fix: improve display health on shutdown

Two extra full refreshes, masquerading as a "shutting down" screen. One is drawn white-on-black, to really shake the pixels up.

src/graphics/niche/InkHUD/Applet.cpp

@@ -799,7 +799,7 @@ uint16_t InkHUD::Applet::getLogoHeight(uint16_t limitWidth, uint16_t limitHeight
    //       //       \\
 
 */
-void InkHUD::Applet::drawLogo(int16_t centerX, int16_t centerY, uint16_t width, uint16_t height)
+void InkHUD::Applet::drawLogo(int16_t centerX, int16_t centerY, uint16_t width, uint16_t height, Color color)
 {
     struct Point {
         int x;
@@ -905,24 +905,24 @@ void InkHUD::Applet::drawLogo(int16_t centerX, int16_t centerY, uint16_t width,
     Point aq2{a2.x - fromPath.x, a2.y - fromPath.y};
     Point aq3{a2.x + fromPath.x, a2.y + fromPath.y};
     Point aq4{a1.x + fromPath.x, a1.y + fromPath.y};
-    fillTriangle(aq1.x, aq1.y, aq2.x, aq2.y, aq3.x, aq3.y, BLACK);
-    fillTriangle(aq1.x, aq1.y, aq3.x, aq3.y, aq4.x, aq4.y, BLACK);
+    fillTriangle(aq1.x, aq1.y, aq2.x, aq2.y, aq3.x, aq3.y, color);
+    fillTriangle(aq1.x, aq1.y, aq3.x, aq3.y, aq4.x, aq4.y, color);
 
     // Make the path thick: path b becomes quad b
     Point bq1{b1.x - fromPath.x, b1.y - fromPath.y};
     Point bq2{b2.x - fromPath.x, b2.y - fromPath.y};
     Point bq3{b2.x + fromPath.x, b2.y + fromPath.y};
     Point bq4{b1.x + fromPath.x, b1.y + fromPath.y};
-    fillTriangle(bq1.x, bq1.y, bq2.x, bq2.y, bq3.x, bq3.y, BLACK);
-    fillTriangle(bq1.x, bq1.y, bq3.x, bq3.y, bq4.x, bq4.y, BLACK);
+    fillTriangle(bq1.x, bq1.y, bq2.x, bq2.y, bq3.x, bq3.y, color);
+    fillTriangle(bq1.x, bq1.y, bq3.x, bq3.y, bq4.x, bq4.y, color);
 
     // Make the path thick: path c becomes quad c
     Point cq1{c1.x - fromPath.x, c1.y + fromPath.y};
     Point cq2{c2.x - fromPath.x, c2.y + fromPath.y};
     Point cq3{c2.x + fromPath.x, c2.y - fromPath.y};
     Point cq4{c1.x + fromPath.x, c1.y - fromPath.y};
-    fillTriangle(cq1.x, cq1.y, cq2.x, cq2.y, cq3.x, cq3.y, BLACK);
-    fillTriangle(cq1.x, cq1.y, cq3.x, cq3.y, cq4.x, cq4.y, BLACK);
+    fillTriangle(cq1.x, cq1.y, cq2.x, cq2.y, cq3.x, cq3.y, color);
+    fillTriangle(cq1.x, cq1.y, cq3.x, cq3.y, cq4.x, cq4.y, color);
 
     // Radius the intersection of quad b and quad c
     /*
@@ -941,7 +941,7 @@ void InkHUD::Applet::drawLogo(int16_t centerX, int16_t centerY, uint16_t width,
         // The radius for the cap *should* be the same as logoTh, but it's not, due to accumulated rounding
         // We get better results just re-deriving it
         int16_t capRad = sqrt(pow(fromPath.x, 2) + pow(fromPath.y, 2));
-        fillCircle(b2.x, b2.y, capRad, BLACK);
+        fillCircle(b2.x, b2.y, capRad, color);
     }
 }
 

