Move to SDK EInkDisplay and enable anti-aliased 2-bit text (#5)

* First pass at moving to SDK EInkDisplay library

* Add 2-bit grayscale text and anti-aliased rendering of text

* Render status bar for empty chapters

* Refresh screen every 15 pages to avoid ghosting

* Simplify boot and sleep screens

* Give FileSelectionScreen task more stack memory

* Move text around slightly on Boot and Sleep screens

* Re-use existing buffer and write to whole screen for 'partial update'

lib/EpdFont/EpdFontData.h

@@ -31,4 +31,5 @@ typedef struct {
   uint8_t advanceY;                     ///< Newline distance (y axis)
   int ascender;                         ///< Maximal height of a glyph above the base line
   int descender;                        ///< Maximal height of a glyph below the base line
+  bool is2Bit;
 } EpdFontData;

lib/EpdFont/builtinFonts/babyblue.h

@@ -2,6 +2,7 @@
  * generated by fontconvert.py
  * name: babyblue
  * size: 8
+ * mode: 1-bit
  */
 #pragma once
 #include "EpdFontData.h"
@@ -500,5 +501,5 @@ static const EpdUnicodeInterval babyblueIntervals[] = {
 };
 
 static const EpdFontData babyblue = {
-    babyblueBitmaps, babyblueGlyphs, babyblueIntervals, 5, 17, 13, -4,
+    babyblueBitmaps, babyblueGlyphs, babyblueIntervals, 5, 17, 13, -4, false,
 };

lib/EpdFont/builtinFonts/ubuntu_10.h

@@ -2,6 +2,7 @@
  * generated by fontconvert.py
  * name: ubuntu_10
  * size: 10
+ * mode: 1-bit
  */
 #pragma once
 #include "EpdFontData.h"
@@ -762,5 +763,5 @@ static const EpdUnicodeInterval ubuntu_10Intervals[] = {
 };
 
 static const EpdFontData ubuntu_10 = {
-    ubuntu_10Bitmaps, ubuntu_10Glyphs, ubuntu_10Intervals, 31, 24, 20, -4,
+    ubuntu_10Bitmaps, ubuntu_10Glyphs, ubuntu_10Intervals, 31, 24, 20, -4, false,
 };

lib/EpdFont/builtinFonts/ubuntu_bold_10.h

@@ -2,6 +2,7 @@
  * generated by fontconvert.py
  * name: ubuntu_bold_10
  * size: 10
+ * mode: 1-bit
  */
 #pragma once
 #include "EpdFontData.h"
@@ -806,5 +807,5 @@ static const EpdUnicodeInterval ubuntu_bold_10Intervals[] = {
 };
 
 static const EpdFontData ubuntu_bold_10 = {
-    ubuntu_bold_10Bitmaps, ubuntu_bold_10Glyphs, ubuntu_bold_10Intervals, 31, 24, 20, -4,
+    ubuntu_bold_10Bitmaps, ubuntu_bold_10Glyphs, ubuntu_bold_10Intervals, 31, 24, 20, -4, false,
 };

lib/EpdFont/scripts/fontconvert.py

@@ -13,12 +13,14 @@ parser = argparse.ArgumentParser(description="Generate a header file from a font
 parser.add_argument("name", action="store", help="name of the font.")
 parser.add_argument("size", type=int, help="font size to use.")
 parser.add_argument("fontstack", action="store", nargs='+', help="list of font files, ordered by descending priority.")
+parser.add_argument("--2bit", dest="is2Bit", action="store_true", help="generate 2-bit greyscale bitmap instead of 1-bit black and white.")
 parser.add_argument("--additional-intervals", dest="additional_intervals", action="append", help="Additional code point intervals to export as min,max. This argument can be repeated.")
 args = parser.parse_args()
 
 GlyphProps = namedtuple("GlyphProps", ["width", "height", "advance_x", "left", "top", "data_length", "data_offset", "code_point"])
 
 font_stack = [freetype.Face(f) for f in args.fontstack]
+is2Bit = args.is2Bit
 size = args.size
 font_name = args.name
 
@@ -173,6 +175,42 @@ for i_start, i_end in intervals:
                 pixels4g.append(px)
                 px = 0
 
+        if is2Bit:
+            # 0 = white, 15 black, 8+ dark grey, 7- light grey
+            # Downsample to 2-bit bitmap
+            pixels2b = []
+            px = 0
+            pitch = (bitmap.width // 2) + (bitmap.width % 2)
+            for y in range(bitmap.rows):
+                for x in range(bitmap.width):
+                    px = px << 2
+                    bm = pixels4g[y * pitch + (x // 2)]
+                    bm = (bm >> ((x % 2) * 4)) & 0xF
+
+                    if bm == 15:
+                        px += 3
+                    elif bm >= 8:
+                        px += 2
+                    elif bm > 0:
+                        px += 1
+
+                    if (y * bitmap.width + x) % 4 == 3:
+                        pixels2b.append(px)
+                        px = 0
+            if (bitmap.width * bitmap.rows) % 4 != 0:
+                px = px << (4 - (bitmap.width * bitmap.rows) % 4) * 2
+                pixels2b.append(px)
+
+            # for y in range(bitmap.rows):
+            #     line = ''
+            #     for x in range(bitmap.width):
+            #         pixelPosition = y * bitmap.width + x
+            #         byte = pixels2b[pixelPosition // 4]
+            #         bit_index = (3 - (pixelPosition % 4)) * 2
+            #         line += '#' if ((byte >> bit_index) & 3) > 0 else '.'
+            #     print(line)
+            # print('')
+        else:
             # Downsample to 1-bit bitmap - treat any non-zero as black
             pixelsbw = []
             px = 0
@@ -190,9 +228,20 @@ for i_start, i_end in intervals:
                 px = px << (8 - (bitmap.width * bitmap.rows) % 8)
                 pixelsbw.append(px)
 
+            # for y in range(bitmap.rows):
+            #     line = ''
+            #     for x in range(bitmap.width):
+            #         pixelPosition = y * bitmap.width + x
+            #         byte = pixelsbw[pixelPosition // 8]
+            #         bit_index = 7 - (pixelPosition % 8)
+            #         line += '#' if (byte >> bit_index) & 1 else '.'
+            #     print(line)
+            # print('')
+
+        pixels = pixels2b if is2Bit else pixelsbw
 
