first working linux and mac

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2025 oomer
+Copyright (c) 2025 Harvey Fong
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1 +1,48 @@
-# poomer-raylib-bella_onimage
+# poomer-raylib-bella_onimage
+
+
+
+# Build
+
+```
+workdir/
+├── bella_engine_sdk/
+├── raylib/
+├── raygui/
+└── poomer-raylib-bella_onimage/
+```
+
+Download SDK for your OS and drag bella_engine_sdk into your workdir
+
+[bella_engine_sdk MacOS](https://downloads.bellarender.com/bella_engine_sdk-24.6.0.dmg)
+[bella_engine_sdk Linux](https://downloads.bellarender.com/bella_engine_sdk-24.6.0.tar.gz)
+[bella_engine_sdk Win](https://downloads.bellarender.com/bella_engine_sdk-24.6.0.zip)
+
+MacOS/Linux
+
+extra linux
+```
+apt install libx11-dev
+apt install xorg-dev
+```
+
+```
+cd workdir
+git clone https://github.com/raysan5/raylib.git
+cd raylib/src
+make
+cd ../examples
+make
+cd ../..
+git clone https://github.com/raysan5/raygui.git
+git clone https://github.com/oomer/poomer-raylib-bella_onimage.git
+cd poomer-raylib-bella_onimage
+make
+```
+
+Windows
+```
+[TODO] document how to build raylib 
+git clone https://github.com/oomer/poomer-raylib-bella_onimage.git
+msbuild poomer-raylib-bella_onimage.vcxproj /p:Configuration=release /p:Platform=x64 /p:PlatformToolset=v143
+```

makefile

@@ -0,0 +1,139 @@
+SDKNAME			=bella_engine_sdk
+OUTNAME			=poomer-raylib-bella_onimage
+UNAME           =$(shell uname)
+
+ifeq ($(UNAME), Darwin)
+
+	SDKBASE		= ../bella_engine_sdk
+
+	SDKFNAME    = lib$(SDKNAME).dylib
+	INCLUDEDIRS	= -I$(SDKBASE)/src
+	INCLUDEDIRS2	= -I../raygui/src 
+	INCLUDEDIRS3	= -I../raylib/src
+	RAYLIBDIR		= ../raylib/src
+	RAYLIBNAME    = libraylib.dylib
+	LIBDIR		= $(SDKBASE)/lib
+	LIBDIRS		= -L$(LIBDIR) -L$(RAYLIBDIR)
+	OBJDIR		= obj/$(UNAME)
+	BINDIR		= bin/$(UNAME)
+	OUTPUT      = $(BINDIR)/$(OUTNAME)
+
+	ISYSROOT	= /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk
+
+	CC			= clang
+	CXX			= clang++
+
+	CCFLAGS		= -arch x86_64\
+				  -arch arm64\
+				  -mmacosx-version-min=11.0\
+				  -isysroot $(ISYSROOT)\
+				  -fvisibility=hidden\
+				  -O3\
+				  $(INCLUDEDIRS)\
+				  $(INCLUDEDIRS2)\
+				  $(INCLUDEDIRS3)
+
+	CFLAGS		= $(CCFLAGS)\
+				  -std=c11
+
+	CXXFLAGS    = $(CCFLAGS)\
+				  -std=c++11
+				
+	CPPDEFINES  = -DNDEBUG=1\
+				  -DDL_USE_SHARED
+
+	LIBS		= -l$(SDKNAME)\
+				  -lraylib\
+				  -lm\
+				  -ldl\
+				  -framework OpenGL\
+				  -framework CoreFoundation\
+				  -framework AppKit\
+				  -framework IOKit\
+				  -framework CoreGraphics\
+				  -framework Foundation
+
+	LINKFLAGS   = -mmacosx-version-min=11.0\
+				  -isysroot $(ISYSROOT)\
+				  -framework Cocoa\
+				  -framework IOKit\
+				  -framework CoreVideo\
+				  -framework CoreFoundation\
+				  -framework Accelerate\
+				  -fvisibility=hidden\
+				  -O5\
+				  -rpath @executable_path\
+				  -weak_library $(LIBDIR)/libvulkan.dylib
+else
+
+	SDKBASE		= ../bella_engine_sdk
+
+	SDKFNAME    = lib$(SDKNAME).so
+	INCLUDEDIRS	= -I$(SDKBASE)/src
+	INCLUDEDIRS2    = -I../raygui/src
+	INCLUDEDIRS3    = -I../raylib/src
+	LIBDIR		= $(SDKBASE)/lib
+	RAYLIBDIR		= ../raylib/src
+	RAYLIBNAME    = libraylib.so
+	SODDIR		= /usr/lib/x86_64-linux-gnu/
+	LIBDIRS		= -L$(LIBDIR) -L$(RAYLIBDIR)
+	OBJDIR		= obj/$(UNAME)
+	BINDIR		= bin/$(UNAME)
+	OUTPUT      = $(BINDIR)/$(OUTNAME)
+
+	CC			= gcc
+	CXX			= g++
+
+	CCFLAGS		= -m64\
+				  -Wall\
+				  -fvisibility=hidden\
+				  -D_FILE_OFFSET_BITS=64\
+				  -O3\
+				  $(INCLUDEDIRS)\
+				  $(INCLUDEDIRS2)\
+                  $(INCLUDEDIRS3)
+
+	CFLAGS		= $(CCFLAGS)\
+				  -std=c11
+
+	CXXFLAGS    = $(CCFLAGS)\
+				  -std=c++11
+				
+	CPPDEFINES  = -DNDEBUG=1\
+				  -DDL_USE_SHARED
+
+	LIBS		= -l$(SDKNAME)\
+				  -lraylib\
+				  -lm\
+				  -ldl\
+				  -lrt\
+				  -lpthread\
+				  -lX11\
+				  -lGL\
+				  -lvulkan
+
+	LINKFLAGS   = -m64\
+				  -fvisibility=hidden\
+				  -O3\
