Add UI scaling support for touch vs button devices

Introduces uiScale() method to apply per-board UI scaling based on device type (1.0 for button devices, >1 for touch devices to make UI elements finger-sized). Adds scaledMetrics member to store scaled theme metrics that are returned by getMetrics().

lib/GfxRenderer/GfxRenderer.cpp

@@ -100,6 +100,23 @@ void GfxRenderer::insertFont(const int fontId, EpdFontFamily font) {
   }
 }
 
+void GfxRenderer::setUiFontRemap(const int* from, const int* to, int count) {
+  if (count < 0) count = 0;
+  if (count > MAX_UI_FONT_REMAP) count = MAX_UI_FONT_REMAP;
+  for (int i = 0; i < count; ++i) {
+    uiFontFrom_[i] = from[i];
+    uiFontTo_[i] = to[i];
+  }
+  uiFontRemapCount_ = count;
+}
+
+int GfxRenderer::remapUiFont(const int fontId) const {
+  for (int i = 0; i < uiFontRemapCount_; ++i) {
+    if (uiFontFrom_[i] == fontId) return uiFontTo_[i];
+  }
+  return fontId;
+}
+
 // Translate logical (x,y) coordinates to physical panel coordinates based on current orientation
 // This should always be inlined for better performance
 static inline void rotateCoordinates(const GfxRenderer::Orientation orientation, const int x, const int y, int* phyX,
@@ -365,7 +382,7 @@ int GfxRenderer::getTextWidth(const int fontId, const char* text, const EpdFontF
     return 0;
   }
 
-  const auto fontIt = fontMap.find(fontId);
+  const auto fontIt = fontMap.find(remapUiFont(fontId));
   if (fontIt == fontMap.end()) {
     LOG_ERR("GFX", "Font %d not found", fontId);
     return 0;
@@ -407,7 +424,7 @@ void GfxRenderer::drawText(const int fontId, const int x, const int y, const cha
     return;
   }
 
-  const auto fontIt = fontMap.find(fontId);
+  const auto fontIt = fontMap.find(remapUiFont(fontId));
   if (fontIt == fontMap.end()) {
     LOG_ERR("GFX", "Font %d not found", fontId);
     return;
@@ -1419,7 +1436,7 @@ int GfxRenderer::getSpaceWidth(const int fontId, const EpdFontFamily::Style styl
     return fp4::toPixel(sdIt->second->getAdvance(' ', resolvedStyle));
   }
 
-  const auto fontIt = fontMap.find(fontId);
+  const auto fontIt = fontMap.find(remapUiFont(fontId));
   if (fontIt == fontMap.end()) {
     LOG_ERR("GFX", "Font %d not found", fontId);
     return 0;
@@ -1440,7 +1457,7 @@ int GfxRenderer::getSpaceAdvance(const int fontId, const uint32_t leftCp, const
     return fp4::toPixel(sdIt->second->getAdvance(' ', resolvedStyle));
   }
 
-  const auto fontIt = fontMap.find(fontId);
+  const auto fontIt = fontMap.find(remapUiFont(fontId));
   if (fontIt == fontMap.end()) return 0;
   const auto& font = fontIt->second;
   const EpdGlyph* spaceGlyph = font.getGlyph(' ', style);
@@ -1454,7 +1471,7 @@ int GfxRenderer::getSpaceAdvance(const int fontId, const uint32_t leftCp, const
 
 int GfxRenderer::getKerning(const int fontId, const uint32_t leftCp, const uint32_t rightCp,
                             const EpdFontFamily::Style style) const {
-  const auto fontIt = fontMap.find(fontId);
+  const auto fontIt = fontMap.find(remapUiFont(fontId));
   if (fontIt == fontMap.end()) return 0;
   const int kernFP = fontIt->second.getKerning(leftCp, rightCp, style);  // 4.4 fixed-point
   return fp4::toPixel(kernFP);                                           // snap 4.4 fixed-point to nearest pixel
@@ -1476,7 +1493,7 @@ int GfxRenderer::getTextAdvanceX(const int fontId, const char* text, EpdFontFami
     return fp4::toPixel(widthFP);
   }
 
-  const auto fontIt = fontMap.find(fontId);
+  const auto fontIt = fontMap.find(remapUiFont(fontId));
   if (fontIt == fontMap.end()) {
     LOG_ERR("GFX", "Font %d not found", fontId);
     return 0;
@@ -1512,7 +1529,7 @@ int GfxRenderer::getTextAdvanceX(const int fontId, const char* text, EpdFontFami
 }
 
 int GfxRenderer::getFontAscenderSize(const int fontId) const {
-  const auto fontIt = fontMap.find(fontId);
+  const auto fontIt = fontMap.find(remapUiFont(fontId));
   if (fontIt == fontMap.end()) {
     LOG_ERR("GFX", "Font %d not found", fontId);
     return 0;
@@ -1522,7 +1539,7 @@ int GfxRenderer::getFontAscenderSize(const int fontId) const {
 }
 
 int GfxRenderer::getLineHeight(const int fontId) const {
-  const auto fontIt = fontMap.find(fontId);
+  const auto fontIt = fontMap.find(remapUiFont(fontId));
   if (fontIt == fontMap.end()) {
     LOG_ERR("GFX", "Font %d not found", fontId);
     return 0;
@@ -1532,7 +1549,7 @@ int GfxRenderer::getLineHeight(const int fontId) const {
 }
 
 int GfxRenderer::getTextHeight(const int fontId) const {
-  const auto fontIt = fontMap.find(fontId);
+  const auto fontIt = fontMap.find(remapUiFont(fontId));
   if (fontIt == fontMap.end()) {
     LOG_ERR("GFX", "Font %d not found", fontId);
     return 0;
@@ -1540,6 +1557,31 @@ int GfxRenderer::getTextHeight(const int fontId) const {
   return fontIt->second.getData(EpdFontFamily::REGULAR)->ascender;
 }
 
+// Height of a reference glyph above the baseline (glyph->top). 'H' gives the real
+// cap height, 'x' the x-height — the actual visible extents of the font, for
+// vertical centering that follows the font instead of a guessed ascender fraction.
+int GfxRenderer::glyphTop(const int fontId, const uint32_t cp) const {
+  const auto fontIt = fontMap.find(remapUiFont(fontId));
+  if (fontIt == fontMap.end()) return 0;
+  const EpdGlyph* g = fontIt->second.getGlyph(cp, EpdFontFamily::REGULAR);
+  return g ? g->top : 0;
+}
+
+int GfxRenderer::getFontCapHeight(const int fontId) const { return glyphTop(fontId, 'H'); }
+int GfxRenderer::getFontXHeight(const int fontId) const { return glyphTop(fontId, 'x'); }
+
+int GfxRenderer::getTextVisualCenterOffset(const int fontId) const {
+  // Distance from drawText's y (text top) down to the text's optical middle. The
+  // baseline is at y + ascender; the lowercase mass is centered at half the
+  // x-height above it, so the optical center is ascender - xHeight/2 below the top.
+  // x-height-based (UI text is lowercase-heavy); falls back to ascender*0.7 if the
+  // 'x' glyph is missing. Scales with the font, so no per-size tweaking.
+  const int ascender = getFontAscenderSize(fontId);
+  const int xHeight = getFontXHeight(fontId);
+  if (xHeight <= 0) return (ascender * 7) / 10;
+  return ascender - xHeight / 2;
+}
+
 void GfxRenderer::drawTextRotated90CW(const int fontId, const int x, const int y, const char* text, const bool black,
                                       const EpdFontFamily::Style style) const {
   // Cannot draw a NULL / empty string
@@ -1547,7 +1589,7 @@ void GfxRenderer::drawTextRotated90CW(const int fontId, const int x, const int y
     return;
   }
 
-  const auto fontIt = fontMap.find(fontId);
+  const auto fontIt = fontMap.find(remapUiFont(fontId));
   if (fontIt == fontMap.end()) {
     LOG_ERR("GFX", "Font %d not found", fontId);
     return;

