Merge aa2467de9e into d403044f76

Adds an inverseDisplay setting that renders white text on a black
background in both EPUB and TXT readers. The grayscale anti-aliasing
passes swap the LSB gray level condition based on text direction
(pixelState/black parameter) so intermediate gray values render
correctly against the dark background.

lib/Epub/Epub/Page.cpp

@@ -3,8 +3,8 @@
 #include <HardwareSerial.h>
 #include <Serialization.h>
 
-void PageLine::render(GfxRenderer& renderer, const int fontId, const int xOffset, const int yOffset) {
-  block->render(renderer, fontId, xPos + xOffset, yPos + yOffset);
+void PageLine::render(GfxRenderer& renderer, const int fontId, const int xOffset, const int yOffset, const bool black) {
+  block->render(renderer, fontId, xPos + xOffset, yPos + yOffset, black);
 }
 
 bool PageLine::serialize(FsFile& file) {
@@ -25,9 +25,10 @@ std::unique_ptr<PageLine> PageLine::deserialize(FsFile& file) {
   return std::unique_ptr<PageLine>(new PageLine(std::move(tb), xPos, yPos));
 }
 
-void Page::render(GfxRenderer& renderer, const int fontId, const int xOffset, const int yOffset) const {
+void Page::render(GfxRenderer& renderer, const int fontId, const int xOffset, const int yOffset,
+                  const bool black) const {
   for (auto& element : elements) {
-    element->render(renderer, fontId, xOffset, yOffset);
+    element->render(renderer, fontId, xOffset, yOffset, black);
   }
 }
 

lib/Epub/Epub/Page.h

@@ -17,7 +17,7 @@ class PageElement {
   int16_t yPos;
   explicit PageElement(const int16_t xPos, const int16_t yPos) : xPos(xPos), yPos(yPos) {}
   virtual ~PageElement() = default;
-  virtual void render(GfxRenderer& renderer, int fontId, int xOffset, int yOffset) = 0;
+  virtual void render(GfxRenderer& renderer, int fontId, int xOffset, int yOffset, bool black = true) = 0;
   virtual bool serialize(FsFile& file) = 0;
 };
 
@@ -28,7 +28,7 @@ class PageLine final : public PageElement {
  public:
   PageLine(std::shared_ptr<TextBlock> block, const int16_t xPos, const int16_t yPos)
       : PageElement(xPos, yPos), block(std::move(block)) {}
-  void render(GfxRenderer& renderer, int fontId, int xOffset, int yOffset) override;
+  void render(GfxRenderer& renderer, int fontId, int xOffset, int yOffset, bool black = true) override;
   bool serialize(FsFile& file) override;
   static std::unique_ptr<PageLine> deserialize(FsFile& file);
 };
@@ -37,7 +37,7 @@ class Page {
  public:
   // the list of block index and line numbers on this page
   std::vector<std::shared_ptr<PageElement>> elements;
-  void render(GfxRenderer& renderer, int fontId, int xOffset, int yOffset) const;
+  void render(GfxRenderer& renderer, int fontId, int xOffset, int yOffset, bool black = true) const;
   bool serialize(FsFile& file) const;
   static std::unique_ptr<Page> deserialize(FsFile& file);
 };

lib/Epub/Epub/blocks/TextBlock.cpp

@@ -3,7 +3,8 @@
 #include <GfxRenderer.h>
 #include <Serialization.h>
 
-void TextBlock::render(const GfxRenderer& renderer, const int fontId, const int x, const int y) const {
+void TextBlock::render(const GfxRenderer& renderer, const int fontId, const int x, const int y,
+                       const bool black) const {
   // Validate iterator bounds before rendering
   if (words.size() != wordXpos.size() || words.size() != wordStyles.size()) {
     Serial.printf("[%lu] [TXB] Render skipped: size mismatch (words=%u, xpos=%u, styles=%u)\n", millis(),
@@ -16,7 +17,7 @@ void TextBlock::render(const GfxRenderer& renderer, const int fontId, const int
   auto wordXposIt = wordXpos.begin();
 
   for (size_t i = 0; i < words.size(); i++) {
-    renderer.drawText(fontId, *wordXposIt + x, y, wordIt->c_str(), true, *wordStylesIt);
+    renderer.drawText(fontId, *wordXposIt + x, y, wordIt->c_str(), black, *wordStylesIt);
 
     std::advance(wordIt, 1);
     std::advance(wordStylesIt, 1);

