add init code as a determineMode() check

src/graphics/EInkDisplay2.cpp

@@ -184,7 +184,6 @@ bool EInkDisplay::connect()
         // Init GxEPD2
         adafruitDisplay->init();
         adafruitDisplay->setRotation(3);
-        adafruitDisplay->clearScreen(); // Clearing now, so the boot logo will draw nice and smoothe (fast refresh)
     }
 #elif defined(PCA10059)
     {

src/graphics/EInkDynamicDisplay.cpp

@@ -111,6 +111,7 @@ bool EInkDynamicDisplay::update()
 // Assess situation, pick a refresh type
 bool EInkDynamicDisplay::determineMode()
 {
+    checkInitialized();
     checkForPromotion();
 #if defined(HAS_EINK_ASYNCFULL)
     checkAsyncFullRefresh();
@@ -157,6 +158,21 @@ bool EInkDynamicDisplay::determineMode()
         return true; // Do trigger a refresh
 }
 
+// Is this the very first frame?
+void EInkDynamicDisplay::checkInitialized()
+{
+    if (!initialized) {
+        // Undo GxEPD2_BW::partialWindow(), if set by developer in EInkDisplay::connect()
+        configForFullRefresh();
+
+        // Clear any existing image, so we can draw logo with fast-refresh, but also to set GxEPD2_EPD::_initial_write
+        adafruitDisplay->clearScreen();
+
+        LOG_DEBUG("initialized, ");
+        initialized = true;
+
+        // Use a fast-refresh for the next frame; no skipping or else blank screen when waking from deep sleep
+        addFrameFlag(DEMAND_FAST);
     }
 }
 

src/graphics/EInkDynamicDisplay.h

@@ -69,6 +69,7 @@ class EInkDynamicDisplay : public EInkDisplay
     bool update();                // Trigger the display update - determine mode, then call base class
 
     // Checks as part of determineMode()
+    void checkInitialized();              // Is this the very first frame?
     void checkForPromotion();             // Was a frame skipped (rate, display busy) that should have been a FAST refresh?
     void checkRateLimiting();             // Is this frame too soon?
     void checkCosmetic();                 // Was the COSMETIC flag set?
@@ -91,6 +92,7 @@ class EInkDynamicDisplay : public EInkDisplay
     refreshTypes previousRefresh = UNSPECIFIED;     // (Previous) Outcome
     reasonTypes previousReason = NO_OBJECTIONS;     // (Previous) Reason
 
+    bool initialized = false;          // Have we drawn at least one frame yet?
     uint32_t previousRunMs = -1;       // When did determineMode() last run (rather than rejecting for rate-limiting)
     uint32_t imageHash = 0;            // Hash of the current frame. Don't bother updating if nothing has changed!
     uint32_t previousImageHash = 0;    // Hash of the previous update's frame