Merge branch 'master' of https://github.com/jpirnay/crosspoint-reader into mybuild

src/CrossPointState.cpp

@@ -63,7 +63,7 @@ bool CrossPointState::loadFromBinaryFile() {
   if (version >= 2) {
     serialization::readPod(inputFile, lastSleepImage);
   } else {
-    lastSleepImage = 0;
+    lastSleepImage = UINT8_MAX;
   }
 
   if (version >= 3) {

src/CrossPointState.h

@@ -1,4 +1,5 @@
 #pragma once
+#include <cstdint>
 #include <iosfwd>
 #include <string>
 
@@ -8,7 +9,7 @@ class CrossPointState {
 
  public:
   std::string openEpubPath;
-  uint8_t lastSleepImage;
+  uint8_t lastSleepImage = UINT8_MAX;  // UINT8_MAX = unset sentinel
   uint8_t readerActivityLoadCount = 0;
   bool lastSleepFromReader = false;
   ~CrossPointState() = default;

src/JsonSettingsIO.cpp

@@ -87,7 +87,7 @@ bool JsonSettingsIO::loadState(CrossPointState& s, const char* json) {
   }
 
   s.openEpubPath = doc["openEpubPath"] | std::string("");
-  s.lastSleepImage = doc["lastSleepImage"] | (uint8_t)0;
+  s.lastSleepImage = doc["lastSleepImage"] | (uint8_t)UINT8_MAX;
   s.readerActivityLoadCount = doc["readerActivityLoadCount"] | (uint8_t)0;
   s.lastSleepFromReader = doc["lastSleepFromReader"] | false;
   return true;

src/activities/boot_sleep/SleepActivity.cpp

@@ -231,7 +231,7 @@ void SleepActivity::renderCustomSleepScreen() const {
       // Generate a random number between 1 and numFiles
       auto randomFileIndex = random(numFiles);
       // If we picked the same image as last time, reroll
-      while (numFiles > 1 && randomFileIndex == APP_STATE.lastSleepImage) {
+      while (numFiles > 1 && APP_STATE.lastSleepImage != UINT8_MAX && randomFileIndex == APP_STATE.lastSleepImage) {
         randomFileIndex = random(numFiles);
       }
       APP_STATE.lastSleepImage = randomFileIndex;

src/activities/reader/EpubReaderActivity.cpp

@@ -2,11 +2,13 @@
 
 #include <Epub/Page.h>
 #include <Epub/blocks/TextBlock.h>
+#include <FontCacheManager.h>
 #include <FsHelpers.h>
 #include <GfxRenderer.h>
 #include <HalStorage.h>
 #include <I18n.h>
 #include <Logging.h>
+#include <esp_system.h>
 
 #include <memory>
 
@@ -19,6 +21,7 @@
 #include "KOReaderSyncActivity.h"
 #include "MappedInputManager.h"
 #include "QrDisplayActivity.h"
+#include "ReaderUtils.h"
 #include "RecentBooksStore.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
@@ -27,7 +30,6 @@
 namespace {
 // pagesPerRefresh now comes from SETTINGS.getRefreshFrequency()
 constexpr unsigned long skipChapterMs = 700;
-constexpr unsigned long goHomeMs = 1000;
 // pages per minute, first item is 1 to prevent division by zero if accessed
 const std::vector<int> PAGE_TURN_LABELS = {1, 1, 3, 6, 12};
 