+				  -Wl,-rpath,'$$ORIGIN'\
+				  -Wl,-rpath,'$$ORIGIN/lib'
+endif
+
+OBJS = poomer-raylib-bella_onimage.o 
+OBJ = $(patsubst %,$(OBJDIR)/%,$(OBJS))
+
+$(OBJDIR)/%.o: %.cpp
+	@mkdir -p $(@D)
+	$(CXX) -c -o $@ $< $(CXXFLAGS) $(CPPDEFINES)
+
+$(OUTPUT): $(OBJ)
+	@mkdir -p $(@D)
+	$(CXX) -o $@ $^ $(LINKFLAGS) $(LIBDIRS) $(LIBS)
+	@cp $(LIBDIR)/$(SDKFNAME) $(BINDIR)/$(SDKFNAME)
+
+.PHONY: clean
+clean:
+	rm -f $(OBJDIR)/*.o
+	rm -f $(OUTPUT)
+	rm -f $(BINDIR)/$(SDKFNAME)
+	rm -f $(BINDIR)/$(RAYLIBNAME)

poomer-raylib-bella_onimage.cpp

@@ -0,0 +1,654 @@
+#include <functional>
+#include <string>
+#include <cmath>
+#include <iostream>
+// Include raylib directly but don't use its namespace
+#include <raylib.h>
+#include <mutex>  // For thread synchronization
+#include <queue>  // For the thread-safe image queue
+
+#include "bella_sdk/bella_engine.h"
+#include "dl_core/dl_fs.h"
+using namespace dl;
+using namespace dl::bella_sdk;
+
+// Create namespace aliases for raylib types that conflict with bella_sdk
+namespace rl {
+    // Explicitly alias raylib types that conflict with bella_sdk
+    using Image = ::Image;
+    using Texture2D = ::Texture2D;
+    using Vector2 = ::Vector2;
+    using Color = ::Color;
+    
+    // Add function aliases
+    using ::InitWindow;
+    using ::CloseWindow;
+    using ::IsWindowReady;
+    using ::WindowShouldClose;
+    using ::IsWindowResized;
+    using ::GetScreenWidth;
+    using ::GetScreenHeight;
+    using ::SetTargetFPS;
+    using ::SetConfigFlags;
+    using ::BeginDrawing;
+    using ::EndDrawing;
+    using ::ClearBackground;
+    using ::DrawText;
+    using ::DrawTextureEx;
+    using ::LoadImage;
+    using ::UnloadImage;
+    using ::LoadTextureFromImage;
+    using ::UnloadTexture;
+    using ::GetMousePosition;
+    using ::GetMouseWheelMove;
+    using ::IsMouseButtonPressed;
+    using ::IsMouseButtonReleased;
+}
+
+// Define a callback type for receiving image data from the path tracer
+using OnImageCallback = std::function<void(const unsigned char* data, int width, int height, int channels)>;
+
+// Structure to hold image data in the queue
+// This allows us to safely pass image data between threads
+struct ImageData {
+    unsigned char* data;
+    int width;
+    int height;
+    int channels;
+    
+    ImageData(unsigned char* d, int w, int h, int c) 
+        : data(d), width(w), height(h), channels(c) {}
+};
+
+class PathTracerPreview {
+private:
+    // Window properties
+    int screenWidth;
+    int screenHeight;
+    const char* windowTitle;
+    
+    // Image/texture properties - use raylib's Texture2D
+    rl::Texture2D texture;
+    bool imageLoaded;
+    float imageScale;
+    
+    // THREAD SAFETY: These members handle safe communication between threads
+    // The mutex protects access to the queue, ensuring only one thread can modify it at a time
+    std::mutex queueMutex;
+    // The queue stores image data that needs to be processed by the main thread
+    // This is crucial because OpenGL operations (like texture creation) must happen on the main thread
+    std::queue<ImageData> imageQueue;
+    
+    // Callback for receiving image data
+    OnImageCallback onImageCallback;
+    
+    // Mouse interaction properties
+    bool orbiting = false;
+    bool panning = false;
+    float orbitSpeed = 0.5f;
+    float panSpeed = 0.01f;
+    rl::Vector2 prevMousePos = {0, 0};
+    Engine* engine = nullptr;  // Reference to the bella engine for camera control
+    
+    // Store initial camera state for reset functionality
+    bool hasInitialCamera = false;
+    // We won't store the transform directly since the API doesn't support it
+    // Instead, we'll just remember that we've initialized
+
+public:
+    PathTracerPreview(int width, int height, const char* title) 
+        : screenWidth(width), screenHeight(height), windowTitle(title), 
+          texture({0}), imageLoaded(false), imageScale(1.0f) {
