Split out option handling into its own file.

4 files changed, 373 insertions, 338 deletions

diff --git a/Makefile b/Makefile
index 5a9f5dd..ae18799 100644
--- a/Makefile
+++ b/Makefile
@@ -10,14 +10,14 @@
 #####################################################################
 
 CC ?= gcc
-CFLAGS ?= -std=c99 -pipe -g -O3 -flto -Werror -Wall -Wpedantic -Wextra -Wno-sign-compare -Wno-unused-parameter -Wunreachable-code -Wshadow -Wpointer-arith -Wwrite-strings -Wcast-align -Wstrict-prototypes
+CFLAGS ?= -std=c99 -D_POSIX_C_SOURCE=200809L -pipe -g -O3 -flto -Werror -Wall -Wpedantic -Wextra -Wno-sign-compare -Wno-unused-parameter -Wunreachable-code -Wshadow -Wpointer-arith -Wwrite-strings -Wcast-align -Wstrict-prototypes
 LDFLAGS ?= -Wl,-O1,--sort-common,--as-needed,-z,relro
 LIBS ?= -lm -lpng
 RM ?= rm -f
 
-HEADERS = color.h kd-forest.h util.h
+HEADERS = color.h kd-forest.h options.h util.h
 
-kd-forest: color.o kd-forest.o main.o util.o
+kd-forest: color.o kd-forest.o main.o options.o util.o
 	$(CC) $(CFLAGS) $(LDFLAGS) $^ $(LIBS) -o kd-forest
 
 %.o: %.c $(HEADERS)
diff --git a/main.c b/main.c
index a385e3d..eaa7f01 100644
--- a/main.c
+++ b/main.c
@@ -9,52 +9,22 @@
  * the COPYING file or http://www.wtfpl.net/ for more details.       *
  *********************************************************************/
 
-#define _POSIX_C_SOURCE 200809L
-
+#include "color.h"
 #include "kd-forest.h"
+#include "options.h"
 #include "util.h"
-#include "color.h"
-#include <errno.h>
 #include <math.h>
 #include <png.h>
 #include <setjmp.h>
 #include <stdarg.h>
-#include <stdio.h>
 #include <stdbool.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <ctype.h>
 #if __unix__
 #  include <unistd.h>
 #endif
 
-// Possible generation modes
-typedef enum {
-  MODE_HUE_SORT,
-  MODE_RANDOM,
-} mode_t;
-
-// Possible color spaces
-typedef enum {
-  COLOR_SPACE_RGB,
-  COLOR_SPACE_LAB,
-  COLOR_SPACE_LUV,
-} color_space_t;
-
-// Command-line options
-typedef struct {
-  unsigned int bit_depth;
-  mode_t mode;
-  color_space_t color_space;
-  bool animate;
-  const char *filename;
-  unsigned int seed;
-  bool help;
-} options_t;
-
-static bool parse_options(options_t *options, int argc, char *argv[]);
-static void print_usage(FILE *file, const char *command);
-
 // All-encompasing state struct
 typedef struct {
   const options_t *options;
@@ -92,308 +62,6 @@ main(int argc, char *argv[])
   return EXIT_SUCCESS;
 }
 