@@ -41,27 +43,6 @@ int clampPercent(int percent) {
   return percent;
 }
 
-// Apply the logical reader orientation to the renderer.
-// This centralizes orientation mapping so we don't duplicate switch logic elsewhere.
-void applyReaderOrientation(GfxRenderer& renderer, const uint8_t orientation) {
-  switch (orientation) {
-    case CrossPointSettings::ORIENTATION::PORTRAIT:
-      renderer.setOrientation(GfxRenderer::Orientation::Portrait);
-      break;
-    case CrossPointSettings::ORIENTATION::LANDSCAPE_CW:
-      renderer.setOrientation(GfxRenderer::Orientation::LandscapeClockwise);
-      break;
-    case CrossPointSettings::ORIENTATION::INVERTED:
-      renderer.setOrientation(GfxRenderer::Orientation::PortraitInverted);
-      break;
-    case CrossPointSettings::ORIENTATION::LANDSCAPE_CCW:
-      renderer.setOrientation(GfxRenderer::Orientation::LandscapeCounterClockwise);
-      break;
-    default:
-      break;
-  }
-}
-
 }  // namespace
 
 void EpubReaderActivity::onEnter() {
@@ -73,7 +54,7 @@ void EpubReaderActivity::onEnter() {
 
   // Configure screen orientation based on settings
   // NOTE: This affects layout math and must be applied before any render calls.
-  applyReaderOrientation(renderer, SETTINGS.orientation);
+  ReaderUtils::applyOrientation(renderer, SETTINGS.orientation);
 
   epub->setupCacheDir();
 
@@ -183,13 +164,14 @@ void EpubReaderActivity::loop() {
   }
 
   // Long press BACK (1s+) goes to file selection
-  if (mappedInput.isPressed(MappedInputManager::Button::Back) && mappedInput.getHeldTime() >= goHomeMs) {
+  if (mappedInput.isPressed(MappedInputManager::Button::Back) && mappedInput.getHeldTime() >= ReaderUtils::GO_HOME_MS) {
     activityManager.goToFileBrowser(epub ? epub->getPath() : "");
     return;
   }
 
   // Short press BACK goes directly to home (or restores position if viewing footnote)
-  if (mappedInput.wasReleased(MappedInputManager::Button::Back) && mappedInput.getHeldTime() < goHomeMs) {
+  if (mappedInput.wasReleased(MappedInputManager::Button::Back) &&
+      mappedInput.getHeldTime() < ReaderUtils::GO_HOME_MS) {
     if (footnoteDepth > 0) {
       restoreSavedPosition();
       return;
@@ -198,20 +180,7 @@ void EpubReaderActivity::loop() {
     return;
   }
 
-  // When long-press chapter skip is disabled, turn pages on press instead of release.
-  const bool usePressForPageTurn = !SETTINGS.longPressChapterSkip;
-  const bool prevTriggered = usePressForPageTurn ? (mappedInput.wasPressed(MappedInputManager::Button::PageBack) ||
-                                                    mappedInput.wasPressed(MappedInputManager::Button::Left))
-                                                 : (mappedInput.wasReleased(MappedInputManager::Button::PageBack) ||
-                                                    mappedInput.wasReleased(MappedInputManager::Button::Left));
-  const bool powerPageTurn = SETTINGS.shortPwrBtn == CrossPointSettings::SHORT_PWRBTN::PAGE_TURN &&
-                             mappedInput.wasReleased(MappedInputManager::Button::Power);
-  const bool nextTriggered = usePressForPageTurn
-                                 ? (mappedInput.wasPressed(MappedInputManager::Button::PageForward) || powerPageTurn ||
-                                    mappedInput.wasPressed(MappedInputManager::Button::Right))
-                                 : (mappedInput.wasReleased(MappedInputManager::Button::PageForward) || powerPageTurn ||
-                                    mappedInput.wasReleased(MappedInputManager::Button::Right));
-
+  auto [prevTriggered, nextTriggered] = ReaderUtils::detectPageTurn(mappedInput);
   if (!prevTriggered && !nextTriggered) {
     return;
   }
@@ -459,7 +428,7 @@ void EpubReaderActivity::applyOrientation(const uint8_t orientation) {
     SETTINGS.saveToFile();
 
     // Update renderer orientation to match the new logical coordinate system.
-    applyReaderOrientation(renderer, SETTINGS.orientation);
+    ReaderUtils::applyOrientation(renderer, SETTINGS.orientation);
 
