diff options
| -rw-r--r-- | pnmtilesplit/Makefile | 19 | ||||
| -rw-r--r-- | pnmtilesplit/pnmtilesplit.c | 250 |
2 files changed, 269 insertions, 0 deletions
diff --git a/pnmtilesplit/Makefile b/pnmtilesplit/Makefile new file mode 100644 index 000000000..be40c2642 --- /dev/null +++ b/pnmtilesplit/Makefile @@ -0,0 +1,19 @@ +# +# Makefile: +# Build pnmtilesplit. +# +# Copyright (c) 2006 UK Citizens Online Democracy. All rights reserved. +# Email: chris@mysociety.org; WWW: http://www.mysociety.org/ +# +# $Id: Makefile,v 1.1 2006-09-13 18:40:29 chris Exp $ +# + +CFLAGS = -Wall -g +LDFLAGS = +LDLIBS = -lnetpbm # is this a debianism? + +pnmtilesplit: pnmtilesplit.c + $(CC) $(CFLAGS) pnmtilesplit.c $(LDFLAGS) $(LDLIBS) -o pnmtilesplit + +clean: + rm -f pnmtilesplit *~ core diff --git a/pnmtilesplit/pnmtilesplit.c b/pnmtilesplit/pnmtilesplit.c new file mode 100644 index 000000000..f7820d31d --- /dev/null +++ b/pnmtilesplit/pnmtilesplit.c @@ -0,0 +1,250 @@ +/* + * pnmtilesplit.c: + * Split a single large PNM file into numerous smaller tiles. + * + * Copyright (c) 2005 UK Citizens Online Democracy. All rights reserved. + * Email: chris@mysociety.org; WWW: http://www.mysociety.org/ + * + */ + +static const char rcsid[] = "$Id: pnmtilesplit.c,v 1.1 2006-09-13 18:40:29 chris Exp $"; + +#include <sys/types.h> + +#include <errno.h> +#include <fcntl.h> +#include <pam.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <sys/wait.h> + +#define err(...) do { fprintf(stderr, "pnmtilesplit: "); fprintf(stderr, __VA_ARGS__); fprintf(stderr, "\n"); } while (0) +#define die(...) do { err(__VA_ARGS__); exit(1); } while (0) + +/* open_output_file FORMAT PIPE I J [PID] + * Open a new output file, constructing it from FORMAT and the column- and + * row-index values I and J. If PIPE is non-NULL, open the file via a pipe + * through the shell. Returns a stdio file handle on success or abort on + * failure. If PIPE is non-NULL then the process ID of the child process is + * saved in *PID. */ +FILE *open_output_file(const char *fmt, const char *pipe_via, + const int i, const int j, pid_t *child_pid) { + FILE *fp; + char *filename; + filename = malloc(strlen(fmt) + 64); + sprintf(filename, fmt, i, j); + /* XXX consider creating directories if they don't already exist? */ + if (pipe_via) { + pid_t p; + int fd, pp[2]; + if (-1 == (fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0644))) + die("%s: open: %s", filename, strerror(errno)); + else if (-1 == pipe(pp)) + die("pipe: %s", strerror(errno)); + else if (!(fp = fdopen(pp[1], "w"))) + die("fdopen: %s", strerror(errno)); + + if (-1 == (p = fork())) + die("fork: %s", strerror(errno)); + else if (0 == p) { + /* run the pipe command via /bin/sh */ + char *argv[4] = {"/bin/sh", "-c", 0}; + close(0); + close(1); + close(pp[1]); + dup(pp[0]); /* standard input */ + close(pp[0]); + dup(fd); /* standard output */ + close(fd); + argv[2] = (char*)pipe_via; + execve("/bin/sh", argv, NULL); + err("%s: %s", pipe_via, strerror(errno)); + _exit(1); + } else if (child_pid) + *child_pid = p; + } else if (!(fp = fopen(filename, "w"))) + die("%s: open: %s", filename, strerror(errno)); + + free(filename); + + return fp; +} + +/* usage STREAM + * Write a usage message to STREAM. */ +void usage(FILE *fp) { + fprintf(fp, +"pnmtilesplit - split a PNM file into fixed-size tiles\n" +"\n" +"Usage: pnmtilesplit -h | [OPTIONS] WIDTH HEIGHT [INPUT]\n" +"\n" +"Split the INPUT image, or, if it is not specified, the image on standard\n" +"input, into WIDTH-by-HEIGHT pixel tiles. If WIDTH or HEIGHT do not divide\n" +"the dimensions of the input image exactly, a warning will be printed and\n" +"the pixels at the extreme right and bottom of the input image will be\n" +"discarded.\n" +"\n" +"Options:\n" +"\n" +" -h Display this help message on standard output\n" +"\n" +" -f FORMAT Use the printf-style FORMAT for the name of the output file,\n" +" instead of \"%%d,%%d.pnm\".\n" +"\n" +" -p COMMAND Don't write files directly, but pipe them via COMMAND. The\n" +" COMMAND is interpreted by the shell.