         # Build output data
-        packed = bytes(pixelsbw)
+        packed = bytes(pixels)
         glyph = GlyphProps(
             width = bitmap.width,
             height = bitmap.rows,
@@ -216,7 +265,7 @@ for index, glyph in enumerate(all_glyphs):
     glyph_data.extend([b for b in packed])
     glyph_props.append(props)
 
-print(f"/**\n * generated by fontconvert.py\n * name: {font_name}\n * size: {size}\n */")
+print(f"/**\n * generated by fontconvert.py\n * name: {font_name}\n * size: {size}\n * mode: {'2-bit' if is2Bit else '1-bit'}\n */")
 print("#pragma once")
 print("#include \"EpdFontData.h\"\n")
 print(f"static const uint8_t {font_name}Bitmaps[{len(glyph_data)}] = {{")
@@ -244,4 +293,5 @@ print(f"    {len(intervals)},")
 print(f"    {norm_ceil(face.size.height)},")
 print(f"    {norm_ceil(face.size.ascender)},")
 print(f"    {norm_floor(face.size.descender)},")
+print(f"    {'true' if is2Bit else 'false'},")
 print("};")

lib/EpdFontRenderer/EpdFontRenderer.hpp

@@ -6,22 +6,27 @@
 inline int min(const int a, const int b) { return a < b ? a : b; }
 inline int max(const int a, const int b) { return a > b ? a : b; }
 
+enum EpdFontRendererMode { BW, GRAYSCALE_LSB, GRAYSCALE_MSB };
+
 template <typename Renderable>
 class EpdFontRenderer {
   Renderable& renderer;
-  void renderChar(uint32_t cp, int* x, const int* y, uint16_t color, EpdFontStyle style = REGULAR);
+  void renderChar(uint32_t cp, int* x, const int* y, bool pixelState, EpdFontStyle style = REGULAR,
+                  EpdFontRendererMode mode = BW);
 
  public:
   const EpdFontFamily* fontFamily;
   explicit EpdFontRenderer(const EpdFontFamily* fontFamily, Renderable& renderer)
       : fontFamily(fontFamily), renderer(renderer) {}
   ~EpdFontRenderer() = default;
-  void renderString(const char* string, int* x, int* y, uint16_t color, EpdFontStyle style = REGULAR);
+  void renderString(const char* string, int* x, int* y, bool pixelState = true, EpdFontStyle style = REGULAR,
+                    EpdFontRendererMode mode = BW);
+  void drawPixel(int x, int y, bool pixelState);
 };
 
 template <typename Renderable>
-void EpdFontRenderer<Renderable>::renderString(const char* string, int* x, int* y, const uint16_t color,
+void EpdFontRenderer<Renderable>::renderString(const char* string, int* x, int* y, const bool pixelState,
-                                               const EpdFontStyle style) {
+                                               const EpdFontStyle style, const EpdFontRendererMode mode) {
   // cannot draw a NULL / empty string
   if (string == nullptr || *string == '\0') {
     return;
@@ -34,15 +39,49 @@ void EpdFontRenderer<Renderable>::renderString(const char* string, int* x, int*
 
   uint32_t cp;
   while ((cp = utf8NextCodepoint(reinterpret_cast<const uint8_t**>(&string)))) {
-    renderChar(cp, x, y, color, style);
+    renderChar(cp, x, y, pixelState, style, mode);
   }
 
   *y += fontFamily->getData(style)->advanceY;
 }
 
+// TODO: Consolidate this with EpdRenderer implementation
 template <typename Renderable>
-void EpdFontRenderer<Renderable>::renderChar(const uint32_t cp, int* x, const int* y, uint16_t color,
+void EpdFontRenderer<Renderable>::drawPixel(const int x, const int y, const bool pixelState) {
-                                             const EpdFontStyle style) {
+  uint8_t* frameBuffer = renderer.getFrameBuffer();
+
+  // Early return if no framebuffer is set
+  if (!frameBuffer) {
+    Serial.printf("!!No framebuffer\n");
+    return;
+  }
+
+  // Bounds checking (portrait: 480x800)
+  if (x < 0 || x >= EInkDisplay::DISPLAY_HEIGHT || y < 0 || y >= EInkDisplay::DISPLAY_WIDTH) {
+    Serial.printf("!!Outside range (%d, %d)\n", x, y);
+    return;
+  }
+
+  // Rotate coordinates: portrait (480x800) -> landscape (800x480)
+  // Rotation: 90 degrees clockwise
+  const int16_t rotatedX = y;
+  const int16_t rotatedY = EInkDisplay::DISPLAY_HEIGHT - 1 - x;
+
+  // Calculate byte position and bit position
+  const uint16_t byteIndex = rotatedY * EInkDisplay::DISPLAY_WIDTH_BYTES + (rotatedX / 8);
+  const uint8_t bitPosition = 7 - (rotatedX % 8);  // MSB first
+
+  // Set or clear the bit
+  if (pixelState) {
+    frameBuffer[byteIndex] &= ~(1 << bitPosition);  // Clear bit
+  } else {
+    frameBuffer[byteIndex] |= (1 << bitPosition);  // Set bit
+  }
+}
+
+template <typename Renderable>
+void EpdFontRenderer<Renderable>::renderChar(const uint32_t cp, int* x, const int* y, const bool pixelState,
+                                             const EpdFontStyle style, const EpdFontRendererMode mode) {
   const EpdGlyph* glyph = fontFamily->getGlyph(cp, style);
   if (!glyph) {
     // TODO: Replace with fallback glyph property?
@@ -55,6 +94,7 @@ void EpdFontRenderer<Renderable>::renderChar(const uint32_t cp, int* x, const in
     return;
   }
 
+  const int is2Bit = fontFamily->getData(style)->is2Bit;
   const uint32_t offset = glyph->dataOffset;
   const uint8_t width = glyph->width;
   const uint8_t height = glyph->height;
@@ -70,11 +110,26 @@ void EpdFontRenderer<Renderable>::renderChar(const uint32_t cp, int* x, const in
         const int pixelPosition = glyphY * width + glyphX;
         int screenX = *x + left + glyphX;
 