+        
+        // Set configuration flags before initializing window
+        rl::SetConfigFlags(FLAG_MSAA_4X_HINT | FLAG_WINDOW_RESIZABLE);
+        
+        // Initialize window
+        rl::InitWindow(screenWidth, screenHeight, windowTitle);
+        
+        // Check if window was initialized successfully
+        if (!rl::IsWindowReady()) {
+            std::cerr << "ERROR: Failed to initialize window" << std::endl;
+            return;
+        }
+        
+        // Set target FPS
+        rl::SetTargetFPS(60);
+        
+        // THREAD SAFETY: Set up the callback that will be called by the path tracer
+        // Instead of directly updating the image (which would create textures in a non-main thread),
+        // we queue the image data for later processing by the main thread
+        onImageCallback = [this](const unsigned char* data, int width, int height, int channels) {
+            this->queueImageData(data, width, height, channels);
+        };
+        
+        //std::cout << "Window initialized successfully" << std::endl;
+    }
+    
+    // Set the engine reference for camera control
+    void setEngine(Engine* engineRef) {
+        engine = engineRef;
+        
+        // Mark that we have an initial camera state
+        /*
+        if (engine) {
+            storeInitialCameraTransform();
+        }
+        */
+    }
+    
+    ~PathTracerPreview() {
+        // Clean up resources
+        if (texture.id != 0) rl::UnloadTexture(texture);
+        
+        // THREAD SAFETY: Clean up any remaining image data in the queue
+        clearImageQueue();
+        
+        rl::CloseWindow();
+    }
+    
+    // Get the callback that the path tracer should call when new image data is available
+    OnImageCallback getCallback() const {
+        return onImageCallback;
+    }
+    
+    // THREAD SAFETY: Queue image data to be processed by the main thread
+    // This method can be safely called from any thread
+    // It copies the image data and adds it to a thread-safe queue
+    void queueImageData(const unsigned char* data, int width, int height, int channels) {
+        if (!data || width <= 0 || height <= 0 || channels <= 0) {
+            std::cerr << "ERROR: Invalid image data parameters" << std::endl;
+            return;
+        }
+        
+        // Create a copy of the data to ensure it remains valid even after the caller frees their copy
+        size_t dataSize = width * height * channels;
+        unsigned char* dataCopy = new unsigned char[dataSize];
+        std::memcpy(dataCopy, data, dataSize);
+        
+        // THREAD SAFETY: Add to queue with lock to prevent race conditions
+        {
+            std::lock_guard<std::mutex> lock(queueMutex);
+            imageQueue.push(ImageData(dataCopy, width, height, channels));
+        }
+    }
+    
+    // THREAD SAFETY: Process any queued image data - call this from the main thread
+    // This is a key method that bridges between threads:
+    // 1. The bella engine thread adds data to the queue via queueImageData()
+    // 2. The main thread calls this method to safely retrieve and process that data
+    void processImageQueue() {
+        ImageData imageData(nullptr, 0, 0, 0);
+        bool hasData = false;
+        
+        // THREAD SAFETY: Get the next image data from the queue with proper locking
+        {
+            std::lock_guard<std::mutex> lock(queueMutex);
+            if (!imageQueue.empty()) {
+                imageData = imageQueue.front();
+                imageQueue.pop();
+                hasData = true;
+            }
+        }
+        
+        // Process the image data if we got any
+        // This happens in the main thread where OpenGL operations are safe
+        if (hasData) {
+            updateImage(imageData.data, imageData.width, imageData.height, imageData.channels);
+            delete[] imageData.data; // Clean up the data copy
