Cut release 0.3.0

* 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'

README.md

@@ -6,10 +6,7 @@ Built using **PlatformIO** and targeting the **ESP32-C3** microcontroller.
 CrossPoint Reader is a purpose-built firmware designed to be a drop-in, fully open-source replacement for the official 
 Xteink firmware. It aims to match or improve upon the standard EPUB reading experience.
 
-// TODO include some images
-
-I look at the [**diy-esp32-epub-reader** by atomic14](https://github.com/atomic14/diy-esp32-epub-reader) project a lot 
-when making CrossPoint and a handful of lessons and some direct source code comes directly from that repo.
+![](./docs/cover.jpg)
 
 ## Motivation
 
@@ -31,7 +28,9 @@ This project is **not affiliated with Xteink**; it's built as a community projec
 - [x] EPUB parsing and rendering
 - [x] Saved reading position
 - [ ] File explorer with file picker
-  - Currently CrossPoint will just open the first EPUB it finds at the root of the SD card
+  - [x] Basic EPUB picker from root directory
+  - [x] Support nested folders
+  - [ ] EPUB picker with cover art
 - [ ] Image support within EPUB
 - [ ] Configurable font, layout, and display options
 - [ ] WiFi connectivity
@@ -46,14 +45,37 @@ This project is **not affiliated with Xteink**; it's built as a community projec
 * USB-C cable for flashing the ESP32-C3
 * Xteink X4
 
+### Checking out the code
+
+CrossPoint uses PlatformIO for building and flashing the firmware. To get started, clone the repository:
+
+```
+git clone --recursive https://github.com/daveallie/crosspoint-reader
+
+# Or, if you've already cloned without --recursive:
+git submodule update --init --recursive
+```
+
 ### Flashing your device
 
 #### Command line
 
+Connect your Xteink X4 to your computer via USB-C and run the following command.
+
 ```sh
 pio run --target upload
 ```
 
+#### Web
+
+1. Connect your Xteink X4 to your computer via USB-C
+2. Download the `firmware.bin` file from the latest release via the [releases page](https://github.com/daveallie/crosspoint-reader/releases)
+3. Go to https://xteink.dve.al/ and flash the firmware file using the "OTA fast flash controls" section
+4. Press the reset button on the Xteink X4 to restart the device
+
+To revert back to the official firmware, you can flash the latest official firmware from https://xteink.dve.al/, or swap
+back to the other partition using the "Swap boot partition" button here https://xteink.dve.al/debug. 
+
 ## Internals
 
 CrossPoint Reader is pretty aggressive about caching data down to the SD card to minimise RAM usage. The ESP32-C3 only
@@ -104,3 +126,6 @@ Contributions are very welcome!
 ---
 
 CrossPoint Reader is **not affiliated with Xteink or any manufacturer of the X4 hardware**.
+
+Huge shoutout to [**diy-esp32-epub-reader** by atomic14](https://github.com/atomic14/diy-esp32-epub-reader), which was a project I took a lot of inspiration from as I
+was making CrossPoint.

lib/EpdFont/EpdFont.cpp

@@ -2,12 +2,9 @@
 
 #include <Utf8.h>
 
-EpdFont::EpdFont(const EpdFontData* data) { this->data = data; }
-
 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 ? b : a; }
 
-// TODO: Text properties??
 void EpdFont::getTextBounds(const char* string, const int startX, const int startY, int* minX, int* minY, int* maxX,
                             int* maxY) const {
   *minX = startX;

lib/EpdFont/EpdFont.h

@@ -6,7 +6,7 @@ class EpdFont {
 
  public:
   const EpdFontData* data;
-  explicit EpdFont(const EpdFontData* data);
+  explicit EpdFont(const EpdFontData* data) : data(data) {}
   ~EpdFont() = default;
   void getTextDimensions(const char* string, int* w, int* h) const;
   bool hasPrintableChars(const char* string) const;

