diff options
Diffstat (limited to 'editor/pamhue.c')
| -rw-r--r-- | editor/pamhue.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/editor/pamhue.c b/editor/pamhue.c new file mode 100644 index 00000000..7dddedd8 --- /dev/null +++ b/editor/pamhue.c @@ -0,0 +1,209 @@ +/*============================================================================= + pamhue +=============================================================================== + Change the hue, the Hue-Saturation-Value model, every pixel in an image + by a specified angle. +=============================================================================*/ +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <math.h> +#include "mallocvar.h" +#include "shhopt.h" +#include "pam.h" + + + +struct CmdlineInfo { + /* All the information the user supplied in the command line, + in a form easy for the program to use. + */ + const char * inputFileName; /* '-' if stdin */ + float huechange; +}; + + + +static void +parseCommandLine(int argc, + const char ** argv, + struct CmdlineInfo * const cmdlineP ) { +/*---------------------------------------------------------------------------- + Parse program command line described in Unix standard form by argc + and argv. Return the information in the options as *cmdlineP. + + If command line is internally inconsistent (invalid options, etc.), + issue error message to stderr and abort program. + + Note that the strings we return are stored in the storage that + was passed to us as the argv array. We also trash *argv. +-----------------------------------------------------------------------------*/ + optEntry * option_def; + /* Instructions to pm_optParseOptions3 on how to parse our options. + */ + optStruct3 opt; + + unsigned int option_def_index; + + unsigned int huechangeSpec; + + MALLOCARRAY_NOFAIL(option_def, 100); + + option_def_index = 0; /* incremented by OPTENT3 */ + OPTENT3(0, "huechange", OPT_FLOAT, + &cmdlineP->huechange, &huechangeSpec, 0); + + opt.opt_table = option_def; + opt.short_allowed = false; /* We have no short (old-fashioned) options */ + opt.allowNegNum = false; /* No negative arguments */ + + pm_optParseOptions3(&argc, (char **)argv, opt, sizeof(opt), 0); + /* Uses and sets argc, argv, and some of *cmdlineP and others. */ + + if (!huechangeSpec) + pm_error("You must specify -huechange"); + + if (argc-1 < 1) + cmdlineP->inputFileName = "-"; + else if (argc-1 == 1) + cmdlineP->inputFileName = argv[1]; + else + pm_error("Program takes at most one argument: file specification"); +} + + + +static float +positiveMod(float const arg, + float const modulus) { +/*---------------------------------------------------------------------------- + 'arg' mod 'modulus', but positive (i.e. in the range 0.0 - 'modulus'). +-----------------------------------------------------------------------------*/ + float const mod = fmodf(arg, modulus); + + return mod >= 0.0 ? mod : 360 + mod; +} + + + +static void +changeHue(tuple const tupleval, + float const huechange, + sample const maxval) { + + pixel oldRgb, newRgb; + struct hsv oldHsv, newHsv; + + PPM_PUTR(oldRgb, tupleval[PAM_RED_PLANE]); + PPM_PUTG(oldRgb, tupleval[PAM_GRN_PLANE]); + PPM_PUTB(oldRgb, tupleval[PAM_BLU_PLANE]); + + oldHsv = ppm_hsv_from_color(oldRgb, maxval); + + newHsv.h = positiveMod(oldHsv.h + huechange, 360.0); + newHsv.s = oldHsv.s; + newHsv.v = oldHsv.v; + + newRgb = ppm_color_from_hsv(newHsv, maxval); + + tupleval[PAM_RED_PLANE] = PPM_GETR(newRgb); + tupleval[PAM_GRN_PLANE] = PPM_GETG(newRgb); + tupleval[PAM_BLU_PLANE] = PPM_GETB(newRgb); +} + + + +static void +convertRow(tuple * const tuplerow, + float const huechange, + const struct pam * const pamP) { + + unsigned int col; + + for (col = 0; col < pamP->width; ++col) { + if ((pamP->format == PPM_FORMAT) || (pamP->format == RPPM_FORMAT) || + ((pamP->format == PAM_FORMAT) && (pamP->depth >= 3))) { + /* It's a color image, so there is a hue to change */ + + changeHue(tuplerow[col], huechange, pamP->maxval); + } else { + /* It's black and white or grayscale, which means fully + desaturated, so hue is meaningless. Nothing to change. + */ + } + } +} + + + +static void +pamhue(struct CmdlineInfo const cmdline, + FILE * const ifP, + FILE * const ofP) { + + struct pam inpam, outpam; + tuple * tuplerow; + unsigned int row; + + pnm_readpaminit(ifP, &inpam, PAM_STRUCT_SIZE(tuple_type)); + + outpam = inpam; + outpam.file = ofP; + + pnm_writepaminit(&outpam); + + tuplerow = pnm_allocpamrow(&inpam); + + for (row = 0; row < inpam.height; ++row) { + pnm_readpamrow(&inpam, tuplerow); + + convertRow(tuplerow, cmdline.huechange, &inpam); + + pnm_writepamrow(&outpam, tuplerow); + } + + pnm_freepamrow(tuplerow); +} + + + +int +main(int argc, const char *argv[]) { + + struct CmdlineInfo cmdline; + FILE * ifP; + + pm_proginit(&argc, argv); + + parseCommandLine(argc, argv, &cmdline); + + ifP = pm_openr(cmdline.inputFileName); + + pamhue(cmdline, ifP, stdout); + + pm_close(ifP); + pm_close(stdout); + + return 0; +} + + + +/* This was derived by Bryan Henderson from code by Willem van Schaik + (willem@schaik.com), which was derived from Ppmbrighten code written by Jef + Poskanzer and Brian Moffet. + + Copyright (C) 1989 by Jef Poskanzer. + Copyright (C) 1990 by Brian Moffet. + Copyright (C) 2019 by Willem van Schaik (willem@schaik.com) + + 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. + + Bryan contributes his work to the public domain. +*/ |