feat: complete first geodesic 3D raytracing

1 files changed, 113 insertions, 204 deletions

diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index 29fa65a..c2a84a8 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -1,251 +1,144 @@
-#include "engine.h"
-#include <GLFW/glfw3.h>
-#include <glad/glad.h>
 #include <iostream>
 #include <fstream>
 #include <sstream>
-#include <limits>
+
+#include <GLFW/glfw3.h>
+
+#include "engine.h"
 #include "rendering/vertex_buffer.h"
 #include "rendering/index_buffer.h"
 
 namespace Donut
 {
-    Engine::Engine() 
-        : m_sag_a(glm::vec3(0.0f, 0.0f, 0.0f), 
-          static_cast<float>(8.54e36)) 
+    Engine::Engine()
+        : m_sag_a(glm::vec3(0.0f, 0.0f, 0.0f), 8.54e36f)
     {
         GLFWwindow* window = static_cast<GLFWwindow*>(Application::get().get_window().get_native_window());
         glfwGetFramebufferSize(window, &m_width, &m_height);
-        m_compute_height = 420;
-        m_compute_width = (m_width * 420) / m_height;
         
-        m_camera.set_orbital_mode(true);
-        m_camera.set_radius(6.34194e10);
-        m_camera.set_min_radius(1e10);
-        m_camera.set_max_radius(1e12);
-        m_camera.set_orbit_speed(0.01f);
+        m_camera.set_camera_mode(CameraMode::Orbital);
+        m_camera.set_orbital_radius(6.34194e10);
+        m_camera.set_orbital_limits(1e10, 1e12);
+        m_camera.set_orbital_speed(0.01f);
         m_camera.set_zoom_speed(25e9f);
         
         m_objects = 
         {
-            { glm::vec4(4e11f, 0.0f, 0.0f, 4e10f), glm::vec4(1,1,0,1), static_cast<float>(1.98892e30) },
-            { glm::vec4(0.0f, 0.0f, 4e11f, 4e10f), glm::vec4(1,0,0,1), static_cast<float>(1.98892e30) },
-            { glm::vec4(0.0f, 0.0f, 0.0f, m_sag_a.m_rs), glm::vec4(0,0,0,1), static_cast<float>(m_sag_a.m_mass) }
+            { glm::vec4(4e11f, 0.00f, 0.00f, 4e10f),       glm::vec4(1, 1, 0, 1), static_cast<float>(1.98892e30)    },
+            { glm::vec4(0.00f, 0.00f, 4e11f, 4e10f),       glm::vec4(1, 0, 0, 1), static_cast<float>(1.98892e30)    },
+            { glm::vec4(0.00f, 0.00f, 0.00f, m_sag_a.m_rs), glm::vec4(0, 0, 0, 1), static_cast<float>(m_sag_a.m_mass) }
         };
 
-        m_quad_shader    = Shader::create("assets/shaders/quad.glsl");
-        m_grid_shader    = Shader::create("assets/shaders/grid.glsl");
-        m_compute_shader = Shader::create_compute("Geodesic", load_compute_shader("assets/shaders/geodesic.glsl"));
+        m_shader_program  = Ref<Shader>(Shader::create("assets/shaders/compute_texture_quad.glsl"));
+        m_compute_program = create_compute_program("assets/shaders/geodesic.glsl");
         
         m_camera_ubo = UniformBuffer::create(128, 1);
-        m_disk_ubo = UniformBuffer::create(sizeof(float) * 4, 2);
+        m_disk_ubo   = UniformBuffer::create(sizeof(float) * 4, 2);
         
         uint32_t obj_ubo_size = sizeof(int) + 3 * sizeof(float)
             + 16 * (sizeof(glm::vec4) + sizeof(glm::vec4))
             + 16 * sizeof(float);
         m_objects_ubo = UniformBuffer::create(obj_ubo_size, 3);
 