     // Reset section to force re-layout in the new orientation.
     section.reset();
@@ -669,7 +638,6 @@ void EpubReaderActivity::render(RenderLock&& lock) {
     const auto start = millis();
     renderContents(std::move(p), orientedMarginTop, orientedMarginRight, orientedMarginBottom, orientedMarginLeft);
     LOG_DBG("ERS", "Rendered page in %dms", millis() - start);
-    renderer.clearFontCache();
   }
   saveProgress(currentSpineIndex, section->currentPage, section->pageCount);
 
@@ -699,11 +667,30 @@ void EpubReaderActivity::saveProgress(int spineIndex, int currentPage, int pageC
 void EpubReaderActivity::renderContents(std::unique_ptr<Page> page, const int orientedMarginTop,
                                         const int orientedMarginRight, const int orientedMarginBottom,
                                         const int orientedMarginLeft) {
+  const auto t0 = millis();
+  auto* fcm = renderer.getFontCacheManager();
+  fcm->resetStats();
+
+  // Font prewarm: scan pass accumulates text, then prewarm, then real render
+  const uint32_t heapBefore = esp_get_free_heap_size();
+  auto scope = fcm->createPrewarmScope();
+  page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop);  // scan pass
+  scope.endScanAndPrewarm();
+  const uint32_t heapAfter = esp_get_free_heap_size();
+  fcm->logStats("prewarm");
+  const auto tPrewarm = millis();
+
+  LOG_DBG("ERS", "Heap: before=%lu after=%lu delta=%ld", heapBefore, heapAfter,
+          (int32_t)heapAfter - (int32_t)heapBefore);
+
   // Force special handling for pages with images when anti-aliasing is on
   bool imagePageWithAA = page->hasImages() && SETTINGS.textAntiAliasing;
 
   page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop);
   renderStatusBar();
+  fcm->logStats("bw_render");
+  const auto tBwRender = millis();
+
   if (imagePageWithAA) {
     // Double FAST_REFRESH with selective image blanking (pablohc's technique):
     // HALF_REFRESH sets particles too firmly for the grayscale LUT to adjust.
@@ -723,16 +710,14 @@ void EpubReaderActivity::renderContents(std::unique_ptr<Page> page, const int or
       renderer.displayBuffer(HalDisplay::HALF_REFRESH);
     }
     // Double FAST_REFRESH handles ghosting for image pages; don't count toward full refresh cadence
-  } else if (pagesUntilFullRefresh <= 1) {
-    renderer.displayBuffer(HalDisplay::HALF_REFRESH);
-    pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
   } else {
-    renderer.displayBuffer();
-    pagesUntilFullRefresh--;
+    ReaderUtils::displayWithRefreshCycle(renderer, pagesUntilFullRefresh);
   }
+  const auto tDisplay = millis();
 
   // Save bw buffer to reset buffer state after grayscale data sync
   renderer.storeBwBuffer();
+  const auto tBwStore = millis();
 
   // grayscale rendering
   // TODO: Only do this if font supports it
@@ -741,20 +726,42 @@ void EpubReaderActivity::renderContents(std::unique_ptr<Page> page, const int or
     renderer.setRenderMode(GfxRenderer::GRAYSCALE_LSB);
     page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop);
     renderer.copyGrayscaleLsbBuffers();
+    const auto tGrayLsb = millis();
 
     // Render and copy to MSB buffer
     renderer.clearScreen(0x00);
     renderer.setRenderMode(GfxRenderer::GRAYSCALE_MSB);
     page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop);
     renderer.copyGrayscaleMsbBuffers();
+    const auto tGrayMsb = millis();
 
     // display grayscale part
     renderer.displayGrayBuffer();
+    const auto tGrayDisplay = millis();
     renderer.setRenderMode(GfxRenderer::BW);
-  }
+    fcm->logStats("gray");
 
