- libpng if standard C streams aren't being used.
-
- This function takes as its arguments:
- png_ptr - pointer to a png output data structure
- io_ptr - pointer to user supplied structure containing info about
- the output functions. May be NULL.
- write_data_fn - pointer to a new output function that takes as its
- arguments a pointer to a png_struct, a pointer to
- data to be written, and a 32-bit unsigned int that is
- the number of bytes to be written. The new write
- function should call png_error(png_ptr, "Error msg")
- to exit and output any fatal error messages.
- flush_data_fn - pointer to a new flush function that takes as its
- arguments a pointer to a png_struct. After a call to
- the flush function, there should be no data in any buffers
- or pending transmission. If the output method doesn't do
- any buffering of ouput, a function prototype must still be
- supplied although it doesn't have to do anything. If
- PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
- time, output_flush_fn will be ignored, although it must be
- supplied for compatibility. */
+ * libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ * png_ptr - pointer to a png output data structure
+ * io_ptr - pointer to user supplied structure containing info about
+ * the output functions. May be NULL.
+ * write_data_fn - pointer to a new output function that takes as its
+ * arguments a pointer to a png_struct, a pointer to
+ * data to be written, and a 32-bit unsigned int that is
+ * the number of bytes to be written. The new write
+ * function should call png_error(png_ptr, "Error msg")
+ * to exit and output any fatal error messages. May be
+ * NULL, in which case libpng's default function will
+ * be used.
+ * flush_data_fn - pointer to a new flush function that takes as its
+ * arguments a pointer to a png_struct. After a call to
+ * the flush function, there should be no data in any buffers
+ * or pending transmission. If the output method doesn't do
+ * any buffering of output, a function prototype must still be
+ * supplied although it doesn't have to do anything. If
+ * PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
+ * time, output_flush_fn will be ignored, although it must be
+ * supplied for compatibility. May be NULL, in which case
+ * libpng's default function will be used, if
+ * PNG_WRITE_FLUSH_SUPPORTED is defined. This is not
+ * a good idea if io_ptr does not point to a standard
+ * *FILE structure.
+ */