Feature: Implement initial macOS SimpleRemoter client

macos/ScreenHandler.h

@@ -0,0 +1,129 @@
+#pragma once
+
+#import <CoreGraphics/CoreGraphics.h>
+#import <dispatch/dispatch.h>
+#import "../client/IOCPClient.h"
+#include <vector>
+#include <atomic>
+#include <mutex>
+#include <thread>
+#include <cstdint>
+#include <memory>
+
+// Forward declarations
+class IOCPClient;
+class H264Encoder;
+class InputHandler;
+
+// macOS BITMAPINFOHEADER (compatible with Windows)
+#pragma pack(push, 1)
+struct BITMAPINFOHEADER_MAC {
+    uint32_t biSize;            // 40
+    int32_t  biWidth;
+    int32_t  biHeight;
+    uint16_t biPlanes;          // 1
+    uint16_t biBitCount;        // 32
+    uint32_t biCompression;     // 0 (BI_RGB)
+    uint32_t biSizeImage;
+    int32_t  biXPelsPerMeter;   // 0
+    int32_t  biYPelsPerMeter;   // 0
+    uint32_t biClrUsed;         // 0
+    uint32_t biClrImportant;    // 0
+};
+#pragma pack(pop)
+
+// Screen algorithm constants
+#define ALGORITHM_GRAY    0
+#define ALGORITHM_DIFF    1
+#define ALGORITHM_H264    2
+#define ALGORITHM_RGB565  3
+
+class ScreenHandler : public IOCPManager {
+public:
+    ScreenHandler(IOCPClient* client);
+    ~ScreenHandler();
+
+    // Initialize screen capture (returns false if permission denied)
+    bool init();
+
+    // Start/stop capture loop
+    void start(IOCPClient* client, uint64_t clientID);
+    void stop();
+
+    // Check if running
+    bool isRunning() const { return m_running; }
+
+    // Get screen dimensions
+    int getWidth() const { return m_width; }
+    int getHeight() const { return m_height; }
+
+    // Send bitmap info to server (called after connection)
+    void sendBitmapInfo();
+
+    // Handle received commands
+    void OnReceive(uint8_t* data, ULONG size);
+
+    // Apply quality level
+    void applyQualityLevel(int8_t level, bool persist = false);
+
+private:
+    // Capture the screen (returns BGRA data, bottom-up)
+    bool captureScreen(std::vector<uint8_t>& buffer);
+
+    // Send first full screen frame
+    void sendFirstScreen();
+
+    // Send differential frame
+    void sendDiffFrame();
+
+    // Send H264 encoded frame
+    void sendH264Frame(bool keyframe);
+
+    // Compare bitmaps and generate diff data
+    uint32_t compareBitmap(const uint8_t* curr, const uint8_t* prev,
+                           uint8_t* outBuf, uint32_t totalBytes, uint8_t algo);
+
+    // Color conversion helpers
+    void convertBGRAtoGray(const uint8_t* src, uint8_t* dst, uint32_t pixelCount);
+    void convertBGRAtoRGB565(const uint8_t* src, uint16_t* dst, uint32_t pixelCount);
+
+    // Capture loop thread function
+    void captureLoop();
+
+    // Get current time in milliseconds
+    static uint64_t getTickMs();
+
+private:
+    IOCPClient* m_client;
+    uint64_t m_clientID;
+
+    std::atomic<bool> m_running;
+    std::thread m_captureThread;
+    std::mutex m_mutex;
+
+    // Screen info
+    int m_width;          // Physical pixel width (sent to server)
+    int m_height;         // Physical pixel height (sent to server)
+    int m_logicalWidth;   // Logical point width (for CGEvent)
+    int m_logicalHeight;  // Logical point height (for CGEvent)
+    double m_scaleFactor; // Retina scale factor (physical / logical)
+    CGDirectDisplayID m_displayID;
+
+    // Protocol
+    BITMAPINFOHEADER_MAC m_bmpHeader;
+    std::vector<uint8_t> m_prevFrame;
+    std::vector<uint8_t> m_currFrame;
+    std::vector<uint8_t> m_diffBuffer;
+
+    // Quality settings
+    std::atomic<uint8_t> m_algorithm;
+    std::atomic<int> m_maxFPS;
+    int8_t m_qualityLevel;
+
+    // H264 encoder
+    std::unique_ptr<H264Encoder> m_h264Encoder;
+    int m_h264Bitrate;
+
+    // Input handler for mouse/keyboard control
+    std::unique_ptr<InputHandler> m_inputHandler;
+};