-        float quad_vertices[] = 
-        {
-            -1.0f,  1.0f,  0.0f, 1.0f,
-            -1.0f, -1.0f,  0.0f, 0.0f,
-             1.0f, -1.0f,  1.0f, 0.0f,
-            
-            -1.0f,  1.0f,  0.0f, 1.0f,
-             1.0f, -1.0f,  1.0f, 0.0f,
-             1.0f,  1.0f,  1.0f, 1.0f
-        };
-
-        m_quad_vao = VertexArray::create();
-        
-        auto vertex_buffer = VertexBuffer::create(quad_vertices, static_cast<uint32_t>(sizeof(quad_vertices)));
-        VertexBufferLayout layout;
-        layout.push<float>(2);
-        layout.push<float>(2);
-        vertex_buffer->set_layout(layout);
-        m_quad_vao->add_vertex_buffer(vertex_buffer);
-
-        m_texture = Texture2D::create(m_width, m_height);
+        auto result = quad_vao();
+        m_quad_vao = result.first;
+        m_texture = result.second;
     }
 
-    void Engine::generate_grid(const std::vector<ObjectData>& objects) 
+    void Engine::update_window_dimensions()
     {
-        const int grid_size = 25;
-        const float spacing = 1e10f;
-
-        std::vector<glm::vec3> vertices;
-        std::vector<uint32_t> indices;
-
-        for (int z = 0; z <= grid_size; ++z) 
-        {
-            for (int x = 0; x <= grid_size; ++x) 
-            {
-                float world_x = (x - grid_size / 2) * spacing;
-                float world_z = (z - grid_size / 2) * spacing;
-                float y = 0.0f;
-
-                for (const auto& obj : objects) 
-                {
-                    glm::vec3 obj_pos = glm::vec3(obj.m_pos_radius);
-                    double mass = obj.m_mass;
-                    double radius = obj.m_pos_radius.w;
-
-                    double r_s = 2.0 * G * mass / (c * c);
-                    double dx = world_x - obj_pos.x;
-                    double dz = world_z - obj_pos.z;
-                    double dist = sqrt(dx * dx + dz * dz);
-
-                    if (dist > r_s) 
-                    {
-                        double delta_y = 2.0 * sqrt(r_s * (dist - r_s));
-                        y += static_cast<float>(delta_y) - 3e10f;
-                    } 
-                    else 
-                    {
-                        y += 2.0f * static_cast<float>(sqrt(r_s * r_s)) - 3e10f;
-                    }
-                }
-
-                vertices.emplace_back(world_x, y, world_z);
-            }
-        }
-
-        for (int z = 0; z < grid_size; ++z) 
-        {
-            for (int x = 0; x < grid_size; ++x) 
-            {
-                int i = z * (grid_size + 1) + x;
-                indices.push_back(i);
-                indices.push_back(i + 1);
-                indices.push_back(i);
-                indices.push_back(i + grid_size + 1);
-            }
-        }
-
-        if (!m_grid_vao)
-        {
-            m_grid_vao = Ref<VertexArray>(VertexArray::create());
-            
-            auto vertex_buffer = Ref<VertexBuffer>(VertexBuffer::create(vertices.data(), static_cast<uint32_t>(vertices.size() * sizeof(glm::vec3))));
-            VertexBufferLayout layout;
-            layout.push<float>(3);
-            vertex_buffer->set_layout(layout);
-            m_grid_vao->add_vertex_buffer(vertex_buffer);
-
-            auto index_buffer = Ref<IndexBuffer>(IndexBuffer::create(indices.data(), static_cast<uint32_t>(indices.size())));
-            m_grid_vao->set_index_buffer(index_buffer);
-        }
-        else
-        {
-            auto vertex_buffer = m_grid_vao->get_vertex_buffers()[0];
-            vertex_buffer->set_data(vertices.data(), static_cast<uint32_t>(vertices.size() * sizeof(glm::vec3)));
-        }
-
-        m_grid_index_count = static_cast<int>(indices.size());
+        GLFWwindow* window = static_cast<GLFWwindow*>(Application::get().get_window().get_native_window());
+        int old_width = m_width;
+        int old_height = m_height;
+        int old_compute_height = m_compute_height;
+        
+        glfwGetFramebufferSize(window, &m_width, &m_height);
+        
+        if (old_width         != m_width  || 
+            old_height        != m_height || 
+            old_compute_height != m_compute_height)
+            update_compute_dimensions();
     }
 