+        if (is2Bit) {
+          const uint8_t byte = bitmap[pixelPosition / 4];
+          const uint8_t bit_index = (3 - pixelPosition % 4) * 2;
+
+          const uint8_t val = (byte >> bit_index) & 0x3;
+          if (mode == BW && val > 0) {
+            drawPixel(screenX, screenY, pixelState);
+          } else if (mode == GRAYSCALE_MSB && val == 1) {
+            // TODO: Not sure how this anti-aliasing goes on black backgrounds
+            drawPixel(screenX, screenY, false);
+          } else if (mode == GRAYSCALE_LSB && val == 2) {
+            drawPixel(screenX, screenY, false);
+          }
+        } else {
           const uint8_t byte = bitmap[pixelPosition / 8];
           const uint8_t bit_index = 7 - (pixelPosition % 8);
 
           if ((byte >> bit_index) & 1) {
-          renderer.drawPixel(screenX, screenY, color);
+            drawPixel(screenX, screenY, pixelState);
+          }
         }
       }
     }

lib/EpdRenderer/EpdRenderer.cpp

@@ -1,17 +1,17 @@
 #include "EpdRenderer.h"
 
 #include "builtinFonts/babyblue.h"
-#include "builtinFonts/bookerly.h"
+#include "builtinFonts/bookerly_2b.h"
-#include "builtinFonts/bookerly_bold.h"
+#include "builtinFonts/bookerly_bold_2b.h"
-#include "builtinFonts/bookerly_bold_italic.h"
+#include "builtinFonts/bookerly_bold_italic_2b.h"
-#include "builtinFonts/bookerly_italic.h"
+#include "builtinFonts/bookerly_italic_2b.h"
 #include "builtinFonts/ubuntu_10.h"
 #include "builtinFonts/ubuntu_bold_10.h"
 
-EpdFont bookerlyFont(&bookerly);
+EpdFont bookerlyFont(&bookerly_2b);
-EpdFont bookerlyBoldFont(&bookerly_bold);
+EpdFont bookerlyBoldFont(&bookerly_bold_2b);
-EpdFont bookerlyItalicFont(&bookerly_italic);
+EpdFont bookerlyItalicFont(&bookerly_italic_2b);
-EpdFont bookerlyBoldItalicFont(&bookerly_bold_italic);
+EpdFont bookerlyBoldItalicFont(&bookerly_bold_italic_2b);
 EpdFontFamily bookerlyFontFamily(&bookerlyFont, &bookerlyBoldFont, &bookerlyItalicFont, &bookerlyBoldItalicFont);
 
 EpdFont smallFont(&babyblue);
@@ -21,11 +21,17 @@ EpdFont ubuntu10Font(&ubuntu_10);
 EpdFont ununtuBold10Font(&ubuntu_bold_10);
 EpdFontFamily ubuntuFontFamily(&ubuntu10Font, &ununtuBold10Font);
 
-EpdRenderer::EpdRenderer(XteinkDisplay& display)
+EpdRenderer::EpdRenderer(EInkDisplay& einkDisplay)
-    : display(display), marginTop(11), marginBottom(30), marginLeft(10), marginRight(10), lineCompression(0.95f) {
+    : einkDisplay(einkDisplay),
-  this->regularFontRenderer = new EpdFontRenderer<XteinkDisplay>(&bookerlyFontFamily, display);
+      marginTop(11),
-  this->smallFontRenderer = new EpdFontRenderer<XteinkDisplay>(&smallFontFamily, display);
+      marginBottom(30),
-  this->uiFontRenderer = new EpdFontRenderer<XteinkDisplay>(&ubuntuFontFamily, display);
+      marginLeft(10),
+      marginRight(10),
+      fontRendererMode(BW),
+      lineCompression(0.95f) {
+  this->regularFontRenderer = new EpdFontRenderer<EInkDisplay>(&bookerlyFontFamily, einkDisplay);
+  this->smallFontRenderer = new EpdFontRenderer<EInkDisplay>(&smallFontFamily, einkDisplay);
+  this->uiFontRenderer = new EpdFontRenderer<EInkDisplay>(&ubuntuFontFamily, einkDisplay);
 }
 
 EpdRenderer::~EpdRenderer() {
@@ -34,6 +40,40 @@ EpdRenderer::~EpdRenderer() {
   delete uiFontRenderer;
 }
 
+void EpdRenderer::drawPixel(const int x, const int y, const bool state) const {
+  uint8_t* frameBuffer = einkDisplay.getFrameBuffer();
+
+  // Early return if no framebuffer is set
+  if (!frameBuffer) {
+    Serial.printf("!!No framebuffer\n");
+    return;
+  }
+
+  const int adjX = x + marginLeft;
+  const int adjY = y + marginTop;
+
+  // Bounds checking (portrait: 480x800)
+  if (adjX < 0 || adjX >= EInkDisplay::DISPLAY_HEIGHT || adjY < 0 || adjY >= EInkDisplay::DISPLAY_WIDTH) {
+    Serial.printf("!!Outside range (%d, %d)\n", adjX, adjY);
+    return;
+  }
+
+  // Rotate coordinates: portrait (480x800) -> landscape (800x480)
+  // Rotation: 90 degrees clockwise
+  const int rotatedX = adjY;
+  const int rotatedY = EInkDisplay::DISPLAY_HEIGHT - 1 - adjX;
+
+  // Calculate byte position and bit position
+  const uint16_t byteIndex = rotatedY * EInkDisplay::DISPLAY_WIDTH_BYTES + (rotatedX / 8);
+  const uint8_t bitPosition = 7 - (rotatedX % 8);  // MSB first
+
+  if (state) {
+    frameBuffer[byteIndex] &= ~(1 << bitPosition);  // Clear bit
+  } else {
+    frameBuffer[byteIndex] |= 1 << bitPosition;  // Set bit
+  }
+}
+
 int EpdRenderer::getTextWidth(const char* text, const EpdFontStyle style) const {
   int w = 0, h = 0;
 
