+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+png_uint_32 PNGAPI
+png_get_unknown_chunks(png_structp png_ptr, png_infop info_ptr,
+ png_unknown_chunkpp unknowns)
+{
+ if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
+ {
+ *unknowns = info_ptr->unknown_chunks;
+ return ((png_uint_32)info_ptr->unknown_chunks_num);
+ }
+ return (0);
+}
+#endif
+
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+png_byte PNGAPI
+png_get_rgb_to_gray_status (png_structp png_ptr)
+{
+ return (png_byte)(png_ptr? png_ptr->rgb_to_gray_status : 0);
+}
+#endif
+
+#ifdef PNG_USER_CHUNKS_SUPPORTED
+png_voidp PNGAPI
+png_get_user_chunk_ptr(png_structp png_ptr)
+{
+ return (png_ptr? png_ptr->user_chunk_ptr : NULL);
+}
+#endif
+
+png_size_t PNGAPI
+png_get_compression_buffer_size(png_structp png_ptr)
+{
+ return (png_ptr ? png_ptr->zbuf_size : 0L);
+}
+
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+/* These functions were added to libpng 1.2.6 and were enabled
+ * by default in libpng-1.4.0 */
+png_uint_32 PNGAPI
+png_get_user_width_max (png_structp png_ptr)
+{
+ return (png_ptr? png_ptr->user_width_max : 0);
+}
+png_uint_32 PNGAPI
+png_get_user_height_max (png_structp png_ptr)
+{
+ return (png_ptr? png_ptr->user_height_max : 0);
+}
+/* This function was added to libpng 1.4.0 */
+png_uint_32 PNGAPI
+png_get_chunk_cache_max (png_structp png_ptr)
+{
+ return (png_ptr? png_ptr->user_chunk_cache_max : 0);
+}
+/* This function was added to libpng 1.4.1 */
+png_alloc_size_t PNGAPI
+png_get_chunk_malloc_max (png_structp png_ptr)
+{
+ return (png_ptr?
+ png_ptr->user_chunk_malloc_max : 0);
+}
+#endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
+
+/* These functions were added to libpng 1.4.0 */
+#ifdef PNG_IO_STATE_SUPPORTED
+png_uint_32 PNGAPI
+png_get_io_state (png_structp png_ptr)
+{
+ return png_ptr->io_state;
+}
+
+png_bytep PNGAPI
+png_get_io_chunk_name (png_structp png_ptr)
+{
+ return png_ptr->chunk_name;
+}
+#endif /* ?PNG_IO_STATE_SUPPORTED */
+
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */