f), "HDRI Settings:");
+
+            static int selected_hdri = 0;
+            ImGui::PushID("WorldBuilderHDRI");
+            auto& hdri_manager = HDRIManager::get();
+            const auto& available_hdri = hdri_manager.get_available_hdri();
+            
+            static std::vector<std::string> hdri_option_names;
+            static std::vector<const char*> hdri_options;
+            
+            if (hdri_option_names.size() != available_hdri.size())
+            {
+                hdri_option_names.clear();
+                hdri_options.clear();
+                
+                for (const auto& path : available_hdri)
+                {
+                    hdri_option_names.push_back(hdri_manager.get_hdri_name(path));
+                    hdri_options.push_back(hdri_option_names.back().c_str());
+                }
+            }
+
+            if (ImGui::Combo("HDRI Environment", &selected_hdri, hdri_options.data(), static_cast<int>(hdri_options.size())))
+            {
+                auto& hdri_manager = HDRIManager::get();
+                hdri_manager.set_current_hdri(available_hdri[selected_hdri]);
+                m_hdri_environment = hdri_manager.get_current_hdri();
+            }
+
+            ImGui::Spacing();
+            ImGui::TextColored(ImVec4(0.7f, 0.7f, 0.7f, 1.0f), "HDRI provides background skybox and lighting for the scene");
+            ImGui::PopID();
+        }
         
         ImGui::Spacing();
         ImGui::Separator();
@@ -484,7 +549,6 @@ namespace Donut
         {
             auto& engine = Application::get().get_engine();
             engine.load_objects_from_scene(m_scene.objs);
-            
             Application::get().get_state_manager().switch_to_state("Simulation");
         }
         
@@ -761,6 +825,12 @@ namespace Donut
         m_sphere_shader->set_float3("u_OutlineColor", m_outline_color);
         m_sphere_shader->set_float("u_OutlineWidth",  m_outline_width);
         
+        if (m_hdri_environment)
+        {
+            m_hdri_environment->bind(1);
+            m_sphere_shader->set_int("u_HDRIEnvironment", 1);
+        }
+        
         if (m_black_hole_initialized)
         {
             glm::mat4 black_hole_transform = glm::translate(glm::mat4(1.0f), m_black_hole.m_centre);
@@ -811,4 +881,94 @@ namespace Donut
         
         RenderCommand::disable_depth_test();
     }
+    
+
+    
+    void WorldBuilderState::initialize_skybox_geometry()
+    {
+        float skybox_vertices[] = 
+        {
+            -1.0f,  1.0f, -1.0f,
+            -1.0f, -1.0f, -1.0f,
+             1.0f, -1.0f, -1.0f,
+             1.0f, -1.0f, -1.0f,
+             1.0f,  1.0f, -1.0f,
+            -1.0f,  1.0f, -1.0f,
+
+            -1.0f, -1.0f,  1.0f,
+            -1.0f, -1.0f, -1.0f,
+            -1.0f,  1.0f, -1.0f,
+            -1.0f,  1.0f, -1.0f,
+            -1.0f,  1.0f,  1.0f,
+            -1.0f, -1.0f,  1.0f,
+
+             1.0f, -1.0f, -1.0f,
+             1.0f, -1.0f,  1.0f,
+             1.0f,  1.0f,  1.0f,
+             1.0f,  1.0f,  1.0f,
+             1.0f,  1.0f, -1.0f,
+             1.0f, -1.0f, -1.0f,
+
+            -1.0f, -1.0f,  1.0f,
+            -1.0f,  1.0f,  1.0f,
+             1.0f,  1.0f,  1.0f,
+             1.0f,  1.0f,  1.0f,
+             1.0f, -1.0f,  1.0f,
+            -1.0f, -1.0f,  1.0f,
+
+            -1.0f,  1.0f, -1.0f,
+             1.0f,  1.0f, -1.0f,
+             1.0f,  1.0f,  1.0f,
+             1.0f,  1.0f,  1.0f,
+            -1.0f,  1.0f,  1.0f,
+            -1.0f,  1.0f, -1.0f,
+
+            -1.0f, -1.0f, -1.0f,
+            -1.0f, -1.0f,  1.0f,
+             1.0f, -1.0f, -1.0f,
+             1.0f, -1.0f, -1.0f,
+            -1.0f, -1.0f,  1.0f,
+             1.0f, -1.0f,  1.0f
+        };
+
+        auto vertex_buffer = Ref<VertexBuffer>(VertexBuffer::create(skybox_vertices, sizeof(skybox_vertices)));
+        VertexBufferLayout layout;
+        layout.push<float>(3);
+        vertex_buffer->set_layout(layout);
+
+        m_skybox_vao = Ref<VertexArray>(VertexArray::create());
+        m_skybox_vao->add_vertex_buffer(vertex_buffer);
+    }
+    
+    void WorldBuilderState::render_skybox()
+    {
+        if (!m_skybox_shader || !m_skybox_vao || !m_hdri_environment)
+        {
+            return;
+        }
+        
+        GLFWwindow* window = static_cast<GLFWwindow*>(Application::get().get_window().get_native_window());
+        int width, height;
+        glfwGetFramebufferSize(window, &width, &height);
+
+        RenderCommand::set_viewport(0, 0, width, height);
+        RenderCommand::disable_depth_test();
+        
+        glm::mat4 view = m_camera.get_view_matrix();
+        glm::mat4 projection = m_camera.get_projection_matrix();
+        
+        view = glm::mat4(glm::mat3(view));
+        
+        m_skybox_shader->bind();
+        m_skybox_shader->set_mat4("u_View", view);
+        m_skybox_shader->set_mat4("u_Projection", projection);
+        
+        m_hdri_environment->bind(0);
+        m_skybox_shader->set_int("u_Skybox", 0);
+        
+        m_skybox_vao->bind();
+        RenderCommand::draw_arrays(36);
+        
+        RenderCommand::enable_depth_test();
+    }
 };