Set custom metafile input-stream handler functions.
Parameters:
API
the API handle
fp_read
function to read a byte
fp_seek
function to set position
fp_tell
function to get position
user_data
handle for user data
libwmf has simple methods for reading either from file or from memory, but many applications will want to use customized variants of these. wmf_bbuf_input() enables this.
typedef int (*wmfRead) (void* user_data);
typedef int (*wmfSeek) (void* user_data,long position);
typedef long (*wmfTell) (void* user_data);
wmfRead returns unsigned char cast to int, or EOF (cf. fgetc())
wmfSeek returns (-1) on error, otherwise 0 (cf. fseek())
wmfTell returns (-1) on error, otherwise current position (cf. ftell())
Returns:
Returns the library error state (wmf_E_None on success). Possible library error state of wmf_E_Glitch, if any of the three functions is zero.