+        }
+    }
+    
+    // THREAD SAFETY: Clear the image queue
+    // This ensures we don't leak memory if there are pending images when the program exits
+    void clearImageQueue() {
+        std::lock_guard<std::mutex> lock(queueMutex);
+        while (!imageQueue.empty()) {
+            ImageData& imageData = imageQueue.front();
+            delete[] imageData.data;
+            imageQueue.pop();
+        }
+    }
+    
+    // Update the displayed image with new data from the path tracer
+    // IMPORTANT: This method must ONLY be called from the main thread
+    // because it creates OpenGL textures which are context-dependent
+    void updateImage(const unsigned char* data, int width, int height, int channels) {
+        
+        try {
+            // Check if data is valid
+            if (!data) {
+                std::cerr << "ERROR: Data pointer is NULL" << std::endl;
+                return;
+            }
+            
+            // Unload existing texture if any
+            if (texture.id != 0) {
+                rl::UnloadTexture(texture);
+                texture = {0};
+            }
+            
+            // Create a copy of the data
+            unsigned char* dataCopy = new unsigned char[width * height * 4]; // Always use 4 channels (RGBA)
+            
+            // Convert the data to RGBA format
+            for (int i = 0; i < width * height; i++) {
+                int srcIdx = i * channels;
+                int destIdx = i * 4;
+                
+                if (channels >= 3) {
+                    dataCopy[destIdx] = data[srcIdx];     // R
+                    dataCopy[destIdx + 1] = data[srcIdx + 1]; // G
+                    dataCopy[destIdx + 2] = data[srcIdx + 2]; // B
+                    dataCopy[destIdx + 3] = (channels >= 4) ? data[srcIdx + 3] : 255; // A
+                } else if (channels == 1) {
+                    // Grayscale
+                    dataCopy[destIdx] = dataCopy[destIdx + 1] = dataCopy[destIdx + 2] = data[srcIdx];
+                    dataCopy[destIdx + 3] = 255;
+                }
+            }
+            
+            // Create a simple image using the raw data
+            
+            // Create a new image with the data
+            rl::Image image = {0};
+            image.data = dataCopy;
+            image.width = width;
+            image.height = height;
+            image.mipmaps = 1;
+            image.format = PIXELFORMAT_UNCOMPRESSED_R8G8B8A8;
+            
+            // THREAD SAFETY: Load texture from the image
+            // This is now safe because we're in the main thread with valid OpenGL context
+            // This was the source of our segfault when called from a different thread
+            texture = rl::LoadTextureFromImage(image);
+            
+            // Unload the image data (texture keeps a copy)
+            rl::UnloadImage(image);
+            
+            if (texture.id == 0) {
+                std::cerr << "ERROR: Failed to create texture" << std::endl;
+                return;
+            }
+            
+            
+            // Update display settings
+            imageLoaded = true;
+            
+            // Calculate scale to fit the image in the window with some padding
+            float scaleX = static_cast<float>(screenWidth - 40) / texture.width;
+            float scaleY = static_cast<float>(screenHeight - 40) / texture.height;
+            imageScale = (scaleX < scaleY) ? scaleX : scaleY;  // Use the smaller scale
+            
+        } catch (const std::exception& e) {
+            std::cerr << "ERROR: Exception in updateImage: " << e.what() << std::endl;
+        } catch (...) {
+            std::cerr << "ERROR: Unknown exception in updateImage" << std::endl;
+        }
+    }
+    
+    // Main loop - call this to run the preview window
+    void run() {
+        // Store previous window size to detect resizing
