Method storeBwBuffer

lib/GfxRenderer/GfxRenderer.cpp:1813–1839

* This should be called before grayscale buffers are populated. * A `restoreBwBuffer` call should always follow the grayscale render if this method was called. * Uses chunked allocation to avoid needing 48KB of contiguous memory. * Returns true if buffer was stored successfully, false if allocation failed. */

 * Returns true if buffer was stored successfully, false if allocation failed.
 */
bool GfxRenderer::storeBwBuffer() {
  // Allocate and copy each chunk
  for (size_t i = 0; i < bwBufferChunks.size(); i++) {
    // Check if any chunks are already allocated
    if (bwBufferChunks[i]) {
      LOG_ERR("GFX", "!! BW buffer chunk %zu already stored - this is likely a bug, freeing chunk", i);
      free(bwBufferChunks[i]);
      bwBufferChunks[i] = nullptr;
    }

    const size_t offset = i * BW_BUFFER_CHUNK_SIZE;
    const size_t chunkSize = std::min(BW_BUFFER_CHUNK_SIZE, static_cast<size_t>(frameBufferSize - offset));
    bwBufferChunks[i] = static_cast<uint8_t*>(malloc(chunkSize));

    if (!bwBufferChunks[i]) {
      LOG_ERR("GFX", "!! Failed to allocate BW buffer chunk %zu (%zu bytes)", i, chunkSize);
      // Free previously allocated chunks
      freeBwBufferChunks();
      return false;
    }

    memcpy(bwBufferChunks[i], frameBuffer + offset, chunkSize);
  }

  LOG_DBG("GFX", "Stored BW buffer in %zu chunks (%zu bytes each)", bwBufferChunks.size(), BW_BUFFER_CHUNK_SIZE);
  return true;
}

/**
 * This can only be called if `storeBwBuffer` was called prior to the grayscale render.