-    void Engine::draw_grid(const glm::mat4& view_proj) 
+    void Engine::update_performance(float delta_time)
     {
-        if (!m_grid_shader || !m_grid_vao) 
-            return;
-        
-        m_grid_shader->bind();
-        m_grid_shader->set_mat4("viewProj", view_proj);
-        
-        RenderCommand::disable_depth_test();
-        RenderCommand::enable_blending();
-        
-        m_grid_vao->bind();
-        glDrawElements(GL_LINES, m_grid_index_count, GL_UNSIGNED_INT, nullptr);
-        
-        RenderCommand::enable_depth_test();
+        if (delta_time > 0.0f)
+            m_current_fps = 1.0f / delta_time;
     }
 
-    void Engine::update_window_dimensions() 
+    void Engine::update_compute_dimensions()
     {
-        GLFWwindow* window = static_cast<GLFWwindow*>(Application::get().get_window().get_native_window());
-        int old_width = m_width;
-        int old_height = m_height;
-        glfwGetFramebufferSize(window, &m_width, &m_height);
-        m_compute_height = 420;
-        m_compute_width = (m_width * 420) / m_height;
-        
-        if (old_width != m_width || old_height != m_height)
-            m_texture = Texture2D::create(m_width, m_height);
+        m_texture = Texture2D::create(get_compute_width(), m_compute_height);
     }
 
-    void Engine::draw_full_screen_quad() 
+    void Engine::draw_full_screen_quad()
     {
         RenderCommand::set_viewport(0, 0, m_width, m_height);
         
-        m_quad_shader->bind();
-        std::cout << "Texture ID: " << m_texture->get_renderer_id() << ", Size: " << m_texture->get_width() << "x" << m_texture->get_height() << std::endl;
+        m_shader_program->bind();
+        m_quad_vao->bind();
+
         m_texture->bind(0);
-        m_quad_shader->set_int("screenTexture", 0);
-        std::cout << "Set screenTexture uniform to slot 0\n";
+        m_shader_program->set_int("u_ScreenTexture", 0);
 
         RenderCommand::disable_depth_test();
-        RenderCommand::draw_indexed(m_quad_vao, 6);
+        RenderCommand::draw_arrays(6);
         RenderCommand::enable_depth_test();
     }
 
-    void Engine::dispatch_compute(const Camera& cam) 
+    void Engine::dispatch_compute(const Camera& cam)
     {
-        int cw = m_compute_width;
+        int cw = get_compute_width();
         int ch = m_compute_height;
 
-        if (m_texture->get_width() != cw || m_texture->get_height() != ch) 
-            m_texture = Texture2D::create(cw, ch);
+        m_texture->set_data(nullptr, cw * ch * 4);
 
-        m_compute_shader->bind();
+        m_compute_program->bind();
         upload_camera_ubo(cam);
         upload_disk_ubo();
         upload_objects_ubo(m_objects);
-
         m_texture->bind_as_image(0, false);
 
-        uint32_t groups_x = (uint32_t)std::ceil(cw / 16.0f);
-        uint32_t groups_y = (uint32_t)std::ceil(ch / 16.0f);
-        m_compute_shader->dispatch(groups_x, groups_y, 1);
-        m_compute_shader->memory_barrier(IMAGE_ACCESS_BARRIER_BIT);
-        
-        glMemoryBarrier(GL_SHADER_IMAGE_ACCESS_BARRIER_BIT);
-        glMemoryBarrier(GL_TEXTURE_FETCH_BARRIER_BIT);
+        uint32_t groups_x = static_cast<uint32_t>(std::ceil(cw / 16.0f));
+        uint32_t groups_y = static_cast<uint32_t>(std::ceil(ch / 16.0f));
+        m_compute_program->dispatch(groups_x, groups_y, 1);
+        m_compute_program->memory_barrier(IMAGE_ACCESS_BARRIER_BIT);
     }
 