-  // restore the bw data
-  renderer.restoreBwBuffer();
+    // restore the bw data
+    renderer.restoreBwBuffer();
+    const auto tBwRestore = millis();
+
+    const auto tEnd = millis();
+    LOG_DBG("ERS",
+            "Page render: prewarm=%lums bw_render=%lums display=%lums bw_store=%lums "
+            "gray_lsb=%lums gray_msb=%lums gray_display=%lums bw_restore=%lums total=%lums",
+            tPrewarm - t0, tBwRender - tPrewarm, tDisplay - tBwRender, tBwStore - tDisplay, tGrayLsb - tBwStore,
+            tGrayMsb - tGrayLsb, tGrayDisplay - tGrayMsb, tBwRestore - tGrayDisplay, tEnd - t0);
+  } else {
+    // restore the bw data
+    renderer.restoreBwBuffer();
+    const auto tBwRestore = millis();
+
+    const auto tEnd = millis();
+    LOG_DBG("ERS",
+            "Page render: prewarm=%lums bw_render=%lums display=%lums bw_store=%lums bw_restore=%lums total=%lums",
+            tPrewarm - t0, tBwRender - tPrewarm, tDisplay - tBwRender, tBwStore - tDisplay, tBwRestore - tBwStore,
+            tEnd - t0);
+  }
 }
 
 void EpubReaderActivity::renderStatusBar() const {

src/activities/reader/ReaderUtils.h

@@ -0,0 +1,89 @@
+#pragma once
+
+#include <CrossPointSettings.h>
+#include <GfxRenderer.h>
+#include <Logging.h>
+
+#include "MappedInputManager.h"
+
+namespace ReaderUtils {
+
+constexpr unsigned long GO_HOME_MS = 1000;
+
+inline void applyOrientation(GfxRenderer& renderer, const uint8_t orientation) {
+  switch (orientation) {
+    case CrossPointSettings::ORIENTATION::PORTRAIT:
+      renderer.setOrientation(GfxRenderer::Orientation::Portrait);
+      break;
+    case CrossPointSettings::ORIENTATION::LANDSCAPE_CW:
+      renderer.setOrientation(GfxRenderer::Orientation::LandscapeClockwise);
+      break;
+    case CrossPointSettings::ORIENTATION::INVERTED:
+      renderer.setOrientation(GfxRenderer::Orientation::PortraitInverted);
+      break;
+    case CrossPointSettings::ORIENTATION::LANDSCAPE_CCW:
+      renderer.setOrientation(GfxRenderer::Orientation::LandscapeCounterClockwise);
+      break;
+    default:
+      break;
+  }
+}
+
+struct PageTurnResult {
+  bool prev;
+  bool next;
+};
+
+inline PageTurnResult detectPageTurn(const MappedInputManager& input) {
+  const bool usePress = !SETTINGS.longPressChapterSkip;
+  const bool prev = usePress ? (input.wasPressed(MappedInputManager::Button::PageBack) ||
+                                input.wasPressed(MappedInputManager::Button::Left))
+                             : (input.wasReleased(MappedInputManager::Button::PageBack) ||
+                                input.wasReleased(MappedInputManager::Button::Left));
+  const bool powerTurn = SETTINGS.shortPwrBtn == CrossPointSettings::SHORT_PWRBTN::PAGE_TURN &&
+                         input.wasReleased(MappedInputManager::Button::Power);
+  const bool next = usePress ? (input.wasPressed(MappedInputManager::Button::PageForward) || powerTurn ||
+                                input.wasPressed(MappedInputManager::Button::Right))
+                             : (input.wasReleased(MappedInputManager::Button::PageForward) || powerTurn ||
+                                input.wasReleased(MappedInputManager::Button::Right));
+  return {prev, next};
+}
+
+inline void displayWithRefreshCycle(const GfxRenderer& renderer, int& pagesUntilFullRefresh) {
+  if (pagesUntilFullRefresh <= 1) {
+    renderer.displayBuffer(HalDisplay::HALF_REFRESH);
+    pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
+  } else {
+    renderer.displayBuffer();
+    pagesUntilFullRefresh--;
+  }
+}
+
+// Grayscale anti-aliasing pass. Renders content twice (LSB + MSB) to build
+// the grayscale buffer. Only the content callback is re-rendered — status bars
+// and other overlays should be drawn before calling this.
+// Kept as a template to avoid std::function overhead; instantiated once per reader type.
+template <typename RenderFn>
+void renderAntiAliased(GfxRenderer& renderer, RenderFn&& renderFn) {
+  if (!renderer.storeBwBuffer()) {
+    LOG_ERR("READER", "Failed to store BW buffer for anti-aliasing");
+    return;
+  }
+
+  renderer.clearScreen(0x00);
+  renderer.setRenderMode(GfxRenderer::GRAYSCALE_LSB);
+  renderFn();
+  renderer.copyGrayscaleLsbBuffers();
+
+  renderer.clearScreen(0x00);
+  renderer.setRenderMode(GfxRenderer::GRAYSCALE_MSB);
+  renderFn();
+  renderer.copyGrayscaleMsbBuffers();
+
+  renderer.displayGrayBuffer();
+  renderer.setRenderMode(GfxRenderer::BW);
+
+  renderer.restoreBwBuffer();
+}
+
+}  // namespace ReaderUtils