src/graphics/niche/InkHUD/Applet.h

@@ -130,7 +130,8 @@ class Applet : public GFX
     static constexpr float LOGO_ASPECT_RATIO = 1.9;                    // Width:Height for drawing the Meshtastic logo
     uint16_t getLogoWidth(uint16_t limitWidth, uint16_t limitHeight);  // Size Meshtastic logo to fit within region
     uint16_t getLogoHeight(uint16_t limitWidth, uint16_t limitHeight); // Size Meshtastic logo to fit within region
-    void drawLogo(int16_t centerX, int16_t centerY, uint16_t width, uint16_t height); // Draw the meshtastic logo
+    void drawLogo(int16_t centerX, int16_t centerY, uint16_t width, uint16_t height,
+                  Color color = BLACK); // Draw the Meshtastic logo
 
     std::string hexifyNodeNum(NodeNum num);                  // Style as !0123abdc
     SignalStrength getSignalStrength(float snr, float rssi); // Interpret SNR and RSSI, as an easy to understand value

src/graphics/niche/InkHUD/Applets/System/Logo/LogoApplet.cpp

@@ -34,7 +34,15 @@ void InkHUD::LogoApplet::onRender()
     int16_t logoCX = X(0.5);
     int16_t logoCY = Y(0.5 - 0.05);
 
-    drawLogo(logoCX, logoCY, logoW, logoH);
+    // Invert colors if black-on-white
+    // Used during shutdown, to resport display health
+    // Todo: handle this in InkHUD::Renderer instead
+    if (inverted) {
+        fillScreen(BLACK);
+        setTextColor(WHITE);
+    }
+
+    drawLogo(logoCX, logoCY, logoW, logoH, inverted ? WHITE : BLACK);
 
     if (!textLeft.empty()) {
         setFont(fontSmall);
@@ -74,13 +82,30 @@ void InkHUD::LogoApplet::onBackground()
 // Begin displaying the screen which is shown at shutdown
 void InkHUD::LogoApplet::onShutdown()
 {
+    bringToForeground();
+
+    textLeft = "";
+    textRight = "";
+    textTitle = "Shutting Down...";
+    fontTitle = fontSmall;
+
+    // Draw a shutting down screen, twice.
+    // Once white on black, once black on white.
+    // Intention is to restore display health.
+
+    inverted = true;
+    inkhud->forceUpdate(Drivers::EInk::FULL, false);
+    inverted = false;
+    inkhud->forceUpdate(Drivers::EInk::FULL, false);
+
+    // Prepare for the powered-off screen now
+    // We can change these values because the initial "shutting down" screen has already rendered at this point
     textLeft = "";
     textRight = "";
     textTitle = owner.short_name;
     fontTitle = fontLarge;
 
-    bringToForeground();
-    // This is then drawn by InkHUD::Events::onShutdown, with a blocking FULL update
+    // This is then drawn by InkHUD::Events::onShutdown, with a blocking FULL update, after InkHUD's flash write is complete
 }
 
 int32_t InkHUD::LogoApplet::runOnce()

src/graphics/niche/InkHUD/Applets/System/Logo/LogoApplet.h

@@ -33,6 +33,7 @@ class LogoApplet : public SystemApplet, public concurrency::OSThread
     std::string textRight;
     std::string textTitle;
     AppletFont fontTitle;
+    bool inverted = false; // Invert colors. Used during shutdown, to restore display health.
 };
 
 } // namespace NicheGraphics::InkHUD

src/graphics/niche/InkHUD/Events.cpp

@@ -70,6 +70,9 @@ void InkHUD::Events::onButtonLong()
 // Returns 0 to signal that we agree to sleep now
 int InkHUD::Events::beforeDeepSleep(void *unused)
 {
+    // If a previous display update is in progress, wait for it to complete.
+    inkhud->awaitUpdate();
+
     // Notify all applets that we're shutting down
     for (Applet *ua : inkhud->userApplets) {
         ua->onDeactivate();
@@ -87,8 +90,10 @@ int InkHUD::Events::beforeDeepSleep(void *unused)
     inkhud->persistence->saveSettings();
     inkhud->persistence->saveLatestMessage();
 
-    // LogoApplet::onShutdown will have requested an update, to draw the shutdown screen
-    // Draw that now, and wait here until the update is complete
+    // LogoApplet::onShutdown attempted to heal the display by drawing a "shutting down" screen twice,
+    // then prepared a final powered-off screen for us, which shows device shortname.
+    // We're updating to show that one now.
+
     inkhud->forceUpdate(Drivers::EInk::UpdateTypes::FULL, false);
 
     return 0; // We agree: deep sleep now