add support for images

.envrc

@@ -0,0 +1 @@
+use nix

flake.nix

@@ -0,0 +1,32 @@
+{
+  description = "CrossPoint Reader - ESP32 E-Paper Firmware";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          buildInputs = with pkgs; [
+            platformio
+            python3
+            git
+          ];
+
+          shellHook = ''
+            echo "CrossPoint Reader development environment"
+            echo "Commands:"
+            echo "  pio run           - Build firmware"
+            echo "  pio run -t upload - Build and flash to device"
+            echo "  pio run -t clean  - Clean build artifacts"
+          '';
+        };
+      }
+    );
+}

lib/Epub/Epub/Page.cpp

@@ -1,6 +1,9 @@
 #include "Page.h"
 
+#include <Bitmap.h>
+#include <GfxRenderer.h>
 #include <HardwareSerial.h>
+#include <SDCardManager.h>
 #include <Serialization.h>
 
 void PageLine::render(GfxRenderer& renderer, const int fontId, const int xOffset, const int yOffset) {
@@ -25,6 +28,50 @@ std::unique_ptr<PageLine> PageLine::deserialize(FsFile& file) {
   return std::unique_ptr<PageLine>(new PageLine(std::move(tb), xPos, yPos));
 }
 
+void PageImage::render(GfxRenderer& renderer, const int fontId, const int xOffset, const int yOffset) {
+  FsFile imageFile;
+  if (!SdMan.openFileForRead("PGI", cachePath, imageFile)) {
+    Serial.printf("[%lu] [PGI] Failed to open image: %s\n", millis(), cachePath.c_str());
+    return;
+  }
+
+  Bitmap bitmap(imageFile);
+  if (bitmap.parseHeaders() != BmpReaderError::Ok) {
+    Serial.printf("[%lu] [PGI] Failed to parse image headers: %s\n", millis(), cachePath.c_str());
+    imageFile.close();
+    return;
+  }
+
+  // Draw the bitmap at the specified position
+  renderer.drawBitmap(bitmap, xPos + xOffset, yPos + yOffset, width, height);
+  imageFile.close();
+}
+
+bool PageImage::serialize(FsFile& file) {
+  serialization::writePod(file, xPos);
+  serialization::writePod(file, yPos);
+  serialization::writePod(file, width);
+  serialization::writePod(file, height);
+  serialization::writeString(file, cachePath);
+  return true;
+}
+
+std::unique_ptr<PageImage> PageImage::deserialize(FsFile& file) {
+  int16_t xPos;
+  int16_t yPos;
+  int width;
+  int height;
+  std::string cachePath;
+
+  serialization::readPod(file, xPos);
+  serialization::readPod(file, yPos);
+  serialization::readPod(file, width);
+  serialization::readPod(file, height);
+  serialization::readString(file, cachePath);
+
+  return std::unique_ptr<PageImage>(new PageImage(std::move(cachePath), width, height, xPos, yPos));
+}
+
 void Page::render(GfxRenderer& renderer, const int fontId, const int xOffset, const int yOffset) const {
   for (auto& element : elements) {
     element->render(renderer, fontId, xOffset, yOffset);
@@ -36,8 +83,9 @@ bool Page::serialize(FsFile& file) const {
   serialization::writePod(file, count);
 
   for (const auto& el : elements) {
-    // Only PageLine exists currently
-    serialization::writePod(file, static_cast<uint8_t>(TAG_PageLine));
+    // Write element tag
+    serialization::writePod(file, static_cast<uint8_t>(el->getTag()));
+
     if (!el->serialize(file)) {
       return false;
     }
@@ -59,6 +107,9 @@ std::unique_ptr<Page> Page::deserialize(FsFile& file) {
     if (tag == TAG_PageLine) {
       auto pl = PageLine::deserialize(file);
       page->elements.push_back(std::move(pl));
+    } else if (tag == TAG_PageImage) {
+      auto pi = PageImage::deserialize(file);
+      page->elements.push_back(std::move(pi));
     } else {
       Serial.printf("[%lu] [PGE] Deserialization failed: Unknown tag %u\n", millis(), tag);
       return nullptr;

lib/Epub/Epub/Page.h

@@ -8,6 +8,7 @@
 
 enum PageElementTag : uint8_t {
   TAG_PageLine = 1,
+  TAG_PageImage = 2,
 };
 
