diff options
Diffstat (limited to 'lib/libpgm1.c')
| -rw-r--r-- | lib/libpgm1.c | 33 |
1 files changed, 18 insertions, 15 deletions
diff --git a/lib/libpgm1.c b/lib/libpgm1.c index 6feb1c8b..0656e1e0 100644 --- a/lib/libpgm1.c +++ b/lib/libpgm1.c @@ -65,7 +65,7 @@ pgm_nextimage(FILE * const file, void -pgm_readpgminitrest(FILE * const fileP, +pgm_readpgminitrest(FILE * const ifP, int * const colsP, int * const rowsP, gray * const maxvalP) { @@ -73,14 +73,13 @@ pgm_readpgminitrest(FILE * const fileP, gray maxval; /* Read size. */ - *colsP = (int)pm_getuint(fileP); - *rowsP = (int)pm_getuint(fileP); + pbm_readpbminitrest(ifP, colsP, rowsP); /* Read maxval. */ - maxval = pm_getuint(fileP); + maxval = pm_getuint(ifP); if (maxval > PGM_OVERALLMAXVAL) pm_error("maxval of input image (%u) is too large. " - "The maximum allowed by PGM is %u.", + "The maximum allowed by the format is %u.", maxval, PGM_OVERALLMAXVAL); if (maxval == 0) pm_error("maxval of input image is zero."); @@ -90,9 +89,9 @@ pgm_readpgminitrest(FILE * const fileP, -static void -validateComputableSize(unsigned int const cols, - unsigned int const rows) { +void +pgm_validateComputableSize(unsigned int const cols, + unsigned int const rows) { /*---------------------------------------------------------------------------- Validate that the dimensions of the image are such that it can be processed in typical ways on this machine without worrying about @@ -115,8 +114,8 @@ validateComputableSize(unsigned int const cols, -static void -validateComputableMaxval(gray const maxval) { +void +pgm_validateComputableMaxval(gray const maxval) { /*---------------------------------------------------------------------------- This is similar to validateComputableSize, but for the maxval. -----------------------------------------------------------------------------*/ @@ -126,10 +125,14 @@ validateComputableMaxval(gray const maxval) { Code also sometimes iterates through sample values and quits when the value is greater than the maxval. - */ - if (maxval == 0) - pm_error("Maxval is zero. Must be at least one."); + Code often divides by the maxval, but we don't have to check for maxval + == 0 as a computability problem because that is not a valid maxval. + + Note that in the PNM Plain formats, there is no upper limit for a + maxval, though the 'gray' type does constrain what has been passed to + us. + */ if (maxval > INT_MAX-1) pm_error("Maxval (%u) is too large to be processed", maxval); @@ -193,9 +196,9 @@ pgm_readpgminit(FILE * const fileP, pm_error("bad magic number 0x%x - not a PPM, PGM, PBM, or PAM file", realFormat); } - validateComputableSize(*colsP, *rowsP); + pgm_validateComputableSize(*colsP, *rowsP); - validateComputableMaxval(*maxvalP); + pgm_validateComputableMaxval(*maxvalP); } |