-    void Engine::upload_camera_ubo(const Camera& cam) 
+    void Engine::upload_camera_ubo(const Camera& cam)
     {
-        struct UBOData 
+        struct UBOData
         {
-            glm::vec3 pos; float _pad0;
-            glm::vec3 right; float _pad1;
-            glm::vec3 up; float _pad2;
+            glm::vec3 pos;     float _pad0;
+            glm::vec3 right;   float _pad1;
+            glm::vec3 up;      float _pad2;
             glm::vec3 forward; float _pad3;
             float tan_half_fov;
             float aspect;
-            bool moving;
-            int _pad4;
+            bool  moving;
+            int   _pad4;
         } data;
 
-        glm::vec3 fwd = glm::normalize(cam.get_target() - cam.get_orbital_position());
-        glm::vec3 up = glm::vec3(0, 1, 0);
+        glm::vec3 fwd   = glm::normalize(cam.get_orbital_target() - cam.get_orbital_position());
+        glm::vec3 up    = glm::vec3(0, 1, 0);
         glm::vec3 right = glm::normalize(glm::cross(fwd, up));
         up = glm::cross(right, fwd);
 
-        data.pos = cam.get_orbital_position();
-        data.right = right;
-        data.up = up;
-        data.forward = fwd;
+        data.pos        = cam.get_orbital_position();
+        data.right      = right;
+        data.up         = up;
+        data.forward    = fwd;
         data.tan_half_fov = static_cast<float>(tan(glm::radians(60.0f * 0.5f)));
-        data.aspect = static_cast<float>(m_width) / static_cast<float>(m_height);
-        data.moving = cam.is_dragging() || cam.is_panning();
+        data.aspect     = static_cast<float>(get_compute_width()) / static_cast<float>(m_compute_height);
+        data.moving     = cam.is_dragging() || cam.is_panning();
 
         m_camera_ubo->set_data(&data, sizeof(UBOData));
+        m_camera_ubo->bind(1);
     }
 
-    void Engine::upload_objects_ubo(const std::vector<ObjectData>& objs) 
+    void Engine::upload_objects_ubo(const std::vector<ObjectData>& objs)
     {
-        struct UBOData 
+        struct UBOData
         {
             int num_objects;
             float _pad0, _pad1, _pad2;
@@ -257,7 +150,7 @@ namespace Donut
         size_t count = std::min(objs.size(), size_t(16));
         data.num_objects = static_cast<int>(count);
 
-        for (size_t i = 0; i < count; ++i) 
+        for (size_t i = 0; i < count; ++i)
         {
             data.pos_radius[i] = objs[i].m_pos_radius;
             data.color[i] = objs[i].m_color;
@@ -265,9 +158,10 @@ namespace Donut
         }
 
         m_objects_ubo->set_data(&data, sizeof(data));
+        m_objects_ubo->bind(3);
     }
 
-    void Engine::upload_disk_ubo() 
+    void Engine::upload_disk_ubo()
     {
         float r1 = static_cast<float>(m_sag_a.m_rs * 2.2);
         float r2 = static_cast<float>(m_sag_a.m_rs * 5.2);
@@ -276,28 +170,28 @@ namespace Donut
         float disk_data[4] = { r1, r2, num, thickness };
 
         m_disk_ubo->set_data(disk_data, sizeof(disk_data));
+        m_disk_ubo->bind(2);
     }
 