src/activities/reader/TxtReaderActivity.cpp

@@ -1,5 +1,6 @@
 #include "TxtReaderActivity.h"
 
+#include <FontCacheManager.h>
 #include <GfxRenderer.h>
 #include <HalStorage.h>
 #include <I18n.h>
@@ -9,14 +10,13 @@
 #include "CrossPointSettings.h"
 #include "CrossPointState.h"
 #include "MappedInputManager.h"
+#include "ReaderUtils.h"
 #include "RecentBooksStore.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
 
 namespace {
-constexpr unsigned long goHomeMs = 1000;
 constexpr size_t CHUNK_SIZE = 8 * 1024;  // 8KB chunk for reading
-
 // Cache file magic and version
 constexpr uint32_t CACHE_MAGIC = 0x54585449;  // "TXTI"
 constexpr uint8_t CACHE_VERSION = 2;          // Increment when cache format changes
@@ -88,23 +88,7 @@ void TxtReaderActivity::onEnter() {
     return;
   }
 
-  // Configure screen orientation based on settings
-  switch (SETTINGS.orientation) {
-    case CrossPointSettings::ORIENTATION::PORTRAIT:
-      renderer.setOrientation(GfxRenderer::Orientation::Portrait);
-      break;
-    case CrossPointSettings::ORIENTATION::LANDSCAPE_CW:
-      renderer.setOrientation(GfxRenderer::Orientation::LandscapeClockwise);
-      break;
-    case CrossPointSettings::ORIENTATION::INVERTED:
-      renderer.setOrientation(GfxRenderer::Orientation::PortraitInverted);
-      break;
-    case CrossPointSettings::ORIENTATION::LANDSCAPE_CCW:
-      renderer.setOrientation(GfxRenderer::Orientation::LandscapeCounterClockwise);
-      break;
-    default:
-      break;
-  }
+  ReaderUtils::applyOrientation(renderer, SETTINGS.orientation);
 
   txt->setupCacheDir();
 
@@ -134,31 +118,19 @@ void TxtReaderActivity::onExit() {
 
 void TxtReaderActivity::loop() {
   // Long press BACK (1s+) goes to file selection
-  if (mappedInput.isPressed(MappedInputManager::Button::Back) && mappedInput.getHeldTime() >= goHomeMs) {
+  if (mappedInput.isPressed(MappedInputManager::Button::Back) && mappedInput.getHeldTime() >= ReaderUtils::GO_HOME_MS) {
     activityManager.goToFileBrowser(txt ? txt->getPath() : "");
     return;
   }
 
