limit Ghosting similar to EInkDynamicDisplay

src/graphics/EInkParallelDisplay.h

@@ -5,6 +5,10 @@
 #ifdef USE_EPD
 #include <OLEDDisplay.h>
 
+#include <atomic>
+#include <freertos/FreeRTOS.h>
+#include <freertos/task.h>
+
 class FASTEPD;
 
 /**
@@ -35,6 +39,36 @@ class EInkParallelDisplay : public OLEDDisplay
   protected:
     uint32_t lastDrawMsec = 0;
     FASTEPD *epaper;
+
+  private:
+    // Async full-refresh support
+    std::atomic<bool> asyncFullRunning{false};
+    TaskHandle_t asyncTaskHandle = nullptr;
+    void startAsyncFullUpdate(int clearMode);
+    static void asyncFullUpdateTask(void *pvParameters);
+
+    // helpers
+#ifdef EINK_LIMIT_GHOSTING_PX
+    void resetGhostPixelTracking();
+    void markDirtyBits(const uint8_t *prevBuf, uint32_t pos, uint8_t mask, uint8_t out);
+    void countGhostPixelsAndMaybePromote(int &newTop, int &newBottom, bool &forceFull);
+#endif
+
+    uint32_t previousImageHash = 0;
+    uint32_t lastUpdateMs = 0;
+    int fastRefreshCount = 0;
+    // simple rate-limit (ms) for responsive updates
+    static constexpr uint32_t RESPONSIVE_MIN_MS = 1000;
+    // force a slow full update every N full updates
+    static constexpr int FULL_SLOW_PERIOD = 50;
+
+#ifdef EINK_LIMIT_GHOSTING_PX
+    // per-bit dirty buffer (same format as epaper buffers): one bit == one pixel
+    uint8_t *dirtyPixels = nullptr;
+    size_t dirtyPixelsSize = 0;
+    uint32_t ghostPixelCount = 0;
+    uint32_t ghostPixelLimit = EINK_LIMIT_GHOSTING_PX;
+#endif
 };
 
 #endif