\n" +"\n" +"Copyright (c) 2006 UK Citizens Online Democracy. All rights reserved.\n" +"Email: chris@mysociety.org; WWW: http://www.mysociety.org/\n" +"%s\n", + rcsid); +} + +/* main ARGC ARGV + * Entry point. */ +int main(int argc, char *argv[]) { + int tile_w, tile_h, cols, rows; + char *img_name; + FILE *img_fp, **tile_fp; + struct pam img_pam, *tile_pam; + pid_t *tile_pid; + char *outfile_format = "%d,%d.pnm", *pipe_via = NULL; + extern int opterr, optopt, optind; + static const char optstr[] = "hf:p:"; + int i, j, c; + tuple *img_row, *tile_row = NULL; + + pnm_init(&argc, argv); + opterr = 0; + + while (-1 != (c = getopt(argc, argv, optstr))) { + switch (c) { + case 'h': + usage(stdout); + return 0; + + case 'f': + outfile_format = optarg; + break; + + case 'p': + pipe_via = optarg; + break; + + case '?': + default: + if (strchr(optstr, optopt)) + err("option -%c requires an argument", optopt); + else + err("unknown option -%c", optopt); + die("try -h for help"); + } + } + + if (argc - optind < 2 || argc - optind > 3) { + err("two or three non-option arguments required"); + die("try -h for help"); + } + + if (0 == (tile_w = atoi(argv[optind]))) + die("\"%s\" is not a valid tile width", argv[optind]); + else if (0 == (tile_h = atoi(argv[optind + 1]))) + die("\"%s\" is not a valid tile height", argv[optind + 1]); + + if (argv[optind + 2]) { + img_name = argv[optind + 2]; + if (!(img_fp = fopen(img_name, "rb"))) { + die("%s: %s", img_name, strerror(errno)); + return 1; + } + } else { + img_name = "(standard input)"; + img_fp = stdin; + } + + /* lamely, this will just abort if something goes wrong */ + pnm_readpaminit(img_fp, &img_pam, sizeof img_pam); + + /* couple of checks on the image dimensions */ + if (tile_w > img_pam.width) + die("image width (%d) is smaller than tile width (%d)", + img_pam.width, tile_w); + else if (img_pam.width % tile_w) { + err("warning: tile width does not divide image width exactly"); + err("last %d columns of image will not be included in any tile", + img_pam.width % tile_w); + } + cols = img_pam.width / tile_w; + + if (tile_h > img_pam.height) + die("image height (%d) is smaller than tile height (%d)", + img_pam.height, tile_h); + else if (img_pam.height % tile_h) { + err("warning: tile height does not divide image height exactly"); + err("warning: last %d rows of image will not be included in any tile", + img_pam.height % tile_h); + } + rows = img_pam.height / tile_h; + + tile_fp = malloc(cols * sizeof *tile_fp); + tile_pam = malloc(cols * sizeof *tile_pam); + tile_pid = malloc(cols * sizeof *tile_pid); + + if (!(img_row = pnm_allocpamrow(&img_pam))) + die("unable to allocate storage for input row"); + + for (j = 0; j < rows; ++j) { + int y; + + /* Create output files. */ + for (i = 0; i < cols; ++i) { + tile_pam[i] = img_pam; + tile_pam[i].file = tile_fp[i] + = open_output_file(outfile_format, pipe_via, i, j, + tile_pid + i); + tile_pam[i].width = tile_w; + tile_pam[i].height = tile_h; + pnm_writepaminit(tile_pam + i); + + if (!tile_row && !(tile_row = pnm_allocpamrow(tile_pam + i))) + die("unable to allocate storage for output row"); + } + + /* Copy the image into the various tiles. */ + for (y = 0; y < tile_h; ++y) { + int x; + pnm_readpamrow(&img_pam, img_row); + for (i = 0; i < cols; ++i) { + for (x = 0; x < tile_w; ++x) + tile_row[x] = img_row[x + i * tile_w]; + pnm_writepamrow(tile_pam + i, tile_row); + fflush(tile_fp[i]); + } + } + + /* Close the output files and check status. */ + for (i = 0; i < cols; ++i) { + if (-1 == fclose(tile_fp[i])) + die("while writing tile (%d, %d): %s", i, j, strerror(errno)); + if (pipe_via) { + /* Collect exit status of child process. */ + pid_t p; + int st; + if (-1 == (p = waitpid(tile_pid[i], &st, 0))) + die("waitpid: %s", strerror(errno)); + else if (st) { + if (WIFEXITED(st)) + die("child process for tile (%d, %d) failed with " + "status %d", i, j, WEXITSTATUS(st)); + else + die("child process for tile (%d, %d) killed by " + "signal %d", i, j, WTERMSIG(st)); + } + } + } + } + return 0; +} |