feat: add bloom and blur

2 files changed, 30 insertions, 1 deletions

diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index 435b3e0..9a88e9e 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -34,6 +34,7 @@ namespace Donut
 
         m_shader_program  = Ref<Shader>(Shader::create("assets/shaders/compute_texture_quad.glsl"));
         m_compute_program = create_compute_program("assets/shaders/geodesic.glsl");
+        m_blur_shader     = Ref<Shader>(Shader::create("assets/shaders/blur.glsl"));
         
         m_camera_ubo = UniformBuffer::create(128, 1);
         m_disk_ubo   = UniformBuffer::create(sizeof(float) * 5, 2);
@@ -96,6 +97,24 @@ namespace Donut
         RenderCommand::enable_depth_test();
     }
 
+    void Engine::draw_blur_pass()
+    {
+        RenderCommand::set_viewport(0, 0, m_width, m_height);
+        
+        m_blur_shader->bind();
+        m_quad_vao->bind();
+
+        m_texture->bind(0);
+        m_blur_shader->set_int("u_ScreenTexture", 0);
+        m_blur_shader->set_float2("u_Resolution", glm::vec2(m_width, m_height));
+        m_blur_shader->set_float("u_BlurStrength", m_blur_strength);
+        m_blur_shader->set_float("u_GlowIntensity", m_glow_intensity);
+
+        RenderCommand::disable_depth_test();
+        RenderCommand::draw_arrays(6);
+        RenderCommand::enable_depth_test();
+    }
+
     void Engine::dispatch_compute(const Camera& cam)
     {
         int cw = get_compute_width();
diff --git a/src/engine/engine.h b/src/engine/engine.h
index 524f1a7..95cd1f0 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -66,6 +66,7 @@ namespace Donut
         ~Engine() = default;
 
         void draw_full_screen_quad();
+        void draw_blur_pass();
         void dispatch_compute(const Camera& cam);
         void upload_camera_ubo(const Camera& cam);
         void upload_objects_ubo(const std::vector<ObjectData>& objs);
@@ -109,6 +110,12 @@ namespace Donut
         float get_rotation_speed() const { return m_rotation_speed; }
         void  set_rotation_speed(float speed) { m_rotation_speed = speed; }
         
+        float get_blur_strength() const { return m_blur_strength; }
+        void  set_blur_strength(float strength) { m_blur_strength = strength; }
+        
+        float get_glow_intensity() const { return m_glow_intensity; }
+        void  set_glow_intensity(float intensity) { m_glow_intensity = intensity; }
+        
         void load_objects_from_scene(const std::vector<Donut::Object>& objects);
         void export_high_res_frame(const std::string& filename, int width = 4096, int height = 3072);
         void print_object_info() const;
@@ -120,6 +127,7 @@ namespace Donut
         Ref<Texture2D>     m_texture;
         Ref<Shader>        m_shader_program;
         Ref<Shader>        m_compute_program;
+        Ref<Shader>        m_blur_shader;
         Ref<UniformBuffer> m_camera_ubo;
         Ref<UniformBuffer> m_disk_ubo;
         Ref<UniformBuffer> m_objects_ubo;
@@ -145,7 +153,9 @@ namespace Donut
         float m_early_exit_distance = 5e11f;
         
         float m_disk_thickness = 0.1;    
-        float m_disk_density   = 1.2f;
+        float m_disk_density   = 0.1f;
         float m_rotation_speed = 1.0f;
+        float m_blur_strength  = 2.0f;
+        float m_glow_intensity = 0.1f;
     };
 };