 // represents something that has been added to a page
@@ -19,6 +20,7 @@ class PageElement {
   virtual ~PageElement() = default;
   virtual void render(GfxRenderer& renderer, int fontId, int xOffset, int yOffset) = 0;
   virtual bool serialize(FsFile& file) = 0;
+  virtual PageElementTag getTag() const = 0;
 };
 
 // a line from a block element
@@ -30,9 +32,27 @@ class PageLine final : public PageElement {
       : PageElement(xPos, yPos), block(std::move(block)) {}
   void render(GfxRenderer& renderer, int fontId, int xOffset, int yOffset) override;
   bool serialize(FsFile& file) override;
+  PageElementTag getTag() const override { return TAG_PageLine; }
   static std::unique_ptr<PageLine> deserialize(FsFile& file);
 };
 
+// an image element
+class PageImage final : public PageElement {
+  std::string cachePath;
+  int width;
+  int height;
+
+ public:
+  PageImage(std::string path, int w, int h, const int16_t xPos, const int16_t yPos)
+      : PageElement(xPos, yPos), cachePath(std::move(path)), width(w), height(h) {}
+  void render(GfxRenderer& renderer, int fontId, int xOffset, int yOffset) override;
+  bool serialize(FsFile& file) override;
+  PageElementTag getTag() const override { return TAG_PageImage; }
+  static std::unique_ptr<PageImage> deserialize(FsFile& file);
+  int getWidth() const { return width; }
+  int getHeight() const { return height; }
+};
+
 class Page {
  public:
   // the list of block index and line numbers on this page

lib/Epub/Epub/Section.cpp

@@ -7,7 +7,7 @@
 #include "parsers/ChapterHtmlSlimParser.h"
 
 namespace {
-constexpr uint8_t SECTION_FILE_VERSION = 7;
+constexpr uint8_t SECTION_FILE_VERSION = 8;  // Incremented for image support
 constexpr uint32_t HEADER_SIZE = sizeof(uint8_t) + sizeof(int) + sizeof(float) + sizeof(bool) + sizeof(int) +
                                  sizeof(int) + sizeof(int) + sizeof(uint32_t);
 }  // namespace
@@ -169,8 +169,8 @@ bool Section::createSectionFile(const int fontId, const float lineCompression, c
   std::vector<uint32_t> lut = {};
 
   ChapterHtmlSlimParser visitor(
-      tmpHtmlPath, renderer, fontId, lineCompression, extraParagraphSpacing, viewportWidth, viewportHeight,
-      [this, &lut](std::unique_ptr<Page> page) { lut.emplace_back(this->onPageComplete(std::move(page))); },
+      tmpHtmlPath, renderer, epub.get(), spineIndex, fontId, lineCompression, extraParagraphSpacing, viewportWidth,
+      viewportHeight, [this, &lut](std::unique_ptr<Page> page) { lut.emplace_back(this->onPageComplete(std::move(page))); },
       progressFn);
   success = visitor.parseAndBuildPages();
 

lib/Epub/Epub/blocks/ImageBlock.cpp

@@ -0,0 +1,25 @@
+#include "ImageBlock.h"
+
+#include <GfxRenderer.h>
+
+void ImageBlock::layout(GfxRenderer& renderer) {
+  // ImageBlock doesn't need layout - dimensions are already known
+}
+
+void ImageBlock::getScaledDimensions(const int viewportWidth, const int viewportHeight, int* outWidth,
+                                     int* outHeight) const {
+  if (width <= viewportWidth && height <= viewportHeight) {
+    // Image fits, no scaling needed
+    *outWidth = width;
+    *outHeight = height;
+    return;
+  }
+
+  // Calculate scale factor to fit within viewport
+  float scaleX = static_cast<float>(viewportWidth) / static_cast<float>(width);
+  float scaleY = static_cast<float>(viewportHeight) / static_cast<float>(height);
+  float scale = (scaleX < scaleY) ? scaleX : scaleY;
+
+  *outWidth = static_cast<int>(static_cast<float>(width) * scale);
+  *outHeight = static_cast<int>(static_cast<float>(height) * scale);
+}