@@ -58,25 +98,25 @@ int EpdRenderer::getSmallTextWidth(const char* text, const EpdFontStyle style) c
   return w;
 }
 
-void EpdRenderer::drawText(const int x, const int y, const char* text, const uint16_t color,
+void EpdRenderer::drawText(const int x, const int y, const char* text, const bool state,
                            const EpdFontStyle style) const {
   int ypos = y + getLineHeight() + marginTop;
   int xpos = x + marginLeft;
-  regularFontRenderer->renderString(text, &xpos, &ypos, color > 0 ? GxEPD_BLACK : GxEPD_WHITE, style);
+  regularFontRenderer->renderString(text, &xpos, &ypos, state, style, fontRendererMode);
 }
 
-void EpdRenderer::drawUiText(const int x, const int y, const char* text, const uint16_t color,
+void EpdRenderer::drawUiText(const int x, const int y, const char* text, const bool state,
                              const EpdFontStyle style) const {
   int ypos = y + uiFontRenderer->fontFamily->getData(style)->advanceY + marginTop;
   int xpos = x + marginLeft;
-  uiFontRenderer->renderString(text, &xpos, &ypos, color > 0 ? GxEPD_BLACK : GxEPD_WHITE, style);
+  uiFontRenderer->renderString(text, &xpos, &ypos, state, style, fontRendererMode);
 }
 
-void EpdRenderer::drawSmallText(const int x, const int y, const char* text, const uint16_t color,
+void EpdRenderer::drawSmallText(const int x, const int y, const char* text, const bool state,
                                 const EpdFontStyle style) const {
   int ypos = y + smallFontRenderer->fontFamily->getData(style)->advanceY + marginTop;
   int xpos = x + marginLeft;
-  smallFontRenderer->renderString(text, &xpos, &ypos, color > 0 ? GxEPD_BLACK : GxEPD_WHITE, style);
+  smallFontRenderer->renderString(text, &xpos, &ypos, state, style, fontRendererMode);
 }
 
 void EpdRenderer::drawTextBox(const int x, const int y, const std::string& text, const int width, const int height,
@@ -88,7 +128,7 @@ void EpdRenderer::drawTextBox(const int x, const int y, const std::string& text,
   int ypos = 0;
   while (true) {
     if (end >= length) {
-      drawText(x, y + ypos, text.substr(start, length - start).c_str(), 1, style);
+      drawText(x, y + ypos, text.substr(start, length - start).c_str(), true, style);
       break;
     }
 
@@ -97,7 +137,7 @@ void EpdRenderer::drawTextBox(const int x, const int y, const std::string& text,
     }
 
     if (text[end - 1] == '\n') {
-      drawText(x, y + ypos, text.substr(start, end - start).c_str(), 1, style);
+      drawText(x, y + ypos, text.substr(start, end - start).c_str(), true, style);
       ypos += getLineHeight();
       start = end;
       end = start + 1;
@@ -105,7 +145,7 @@ void EpdRenderer::drawTextBox(const int x, const int y, const std::string& text,
     }
 
     if (getTextWidth(text.substr(start, end - start).c_str(), style) > width) {
-      drawText(x, y + ypos, text.substr(start, end - start - 1).c_str(), 1, style);
+      drawText(x, y + ypos, text.substr(start, end - start - 1).c_str(), true, style);
       ypos += getLineHeight();
       start = end - 1;
       continue;
@@ -115,54 +155,88 @@ void EpdRenderer::drawTextBox(const int x, const int y, const std::string& text,
   }
 }
 
-void EpdRenderer::drawLine(int x1, int y1, int x2, int y2, uint16_t color) const {
+void EpdRenderer::drawLine(int x1, int y1, int x2, int y2, const bool state) const {
-  display.drawLine(x1 + marginLeft, y1 + marginTop, x2 + marginLeft, y2 + marginTop,
+  if (x1 == x2) {
-                   color > 0 ? GxEPD_BLACK : GxEPD_WHITE);
+    if (y2 < y1) {
+      std::swap(y1, y2);
+    }
+    for (int y = y1; y <= y2; y++) {
+      drawPixel(x1, y, state);
+    }
+  } else if (y1 == y2) {
+    if (x2 < x1) {
+      std::swap(x1, x2);
+    }
+    for (int x = x1; x <= x2; x++) {
+      drawPixel(x, y1, state);
+    }
+  } else {
+    // TODO: Implement
+    Serial.println("Line drawing not supported");
+  }
 }
 
-void EpdRenderer::drawRect(const int x, const int y, const int width, const int height, const uint16_t color) const {
+void EpdRenderer::drawRect(const int x, const int y, const int width, const int height, const bool state) const {
-  display.drawRect(x + marginLeft, y + marginTop, width, height, color > 0 ? GxEPD_BLACK : GxEPD_WHITE);
+  drawLine(x, y, x + width - 1, y, state);
+  drawLine(x + width - 1, y, x + width - 1, y + height - 1, state);
+  drawLine(x + width - 1, y + height - 1, x, y + height - 1, state);
+  drawLine(x, y, x, y + height - 1, state);
 }
 
-void EpdRenderer::fillRect(const int x, const int y, const int width, const int height, const uint16_t color) const {
+void EpdRenderer::fillRect(const int x, const int y, const int width, const int height, const bool state) const {
-  display.fillRect(x + marginLeft, y + marginTop, width, height, color > 0 ? GxEPD_BLACK : GxEPD_WHITE);
+  for (int fillY = y; fillY < y + height; fillY++) {
+    drawLine(x, fillY, x + width - 1, fillY, state);
+  }
 }
 
-void EpdRenderer::drawCircle(const int x, const int y, const int radius, const uint16_t color) const {
+void EpdRenderer::drawImage(const uint8_t bitmap[], const int x, const int y, const int width, const int height) const {
-  display.drawCircle(x + marginLeft, y + marginTop, radius, color > 0 ? GxEPD_BLACK : GxEPD_WHITE);
+  drawImageNoMargin(bitmap, x + marginLeft, y + marginTop, width, height);
 }
 