lib/EpdFont/EpdFontData.h

@@ -6,13 +6,13 @@
 
 /// Font data stored PER GLYPH
 typedef struct {
-  uint8_t width;            ///< Bitmap dimensions in pixels
-  uint8_t height;           ///< Bitmap dimensions in pixels
-  uint8_t advanceX;         ///< Distance to advance cursor (x axis)
-  int16_t left;             ///< X dist from cursor pos to UL corner
-  int16_t top;              ///< Y dist from cursor pos to UL corner
-  uint16_t compressedSize;  ///< Size of the zlib-compressed font data.
-  uint32_t dataOffset;      ///< Pointer into EpdFont->bitmap
+  uint8_t width;        ///< Bitmap dimensions in pixels
+  uint8_t height;       ///< Bitmap dimensions in pixels
+  uint8_t advanceX;     ///< Distance to advance cursor (x axis)
+  int16_t left;         ///< X dist from cursor pos to UL corner
+  int16_t top;          ///< Y dist from cursor pos to UL corner
+  uint16_t dataLength;  ///< Size of the font data.
+  uint32_t dataOffset;  ///< Pointer into EpdFont->bitmap
 } EpdGlyph;
 
 /// Glyph interval structure
@@ -28,8 +28,8 @@ typedef struct {
   const EpdGlyph* glyph;                ///< Glyph array
   const EpdUnicodeInterval* intervals;  ///< Valid unicode intervals for this font
   uint32_t intervalCount;               ///< Number of unicode intervals.
-  bool compressed;                      ///< Does this font use compressed glyph bitmaps?
   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/EpdFontFamily.cpp

@@ -0,0 +1,37 @@
+#include "EpdFontFamily.h"
+
+const EpdFont* EpdFontFamily::getFont(const EpdFontStyle style) const {
+  if (style == BOLD && bold) {
+    return bold;
+  }
+  if (style == ITALIC && italic) {
+    return italic;
+  }
+  if (style == BOLD_ITALIC) {
+    if (boldItalic) {
+      return boldItalic;
+    }
+    if (bold) {
+      return bold;
+    }
+    if (italic) {
+      return italic;
+    }
+  }
+
+  return regular;
+}
+
+void EpdFontFamily::getTextDimensions(const char* string, int* w, int* h, const EpdFontStyle style) const {
+  getFont(style)->getTextDimensions(string, w, h);
+}
+
+bool EpdFontFamily::hasPrintableChars(const char* string, const EpdFontStyle style) const {
+  return getFont(style)->hasPrintableChars(string);
+}
+
+const EpdFontData* EpdFontFamily::getData(const EpdFontStyle style) const { return getFont(style)->data; }
+
+const EpdGlyph* EpdFontFamily::getGlyph(const uint32_t cp, const EpdFontStyle style) const {
+  return getFont(style)->getGlyph(cp);
+};

lib/EpdFont/EpdFontFamily.h

@@ -0,0 +1,24 @@
+#pragma once
+#include "EpdFont.h"
+
+enum EpdFontStyle { REGULAR, BOLD, ITALIC, BOLD_ITALIC };
+
+class EpdFontFamily {
+  const EpdFont* regular;
+  const EpdFont* bold;
+  const EpdFont* italic;
+  const EpdFont* boldItalic;
+
+  const EpdFont* getFont(EpdFontStyle style) const;
+
+ public:
+  explicit EpdFontFamily(const EpdFont* regular, const EpdFont* bold = nullptr, const EpdFont* italic = nullptr,
+                         const EpdFont* boldItalic = nullptr)
+      : regular(regular), bold(bold), italic(italic), boldItalic(boldItalic) {}
+  ~EpdFontFamily() = default;
+  void getTextDimensions(const char* string, int* w, int* h, EpdFontStyle style = REGULAR) const;
+  bool hasPrintableChars(const char* string, EpdFontStyle style = REGULAR) const;
+
+  const EpdFontData* getData(EpdFontStyle style = REGULAR) const;
+  const EpdGlyph* getGlyph(uint32_t cp, EpdFontStyle style = REGULAR) const;
+};

lib/EpdFont/scripts/fontconvert.py

@@ -7,20 +7,20 @@ import math
 import argparse
 from collections import namedtuple
 