-    void Engine::update_physics(float delta_time) 
+    void Engine::update_physics(float delta_time)
     {
-        for (auto& obj : m_objects) 
+        for (auto& obj : m_objects)
         {
-            for (auto& obj2 : m_objects) 
+            for (auto& obj2 : m_objects)
             {
                 if (&obj == &obj2) continue;
                 float dx = obj2.m_pos_radius.x - obj.m_pos_radius.x;
                 float dy = obj2.m_pos_radius.y - obj.m_pos_radius.y;
                 float dz = obj2.m_pos_radius.z - obj.m_pos_radius.z;
                 float distance = sqrt(dx * dx + dy * dy + dz * dz);
-
-                if (distance > 0) 
+                if (distance > 0)
                 {
                     std::vector<double> direction = {dx / distance, dy / distance, dz / distance};
                     double Gforce = (G * obj.m_mass * obj2.m_mass) / (distance * distance);
                     double acc1 = Gforce / obj.m_mass;
                     std::vector<double> acc = {direction[0] * acc1, direction[1] * acc1, direction[2] * acc1};
-
-                    if (m_gravity) 
+                    
+                    if (m_gravity)
                     {
                         obj.m_velocity.x += static_cast<float>(acc[0]);
                         obj.m_velocity.y += static_cast<float>(acc[1]);
@@ -314,34 +208,49 @@ namespace Donut
 
     void Engine::render_scene()
     {
-        glm::mat4 view = glm::lookAt(m_camera.get_orbital_position(), m_camera.get_target(), glm::vec3(0,1,0));
-        glm::mat4 proj = glm::perspective(glm::radians(60.0f), float(m_width)/m_height, 1e9f, 1e14f);
-        glm::mat4 view_proj = proj * view;
-        
-        generate_grid(m_objects);
-        draw_grid(view_proj);
-        
-        RenderCommand::set_viewport(0, 0, m_width, m_height);
-        dispatch_compute(m_camera);
-        draw_full_screen_quad();
+        RenderCommand::clear();
+        m_shader_program->bind();
+        m_quad_vao->bind();
+        m_texture->bind(0);
+        RenderCommand::draw_arrays(6);
     }
 
-    std::string Engine::load_compute_shader(const std::string& path)
+    Ref<Shader> Engine::create_compute_program(const char* path)
     {
         std::ifstream in(path);
-        if(!in.is_open()) 
+        if(!in.is_open())
         {
             std::cerr << "Failed to open compute shader: " << path << "\n";
-            return "";
+            return nullptr;
         }
-
         std::stringstream ss;
         ss << in.rdbuf();
-        std::string result = ss.str();
-        if (result.empty()) 
-            std::cerr << "Warning: Compute shader file is empty: " << path << "\n";
-        else 
-            std::cout << "Successfully loaded compute shader: " << path << " (size: " << result.size() << " bytes)\n";
-        return result;
+        std::string src_str = ss.str();
+        return Ref<Shader>(Shader::create_compute("ComputeShader", src_str));
+    }
+
+    std::pair<Ref<VertexArray>, Ref<Texture2D>> Engine::quad_vao()
+    {
+        float quad_vertices[] = 
+        {
+            -1.0f,  1.0f,  0.0f, 1.0f,
+            -1.0f, -1.0f,  0.0f, 0.0f,
+             1.0f, -1.0f,  1.0f, 0.0f,
+            -1.0f,  1.0f,  0.0f, 1.0f,
+             1.0f, -1.0f,  1.0f, 0.0f,
+             1.0f,  1.0f,  1.0f, 1.0f
+        };
+
+        auto vertex_buffer = Ref<VertexBuffer>(VertexBuffer::create(quad_vertices, static_cast<uint32_t>(sizeof(quad_vertices))));
+        VertexBufferLayout layout;
+        layout.push<float>(2);
+        layout.push<float>(2);
+        vertex_buffer->set_layout(layout);
+
+        auto vertex_array = Ref<VertexArray>(VertexArray::create());
+        vertex_array->add_vertex_buffer(vertex_buffer);
+        auto texture = Texture2D::create(get_compute_width(), m_compute_height);
+        
+        return { vertex_array, texture };
     }
 }