lib/Epub/Epub/blocks/TextBlock.h

@@ -34,7 +34,7 @@ class TextBlock final : public Block {
   bool isEmpty() override { return words.empty(); }
   void layout(GfxRenderer& renderer) override {};
   // given a renderer works out where to break the words into lines
-  void render(const GfxRenderer& renderer, int fontId, int x, int y) const;
+  void render(const GfxRenderer& renderer, int fontId, int x, int y, bool black = true) const;
   BlockType getType() override { return TEXT_BLOCK; }
   bool serialize(FsFile& file) const;
   static std::unique_ptr<TextBlock> deserialize(FsFile& file);

lib/GfxRenderer/GfxRenderer.cpp

@@ -638,7 +638,7 @@ void GfxRenderer::drawTextRotated90CW(const int fontId, const int x, const int y
               drawPixel(screenX, screenY, black);
             } else if (renderMode == GRAYSCALE_MSB && (bmpVal == 1 || bmpVal == 2)) {
               drawPixel(screenX, screenY, false);
-            } else if (renderMode == GRAYSCALE_LSB && bmpVal == 1) {
+            } else if (renderMode == GRAYSCALE_LSB && bmpVal == (black ? 1 : 2)) {
               drawPixel(screenX, screenY, false);
             }
           } else {
@@ -822,8 +822,8 @@ void GfxRenderer::renderChar(const EpdFontFamily& fontFamily, const uint32_t cp,
             // Light gray (also mark the MSB if it's going to be a dark gray too)
             // We have to flag pixels in reverse for the gray buffers, as 0 leave alone, 1 update
             drawPixel(screenX, screenY, false);
-          } else if (renderMode == GRAYSCALE_LSB && bmpVal == 1) {
-            // Dark gray
+          } else if (renderMode == GRAYSCALE_LSB && bmpVal == (pixelState ? 1 : 2)) {
+            // Dark gray (swap gray level for inverse display)
             drawPixel(screenX, screenY, false);
           }
         } else {

src/CrossPointSettings.cpp

@@ -22,7 +22,7 @@ void readAndValidate(FsFile& file, uint8_t& member, const uint8_t maxValue) {
 namespace {
 constexpr uint8_t SETTINGS_FILE_VERSION = 1;
 // Increment this when adding new persisted settings fields
-constexpr uint8_t SETTINGS_COUNT = 23;
+constexpr uint8_t SETTINGS_COUNT = 24;
 constexpr char SETTINGS_FILE[] = "/.crosspoint/settings.bin";
 }  // namespace
 
@@ -60,6 +60,7 @@ bool CrossPointSettings::saveToFile() const {
   serialization::writeString(outputFile, std::string(opdsUsername));
   serialization::writeString(outputFile, std::string(opdsPassword));
   serialization::writePod(outputFile, sleepScreenCoverFilter);
+  serialization::writePod(outputFile, inverseDisplay);
   // New fields added at end for backward compatibility
   outputFile.close();
 
@@ -148,6 +149,8 @@ bool CrossPointSettings::loadFromFile() {
     if (++settingsRead >= fileSettingsCount) break;
     readAndValidate(inputFile, sleepScreenCoverFilter, SLEEP_SCREEN_COVER_FILTER_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
+    serialization::readPod(inputFile, inverseDisplay);
+    if (++settingsRead >= fileSettingsCount) break;
     // New fields added at end for backward compatibility
   } while (false);
 

src/CrossPointSettings.h

@@ -137,6 +137,8 @@ class CrossPointSettings {
   uint8_t hideBatteryPercentage = HIDE_NEVER;
   // Long-press chapter skip on side buttons
   uint8_t longPressChapterSkip = 1;
+  // Inverse display (white text on black background)
+  uint8_t inverseDisplay = 0;
 
   ~CrossPointSettings() = default;
 

src/activities/reader/EpubReaderActivity.cpp

@@ -400,11 +400,12 @@ void EpubReaderActivity::renderScreen() {
     }
   }
 
-  renderer.clearScreen();
+  const bool inverse = SETTINGS.inverseDisplay;
+  renderer.clearScreen(inverse ? 0x00 : 0xFF);
 
   if (section->pageCount == 0) {
     Serial.printf("[%lu] [ERS] No pages to render\n", millis());
-    renderer.drawCenteredText(UI_12_FONT_ID, 300, "Empty chapter", true, EpdFontFamily::BOLD);
+    renderer.drawCenteredText(UI_12_FONT_ID, 300, "Empty chapter", !inverse, EpdFontFamily::BOLD);
     renderStatusBar(orientedMarginRight, orientedMarginBottom, orientedMarginLeft);
     renderer.displayBuffer();
     return;
@@ -412,7 +413,7 @@ void EpubReaderActivity::renderScreen() {
 