-# From: https://github.com/vroland/epdiy
+# Originally from https://github.com/vroland/epdiy
 
 parser = argparse.ArgumentParser(description="Generate a header file from a font to be used with epdiy.")
 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("--compress", dest="compress", action="store_true", help="compress glyph bitmaps.")
+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", "compressed_size", "data_offset", "code_point"])
+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]
-compress = args.compress
+is2Bit = args.is2Bit
 size = args.size
 font_name = args.name
 
@@ -148,19 +148,18 @@ for i_start, i_end in unvalidated_intervals:
         intervals.append((start, i_end))
 
 for face in font_stack:
-    # shift by 6 bytes, because sizes are given as 6-bit fractions
-    # the display has about 150 dpi.
     face.set_char_size(size << 6, size << 6, 150, 150)
 
 total_size = 0
-total_packed = 0
 all_glyphs = []
 
 for i_start, i_end in intervals:
     for code_point in range(i_start, i_end + 1):
         face = load_glyph(code_point)
         bitmap = face.glyph.bitmap
-        pixels = []
+
+        # Build out 4-bit greyscale bitmap
+        pixels4g = []
         px = 0
         for i, v in enumerate(bitmap.buffer):
             y = i / bitmap.width
@@ -169,31 +168,92 @@ for i_start, i_end in intervals:
                 px = (v >> 4)
             else:
                 px = px | (v & 0xF0)
-                pixels.append(px);
+                pixels4g.append(px);
                 px = 0
             # eol
             if x == bitmap.width - 1 and bitmap.width % 2 > 0:
-                pixels.append(px)
+                pixels4g.append(px)
                 px = 0
 
-        packed = bytes(pixels);
-        total_packed += len(packed)
-        compressed = packed
-        if compress:
-            compressed = zlib.compress(packed)
+        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
+            pitch = (bitmap.width // 2) + (bitmap.width % 2)
+            for y in range(bitmap.rows):
+                for x in range(bitmap.width):
+                    px = px << 1
+                    bm = pixels4g[y * pitch + (x // 2)]
+                    px += 1 if ((x & 1) == 0 and bm & 0xF > 0) or ((x & 1) == 1 and bm & 0xF0 > 0) else 0
+
+                    if (y * bitmap.width + x) % 8 == 7:
+                        pixelsbw.append(px)
+                        px = 0
+            if (bitmap.width * bitmap.rows) % 8 != 0:
+                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(pixels)
         glyph = GlyphProps(
             width = bitmap.width,
             height = bitmap.rows,
             advance_x = norm_floor(face.glyph.advance.x),
             left = face.glyph.bitmap_left,
             top = face.glyph.bitmap_top,
-            compressed_size = len(compressed),
+            data_length = len(packed),
             data_offset = total_size,
             code_point = code_point,
         )
-        total_size += len(compressed)
-        all_glyphs.append((glyph, compressed))
+        total_size += len(packed)
+        all_glyphs.append((glyph, packed))
 
 # pipe seems to be a good heuristic for the "real" descender
 face = load_glyph(ord('|'))
@@ -201,11 +261,11 @@ face = load_glyph(ord('|'))
 glyph_data = []
 glyph_props = []
 for index, glyph in enumerate(all_glyphs):
-    props, compressed = glyph
-    glyph_data.extend([b for b in compressed])
+    props, packed = glyph
+    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 * compressed: {compress}\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)}] = {{")
@@ -230,8 +290,8 @@ print(f"    {font_name}Bitmaps,")
 print(f"    {font_name}Glyphs,")
 print(f"    {font_name}Intervals,")
 print(f"    {len(intervals)},")
-print(f"    {1 if compress else 0},")
 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