-static bool
-parse_arg(int argc, char *argv[],
-          const char *short_form, const char *long_form,
-          const char **value, int *i, bool *error)
-{
-  size_t short_len = strlen(short_form);
-  size_t long_len = strlen(long_form);
-
-  const char *actual_form;
-  const char *arg = argv[*i];
-  const char *candidate = NULL;
-
-  if (strncmp(arg, short_form, short_len) == 0) {
-    actual_form = short_form;
-    if (strlen(arg) > short_len) {
-      candidate = arg + short_len;
-    }
-  } else if (strncmp(arg, long_form, long_len) == 0) {
-    actual_form = long_form;
-    if (strlen(arg) > long_len) {
-      if (arg[long_len] == '=') {
-        candidate = arg + long_len + 1;
-      } else {
-        return false;
-      }
-    }
-  } else {
-    return false;
-  }
-
-  if (value) {
-    if (candidate) {
-      *value = candidate;
-    } else if (*i < argc - 1) {
-      ++*i;
-      *value = argv[*i];
-    } else {
-      fprintf(stderr, "Expected a value for %s\n", arg);
-      *error = true;
-      return false;
-    }
-  } else if (candidate) {
-    fprintf(stderr, "Unexpected value for %s: `%s'\n",
-            actual_form, candidate);
-    *error = true;
-    return false;
-  }
-
-  return true;
-}
-
-static bool
-str_to_uint(const char *str, unsigned int *value)
-{
-  char *endptr;
-  long result = strtol(str, &endptr, 10);
-  if (*str == '\0' || *endptr != '\0') {
-    return false;
-  }
-  if (result < 0 || result > UINT_MAX) {
-    return false;
-  }
-
-  *value = result;
-  return true;
-}
-
-static void
-strcatinc(char **destp, const char *src)
-{
-  strcpy(*destp, src);
-  *destp += strlen(src);
-}
-
-typedef enum {
-  COLORIZE_NORMAL,
-  COLORIZE_AT,
-  COLORIZE_BANG,
-  COLORIZE_STAR,
-  COLORIZE_SHORT_OPTION,
-  COLORIZE_LONG_OPTION,
-} colorize_state_t;
-
-static void
-print_colorized(FILE *file, bool tty, const char *format, ...)
-{
-  const char *bold = tty ? "\033[1m" : "";
-  const char *red = tty ? "\033[1;31m" : "";
-  const char *green = tty ? "\033[1;32m" : "";
-  const char *normal = tty ? "\033[0m" : "";
-
-  size_t size = strlen(format) + 1;
-  char colorized[16*size];
-  char *builder = colorized;
-
-  colorize_state_t state = COLORIZE_NORMAL;
-  for (size_t i = 0; i < size; ++i) {
-    char c = format[i];
-
-    if (c == '\\') {
-      *builder++ = format[++i];
-      continue;
-    }
-
-    switch (state) {
-    case COLORIZE_AT:
-      if (c == '@') {
-        strcatinc(&builder, normal);
-        state = COLORIZE_NORMAL;
-      } else {
-        *builder++ = c;
-      }
-      break;
-
-    case COLORIZE_BANG:
-      if (c == '!') {
-        strcatinc(&builder, normal);
-        state = COLORIZE_NORMAL;
-      } else {
-        *builder++ = c;
-      }
-      break;
-
-    case COLORIZE_STAR:
-      if (c == '*') {
-        strcatinc(&builder, normal);
-        state = COLORIZE_NORMAL;
-      } else {
-        *builder++ = c;
-      }
-      break;
-
-    case COLORIZE_SHORT_OPTION:
-      *builder++ = c;
-      strcatinc(&builder, normal);
-      state = COLORIZE_NORMAL;
-      break;
-
-    case COLORIZE_LONG_OPTION:
-      if (!isalpha(c) && c != '-') {
-        strcatinc(&builder, normal);
-        state = COLORIZE_NORMAL;
-      }
-      *builder++ = c;
-      break;
-
-    default:
-      switch (c) {
-      case '@':
-        state = COLORIZE_AT;
-        strcatinc(&builder, green);
-        break;
-
-      case '!':
-        state = COLORIZE_BANG;
-        strcatinc(&builder, bold);
-        break;
-
-      case '*':
-        state = COLORIZE_STAR;
-        strcatinc(&builder, red);
-        break;
-
-      case '-':
-        if (c == '-') {
-          if (format[i + 1] == '-') {
-            state = COLORIZE_LONG_OPTION;
-          } else {
-            state = COLORIZE_SHORT_OPTION;
-          }
-          strcatinc(&builder, red);
-        }
-        *builder++ = c;
-        break;
-
-      default:
-        *builder++ = c;
-        break;
-      }
-      break;
-    }
-  }
-
-  va_list args;
-  va_start(args, format);
-  vprintf(colorized, args);
-  va_end(args);
-}
-
-static void
-print_usage(FILE *file, const char *command)
-{
-#if __unix__
-  bool tty = isatty(fileno(file));
-#else
-  bool tty = false;
-#endif
-
-  size_t length = strlen(command);
-  char whitespace[length + 1];
-  memset(whitespace, ' ', length);
-  whitespace[length] = '\0';
-
-#define usage(...) print_colorized(file, tty, __VA_ARGS__)
-  usage("Usage:\n");
-  usage("  !$! *%s* [-b|--bit-depth @DEPTH@]\n", command);
-  usage("    %s [-s|--hue-sort] [-r|--random]\n", whitespace);
-  usage("    %s [-c|--color-space @RGB@|@Lab@|@Luv@]\n", whitespace);
-  usage("    %s [-a|--animate]\n", whitespace);
-  usage("    %s [-o|--output @PATH@]\n", whitespace);
-  usage("    %s [-e|--seed @SEED@]\n", whitespace);
-  usage("    %s [-h|--help]\n", whitespace);
-  usage("\n");
-  usage("  -b, --bit-depth @DEPTH@:\n");
-  usage("          Use all @DEPTH@\\-bit colors (!default!: @24@)\n\n");
