diff options
Diffstat (limited to 'lib/libpm.c')
| -rw-r--r-- | lib/libpm.c | 55 |
1 files changed, 52 insertions, 3 deletions
diff --git a/lib/libpm.c b/lib/libpm.c index 6f9dea3d..4dd19b70 100644 --- a/lib/libpm.c +++ b/lib/libpm.c @@ -442,12 +442,20 @@ pm_maxvaltobits(int const maxval) { assert(false); } + + int -pm_bitstomaxval(int const bits) { - return ( 1 << bits ) - 1; +pm_bitstomaxval(int const bitCt) { + + if (bitCt > 16) + pm_error("Bits per sample %u too large. 16 is maximum acceptable", + bitCt); + + return (1 << bitCt) - 1; } + unsigned int PURE_FN_ATTR pm_lcm(unsigned int const x, unsigned int const y, @@ -698,7 +706,16 @@ pm_proginit(int * const argcP, find. We remove the common options from argv[], updating *argcP accordingly. - This includes calling pm_init() to initialize the Netpbm libraries. + This includes calling 'pm_init' to initialize the Netpbm libraries. + + argv[] is intended to be the program's POSIX arguments (as passed to the + program's main function). But note that POSIX arguments are modifiable and + as such, the conventional way to declare them in a program is with "char + **", as opposed to pm_proginit's "const char **". To avoid a compiler + warning, the program has to use the unconventional "const char **" type in + the declaration of its main function. (Alternatively, it can just cast it + to const char ** later). 'pm_proginit' does not modify any argument + strings. -----------------------------------------------------------------------------*/ const char * const progname = pm_arg0toprogname(argv[0]); /* points to static memory in this library */ @@ -844,6 +861,14 @@ pm_parse_width(const char * const arg) { Return the image width represented by the decimal ASCIIZ string 'arg'. Fail if it doesn't validly represent a width or represents a width that can't be conveniently used in computation. + + See comments at 'validateComputableSize' in libpam.c for details on + the purpose of these validations. + + This isn't just for Netpbm format images. + + Typical places from which widths come: headers of non-Netpbm images; + command line options. -----------------------------------------------------------------------------*/ unsigned int width; const char * error; @@ -890,3 +915,27 @@ pm_parse_height(const char * const arg) { +unsigned int +pm_parse_maxval(const char * const arg) { +/*---------------------------------------------------------------------------- + Same as pm_parse_width(), but for maxval. +-----------------------------------------------------------------------------*/ + unsigned int maxval; + const char * error; + + pm_string_to_uint(arg, &maxval, &error); + + if (error) { + pm_error("'%s' is invalid as a maxval. %s", arg, error); + pm_strfree(error); + } else { + if (maxval > INT_MAX-1) + pm_error("Maxval %u is too large for computations.", maxval); + if (maxval == 0) + pm_error("Maxval argument must be a positive number. You " + "specified 0."); + } + return maxval; +} + + |