-void EpdRenderer::fillCircle(const int x, const int y, const int radius, const uint16_t color) const {
+// TODO: Support y-mirror?
-  display.fillCircle(x + marginLeft, y + marginTop, radius, color > 0 ? GxEPD_BLACK : GxEPD_WHITE);
+void EpdRenderer::drawImageNoMargin(const uint8_t bitmap[], const int x, const int y, const int width,
+                                    const int height) const {
+  einkDisplay.drawImage(bitmap, x, y, width, height);
 }
 
-void EpdRenderer::drawImage(const uint8_t bitmap[], const int x, const int y, const int width, const int height,
+void EpdRenderer::clearScreen(const uint8_t color) const {
-                            const bool invert, const bool mirrorY) const {
-  drawImageNoMargin(bitmap, x + marginLeft, y + marginTop, width, height, invert, mirrorY);
-}
-
-void EpdRenderer::drawImageNoMargin(const uint8_t bitmap[], const int x, const int y, const int width, const int height,
-                                    const bool invert, const bool mirrorY) const {
-  display.drawImage(bitmap, x, y, width, height, invert, mirrorY);
-}
-
-void EpdRenderer::clearScreen(const bool black) const {
   Serial.println("Clearing screen");
-  display.fillScreen(black ? GxEPD_BLACK : GxEPD_WHITE);
+  einkDisplay.clearScreen(color);
 }
 
-void EpdRenderer::flushDisplay(const bool partialUpdate) const { display.display(partialUpdate); }
+void EpdRenderer::invertScreen() const {
-
+  uint8_t *buffer = einkDisplay.getFrameBuffer();
-void EpdRenderer::flushArea(const int x, const int y, const int width, const int height) const {
+  for (int i = 0; i < EInkDisplay::BUFFER_SIZE; i++) {
-  display.displayWindow(x + marginLeft, y + marginTop, width, height);
+    buffer[i] = ~buffer[i];
+  }
 }
 
-int EpdRenderer::getPageWidth() const { return display.width() - marginLeft - marginRight; }
+void EpdRenderer::flushDisplay(const EInkDisplay::RefreshMode refreshMode) const {
+  einkDisplay.displayBuffer(refreshMode);
+}
 
-int EpdRenderer::getPageHeight() const { return display.height() - marginTop - marginBottom; }
+// TODO: Support partial window update
+// void EpdRenderer::flushArea(const int x, const int y, const int width, const int height) const {
+//   const int rotatedX = y;
+//   const int rotatedY = EInkDisplay::DISPLAY_HEIGHT - 1 - x;
+//
+//   einkDisplay.displayBuffer(EInkDisplay::FAST_REFRESH, rotatedX, rotatedY, height, width);
+// }
+
+int EpdRenderer::getPageWidth() const { return EInkDisplay::DISPLAY_HEIGHT - marginLeft - marginRight; }
+
+int EpdRenderer::getPageHeight() const { return EInkDisplay::DISPLAY_WIDTH - marginTop - marginBottom; }
 
 int EpdRenderer::getSpaceWidth() const { return regularFontRenderer->fontFamily->getGlyph(' ', REGULAR)->advanceX; }
 
 int EpdRenderer::getLineHeight() const {
   return regularFontRenderer->fontFamily->getData(REGULAR)->advanceY * lineCompression;
 }
+
+void EpdRenderer::swapBuffers() const { einkDisplay.swapBuffers(); }
+
+void EpdRenderer::copyGrayscaleLsbBuffers() const { einkDisplay.copyGrayscaleLsbBuffers(einkDisplay.getFrameBuffer()); }
+
+void EpdRenderer::copyGrayscaleMsbBuffers() const { einkDisplay.copyGrayscaleMsbBuffers(einkDisplay.getFrameBuffer()); }
+
+void EpdRenderer::displayGrayBuffer() const { einkDisplay.displayGrayBuffer(); }

lib/EpdRenderer/EpdRenderer.h

@@ -1,52 +1,58 @@
 #pragma once
 
-#include <GxEPD2_BW.h>
+#include <EInkDisplay.h>
 
 #include <EpdFontRenderer.hpp>
 
-#define XteinkDisplay GxEPD2_BW<GxEPD2_426_GDEQ0426T82, GxEPD2_426_GDEQ0426T82::HEIGHT>
-
 class EpdRenderer {
-  XteinkDisplay& display;
+  EInkDisplay& einkDisplay;
-  EpdFontRenderer<XteinkDisplay>* regularFontRenderer;
+  EpdFontRenderer<EInkDisplay>* regularFontRenderer;
-  EpdFontRenderer<XteinkDisplay>* smallFontRenderer;
+  EpdFontRenderer<EInkDisplay>* smallFontRenderer;
-  EpdFontRenderer<XteinkDisplay>* uiFontRenderer;
+  EpdFontRenderer<EInkDisplay>* uiFontRenderer;
   int marginTop;
   int marginBottom;
   int marginLeft;
   int marginRight;
+  EpdFontRendererMode fontRendererMode;
   float lineCompression;
 
  public:
-  explicit EpdRenderer(XteinkDisplay& display);
+  explicit EpdRenderer(EInkDisplay& einkDisplay);
   ~EpdRenderer();
+  void drawPixel(int x, int y, bool state = true) const;
   int getTextWidth(const char* text, EpdFontStyle style = REGULAR) const;
   int getUiTextWidth(const char* text, EpdFontStyle style = REGULAR) const;
   int getSmallTextWidth(const char* text, EpdFontStyle style = REGULAR) const;
-  void drawText(int x, int y, const char* text, uint16_t color = 1, EpdFontStyle style = REGULAR) const;
+  void drawText(int x, int y, const char* text, bool state = true, EpdFontStyle style = REGULAR) const;
-  void drawUiText(int x, int y, const char* text, uint16_t color = 1, EpdFontStyle style = REGULAR) const;
+  void drawUiText(int x, int y, const char* text, bool state = true, EpdFontStyle style = REGULAR) const;
-  void drawSmallText(int x, int y, const char* text, uint16_t color = 1, EpdFontStyle style = REGULAR) const;
+  void drawSmallText(int x, int y, const char* text, bool state = true, EpdFontStyle style = REGULAR) const;
   void drawTextBox(int x, int y, const std::string& text, int width, int height, EpdFontStyle style = REGULAR) const;
-  void drawLine(int x1, int y1, int x2, int y2, uint16_t color = 1) const;
+  void drawLine(int x1, int y1, int x2, int y2, bool state = true) const;
-  void drawRect(int x, int y, int width, int height, uint16_t color = 1) const;
+  void drawRect(int x, int y, int width, int height, bool state = true) const;
-  void fillRect(int x, int y, int width, int height, uint16_t color = 1) const;
+  void fillRect(int x, int y, int width, int height, bool state = true) const;
-  void drawCircle(int x, int y, int radius, uint16_t color = 1) const;
+  void drawImage(const uint8_t bitmap[], int x, int y, int width, int height) const;
-  void fillCircle(int x, int y, int radius, uint16_t color = 1) const;
+  void drawImageNoMargin(const uint8_t bitmap[], int x, int y, int width, int height) const;
-  void drawImage(const uint8_t bitmap[], int x, int y, int width, int height, bool invert = false,
+
-                 bool mirrorY = false) const;
+  void swapBuffers() const;
-  void drawImageNoMargin(const uint8_t bitmap[], int x, int y, int width, int height, bool invert = false,
+  void copyGrayscaleLsbBuffers() const;
-                         bool mirrorY = false) const;
+  void copyGrayscaleMsbBuffers() const;
-  void clearScreen(bool black = false) const;
+  void displayGrayBuffer() const;
-  void flushDisplay(bool partialUpdate = true) const;
+  void clearScreen(uint8_t color = 0xFF) const;
-  void flushArea(int x, int y, int width, int height) const;
+
+  void invertScreen() const;
+
+  void flushDisplay(EInkDisplay::RefreshMode refreshMode = EInkDisplay::FAST_REFRESH) const;
+  // void flushArea(int x, int y, int width, int height) const;
 
   int getPageWidth() const;
   int getPageHeight() const;
   int getSpaceWidth() const;
   int getLineHeight() const;
+
   // set margins
   void setMarginTop(const int newMarginTop) { this->marginTop = newMarginTop; }
   void setMarginBottom(const int newMarginBottom) { this->marginBottom = newMarginBottom; }
   void setMarginLeft(const int newMarginLeft) { this->marginLeft = newMarginLeft; }
   void setMarginRight(const int newMarginRight) { this->marginRight = newMarginRight; }
+  void setFontRendererMode(const EpdFontRendererMode mode) { this->fontRendererMode = mode; }
 };

lib/Epub/Epub/Section.cpp

@@ -98,21 +98,15 @@ bool Section::persistPageDataToSD() {
   return true;
 }
 
-void Section::renderPage() const {
+Page* Section::loadPageFromSD() const {
-  if (0 <= currentPage && currentPage < pageCount) {
   const auto filePath = "/sd" + cachePath + "/page_" + std::to_string(currentPage) + ".bin";
-    std::ifstream inputFile(filePath);
+  if (!SD.exists(filePath.c_str() + 3)) {
-    const Page* p = Page::deserialize(inputFile);
+    Serial.printf("Page file does not exist: %s\n", filePath.c_str());
-    inputFile.close();
+    return nullptr;
-    p->render(renderer);
-    delete p;
-  } else if (pageCount == 0) {
-    Serial.println("No pages to render");
-    const int width = renderer.getTextWidth("Empty chapter", BOLD);
-    renderer.drawText((renderer.getPageWidth() - width) / 2, 300, "Empty chapter", 1, BOLD);
-  } else {
-    Serial.printf("Page out of bounds: %d (max %d)\n", currentPage, pageCount);
-    const int width = renderer.getTextWidth("Out of bounds", BOLD);
-    renderer.drawText((renderer.getPageWidth() - width) / 2, 300, "Out of bounds", 1, BOLD);
   }
+
+  std::ifstream inputFile(filePath);
+  Page* p = Page::deserialize(inputFile);
+  inputFile.close();
+  return p;
 }

lib/Epub/Epub/Section.h

@@ -26,5 +26,5 @@ class Section {
   void setupCacheDir() const;
   void clearCache() const;
   bool persistPageDataToSD();
-  void renderPage() const;
+  Page* loadPageFromSD() const;
 };

lib/Epub/Epub/blocks/TextBlock.cpp

@@ -165,7 +165,7 @@ void TextBlock::render(const EpdRenderer& renderer, const int x, const int y) co
     } else if (wordStyles[i] & ITALIC_SPAN) {
       fontStyle = ITALIC;
     }
-    renderer.drawText(x + wordXpos[i], y, words[i].c_str(), 1, fontStyle);
+    renderer.drawText(x + wordXpos[i], y, words[i].c_str(), true, fontStyle);
   }
 }
 

open-x4-sdk

@@ -1 +1 @@
-Subproject commit 8224d278c58e76abf781c2e015f28a09419f27b2
+Subproject commit a126d4b0bf66cd2895d11748774f7ec2c366cc4c

platformio.ini

@@ -34,7 +34,7 @@ build_flags =
 
 ; Libraries
 lib_deps =
-  zinggjm/GxEPD2@^1.6.5
   https://github.com/leethomason/tinyxml2.git#11.0.0
   BatteryMonitor=symlink://open-x4-sdk/libs/hardware/BatteryMonitor
   InputManager=symlink://open-x4-sdk/libs/hardware/InputManager
+  EInkDisplay=symlink://open-x4-sdk/libs/display/EInkDisplay

src/images/CrossLarge.h

@@ -1,7 +1,7 @@
 #pragma once
 #include <cstdint>
 
-extern const uint8_t CrossLarge[] = {
+static const uint8_t CrossLarge[] = {
     0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
     0xEF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xF7, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC7, 0xFF, 0xFF,
     0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xE3, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x83, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

src/main.cpp

@@ -1,7 +1,7 @@
 #include <Arduino.h>
+#include <EInkDisplay.h>
 #include <EpdRenderer.h>
 #include <Epub.h>
-#include <GxEPD2_BW.h>
 #include <InputManager.h>
 #include <SD.h>
 #include <SPI.h>
@@ -28,10 +28,9 @@
 #define SD_SPI_CS 12
 #define SD_SPI_MISO 7
 
-GxEPD2_BW<GxEPD2_426_GDEQ0426T82, GxEPD2_426_GDEQ0426T82::HEIGHT> display(GxEPD2_426_GDEQ0426T82(EPD_CS, EPD_DC,
+EInkDisplay einkDisplay(EPD_SCLK, EPD_MOSI, EPD_CS, EPD_DC, EPD_RST, EPD_BUSY);
-                                                                                                 EPD_RST, EPD_BUSY));
 InputManager inputManager;
-EpdRenderer renderer(display);
+EpdRenderer renderer(einkDisplay);
 Screen* currentScreen;
 CrossPointState appState;
 
@@ -123,7 +122,7 @@ void enterDeepSleep() {
   // Enable Wakeup on LOW (button press)
   esp_deep_sleep_enable_gpio_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_GPIO_WAKEUP_GPIO_LOW);
 
-  display.hibernate();
+  einkDisplay.deepSleep();
 
   // Enter Deep Sleep
   esp_deep_sleep_start();
@@ -142,7 +141,7 @@ void onSelectEpubFile(const std::string& path) {
     enterNewScreen(new EpubReaderScreen(renderer, inputManager, epub, onGoHome));
   } else {
     exitScreen();
-    enterNewScreen(new FullScreenMessageScreen(renderer, inputManager, "Failed to load epub", REGULAR, false, false));
+    enterNewScreen(new FullScreenMessageScreen(renderer, inputManager, "Failed to load epub", REGULAR, EInkDisplay::HALF_REFRESH));
     delay(2000);
     onGoHome();
   }
@@ -170,10 +169,7 @@ void setup() {
   SPI.begin(EPD_SCLK, SD_SPI_MISO, EPD_MOSI, EPD_CS);
 
   // Initialize display
-  const SPISettings spi_settings(SPI_FQ, MSBFIRST, SPI_MODE0);
+  einkDisplay.begin();
-  display.init(115200, true, 2, false, SPI, spi_settings);
-  display.setRotation(3);  // 270 degrees
-  display.setTextColor(GxEPD_BLACK);
   Serial.println("Display initialized");
 
   exitScreen();

src/screens/BootLogoScreen.cpp

@@ -11,4 +11,9 @@ void BootLogoScreen::onEnter() {
   renderer.clearScreen();
   // Location for images is from top right in landscape orientation
   renderer.drawImage(CrossLarge, (pageHeight - 128) / 2, (pageWidth - 128) / 2, 128, 128);
+  const int width = renderer.getUiTextWidth("CrossPoint", BOLD);
+  renderer.drawUiText((pageWidth - width)/ 2, pageHeight / 2 + 70, "CrossPoint", true, BOLD);
+  const int bootingWidth = renderer.getSmallTextWidth("BOOTING");
+  renderer.drawSmallText((pageWidth - bootingWidth) / 2, pageHeight / 2 + 95, "BOOTING");
+  renderer.flushDisplay();
 }

src/screens/EpubReaderScreen.cpp

@@ -1,11 +1,12 @@
 #include "EpubReaderScreen.h"
 
 #include <EpdRenderer.h>
+#include <Epub/Page.h>
 #include <SD.h>
 
 #include "Battery.h"
 
-constexpr int PAGES_PER_REFRESH = 20;
+constexpr int PAGES_PER_REFRESH = 15;
 constexpr unsigned long SKIP_CHAPTER_MS = 700;
 
 void EpubReaderScreen::taskTrampoline(void* param) {
@@ -128,7 +129,7 @@ void EpubReaderScreen::displayTaskLoop() {
     if (updateRequired) {
       updateRequired = false;
       xSemaphoreTake(renderingMutex, portMAX_DELAY);
-      renderPage();
+      renderScreen();
       xSemaphoreGive(renderingMutex);
     }
     vTaskDelay(10 / portTICK_PERIOD_MS);
@@ -136,7 +137,7 @@ void EpubReaderScreen::displayTaskLoop() {
 }
 
 // TODO: Failure handling
-void EpubReaderScreen::renderPage() {
+void EpubReaderScreen::renderScreen() {
   if (!epub) {
     return;
   }
@@ -159,10 +160,12 @@ void EpubReaderScreen::renderPage() {
         constexpr int y = 50;
         const int w = textWidth + margin * 2;
         const int h = renderer.getLineHeight() + margin * 2;
+        renderer.swapBuffers();
         renderer.fillRect(x, y, w, h, 0);
         renderer.drawText(x + margin, y + margin, "Indexing...");
         renderer.drawRect(x + 5, y + 5, w - 10, h - 10);
-        renderer.flushArea(x, y, w, h);
+        renderer.flushDisplay(EInkDisplay::HALF_REFRESH);
+        pagesUntilFullRefresh = 0;
       }
 
       section->setupCacheDir();
@@ -184,16 +187,29 @@ void EpubReaderScreen::renderPage() {
   }
 
   renderer.clearScreen();
-  section->renderPage();
+
+  if (section->pageCount == 0) {
+    Serial.println("No pages to render");
+    const int width = renderer.getTextWidth("Empty chapter", BOLD);
+    renderer.drawText((renderer.getPageWidth() - width) / 2, 300, "Empty chapter", true, BOLD);
     renderStatusBar();
-  if (pagesUntilFullRefresh <= 1) {
-    renderer.flushDisplay(false);
-    pagesUntilFullRefresh = PAGES_PER_REFRESH;
-  } else {
     renderer.flushDisplay();
-    pagesUntilFullRefresh--;
+    return;
   }
 
+  if (section->currentPage < 0 || section->currentPage >= section->pageCount) {
+    Serial.printf("Page out of bounds: %d (max %d)\n", section->currentPage, section->pageCount);
+    const int width = renderer.getTextWidth("Out of bounds", BOLD);
+    renderer.drawText((renderer.getPageWidth() - width) / 2, 300, "Out of bounds", true, BOLD);
+    renderStatusBar();
+    renderer.flushDisplay();
+    return;
+  }
+
+  const Page* p = section->loadPageFromSD();
+  renderContents(p);
+  delete p;
+
   File f = SD.open((epub->getCachePath() + "/progress.bin").c_str(), FILE_WRITE);
   uint8_t data[4];
   data[0] = currentSpineIndex & 0xFF;
@@ -204,6 +220,36 @@ void EpubReaderScreen::renderPage() {
   f.close();
 }
 