+        int prevScreenWidth = screenWidth;
+        int prevScreenHeight = screenHeight;
+        
+        while (!rl::WindowShouldClose()) {
+            // THREAD SAFETY: Process any queued image data in the main thread
+            // This is where we safely handle the image data that was queued by other threads
+            processImageQueue();
+            
+            // Check if window has been resized
+            if (rl::IsWindowResized()) {
+                // Update screen dimensions
+                screenWidth = rl::GetScreenWidth();
+                screenHeight = rl::GetScreenHeight();
+                
+                // Recalculate image scale to fit the new window size
+                if (imageLoaded && texture.id != 0) {
+                    float scaleX = static_cast<float>(screenWidth - 40) / texture.width;
+                    float scaleY = static_cast<float>(screenHeight - 40) / texture.height;
+                    imageScale = (scaleX < scaleY) ? scaleX : scaleY;  // Use the smaller scale
+                }
+            }
+            
+            // Update
+            if (imageLoaded) {
+                // Allow zooming with mouse wheel
+                float wheelMove = rl::GetMouseWheelMove();
+                if (wheelMove != 0.0f) {
+                    if (engine && engine->rendering()) {
+                        Scene::EventScope eventScope(engine->scene());
+                        // Create a Vec2 with y component only for dolly effect
+                        Vec2 dollyDelta;
+                        dollyDelta.y = wheelMove * 0.8;
+                        bella_sdk::zoomCamera( engine->scene().cameraPath(), dollyDelta, true );
+                    }
+                }
+                
+                // Handle mouse interaction for camera orbiting
+                handleMouseInteraction();
+            }
+            
+            // Draw
+            rl::BeginDrawing();
+            
+            rl::ClearBackground(RAYWHITE);
+            
+            if (imageLoaded && texture.id != 0) {
+                // Draw the texture centered in the window
+                rl::DrawTextureEx(
+                    texture, 
+                    { 
+                        static_cast<float>(screenWidth)/2 - texture.width*imageScale/2, 
+                        static_cast<float>(screenHeight)/2 - texture.height*imageScale/2 
+                    }, 
+                    0, imageScale, WHITE
+                );
+                
+                // Display the current scale factor
+                //DrawText(TextFormat("Scale: %.2fx", imageScale), 10, screenHeight - 30, 20, DARKGRAY);
+                
+                // Display orbit/pan status and controls
+                //if (orbiting) {
+                //    DrawText("Orbiting Camera", 10, screenHeight - 60, 20, RED);
+                //} else if (panning) {
+                //    DrawText("Panning Camera", 10, screenHeight - 60, 20, BLUE);
+                //}
+                
+                // Display control instructions
+                //DrawText("Mouse Controls:", 10, 10, 20, DARKGRAY);
+                //DrawText("- Left Click + Drag: Orbit Camera", 10, 35, 18, DARKGRAY);
+                //DrawText("- Middle Click + Drag: Pan Camera", 10, 60, 18, DARKGRAY);
+                //DrawText("- Right Click: Reset Camera", 10, 85, 18, DARKGRAY);
+                //DrawText("- Mouse Wheel: Zoom Image", 10, 110, 18, DARKGRAY);
+                //DrawText("- Shift + Mouse Wheel: Dolly Camera", 10, 135, 18, DARKGRAY);
+            } else {
+                // No image loaded yet
+                rl::DrawText("Waiting for Bella to render...", screenWidth/2 - 150, screenHeight/2 - 10, 20, DARKGRAY);
+            }
+            
+            rl::EndDrawing();
+        }
+    }
+    
+    // Handle mouse interaction for camera orbiting
+    void handleMouseInteraction() {