   // Short press BACK goes directly to home
-  if (mappedInput.wasReleased(MappedInputManager::Button::Back) && mappedInput.getHeldTime() < goHomeMs) {
+  if (mappedInput.wasReleased(MappedInputManager::Button::Back) &&
+      mappedInput.getHeldTime() < ReaderUtils::GO_HOME_MS) {
     onGoHome();
     return;
   }
 
-  // When long-press chapter skip is disabled, turn pages on press instead of release.
-  const bool usePressForPageTurn = !SETTINGS.longPressChapterSkip;
-  const bool prevTriggered = usePressForPageTurn ? (mappedInput.wasPressed(MappedInputManager::Button::PageBack) ||
-                                                    mappedInput.wasPressed(MappedInputManager::Button::Left))
-                                                 : (mappedInput.wasReleased(MappedInputManager::Button::PageBack) ||
-                                                    mappedInput.wasReleased(MappedInputManager::Button::Left));
-  const bool powerPageTurn = SETTINGS.shortPwrBtn == CrossPointSettings::SHORT_PWRBTN::PAGE_TURN &&
-                             mappedInput.wasReleased(MappedInputManager::Button::Power);
-  const bool nextTriggered = usePressForPageTurn
-                                 ? (mappedInput.wasPressed(MappedInputManager::Button::PageForward) || powerPageTurn ||
-                                    mappedInput.wasPressed(MappedInputManager::Button::Right))
-                                 : (mappedInput.wasReleased(MappedInputManager::Button::PageForward) || powerPageTurn ||
-                                    mappedInput.wasReleased(MappedInputManager::Button::Right));
-
+  auto [prevTriggered, nextTriggered] = ReaderUtils::detectPageTurn(mappedInput);
   if (!prevTriggered && !nextTriggered) {
     return;
   }
@@ -316,7 +288,6 @@ void TxtReaderActivity::render(RenderLock&&) {
 
   renderer.clearScreen();
   renderPage();
-  renderer.clearFontCache();
 
   // Save progress
   saveProgress();
@@ -361,39 +332,22 @@ void TxtReaderActivity::renderPage() {
     }
   };
 
-  // First pass: BW rendering
+  // Font prewarm: scan pass accumulates text, then prewarm, then real render
+  auto* fcm = renderer.getFontCacheManager();
+  auto scope = fcm->createPrewarmScope();
+  renderLines();  // scan pass — text accumulated, no drawing
+  scope.endScanAndPrewarm();
+
+  // BW rendering
   renderLines();
   renderStatusBar();
 
-  if (pagesUntilFullRefresh <= 1) {
-    renderer.displayBuffer(HalDisplay::HALF_REFRESH);
-    pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
-  } else {
-    renderer.displayBuffer();
-    pagesUntilFullRefresh--;
-  }
+  ReaderUtils::displayWithRefreshCycle(renderer, pagesUntilFullRefresh);
 
-  // Grayscale rendering pass (for anti-aliased fonts)
   if (SETTINGS.textAntiAliasing) {
-    // Save BW buffer for restoration after grayscale pass
-    renderer.storeBwBuffer();
-
-    renderer.clearScreen(0x00);
-    renderer.setRenderMode(GfxRenderer::GRAYSCALE_LSB);
-    renderLines();
-    renderer.copyGrayscaleLsbBuffers();
-
-    renderer.clearScreen(0x00);
-    renderer.setRenderMode(GfxRenderer::GRAYSCALE_MSB);
-    renderLines();
-    renderer.copyGrayscaleMsbBuffers();
-
-    renderer.displayGrayBuffer();
-    renderer.setRenderMode(GfxRenderer::BW);
-
-    // Restore BW buffer
-    renderer.restoreBwBuffer();
+    ReaderUtils::renderAntiAliased(renderer, [&renderLines]() { renderLines(); });
   }
+  // scope destructor clears font cache via FontCacheManager
 }
 
