[add]: volumetric cloud rendering

3 files changed, 47 insertions, 8 deletions

diff --git a/src/Engine/Engine.cpp b/src/Engine/Engine.cpp
index 245f6fd..37cafd8 100644
--- a/src/Engine/Engine.cpp
+++ b/src/Engine/Engine.cpp
@@ -36,14 +36,14 @@ namespace Donut
         m_ComputeProgram = CreateComputeProgram("Assets/Shaders/Geodesic.glsl");
         
         m_CameraUBO = UniformBuffer::Create(128, 1);
-        m_DiskUBO   = UniformBuffer::Create(sizeof(float) * 4, 2);
+        m_DiskUBO   = UniformBuffer::Create(sizeof(float) * 5, 2);  // Added density parameter
         
         uint32_t objUBOSize = sizeof(int) + 3 * sizeof(float)
             + 16 * (sizeof(glm::vec4) + sizeof(glm::vec4))
             + 16 * sizeof(float);
         m_ObjectsUBO = UniformBuffer::Create(objUBOSize, 3);
         
-        m_SimulationUBO = UniformBuffer::Create(sizeof(int) * 2 + sizeof(float) * 2, 4);
+        m_SimulationUBO = UniformBuffer::Create(sizeof(int) * 2 + sizeof(float) * 2, 4); // time added to existing float
 
         auto result = QuadVAO();
         m_QuadVAO = result.first;
@@ -177,8 +177,8 @@ namespace Donut
         float r1 = static_cast<float>(m_SagA.m_Rs * 2.2);
         float r2 = static_cast<float>(m_SagA.m_Rs * 5.2);
         float num = 2.0f;
-        float thickness = 1e9f;
-        float diskData[4] = { r1, r2, num, thickness };
+        float thickness = static_cast<float>(m_SagA.m_Rs * m_DiskThickness);
+        float diskData[5] = { r1, r2, num, thickness, m_DiskDensity };
 
         m_DiskUBO->SetData(diskData, sizeof(diskData));
         m_DiskUBO->Bind(2);
@@ -191,13 +191,13 @@ namespace Donut
             int maxStepsMoving;
             int maxStepsStatic;
             float earlyExitDistance;
-            int padding;
+            float time;
         } data;
 
         data.maxStepsMoving    = m_MaxStepsMoving;
         data.maxStepsStatic    = m_MaxStepsStatic;
         data.earlyExitDistance = m_EarlyExitDistance;
-        data.padding           = 0;
+        data.time              = static_cast<float>(glfwGetTime()) * m_RotationSpeed;
 
         m_SimulationUBO->SetData(&data, sizeof(data));
         m_SimulationUBO->Bind(4);
diff --git a/src/Engine/Engine.h b/src/Engine/Engine.h
index 328435a..a0b25b5 100644
--- a/src/Engine/Engine.h
+++ b/src/Engine/Engine.h
@@ -100,6 +100,15 @@ namespace Donut
         void  SetMaxStepsStatic(int steps) { m_MaxStepsStatic = steps; }
         void  SetEarlyExitDistance(float distance) { m_EarlyExitDistance = distance; }
         
+        float GetDiskThickness() const { return m_DiskThickness; }
+        void  SetDiskThickness(float thickness) { m_DiskThickness = thickness; }
+        
+        float GetDiskDensity() const { return m_DiskDensity; }
+        void  SetDiskDensity(float density) { m_DiskDensity = density; }
+        
+        float GetRotationSpeed() const { return m_RotationSpeed; }
+        void  SetRotationSpeed(float speed) { m_RotationSpeed = speed; }
+        
         void LoadObjectsFromScene(const std::vector<Donut::Object>& objects);
         void ExportHighResFrame(const std::string& filename, int width = 4096, int height = 3072);
         void PrintObjectInfo() const;
@@ -131,8 +140,12 @@ namespace Donut
         Camera                  m_Camera;
         bool                    m_Gravity = false;
         
-        int   m_MaxStepsMoving = 60000;
-        int   m_MaxStepsStatic = 30000;
+        int   m_MaxStepsMoving    = 60000;
+        int   m_MaxStepsStatic    = 30000;
         float m_EarlyExitDistance = 5e11f;
+        
+        float m_DiskThickness = 0.1;    
+        float m_DiskDensity   = 1.2f;
+        float m_RotationSpeed = 1.0f;
     };
 };
diff --git a/src/States/SimulationState.cpp b/src/States/SimulationState.cpp
index d961f9e..28504e6 100644
--- a/src/States/SimulationState.cpp
+++ b/src/States/SimulationState.cpp
@@ -220,6 +220,32 @@ namespace Donut
         
         ImGui::Spacing();
         
+        ImGui::TextColored(ImVec4(0.9f, 0.9f, 1.0f, 1.0f), "Accretion Disk");
+        ImGui::Separator();
+        
+        float diskThickness = engine.GetDiskThickness();
+        if (ImGui::SliderFloat("Cloud Thickness", &diskThickness, 0.1f, 2.0f, "%.2f"))
+        {
+            engine.SetDiskThickness(diskThickness);
+        }
+        ImGui::TextDisabled("Thickness relative to Schwarzschild radius");
+        
+        float diskDensity = engine.GetDiskDensity();
+        if (ImGui::SliderFloat("Cloud Density", &diskDensity, 0.1f, 3.0f, "%.2f"))
+        {
+            engine.SetDiskDensity(diskDensity);
+        }
+        ImGui::TextDisabled("Overall density multiplier");
+        
+        float rotationSpeed = engine.GetRotationSpeed();
+        if (ImGui::SliderFloat("Rotation Speed", &rotationSpeed, 0.0f, 3.0f, "%.2f"))
+        {
+            engine.SetRotationSpeed(rotationSpeed);
+        }
+        ImGui::TextDisabled("Rotation speed multiplier (0 = no rotation)");
+        
+        ImGui::Spacing();
+        
         ImGui::TextColored(ImVec4(0.9f, 0.9f, 1.0f, 1.0f), "Camera");
         ImGui::Separator();