+        // Only process mouse interaction if we have a valid engine reference
+        if (!engine) return;
+        
+        // Check for mouse button press/release for orbiting (left button)
+        if (rl::IsMouseButtonPressed(MOUSE_LEFT_BUTTON)) {
+            orbiting = true;
+            panning = false;  // Ensure we're not doing both at once
+            prevMousePos = rl::GetMousePosition();
+        } else if (rl::IsMouseButtonReleased(MOUSE_LEFT_BUTTON)) {
+            orbiting = false;
+        }
+        
+        // Check for mouse button press/release for panning (middle button)
+        if (rl::IsMouseButtonPressed(MOUSE_MIDDLE_BUTTON)) {
+            panning = true;
+            orbiting = false;  // Ensure we're not doing both at once
+            prevMousePos = rl::GetMousePosition();
+        } else if (rl::IsMouseButtonReleased(MOUSE_MIDDLE_BUTTON)) {
+            panning = false;
+        }
+        
+        // Check for right-click to reset camera
+        /*if (rl::IsMouseButtonPressed(MOUSE_RIGHT_BUTTON)) {
+            if (engine->rendering()) {
+                // Use our custom reset camera function
+                resetCamera();
+            }
+        }*/
+        
+        // Handle orbiting when left mouse is dragged
+        if (orbiting) {
+            rl::Vector2 currentMousePos = rl::GetMousePosition();
+            
+            // Calculate delta movement
+            float deltaX = (currentMousePos.x - prevMousePos.x) * orbitSpeed;
+            float deltaY = (currentMousePos.y - prevMousePos.y) * orbitSpeed;
+            
+            // Only orbit if there's actual movement
+            if (deltaX != 0.0f || deltaY != 0.0f) {
+                // Create a Vec2 for the delta (using bella_sdk's Vec2)
+                // Fix: Initialize Vec2 properly according to its API
+                Vec2 delta;
+                delta.x = deltaX;
+                delta.y = deltaY;
+                
+                // Orbit the camera - similar to the C# implementation
+                if (engine->rendering()) {
+                    // Create an EventScope to batch scene updates efficiently
+                    // This collects all scene changes within this scope and applies them together
+                    // when the eventScope object is destroyed at the end of this block.
+                    // It improves performance and ensures consistency of multiple scene changes.
+                    Scene::EventScope eventScope(engine->scene());
+                    // Use the bella_sdk namespace to avoid ambiguity with Path
+                    bella_sdk::orbitCamera(engine->scene().cameraPath(), delta);
+                }
+                
+                // Update previous position for next frame
+                prevMousePos = currentMousePos;
+            }
+        }
+        
+        // Handle panning when middle mouse is dragged
+        if (panning) {
+            rl::Vector2 currentMousePos = rl::GetMousePosition();
+            
+            // Calculate delta movement
+            float deltaX = (currentMousePos.x - prevMousePos.x) * panSpeed;
+            float deltaY = (currentMousePos.y - prevMousePos.y) * panSpeed;
+            
+            // Only pan if there's actual movement
+            if (deltaX != 0.0f || deltaY != 0.0f) {
+                // Create a Vec2 for the delta (using bella_sdk's Vec2)
+                Vec2 delta;
+                delta.x = deltaX;
+                delta.y = deltaY;
+                
+                if (engine->rendering()) {
+                    // Create an EventScope to batch scene updates efficiently
+                    // This collects all scene changes within this scope and applies them together
+                    // when the eventScope object is destroyed at the end of this block.
+                    // It improves performance and ensures consistency of multiple scene changes.
