On Thu, 3 Feb 2000, Andreas Beck wrote:
> > +struct file_type_op_t file_type[] =
> > +{
> > + { "ppm", _ggi_file_detect_ppm, NULL, _ggi_file_ppm_write },
> > + { "bmp", _ggi_file_detect_bmp, _ggi_file_bmp_read, NULL },
> > + { NULL, NULL, NULL, NULL }
> > +};
>
> Hmm - I'd like it better, if it would read only P?M and use ppmtools to
> convert any other format as required.
I want to have reading some different file-formats and not only one.
That's why I hack the file-target.
>
> > +/* Read primitives */
> > +
> > +void _ggi_file_read_byte(ggi_visual *vis, int *val)
> > +{
> > + FileHook *ff = FILE_PRIV(vis);
> > +
> > +#if 0
> > + if (ff->buf_len > 0) {
> > + (uint8) val = ff->buffer[ff->buf_len++];
> > + return;
> > + }
> > +
> > + if ((ff->buf_len = read(LIBGGI_FD(vis), ff->buffer, FILE_BUFFER_SIZE) < 0) {
> > + perror("display-file: read error");
> > + }
> > +
> > + if (ff->buf_len < FILE_BUFFER_SIZE) {
> > + /* FIXME: eof is reached */
> > + }
> > +#else
> > +
> > + if ((ff->buf_len = read(LIBGGI_FD(vis), ff->buffer, 1)) < 0) {
> > + perror("display-file: read error");
> > + }
> > +
> > + if (ff->buf_len == 0) {
> > + /* FIXME: eof is reached */
> > + }
> > +
> > + (uint8)(*val) = (uint8)(ff->buffer[0]);
> > +#endif
> > +}
>
> Why don't you just use a file-stream and leave buffering to the libc ?
You mean, I should use FILE * from the libc?
>
> > +void _ggi_file_read_word(ggi_visual *vis, int *val)
> > +{
> > +#ifdef GGI_LITTLE_ENDIAN
> > + _ggi_file_read_byte(vis, (int*)(val) );
> > + _ggi_file_read_byte(vis, (int*)(val+1) );
> > +#else
> > + _ggi_file_read_byte(vis, (int*)(val+1) );
> > + _ggi_file_read_byte(vis, (int*)(val) );
> > +#endif
> > +}
>
> Uh - please don't do this. There is sick stuff like PDP byte ordering and
> the code you have here doesn't do what you want (reading two bytes into
> a single int - right ?) anyway.
>
> A better way would be to use something like
>
> int sum=0
> char byte;
> read_byte(...,&byte);sum =byte;
> read_byte(...,&byte);sum|=byte<<8;
Maybe, when I use the FILE * from the libc, that then bug is fixed.
>
> This is not only independent of host byte ordering, it will also work.
>
> > + for (; strlen > 0; strlen--) {
> More elegant: while(strlen--);
TNX for that tip.
>
> > + _ggi_file_read_byte(vis, (int*)(str));
> This typecast is very ugly BTW. Moreover you will have to increase str, and
> it will only work, if the host is little endian.
>
> > +/* FIXME: compiler fails on using this with: "sizeof applied to an incomplete
>type" */
> > +#define NUM_FILE_TYPES (sizeof(file_type) / sizeof(struct file_type_op_t))
>
> You need to have a complete prototype for file_type_op_t included before you
> can use sizeof.
I see. But maybe is file_type, not file_type_op_t, no?
Christoph Egger
E-Mail: [EMAIL PROTECTED]