lib/Epub/Epub/blocks/ImageBlock.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <string>
+
+#include "Block.h"
+
+class GfxRenderer;
+
+// Represents an image block in the HTML document
+class ImageBlock final : public Block {
+ public:
+  std::string cachePath;  // Path to cached BMP file
+  int width;
+  int height;
+  bool isCached;
+
+  ImageBlock() : width(0), height(0), isCached(false) {}
+  ImageBlock(std::string path, int w, int h)
+      : cachePath(std::move(path)), width(w), height(h), isCached(true) {}
+
+  void layout(GfxRenderer& renderer) override;
+  BlockType getType() override { return IMAGE_BLOCK; }
+  bool isEmpty() override { return cachePath.empty() || !isCached; }
+  void finish() override {}
+
+  // Get scaled dimensions that fit within viewport
+  void getScaledDimensions(int viewportWidth, int viewportHeight, int* outWidth, int* outHeight) const;
+};

lib/Epub/Epub/parsers/ChapterHtmlSlimParser.cpp

@@ -1,11 +1,15 @@
 #include "ChapterHtmlSlimParser.h"
 
+#include <Bitmap.h>
+#include <Epub.h>
 #include <GfxRenderer.h>
 #include <HardwareSerial.h>
+#include <JpegToBmpConverter.h>
 #include <SDCardManager.h>
 #include <expat.h>
 
 #include "../Page.h"
+#include "../blocks/ImageBlock.h"
 #include "../htmlEntities.h"
 
 const char* HEADER_TAGS[] = {"h1", "h2", "h3", "h4", "h5", "h6"};
@@ -65,7 +69,22 @@ void XMLCALL ChapterHtmlSlimParser::startElement(void* userData, const XML_Char*
   }
 