   if (section->currentPage < 0 || section->currentPage >= section->pageCount) {
     Serial.printf("[%lu] [ERS] Page out of bounds: %d (max %d)\n", millis(), section->currentPage, section->pageCount);
-    renderer.drawCenteredText(UI_12_FONT_ID, 300, "Out of bounds", true, EpdFontFamily::BOLD);
+    renderer.drawCenteredText(UI_12_FONT_ID, 300, "Out of bounds", !inverse, EpdFontFamily::BOLD);
     renderStatusBar(orientedMarginRight, orientedMarginBottom, orientedMarginLeft);
     renderer.displayBuffer();
     return;
@@ -453,7 +454,8 @@ 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) {
-  page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop);
+  const bool inverse = SETTINGS.inverseDisplay;
+  page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop, !inverse);
   renderStatusBar(orientedMarginRight, orientedMarginBottom, orientedMarginLeft);
   if (pagesUntilFullRefresh <= 1) {
     renderer.displayBuffer(HalDisplay::HALF_REFRESH);
@@ -471,13 +473,13 @@ void EpubReaderActivity::renderContents(std::unique_ptr<Page> page, const int or
   if (SETTINGS.textAntiAliasing) {
     renderer.clearScreen(0x00);
     renderer.setRenderMode(GfxRenderer::GRAYSCALE_LSB);
-    page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop);
+    page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop, !inverse);
     renderer.copyGrayscaleLsbBuffers();
 
     // Render and copy to MSB buffer
     renderer.clearScreen(0x00);
     renderer.setRenderMode(GfxRenderer::GRAYSCALE_MSB);
-    page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop);
+    page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop, !inverse);
     renderer.copyGrayscaleMsbBuffers();
 
     // display grayscale part

src/activities/reader/TxtReaderActivity.cpp

@@ -393,7 +393,7 @@ void TxtReaderActivity::renderScreen() {
   currentPageLines.clear();
   loadPageAtOffset(offset, currentPageLines, nextOffset);
 
-  renderer.clearScreen();
+  renderer.clearScreen(SETTINGS.inverseDisplay ? 0x00 : 0xFF);
   renderPage();
 
   // Save progress
@@ -412,6 +412,8 @@ void TxtReaderActivity::renderPage() {
   const int lineHeight = renderer.getLineHeight(cachedFontId);
   const int contentWidth = viewportWidth;
 
+  const bool inverse = SETTINGS.inverseDisplay;
+
   // Render text lines with alignment
   auto renderLines = [&]() {
     int y = orientedMarginTop;
@@ -441,7 +443,7 @@ void TxtReaderActivity::renderPage() {
             break;
         }
 
-        renderer.drawText(cachedFontId, x, y, line.c_str());
+        renderer.drawText(cachedFontId, x, y, line.c_str(), !inverse);
       }
       y += lineHeight;
     }

src/activities/settings/SettingsActivity.cpp

@@ -24,7 +24,7 @@ const SettingInfo displaySettings[displaySettingsCount] = {
     SettingInfo::Enum("Refresh Frequency", &CrossPointSettings::refreshFrequency,
                       {"1 page", "5 pages", "10 pages", "15 pages", "30 pages"})};
 
-constexpr int readerSettingsCount = 9;
+constexpr int readerSettingsCount = 10;
 const SettingInfo readerSettings[readerSettingsCount] = {
     SettingInfo::Enum("Font Family", &CrossPointSettings::fontFamily, {"Bookerly", "Noto Sans", "Open Dyslexic"}),
     SettingInfo::Enum("Font Size", &CrossPointSettings::fontSize, {"Small", "Medium", "Large", "X Large"}),
@@ -36,7 +36,8 @@ const SettingInfo readerSettings[readerSettingsCount] = {
     SettingInfo::Enum("Reading Orientation", &CrossPointSettings::orientation,
                       {"Portrait", "Landscape CW", "Inverted", "Landscape CCW"}),
     SettingInfo::Toggle("Extra Paragraph Spacing", &CrossPointSettings::extraParagraphSpacing),
-    SettingInfo::Toggle("Text Anti-Aliasing", &CrossPointSettings::textAntiAliasing)};
+    SettingInfo::Toggle("Text Anti-Aliasing", &CrossPointSettings::textAntiAliasing),
+    SettingInfo::Toggle("Inverse Display", &CrossPointSettings::inverseDisplay)};
 
 constexpr int controlsSettingsCount = 4;
 const SettingInfo controlsSettings[controlsSettingsCount] = {