+void EpubReaderScreen::renderContents(const Page* p) {
+  p->render(renderer);
+  renderStatusBar();
+  if (pagesUntilFullRefresh <= 1) {
+    renderer.flushDisplay(EInkDisplay::HALF_REFRESH);
+    pagesUntilFullRefresh = PAGES_PER_REFRESH;
+  } else {
+    renderer.flushDisplay();
+    pagesUntilFullRefresh--;
+  }
+
+  // grayscale rendering
+  {
+    renderer.clearScreen(0x00);
+    renderer.setFontRendererMode(GRAYSCALE_LSB);
+    p->render(renderer);
+    renderer.copyGrayscaleLsbBuffers();
+
+    // Render and copy to MSB buffer
+    renderer.clearScreen(0x00);
+    renderer.setFontRendererMode(GRAYSCALE_MSB);
+    p->render(renderer);
+    renderer.copyGrayscaleMsbBuffers();
+
+    // display grayscale part
+    renderer.displayGrayBuffer();
+    renderer.setFontRendererMode(BW);
+  }
+}
+
 void EpubReaderScreen::renderStatusBar() const {
   const auto pageWidth = renderer.getPageWidth();
 

src/screens/EpubReaderScreen.h

@@ -20,7 +20,8 @@ class EpubReaderScreen final : public Screen {
 
   static void taskTrampoline(void* param);
   [[noreturn]] void displayTaskLoop();
-  void renderPage();
+  void renderScreen();
+  void renderContents(const Page *p);
   void renderStatusBar() const;
 
  public:

src/screens/FileSelectionScreen.cpp

@@ -51,7 +51,7 @@ void FileSelectionScreen::onEnter() {
   updateRequired = true;
 
   xTaskCreate(&FileSelectionScreen::taskTrampoline, "FileSelectionScreenTask",
-              1024,               // Stack size
+              2048,               // Stack size
               this,               // Parameters
               1,                  // Priority
               &displayTaskHandle  // Task handle
@@ -120,7 +120,7 @@ void FileSelectionScreen::render() const {
 
   const auto pageWidth = renderer.getPageWidth();
   const auto titleWidth = renderer.getTextWidth("CrossPoint Reader", BOLD);
-  renderer.drawText((pageWidth - titleWidth) / 2, 0, "CrossPoint Reader", 1, BOLD);
+  renderer.drawText((pageWidth - titleWidth) / 2, 0, "CrossPoint Reader", true, BOLD);
 
   if (files.empty()) {
     renderer.drawUiText(10, 50, "No EPUBs found");
@@ -130,7 +130,7 @@ void FileSelectionScreen::render() const {
 
     for (size_t i = 0; i < files.size(); i++) {
       const auto file = files[i];
-      renderer.drawUiText(10, 50 + i * 30, file.c_str(), i == selectorIndex ? 0 : 1);
+      renderer.drawUiText(10, 50 + i * 30, file.c_str(), i != selectorIndex);
     }
   }
 

src/screens/FullScreenMessageScreen.cpp

@@ -8,7 +8,7 @@ void FullScreenMessageScreen::onEnter() {
   const auto left = (renderer.getPageWidth() - width) / 2;
   const auto top = (renderer.getPageHeight() - height) / 2;
 
-  renderer.clearScreen(invert);
+  renderer.clearScreen();
-  renderer.drawUiText(left, top, text.c_str(), invert ? 0 : 1, style);
+  renderer.drawUiText(left, top, text.c_str(), true, style);
-  renderer.flushDisplay(partialUpdate);
+  renderer.flushDisplay(refreshMode);
 }

src/screens/FullScreenMessageScreen.h

@@ -2,23 +2,22 @@
 #include <string>
 #include <utility>
 
-#include "EpdFontFamily.h"
+#include <EInkDisplay.h>
+#include <EpdFontFamily.h>
 #include "Screen.h"
 
 class FullScreenMessageScreen final : public Screen {
   std::string text;
   EpdFontStyle style;
-  bool invert;
+  EInkDisplay::RefreshMode refreshMode;
-  bool partialUpdate;
 
  public:
   explicit FullScreenMessageScreen(EpdRenderer& renderer, InputManager& inputManager, std::string text,
-                                   const EpdFontStyle style = REGULAR, const bool invert = false,
+                                   const EpdFontStyle style = REGULAR,
-                                   const bool partialUpdate = true)
+                                   const EInkDisplay::RefreshMode refreshMode = EInkDisplay::FAST_REFRESH)
       : Screen(renderer, inputManager),
         text(std::move(text)),
         style(style),
-        invert(invert),
+        refreshMode(refreshMode) {}
-        partialUpdate(partialUpdate) {}
   void onEnter() override;
 };

src/screens/SleepScreen.cpp

@@ -2,6 +2,18 @@
 
 #include <EpdRenderer.h>
 
-#include "images/SleepScreenImg.h"
+#include "images/CrossLarge.h"
 
-void SleepScreen::onEnter() { renderer.drawImageNoMargin(SleepScreenImg, 0, 0, 800, 480, false, true); }
+void SleepScreen::onEnter() {
+  const auto pageWidth = renderer.getPageWidth();
+  const auto pageHeight = renderer.getPageHeight();
+
+  renderer.clearScreen();
+  renderer.drawImage(CrossLarge, (pageHeight - 128) / 2, (pageWidth - 128) / 2, 128, 128);
+  const int width = renderer.getUiTextWidth("CrossPoint", BOLD);
+  renderer.drawUiText((pageWidth - width)/ 2, pageHeight / 2 + 70, "CrossPoint", true, BOLD);
+  const int bootingWidth = renderer.getSmallTextWidth("SLEEPING");
+  renderer.drawSmallText((pageWidth - bootingWidth) / 2, pageHeight / 2 + 95, "SLEEPING");
+  renderer.invertScreen();
+  renderer.flushDisplay(EInkDisplay::FULL_REFRESH);
+}