lib/GfxRenderer/GfxRenderer.h

@@ -51,6 +51,13 @@ class GfxRenderer {
   uint32_t frameBufferSize = HalDisplay::BUFFER_SIZE;
   std::vector<uint8_t*> bwBufferChunks;
   std::map<int, EpdFontFamily> fontMap;
+  // UI chrome font remap table (see setUiFontRemap). Empty = identity.
+  static constexpr int MAX_UI_FONT_REMAP = 8;
+  int uiFontFrom_[MAX_UI_FONT_REMAP] = {0};
+  int uiFontTo_[MAX_UI_FONT_REMAP] = {0};
+  int uiFontRemapCount_ = 0;
+  int remapUiFont(int fontId) const;
+  int glyphTop(int fontId, uint32_t cp) const;
   // Mutable because ensureSdCardFontReady() is const (called from layout code
   // that holds a const GfxRenderer&) but triggers SD card reads and heap
   // allocation inside the SdCardFont objects. Same pragmatic compromise as
@@ -95,6 +102,11 @@ class GfxRenderer {
   // Setup
   void begin();  // must be called right after display.begin()
   void insertFont(int fontId, EpdFontFamily font);
+  // UI chrome font scaling: firmware supplies a small remap table (from the board
+  // uiScale) that substitutes a larger font for each scaled UI font id at lookup
+  // time, so layout and drawing stay consistent with no call-site changes. Reader
+  // body fonts aren't in the table, so book text is unaffected. count <= 8.
+  void setUiFontRemap(const int* from, const int* to, int count);
   // Clears both the flash-font map and any SD-font registration for fontId.
   // Coupled to avoid dangling SdCardFont* in sdCardFonts_ when callers free
   // the underlying SdCardFont and forget the SD-side unregister.
@@ -207,6 +219,14 @@ class GfxRenderer {
   int getTextAdvanceX(int fontId, const char* text, EpdFontFamily::Style style) const;
   int getFontAscenderSize(int fontId) const;
   int getLineHeight(int fontId) const;
+  // Real visible font metrics (from the 'H' / 'x' glyph geometry) for vertical
+  // alignment that follows the font, not a guessed ascender fraction.
+  int getFontCapHeight(int fontId) const;
+  int getFontXHeight(int fontId) const;
+  // Offset from drawText's y (text top) to the text's optical vertical center.
+  // Center any element (icon, etc.) on a line of text via:
+  //   centerY = textTop + getTextVisualCenterOffset(fontId)
+  int getTextVisualCenterOffset(int fontId) const;
   std::string truncatedText(int fontId, const char* text, int maxWidth,
                             EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
   /// Word-wrap \p text into at most \p maxLines lines, each no wider than

lib/hal/HalGPIO.cpp

@@ -249,8 +249,14 @@ bool HalGPIO::wasTouchDown(float& nx, float& ny) const { return inputMgr.wasTouc
 
 unsigned long HalGPIO::lastTouchHeldMs() const { return inputMgr.lastTouchHeldMs(); }
 
+bool HalGPIO::wasSwipe(float& nxStart, float& nyStart, float& nxEnd, float& nyEnd) const {
+  return inputMgr.wasSwipe(nxStart, nyStart, nxEnd, nyEnd);
+}
+
 bool HalGPIO::hasTouch() const { return inputMgr.hasTouch(); }
 
+bool HalGPIO::wasTouchActivity() const { return inputMgr.wasTouchActivity(); }
+
 bool HalGPIO::isXteinkDevice() const {
   const auto board = BoardConfig::ACTIVE.board;
   return board == BoardConfig::Board::XteinkX3 || board == BoardConfig::Board::XteinkX4;

lib/hal/HalGPIO.h

@@ -90,9 +90,18 @@ class HalGPIO {
   // release frame (alongside wasTouchTap). For tap-vs-long-press decisions.
   unsigned long lastTouchHeldMs() const;
 
+  // Swipe (flick) gesture on the release frame: writes the start/end positions
+  // normalized 0..1 in the panel's native frame (map via GfxRenderer::tapToLogical).
+  // A swipe also raises wasTouchTap(), so check this first. False on non-touch.
+  bool wasSwipe(float& nxStart, float& nyStart, float& nxEnd, float& nyEnd) const;
+
   // True if a touch controller is present/active (runtime gate; false on the C3).
   bool hasTouch() const;
 
+  // True if a touch press or release happened this frame (the touch analogue of
+  // wasAnyPressed/Released), for resetting idle/sleep timers and CPU frequency.
+  bool wasTouchActivity() const;
+
   // Setup wake up GPIO and enter deep sleep
   void startDeepSleep();