fix: Add framebuffer release/realloc and improved lazy indexing (#2563)

lib/PngToBmpConverter/PngToBmpConverter.cpp

@@ -2,7 +2,7 @@
 
 #include <HalDisplay.h>
 #include <HalStorage.h>
-#include <InflateReader.h>
+#include <InflateStream.h>
 #include <Logging.h>
 
 #include <cstdio>
@@ -174,9 +174,8 @@ void writeBmpHeader2bit(Print& bmpOut, const int width, const int height) {
 }  // namespace
 
 // Context for streaming PNG decompression
-// IMPORTANT: reader must be the first field - the uzlib callback casts uzlib_uncomp* to PngDecodeContext*
 struct PngDecodeContext {
-  InflateReader reader;  // Must be first — callback casts uzlib_uncomp* to PngDecodeContext*
+  InflateStream reader;
   HalFile* file;
 
   // PNG image properties
@@ -195,7 +194,7 @@ struct PngDecodeContext {
   uint32_t chunkBytesRemaining;  // bytes left in current IDAT chunk
   bool idatFinished;             // no more IDAT chunks
 
-  // File read buffer for feeding uzlib
+  // File read buffer for feeding the inflate stream
   uint8_t readBuf[2048];
 
   // Palette for indexed color (type 3)
@@ -229,21 +228,21 @@ static bool findNextIdatChunk(PngDecodeContext& ctx) {
   }
 }
 
-// uzlib callback: reads the next batch of IDAT data from the file
-static int pngIdatReadCallback(uzlib_uncomp* uncomp) {
-  auto* ctx = reinterpret_cast<PngDecodeContext*>(uncomp);
+// Fill callback: reads the next batch of IDAT data from the file
+static size_t pngIdatFillCallback(void* vctx, const uint8_t** data) {
+  auto* ctx = static_cast<PngDecodeContext*>(vctx);
 
-  if (ctx->idatFinished) return -1;
+  if (ctx->idatFinished) return 0;
 
   // Skip 4-byte CRC and find next IDAT chunk when current chunk is exhausted
   while (ctx->chunkBytesRemaining == 0) {
     if (!ctx->file->seekCur(4)) {  // skip 4-byte CRC of previous IDAT
       ctx->idatFinished = true;
-      return -1;
+      return 0;
     }
     if (!findNextIdatChunk(*ctx)) {
       ctx->idatFinished = true;
-      return -1;
+      return 0;
     }
   }
 
@@ -251,18 +250,15 @@ static int pngIdatReadCallback(uzlib_uncomp* uncomp) {
   size_t toRead = sizeof(ctx->readBuf);
   if (toRead > ctx->chunkBytesRemaining) toRead = ctx->chunkBytesRemaining;
 
-  int bytesRead = ctx->file->read(ctx->readBuf, toRead);
+  const int bytesRead = ctx->file->read(ctx->readBuf, toRead);
   if (bytesRead <= 0) {
     ctx->idatFinished = true;
-    return -1;
+    return 0;
   }
 
   ctx->chunkBytesRemaining -= bytesRead;
-
-  // Give uzlib the buffer (skip first byte since we return it directly)
-  uncomp->source = ctx->readBuf + 1;
-  uncomp->source_limit = ctx->readBuf + bytesRead;
-  return ctx->readBuf[0];
+  *data = ctx->readBuf;
+  return static_cast<size_t>(bytesRead);
 }
 
 // Decode one scanline: decompress filter byte + raw bytes, then unfilter
@@ -555,16 +551,16 @@ bool PngToBmpConverter::pngFileToBmpStreamInternal(HalFile& pngFile, Print& bmpO
     return false;
   }
 
-  // Initialize streaming decompressor with 32KB ring buffer for back-reference history
+  // Initialize streaming decompressor with 32KB window for back-reference history
   if (!ctx.reader.init(true)) {
-    LOG_ERR("PNG", "Failed to init inflate reader");
+    LOG_ERR("PNG", "Failed to init inflate stream");
     free(ctx.currentRow);
     free(ctx.previousRow);
     return false;
   }
-  ctx.reader.setReadCallback(pngIdatReadCallback);
-  // PNG IDAT data is zlib-wrapped: consume the 2-byte zlib header (CMF + FLG)
-  ctx.reader.skipZlibHeader();
+  ctx.reader.setFill(pngIdatFillCallback, &ctx);
+  // PNG IDAT data is zlib-wrapped (2-byte header + trailing adler32)
+  ctx.reader.setZlibWrapped();
 
   // Calculate output dimensions (same logic as JpegToBmpConverter)
   int outWidth = width;