@@ -1,132 +0,0 @@
-#pragma once
-#include <EpdFont.h>
-#include <HardwareSerial.h>
-#include <Utf8.h>
-#include <miniz.h>
-
-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; }
-
-static tinfl_decompressor decomp;
-
-template <typename Renderable>
-class EpdFontRenderer {
-  Renderable* renderer;
-  void renderChar(uint32_t cp, int* x, const int* y, uint16_t color);
-
- public:
-  const EpdFont* font;
-  explicit EpdFontRenderer(const EpdFont* font, Renderable* renderer);
-  ~EpdFontRenderer() = default;
-  void renderString(const char* string, int* x, int* y, uint16_t color);
-};
-
-inline int uncompress(uint8_t* dest, size_t uncompressedSize, const uint8_t* source, size_t sourceSize) {
-  if (uncompressedSize == 0 || dest == nullptr || sourceSize == 0 || source == nullptr) {
-    return -1;
-  }
-  tinfl_init(&decomp);
-
-  // we know everything will fit into the buffer.
-  const tinfl_status decomp_status =
-      tinfl_decompress(&decomp, source, &sourceSize, dest, dest, &uncompressedSize,
-                       TINFL_FLAG_PARSE_ZLIB_HEADER | TINFL_FLAG_USING_NON_WRAPPING_OUTPUT_BUF);
-  if (decomp_status != TINFL_STATUS_DONE) {
-    return decomp_status;
-  }
-  return 0;
-}
-
-template <typename Renderable>
-EpdFontRenderer<Renderable>::EpdFontRenderer(const EpdFont* font, Renderable* renderer) {
-  this->font = font;
-  this->renderer = renderer;
-}
-
-template <typename Renderable>
-void EpdFontRenderer<Renderable>::renderString(const char* string, int* x, int* y, const uint16_t color) {
-  // cannot draw a NULL / empty string
-  if (string == nullptr || *string == '\0') {
-    return;
-  }
-
-  // no printable characters
-  if (!font->hasPrintableChars(string)) {
-    return;
-  }
-
-  uint32_t cp;
-  while ((cp = utf8NextCodepoint(reinterpret_cast<const uint8_t**>(&string)))) {
-    renderChar(cp, x, y, color);
-  }
-
-  *y += font->data->advanceY;
-}
-
-template <typename Renderable>
-void EpdFontRenderer<Renderable>::renderChar(const uint32_t cp, int* x, const int* y, uint16_t color) {
-  const EpdGlyph* glyph = font->getGlyph(cp);
-  if (!glyph) {
-    // TODO: Replace with fallback glyph property?
-    glyph = font->getGlyph('?');
-  }
-
-  // no glyph?
-  if (!glyph) {
-    Serial.printf("No glyph for codepoint %d\n", cp);
-    return;
-  }
-
-  const uint32_t offset = glyph->dataOffset;
-  const uint8_t width = glyph->width;
-  const uint8_t height = glyph->height;
-  const int left = glyph->left;
-
-  const int byteWidth = width / 2 + width % 2;
-  const unsigned long bitmapSize = byteWidth * height;
-  const uint8_t* bitmap = nullptr;
-
-  if (font->data->compressed) {
-    auto* tmpBitmap = static_cast<uint8_t*>(malloc(bitmapSize));
-    if (tmpBitmap == nullptr && bitmapSize) {
-      // ESP_LOGE("font", "malloc failed.");
-      return;
-    }
-
-    uncompress(tmpBitmap, bitmapSize, &font->data->bitmap[offset], glyph->compressedSize);
-    bitmap = tmpBitmap;
-  } else {
-    bitmap = &font->data->bitmap[offset];
-  }
-
-  if (bitmap != nullptr) {
-    for (int localY = 0; localY < height; localY++) {
-      int yy = *y - glyph->top + localY;
-      const int startPos = *x + left;
-      bool byteComplete = startPos % 2;
-      int localX = max(0, -startPos);
-      const int maxX = startPos + width;
-
-      for (int xx = startPos; xx < maxX; xx++) {
-        uint8_t bm = bitmap[localY * byteWidth + localX / 2];
-        if ((localX & 1) == 0) {
-          bm = bm & 0xF;
-        } else {
-          bm = bm >> 4;
-        }
-
-        if (bm) {
-          renderer->drawPixel(xx, yy, color);
-        }
-        byteComplete = !byteComplete;
-        localX++;
-      }
-    }
-
-    if (font->data->compressed) {
-      free(const_cast<uint8_t*>(bitmap));
-    }
-  }
-
-  *x += glyph->advanceX;
-}