+                    Scene::EventScope eventScope(engine->scene());
+                    bella_sdk::panCamera(engine->scene().cameraPath(), delta, true);
+                }
+                
+                // Update previous position for next frame
+                prevMousePos = currentMousePos;
+            }
+        }
+    }
+    
+    // Simulate receiving data from the path tracer (for testing)
+    void simulateDataFromPathTracer(const char* filename) {
+        // Load an image from file - use raylib's Image type
+        rl::Image image = rl::LoadImage(filename);
+        if (image.data != NULL) {
+            // Call our callback with the image data
+            onImageCallback(
+                static_cast<const unsigned char*>(image.data),
+                image.width,
+                image.height,
+                image.format == PIXELFORMAT_UNCOMPRESSED_GRAYSCALE ? 1 :
+                image.format == PIXELFORMAT_UNCOMPRESSED_GRAY_ALPHA ? 2 :
+                image.format == PIXELFORMAT_UNCOMPRESSED_R8G8B8 ? 3 : 4
+            );
+            rl::UnloadImage(image);
+        }
+    }
+};
+
+// Forward declaration
+class PathTracerPreview;
+
+// Custom engine observer that connects bella_sdk's Image to our PathTracerPreview
+struct BellaEngineObserver : public EngineObserver {
+private:
+    PathTracerPreview* preview;
+
+public:
+    BellaEngineObserver(PathTracerPreview* preview) : preview(preview) {}
+
+    void onStarted(String pass) override {
+        //logInfo("Started pass %s", pass.buf());
+    }
+    
+    void onStatus(String pass, String status) override {
+        //logInfo("%s [%s]", status.buf(), pass.buf());
+    }
+    
+    void onProgress(String pass, Progress progress) override {
+        //logInfo("%s [%s]", progress.toString().buf(), pass.buf());
+    }
+    
+    // This is the key method that receives images from the bella engine
+    // IMPORTANT: This method is called from the bella engine's thread, NOT the main thread
+    void onImage(String pass, dl::bella_sdk::Image image) override {
+        //logInfo("Received image from bella: %d x %d", (int)image.width(), (int)image.height());
+        
+        // Get the dimensions of the image
+        int width = (int)image.width();
+        int height = (int)image.height();
+        
+        if (!preview) {
+            std::cerr << "ERROR: Preview pointer is NULL" << std::endl;
+            return;
+        }
+        
+        try {
+            // Create a buffer for our RGBA data
+            unsigned char* buffer = new unsigned char[width * height * 4];
+            
+            // Get the raw RGBA data pointer - rgba8() returns Rgba8* (RgbaT<unsigned char>*)
+            // No mutex needed as the developers confirmed the data survives within this callback
+            Rgba8* rgba_data = image.rgba8();
+            
+            if (!rgba_data) {
+                std::cerr << "ERROR: rgba8() returned NULL" << std::endl;
+                delete[] buffer;
+                return;
+            }
+            
+            // Direct memory copy for optimal performance
+            std::memcpy(buffer, rgba_data, width * height * 4);
+            
+            // THREAD SAFETY: Instead of directly calling updateImage (which would create textures in the wrong thread),
+            // use the callback which will queue the data for processing by the main thread
+            try {
+                if (preview->getCallback()) {
+                    // This will queue the data for later processing in the main thread
+                    preview->getCallback()(buffer, width, height, 4);
+                    //std::cout << "Image data queued successfully" << std::endl;
+                } else {
+                    std::cerr << "ERROR: Preview callback is NULL" << std::endl;
+                    delete[] buffer;
+                }
+            } catch (const std::exception& e) {
+                std::cerr << "Exception in queueing image data: " << e.what() << std::endl;
+                delete[] buffer;  // Clean up if queueing throws
+            } catch (...) {
+                std::cerr << "Unknown exception in queueing image data" << std::endl;
+                delete[] buffer;  // Clean up if queueing throws
+            }
+        } catch (const std::exception& e) {
+            std::cerr << "Exception in onImage: " << e.what() << std::endl;
+        } catch (...) {
+            std::cerr << "Unknown exception in onImage" << std::endl;
+        }
+    }
+    
+    void onError(String pass, String msg) override {
+        //logError("%s [%s]", msg.buf(), pass.buf());
+    }
+    
+    void onStopped(String pass) override {
+        //logInfo("Stopped %s", pass.buf());
+    }
+};
+
+#include "dl_core/dl_main.inl"
