/* libpnm1.c - pnm utility library part 1 ** ** Copyright (C) 1989 by Jef Poskanzer. ** ** Permission to use, copy, modify, and distribute this software and its ** documentation for any purpose and without fee is hereby granted, provided ** that the above copyright notice appear in all copies and that both that ** copyright notice and this permission notice appear in supporting ** documentation. This software is provided "as is" without express or ** implied warranty. */ #include #include #include "netpbm/mallocvar.h" #include "pnm.h" #include "ppm.h" #include "libppm.h" #include "pgm.h" #include "libpgm.h" #include "pbm.h" #include "libpbm.h" #include "pam.h" #include "libpam.h" xel * pnm_allocrow(unsigned int const cols) { xel * xelrow; MALLOCARRAY(xelrow, cols); if (xelrow == NULL) pm_error("Unable to allocate space for a %u-column xel row", cols); return xelrow; } void pnm_init(int * const argcP, char ** const argv) { ppm_init( argcP, argv ); } void pnm_nextimage(FILE * const file, int * const eofP) { pm_nextimage(file, eofP); } static void 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 overflows. Note that in C, arithmetic is always modulus arithmetic, so if your values are too big, the result is not what you expect. That failed expectation can be disastrous if you use it to allocate memory. It is very normal to allocate space for a pixel row, so we make sure the size of a pixel row, in bytes, can be represented by an 'int'. A common operation is adding 1 or 2 to the highest row or column number in the image, so we make sure that's possible. -----------------------------------------------------------------------------*/ if (cols > INT_MAX/(sizeof(pixval) * 3) || cols > INT_MAX - 2) pm_error("image width (%u) too large to be processed", cols); if (rows > INT_MAX - 2) pm_error("image height (%u) too large to be processed", rows); } static void validateComputableMaxval(pixval const maxval) { /*---------------------------------------------------------------------------- This is similar to validateComputableSize, but for the maxval. -----------------------------------------------------------------------------*/ /* Code sometimes allocates an array indexed by sample values and represents the size of that array as an INT. (UNSIGNED INT would be more proper, but there's no need to be that permissive). 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."); if (maxval > INT_MAX-1) pm_error("Maxval (%u) is too large to be processed", maxval); } void pnm_readpnminit(FILE * const fileP, int * const colsP, int * const rowsP, xelval * const maxvalP, int * const formatP) { int realFormat; /* Check magic number. */ realFormat = pm_readmagicnumber(fileP); switch (PAM_FORMAT_TYPE(realFormat)) { case PPM_TYPE: { pixval maxval; *formatP = realFormat; ppm_readppminitrest(fileP, colsP, rowsP, &maxval); *maxvalP = maxval; } break; case PGM_TYPE: { gray maxval; *formatP = realFormat; pgm_readpgminitrest(fileP, colsP, rowsP, &maxval); *maxvalP = maxval; } break; case PBM_TYPE: *formatP = realFormat; pbm_readpbminitrest(fileP, colsP, rowsP); *maxvalP = 1; break; case PAM_TYPE: { gray maxval; pnm_readpaminitrestaspnm(fileP, colsP, rowsP, &maxval, formatP); *maxvalP = maxval; } break; default: pm_error("bad magic number 0x%x - not a PPM, PGM, PBM, or PAM file", realFormat); } validateComputableSize(*colsP, *rowsP); validateComputableMaxval(*maxvalP); } static void readpgmrow(FILE * const fileP, xel * const xelrow, int const cols, xelval const maxval, int const format) { jmp_buf jmpbuf; jmp_buf * origJmpbufP; gray * grayrow; grayrow = pgm_allocrow(cols); if (setjmp(jmpbuf) != 0) { pgm_freerow(grayrow); pm_setjmpbuf(origJmpbufP); pm_longjmp(); } else { unsigned int col; pm_setjmpbufsave(&jmpbuf, &origJmpbufP); pgm_readpgmrow(fileP, grayrow, cols, (gray) maxval, format); for (col = 0; col < cols; ++col) PNM_ASSIGN1(xelrow[col], grayrow[col]); pm_setjmpbuf(origJmpbufP); } pgm_freerow(grayrow); } static void readpbmrow(FILE * const fileP, xel * const xelrow, int const cols, xelval const maxval, int const format) { jmp_buf jmpbuf; jmp_buf * origJmpbufP; bit * bitrow; bitrow = pbm_allocrow_packed(cols); if (setjmp(jmpbuf) != 0) { pbm_freerow_packed(bitrow); pm_setjmpbuf(origJmpbufP); pm_longjmp(); } else { unsigned int col; pm_setjmpbufsave(&jmpbuf, &origJmpbufP); pbm_readpbmrow_packed(fileP, bitrow, cols, format); for (col = 0; col < cols; ++col) { pixval const g = ((bitrow[col/8] >> (7 - col%8)) & 0x1) == PBM_WHITE ? maxval : 0; PNM_ASSIGN1(xelrow[col], g); } pm_setjmpbuf(origJmpbufP); } pbm_freerow(bitrow); } void pnm_readpnmrow(FILE * const fileP, xel * const xelrow, int const cols, xelval const maxval, int const format) { switch (PNM_FORMAT_TYPE(format)) { case PPM_TYPE: ppm_readppmrow(fileP, (pixel*) xelrow, cols, (pixval) maxval, format); break; case PGM_TYPE: readpgmrow(fileP, xelrow, cols, maxval, format); break; case PBM_TYPE: readpbmrow(fileP, xelrow, cols, maxval, format); break; default: pm_error("INTERNAL ERROR. Impossible format."); } } xel ** pnm_readpnm(FILE * const fileP, int * const colsP, int * const rowsP, xelval * const maxvalP, int * const formatP) { jmp_buf jmpbuf; jmp_buf * origJmpbufP; int cols, rows; xelval maxval; int format; xel ** xels; pnm_readpnminit(fileP, &cols, &rows, &maxval, &format); xels = pnm_allocarray(cols, rows); if (setjmp(jmpbuf) != 0) { pnm_freearray(xels, rows); pm_setjmpbuf(origJmpbufP); pm_longjmp(); } else { unsigned int row; pm_setjmpbufsave(&jmpbuf, &origJmpbufP); for (row = 0; row < rows; ++row) pnm_readpnmrow(fileP, xels[row], cols, maxval, format); pm_setjmpbuf(origJmpbufP); } *colsP = cols; *rowsP = rows; *maxvalP = maxval; *formatP = format; return xels; } void pnm_check(FILE * const fileP, enum pm_check_type const check_type, int const format, int const cols, int const rows, int const maxval, enum pm_check_code * const retvalP) { switch (PNM_FORMAT_TYPE(format)) { case PBM_TYPE: pbm_check(fileP, check_type, format, cols, rows, retvalP); break; case PGM_TYPE: pgm_check(fileP, check_type, format, cols, rows, maxval, retvalP); break; case PPM_TYPE: ppm_check(fileP, check_type, format, cols, rows, maxval, retvalP); break; default: pm_error("pnm_check() called with invalid format parameter"); } }