   if (matches(name, IMAGE_TAGS, NUM_IMAGE_TAGS)) {
-    // TODO: Start processing image tags
+    // Process image tag - extract src attribute
+    const char* src = nullptr;
+    if (atts != nullptr) {
+      for (int i = 0; atts[i]; i += 2) {
+        if (strcmp(atts[i], "src") == 0) {
+          src = atts[i + 1];
+          break;
+        }
+      }
+    }
+
+    if (src && self->epub) {
+      self->processImage(src);
+    }
+
+    // Skip content inside image tag
     self->skipUntilDepth = self->depth;
     self->depth += 1;
     return;
@@ -330,3 +349,190 @@ void ChapterHtmlSlimParser::makePages() {
     currentPageNextY += lineHeight / 2;
   }
 }
+
+std::string ChapterHtmlSlimParser::resolveImagePath(const char* src) const {
+  if (!src || !epub) {
+    return "";
+  }
+
+  std::string srcPath(src);
+
+  // If the path is absolute (starts with /), it's relative to the EPUB root
+  if (srcPath[0] == '/') {
+    return srcPath.substr(1);  // Remove leading slash
+  }
+
+  // Otherwise, resolve relative to the current chapter's directory
+  std::string basePath = epub->getBasePath();
+
+  // Simple path resolution - combine basePath with src
+  if (basePath.empty()) {
+    return srcPath;
+  }
+
+  // Ensure basePath ends with /
+  if (basePath.back() != '/') {
+    basePath += '/';
+  }
+
+  return basePath + srcPath;
+}
+
+void ChapterHtmlSlimParser::processImage(const char* src) {
+  if (!src || !epub) {
+    Serial.printf("[%lu] [IMG] Invalid image source or epub pointer\n", millis());
+    return;
+  }
+
+  // Flush any pending text before adding image
+  if (currentTextBlock && !currentTextBlock->isEmpty()) {
+    makePages();
+    currentTextBlock.reset(new ParsedText(TextBlock::JUSTIFIED, extraParagraphSpacing));
+  }
+
+  // Resolve the image path relative to the EPUB structure
+  std::string imagePath = resolveImagePath(src);
+  if (imagePath.empty()) {
+    Serial.printf("[%lu] [IMG] Failed to resolve image path: %s\n", millis(), src);
+    return;
+  }
+
+  // Generate cache path for this image
+  std::string cachePath = epub->getCachePath() + "/sections/" + std::to_string(spineIndex) + "_img_" +
+                          std::to_string(imageCounter++) + ".bmp";
+
+  // Check if image is already cached
+  if (!SdMan.exists(cachePath.c_str())) {
+    // Determine file extension
+    bool isJpeg = false;
+    bool isBmp = false;
+    size_t dotPos = imagePath.rfind('.');
+    if (dotPos != std::string::npos) {
+      std::string ext = imagePath.substr(dotPos);
+      isJpeg = (ext == ".jpg" || ext == ".jpeg" || ext == ".JPG" || ext == ".JPEG");
+      isBmp = (ext == ".bmp" || ext == ".BMP");
+    }
+
+    if (isJpeg) {
+      // Extract JPEG and convert to BMP
+      std::string tempJpgPath = epub->getCachePath() + "/.temp_img.jpg";
+
+      FsFile tempJpg;
+      if (!SdMan.openFileForWrite("IMG", tempJpgPath.c_str(), tempJpg)) {
+        Serial.printf("[%lu] [IMG] Failed to create temp JPEG file\n", millis());
+        return;
+      }
+
+      if (!epub->readItemContentsToStream(imagePath, tempJpg, 1024)) {
+        Serial.printf("[%lu] [IMG] Failed to extract JPEG: %s\n", millis(), imagePath.c_str());
+        tempJpg.close();
+        SdMan.remove(tempJpgPath.c_str());
+        return;
+      }
+      tempJpg.close();
+
+      // Convert JPEG to BMP
+      if (!SdMan.openFileForRead("IMG", tempJpgPath.c_str(), tempJpg)) {
+        Serial.printf("[%lu] [IMG] Failed to reopen temp JPEG\n", millis());
+        SdMan.remove(tempJpgPath.c_str());
+        return;
+      }
+
+      FsFile bmpFile;
+      if (!SdMan.openFileForWrite("IMG", cachePath.c_str(), bmpFile)) {
+        Serial.printf("[%lu] [IMG] Failed to create BMP file\n", millis());
+        tempJpg.close();
+        SdMan.remove(tempJpgPath.c_str());
+        return;
+      }
+
+      bool success = JpegToBmpConverter::jpegFileToBmpStream(tempJpg, bmpFile);
+      tempJpg.close();
+      bmpFile.close();
+      SdMan.remove(tempJpgPath.c_str());
+
+      if (!success) {
+        Serial.printf("[%lu] [IMG] Failed to convert JPEG to BMP: %s\n", millis(), imagePath.c_str());
+        SdMan.remove(cachePath.c_str());
+        return;
+      }
+    } else if (isBmp) {
+      // Extract BMP directly
+      FsFile bmpFile;
+      if (!SdMan.openFileForWrite("IMG", cachePath.c_str(), bmpFile)) {
+        Serial.printf("[%lu] [IMG] Failed to create BMP file\n", millis());
+        return;
+      }
+
+      if (!epub->readItemContentsToStream(imagePath, bmpFile, 1024)) {
+        Serial.printf("[%lu] [IMG] Failed to extract BMP: %s\n", millis(), imagePath.c_str());
+        bmpFile.close();
+        SdMan.remove(cachePath.c_str());
+        return;
+      }
+      bmpFile.close();
+    } else {
+      // Unsupported format
+      Serial.printf("[%lu] [IMG] Unsupported image format (not JPEG or BMP): %s\n", millis(), imagePath.c_str());
+      return;
+    }
+  }
+
+  // Read image dimensions
+  FsFile imageFile;
+  if (!SdMan.openFileForRead("IMG", cachePath.c_str(), imageFile)) {
+    Serial.printf("[%lu] [IMG] Failed to open cached image: %s\n", millis(), cachePath.c_str());
+    return;
+  }
+
+  Bitmap bitmap(imageFile);
+  BmpReaderError err = bitmap.parseHeaders();
+  if (err != BmpReaderError::Ok) {
+    Serial.printf("[%lu] [IMG] Failed to parse BMP headers: %s\n", millis(), Bitmap::errorToString(err));
+    imageFile.close();
+    return;
+  }
+
+  int width = bitmap.getWidth();
+  int height = bitmap.getHeight();
+  imageFile.close();
+
+  // Add image to page
+  addImageToPage(cachePath, width, height);
+
+  Serial.printf("[%lu] [IMG] Successfully processed image: %s (%dx%d)\n", millis(), imagePath.c_str(), width, height);
+}
+
+void ChapterHtmlSlimParser::addImageToPage(const std::string& cachePath, int width, int height) {
+  // Calculate scaled dimensions to fit viewport
+  ImageBlock imageBlock(cachePath, width, height);
+  int scaledWidth, scaledHeight;
+  imageBlock.getScaledDimensions(viewportWidth, viewportHeight, &scaledWidth, &scaledHeight);
+
+  // Check if image fits on current page
+  if (currentPageNextY + scaledHeight > viewportHeight && currentPageNextY > 0) {
+    // Start new page for image
+    if (currentPage && !currentPage->elements.empty()) {
+      completePageFn(std::move(currentPage));
+    }
+    currentPage.reset(new Page());
+    currentPageNextY = 0;
+  }
+
+  if (!currentPage) {
+    currentPage.reset(new Page());
+    currentPageNextY = 0;
+  }
+
+  // Center image horizontally
+  int xPos = (viewportWidth - scaledWidth) / 2;
+  if (xPos < 0) xPos = 0;
+
+  // Add image to page
+  currentPage->elements.push_back(std::make_shared<PageImage>(cachePath, scaledWidth, scaledHeight, xPos, currentPageNextY));
+  currentPageNextY += scaledHeight;
+
+  // Add some spacing after image
+  const int lineHeight = renderer.getLineHeight(fontId) * lineCompression;
+  currentPageNextY += lineHeight;
+}

lib/Epub/Epub/parsers/ChapterHtmlSlimParser.h

@@ -11,12 +11,16 @@
 
 class Page;
 class GfxRenderer;
+class Epub;
 
 #define MAX_WORD_SIZE 200
 
 class ChapterHtmlSlimParser {
   const std::string& filepath;
   GfxRenderer& renderer;
+  Epub* epub;  // Pointer to epub for image extraction
+  int spineIndex;
+  int imageCounter = 0;  // Counter for naming cached images
   std::function<void(std::unique_ptr<Page>)> completePageFn;
   std::function<void(int)> progressFn;  // Progress callback (0-100)
   int depth = 0;
@@ -38,19 +42,24 @@ class ChapterHtmlSlimParser {
 
   void startNewTextBlock(TextBlock::BLOCK_STYLE style);
   void makePages();
+  void processImage(const char* src);
+  void addImageToPage(const std::string& cachePath, int width, int height);
+  std::string resolveImagePath(const char* src) const;
   // XML callbacks
   static void XMLCALL startElement(void* userData, const XML_Char* name, const XML_Char** atts);
   static void XMLCALL characterData(void* userData, const XML_Char* s, int len);
   static void XMLCALL endElement(void* userData, const XML_Char* name);
 
  public:
-  explicit ChapterHtmlSlimParser(const std::string& filepath, GfxRenderer& renderer, const int fontId,
-                                 const float lineCompression, const bool extraParagraphSpacing, const int viewportWidth,
-                                 const int viewportHeight,
+  explicit ChapterHtmlSlimParser(const std::string& filepath, GfxRenderer& renderer, Epub* epub, const int spineIndex,
+                                 const int fontId, const float lineCompression, const bool extraParagraphSpacing,
+                                 const int viewportWidth, const int viewportHeight,
                                  const std::function<void(std::unique_ptr<Page>)>& completePageFn,
                                  const std::function<void(int)>& progressFn = nullptr)
       : filepath(filepath),
         renderer(renderer),
+        epub(epub),
+        spineIndex(spineIndex),
         fontId(fontId),
         lineCompression(lineCompression),
         extraParagraphSpacing(extraParagraphSpacing),

shell.nix

@@ -0,0 +1,15 @@
+{ pkgs ? import <nixpkgs> {} }:
+
+pkgs.mkShell {
+  buildInputs = with pkgs; [
+    platformio
+    python3
+    git
+  ];
+
+  shellHook = ''
+    echo "PlatformIO development environment loaded"
+    echo "Run 'pio run' to build the firmware"
+    echo "Run 'pio run -t upload' to build and flash"
+  '';
+}