+int DL_main(Args& args)
+{
+    try {
+        SetTraceLogLevel(LOG_ERROR); 
+        // Set raylib configuration flags before creating the window
+        rl::SetConfigFlags(FLAG_MSAA_4X_HINT | FLAG_WINDOW_RESIZABLE);
+        PathTracerPreview preview(400, 400, "poomer-raylib-bella_onimage");
+        if (!rl::IsWindowReady()) {
+            std::cerr << "ERROR: Window initialization failed" << std::endl;
+            return 1;
+        }
+        
+        // Add a small delay to ensure the OpenGL context is fully set up
+        //std::cout << "Waiting for OpenGL context to initialize..." << std::endl;
+        for (int i = 0; i < 5; i++) {
+            rl::BeginDrawing();
+            rl::ClearBackground(RAYWHITE);
+            rl::DrawText("Initializing...", 10, 10, 20, DARKGRAY);
+            rl::EndDrawing();
+        }
+        //std::cout << "OpenGL context initialized" << std::endl;
+        
+        // Initialize the bella engine
+        Engine engine;
+        engine.scene().loadDefs();
+        engine.enableInteractiveMode();
+        engine.enableDisplayTransform();
+        
+        // Pass the engine reference to the preview window for camera control
+        preview.setEngine(&engine);
+        
+        // Create our custom observer and connect it to the preview window
+        BellaEngineObserver engineObserver(&preview);
+        engine.subscribe(&engineObserver);
+
+        // Get the preview scene with material sphere
+        auto path = bella_sdk::previewPath();
+        if (path != "") {
+            //std::cout << "Loading scene: " << path.buf() << std::endl;
+            //logInfo("Loading scene: %s", path.buf());
+            
+            // Use the read method to load the scene
+            if (!engine.scene().read(path)) {
+                std::cerr << "ERROR: Failed to read " << path.buf() << " from " << fs::currentDir().buf() << std::endl;
+                logError("Failed to read %s from %s", path.buf(), fs::currentDir().buf());
+                return 1;
+            }
+            
+            if (!engine.start()) {
+                std::cerr << "ERROR: Engine failed to start" << std::endl;
+                logError("Engine failed to start.");
+                return 1;
+            }
+            
+            // Store the initial camera state after the scene is loaded and engine started
+            //preview.storeInitialCameraTransform();
+            
+            //std::cout << "Engine started successfully" << std::endl;
+        } else {
+            // For testing, load a sample image
+            preview.simulateDataFromPathTracer("oomer.png");
+        }
+
+        // Run the preview window - this will block until the window is closed
+        preview.run();
+        
+        // Clean up
+        engine.stop();
+        engine.unsubscribe(&engineObserver);
+        
+        return 0;
+    } catch (const std::exception& e) {
+        std::cerr << "FATAL ERROR: Exception in main: " << e.what() << std::endl;
+        return 1;
+    } catch (...) {
+        std::cerr << "FATAL ERROR: Unknown exception in main" << std::endl;
+        return 1;
+    }
+} 

poomer-raylib-bella_onimage.vcxproj

@@ -0,0 +1,161 @@
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+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <SDLCheck>false</SDLCheck>
+      <PreprocessorDefinitions>PSEUDODEBUG;_CONSOLE;DL_USE_SHARED;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <Optimization>Disabled</Optimization>
+      <InlineFunctionExpansion>Disabled</InlineFunctionExpansion>
+      <AdditionalIncludeDirectories>..\bella_engine_sdk\src;..\raylib\src;..\raygui\src</AdditionalIncludeDirectories>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalLibraryDirectories>lib;..\raylib\src</AdditionalLibraryDirectories>
+      <AdditionalDependencies>bella_engine_sdk.lib;raylib.lib;Shlwapi.lib;vulkan-1.lib;%(AdditionalDependencies)</AdditionalDependencies>
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+    <Link>
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+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalLibraryDirectories>lib;..\raylib\src;..\bella_engine_sdk\lib</AdditionalLibraryDirectories>
+      <AdditionalDependencies>bella_engine_sdk.lib;raylib.lib;Shlwapi.lib;vulkan-1.lib;%(AdditionalDependencies)</AdditionalDependencies>
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+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="$(PlatformToolset.Contains('Intel'))">
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+    <Link>
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+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup>
+    <PostBuildEvent>
+      <Command>echo Post-build event started &amp; 
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