 void TxtReaderActivity::renderStatusBar() const {

src/activities/settings/SettingsActivity.cpp

@@ -89,8 +89,13 @@ void SettingsActivity::loop() {
   }
 
   if (mappedInput.wasPressed(MappedInputManager::Button::Back)) {
-    SETTINGS.saveToFile();
-    onGoHome();
+    if (selectedSettingIndex > 0) {
+      selectedSettingIndex = 0;
+      requestUpdate();
+    } else {
+      SETTINGS.saveToFile();
+      onGoHome();
+    }
     return;
   }
 

src/main.cpp

@@ -1,5 +1,6 @@
 #include <Arduino.h>
 #include <Epub.h>
+#include <FontCacheManager.h>
 #include <FontDecompressor.h>
 #include <GfxRenderer.h>
 #include <HalDisplay.h>
@@ -32,6 +33,7 @@ MappedInputManager mappedInputManager(gpio);
 GfxRenderer renderer(display);
 ActivityManager activityManager(renderer, mappedInputManager);
 FontDecompressor fontDecompressor;
+FontCacheManager fontCacheManager(renderer.getFontMap());
 
 // Fonts
 EpdFont bookerly14RegularFont(&bookerly_14_regular);
@@ -203,7 +205,8 @@ void setupDisplayAndFonts() {
   if (!fontDecompressor.init()) {
     LOG_ERR("MAIN", "Font decompressor init failed");
   }
-  renderer.setFontDecompressor(&fontDecompressor);
+  fontCacheManager.setFontDecompressor(&fontDecompressor);
+  renderer.setFontCacheManager(&fontCacheManager);
   renderer.insertFont(BOOKERLY_14_FONT_ID, bookerly14FontFamily);
 #ifndef OMIT_FONTS
   renderer.insertFont(BOOKERLY_12_FONT_ID, bookerly12FontFamily);

src/util/QrUtils.cpp

@@ -1,5 +1,6 @@
 #include "QrUtils.h"
 
+#include <Utf8.h>
 #include <qrcode.h>
 
 #include <algorithm>
@@ -12,7 +13,18 @@ void QrUtils::drawQrCode(const GfxRenderer& renderer, const Rect& bounds, const
   // Version 4 holds ~114 bytes, Version 10 ~395, Version 20 ~1066, up to 40
   // qrcode.h max version is 40.
   // Formula: approx version = size / 26 + 1 (very rough estimate, better to find best fit)
-  const size_t len = textPayload.length();
+  size_t len = textPayload.length();
+
+  // Truncate to max QR capacity at a UTF-8 safe boundary to avoid splitting multi-byte sequences
+  static constexpr size_t MAX_QR_CAPACITY = 2953;  // Version 40, ECC_LOW, byte mode
+  std::string truncated;
+  const char* payload = textPayload.c_str();
+  if (len > MAX_QR_CAPACITY) {
+    len = utf8SafeTruncateBuffer(textPayload.c_str(), static_cast<int>(MAX_QR_CAPACITY));
+    truncated = textPayload.substr(0, len);
+    payload = truncated.c_str();
+  }
+
   int version = 4;
   if (len > 114) version = 10;
   if (len > 395) version = 20;
@@ -25,7 +37,7 @@ void QrUtils::drawQrCode(const GfxRenderer& renderer, const Rect& bounds, const
 
   QRCode qrcode;
   // Initialize the QR code. We use ECC_LOW for max capacity.
-  int8_t res = qrcode_initText(&qrcode, qrcodeBytes.get(), version, ECC_LOW, textPayload.c_str());
+  int8_t res = qrcode_initText(&qrcode, qrcodeBytes.get(), version, ECC_LOW, payload);
 
   if (res == 0) {
     // Determine the optimal pixel size.