diff options
Diffstat (limited to 'editor/specialty/ppmshift.c')
| -rw-r--r-- | editor/specialty/ppmshift.c | 125 |
1 files changed, 67 insertions, 58 deletions
diff --git a/editor/specialty/ppmshift.c b/editor/specialty/ppmshift.c index cdb0f173..37ed3785 100644 --- a/editor/specialty/ppmshift.c +++ b/editor/specialty/ppmshift.c @@ -1,4 +1,3 @@ - /*********************************************************************/ /* ppmshift - shift lines of a picture left or right by x pixels */ /* Frank Neumann, October 1993 */ @@ -12,11 +11,11 @@ #include <stdbool.h> #include "mallocvar.h" +#include "rand.h" #include "shhopt.h" #include "ppm.h" - struct CmdlineInfo { /* All the information the user supplied in the command line, in a form easy for the program to use. @@ -24,6 +23,7 @@ struct CmdlineInfo { const char * inputFileName; unsigned int shift; + unsigned int seedSpec; unsigned int seed; }; @@ -42,8 +42,6 @@ parseCommandLine(int argc, const char ** const argv, unsigned int option_def_index; - unsigned int seedSpec; - MALLOCARRAY(option_def, 100); opt.opt_table = option_def; @@ -52,14 +50,11 @@ parseCommandLine(int argc, const char ** const argv, option_def_index = 0; /* incremented by OPTENT3 */ OPTENT3(0, "seed", OPT_UINT, &cmdlineP->seed, - &seedSpec, 0); + &cmdlineP->seedSpec, 0); pm_optParseOptions3(&argc, (char **)argv, opt, sizeof(opt), 0); /* Uses and sets argc, argv, and some of *cmdlineP and others. */ - if (!seedSpec) - cmdlineP->seed = pm_randseed(); - if (argc-1 < 1) pm_error("You must specify the shift factor as an argument"); else { @@ -84,6 +79,62 @@ parseCommandLine(int argc, const char ** const argv, +static void +shiftRow(pixel * const srcrow, + unsigned int const cols, + unsigned int const shift, + pixel * const destrow, + struct pm_randSt * const randStP) { + + /* the range by which a line is shifted lays in the range from */ + /* -shift/2 .. +shift/2 pixels; however, within this range it is */ + /* randomly chosen */ + + pixel * pP; + pixel * pP2; + int nowshift; + + if (shift != 0) + nowshift = (pm_rand(randStP) % (shift+1)) - ((shift+1) / 2); + else + nowshift = 0; + + pP = &srcrow[0]; + pP2 = &destrow[0]; + + /* if the shift value is less than zero, we take the original + pixel line and copy it into the destination line translated + to the left by x pixels. The empty pixels on the right end + of the destination line are filled up with the pixel that + is the right-most in the original pixel line. + */ + if (nowshift < 0) { + unsigned int col; + pP += abs(nowshift); + for (col = 0; col < cols; ++col) { + PPM_ASSIGN(*pP2, PPM_GETR(*pP), PPM_GETG(*pP), PPM_GETB(*pP)); + ++pP2; + if (col < (cols + nowshift) - 1) + ++pP; + } + } else { + unsigned int col; + /* The shift value is 0 or positive, so fill the first + <nowshift> pixels of the destination line with the + first pixel from the source line, and copy the rest of + the source line to the dest line + */ + for (col = 0; col < cols; ++col) { + PPM_ASSIGN(*pP2, PPM_GETR(*pP), PPM_GETG(*pP), PPM_GETB(*pP)); + ++pP2; + if (col >= nowshift) + ++pP; + } + } +} + + + int main(int argc, const char ** argv) { @@ -95,13 +146,15 @@ main(int argc, const char ** argv) { pixel * destrow; unsigned int row; unsigned int shift; + struct pm_randSt randSt; /* parse in 'default' parameters */ pm_proginit(&argc, argv); parseCommandLine(argc, argv, &cmdline); - srand(cmdline.seed); + pm_randinit(&randSt); + pm_srand2(&randSt, cmdline.seedSpec, cmdline.seed); ifP = pm_openr(cmdline.inputFileName); @@ -115,67 +168,23 @@ main(int argc, const char ** argv) { } else shift = cmdline.shift; - srcrow = ppm_allocrow(cols); - + srcrow = ppm_allocrow(cols); destrow = ppm_allocrow(cols); ppm_writeppminit(stdout, cols, rows, maxval, 0); - /** now do the shifting **/ - /* the range by which a line is shifted lays in the range from */ - /* -shift/2 .. +shift/2 pixels; however, within this range it is */ - /* randomly chosen */ for (row = 0; row < rows; ++row) { - pixel * pP; - pixel * pP2; - unsigned int nowshift; - - if (shift != 0) - nowshift = (rand() % (shift+1)) - ((shift+1) / 2); - else - nowshift = 0; - ppm_readppmrow(ifP, srcrow, cols, maxval, format); - pP = &srcrow[0]; - pP2 = &destrow[0]; - - /* if the shift value is less than zero, we take the original - pixel line and copy it into the destination line translated - to the left by x pixels. The empty pixels on the right end - of the destination line are filled up with the pixel that - is the right-most in the original pixel line. - */ - if (nowshift < 0) { - unsigned int col; - pP += abs(nowshift); - for (col = 0; col < cols; ++col) { - PPM_ASSIGN(*pP2, PPM_GETR(*pP), PPM_GETG(*pP), PPM_GETB(*pP)); - ++pP2; - if (col < (cols + nowshift) - 1) - ++pP; - } - } else { - unsigned int col; - /* The shift value is 0 or positive, so fill the first - <nowshift> pixels of the destination line with the - first pixel from the source line, and copy the rest of - the source line to the dest line - */ - for (col = 0; col < cols; ++col) { - PPM_ASSIGN(*pP2, PPM_GETR(*pP), PPM_GETG(*pP), PPM_GETB(*pP)); - ++pP2; - if (col >= nowshift) - ++pP; - } - } + shiftRow(srcrow, cols, shift, destrow, &randSt); ppm_writeppmrow(stdout, destrow, cols, maxval, 0); } - pm_close(ifP); - ppm_freerow(srcrow); ppm_freerow(destrow); + ppm_freerow(srcrow); + pm_close(ifP); + pm_randterm(&randSt); return 0; } |