Method getGlyphBitmap

lib/GfxRenderer/GfxRenderer.cpp:29–55

}  // namespace

const uint8_t* GfxRenderer::getGlyphBitmap(const EpdFontData* fontData, const EpdGlyph* glyph) const {
  if (fontData->groups != nullptr) {
    auto* fd = fontCacheManager_ ? fontCacheManager_->getDecompressor() : nullptr;
    if (!fd) {
      LOG_ERR("GFX", "Compressed font but no FontDecompressor set");
      return nullptr;
    }
    uint32_t glyphIndex = static_cast<uint32_t>(glyph - fontData->glyph);
    // For page-buffer hits the pointer is stable for the page lifetime.
    // For hot-group hits it is valid only until the next getBitmap() call — callers
    // must consume it (draw the glyph) before requesting another bitmap.
    return fd->getBitmap(fontData, glyph, glyphIndex);
  }
  // For SD card fonts, check if the glyph was loaded on demand into the overflow
  // buffer.  getOverflowBitmap() returns:
  //   - bitmap pointer for overflow glyphs with bitmap data
  //   - nullptr for overflow glyphs without bitmap data (e.g. space: width=0, height=0)
  //   - nullptr for non-overflow glyphs (normal prewarmed path)
  // We distinguish overflow-with-no-bitmap from non-overflow by checking isOverflowGlyph().
  if (fontData->glyphMissCtx) {
    auto* sdFont = SdCardFont::fromMissCtx(fontData->glyphMissCtx);
    if (sdFont->isOverflowGlyph(glyph)) {
      return sdFont->getOverflowBitmap(glyph);  // may be nullptr for zero-width glyphs
    }
  }
  return &fontData->bitmap[glyph->dataOffset];
}

void GfxRenderer::ensureSdCardFontReady(int fontId, const char* utf8Text, uint8_t styleMask) const {
  auto it = sdCardFonts_.find(fontId);