-  usage("  -s, --hue-sort:\n");
-  usage("          Sort colors by hue first (!default!)\n");
-  usage("  -r, --random:\n");
-  usage("          Randomize colors first\n\n");
-  usage("  -c, --color-space @RGB@|@Lab@|@Luv@:\n");
-  usage("          Use the given color space (!default!: @Lab@)\n\n");
-  usage("  -a, --animate:\n");
-  usage("          Generate frames of an animation\n\n");
-  usage("  -o, --output @PATH@:\n");
-  usage("          Output a PNG file at @PATH@ (!default!: @kd\\-forest.png@)\n\n");
-  usage("          If -a/--animate is specified, this is treated as a directory which\n");
-  usage("          will hold many frames\n\n");
-  usage("  -e, --seed @SEED@:\n");
-  usage("          Seed the random number generator (!default!: @0@)\n\n");
-  usage("  -h, --help:\n");
-  usage("          Show this message\n");
-#undef usage
-}
-
-static bool
-parse_options(options_t *options, int argc, char *argv[])
-{
-  // Set defaults
-  options->bit_depth = 24;
-  options->mode = MODE_HUE_SORT;
-  options->seed = 0;
-  options->color_space = COLOR_SPACE_LAB;
-  options->animate = false;
-  options->filename = NULL;
-  options->help = false;
-
-  bool result = true;
-
-  for (int i = 1; i < argc; ++i) {
-    const char *value;
-    bool error = false;
-
-    if (parse_arg(argc, argv, "-b", "--bit-depth", &value, &i, &error)) {
-      if (!str_to_uint(value, &options->bit_depth)
-          || options->bit_depth <= 1
-          || options->bit_depth > 24) {
-        fprintf(stderr, "Invalid bit depth: `%s'\n", value);
-        error = true;
-      }
-    } else if (parse_arg(argc, argv, "-s", "--hue-sort", NULL, &i, &error)) {
-      options->mode = MODE_HUE_SORT;
-    } else if (parse_arg(argc, argv, "-r", "--random", NULL, &i, &error)) {
-      options->mode = MODE_RANDOM;
-    } else if (parse_arg(argc, argv, "-e", "--seed", &value, &i, &error)) {
-      if (!str_to_uint(value, &options->seed)) {
-        fprintf(stderr, "Invalid random seed: `%s'\n", value);
-        error = true;
-      }
-    } else if (parse_arg(argc, argv, "-a", "--animate", NULL, &i, &error)) {
-      options->animate = true;
-    } else if (parse_arg(argc, argv, "-o", "--output", &value, &i, &error)) {
-      options->filename = value;
-    } else if (parse_arg(argc, argv, "-c", "--color-space", &value, &i, &error)) {
-      if (strcmp(value, "RGB") == 0) {
-        options->color_space = COLOR_SPACE_RGB;
-      } else if (strcmp(value, "Lab") == 0) {
-        options->color_space = COLOR_SPACE_LAB;
-      } else if (strcmp(value, "Luv") == 0) {
-        options->color_space = COLOR_SPACE_LUV;
-      } else {
-        fprintf(stderr, "Invalid color space: `%s'\n", value);
-      }
-    } else if (parse_arg(argc, argv, "-h", "--help", NULL, &i, &error)) {
-      options->help = true;
-    } else if (!error) {
-      fprintf(stderr, "Unexpected argument `%s'\n", argv[i]);
-      error = true;
-    }
-
-    if (error) {
-      result = false;
-    }
-  }
-
-  // Default filename depends on -a flag
-  if (!options->filename) {
-    options->filename = options->animate ? "frames" : "kd-forest.png";
-  }
-
-  return result;
-}
-
 static uint32_t *
 create_colors(const state_t *state)
 {
diff --git a/options.c b/options.c
new file mode 100644
index 0000000..04f1f82
--- /dev/null
+++ b/options.c
@@ -0,0 +1,322 @@
+/*********************************************************************
+ * kd-forest                                                         *
+ * Copyright (C) 2014 Tavian Barnes <tavianator@tavianator.com>      *
+ *                                                                   *
+ * This program is free software. It comes without any warranty, to  *
+ * the extent permitted by applicable law. You can redistribute it   *
+ * and/or modify it under the terms of the Do What The Fuck You Want *
+ * To Public License, Version 2, as published by Sam Hocevar. See    *
+ * the COPYING file or http://www.wtfpl.net/ for more details.       *
+ *********************************************************************/
+
+#include "options.h"
+#include <ctype.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#if __unix__
+#  include <unistd.h>
+#endif
+
+static bool
+parse_arg(int argc, char *argv[],
+          const char *short_form, const char *long_form,
+          const char **value, int *i, bool *error)
+{
+  size_t short_len = strlen(short_form);
+  size_t long_len = strlen(long_form);
+
+  const char *actual_form;
+  const char *arg = argv[*i];
+  const char *candidate = NULL;
+
+  if (strncmp(arg, short_form, short_len) == 0) {
+    actual_form = short_form;
+    if (strlen(arg) > short_len) {
+      candidate = arg + short_len;
+    }
+  } else if (strncmp(arg, long_form, long_len) == 0) {
+    actual_form = long_form;
+    if (strlen(arg) > long_len) {
+      if (arg[long_len] == '=') {
+        candidate = arg + long_len + 1;
+      } else {
+        return false;
+      }
+    }
+  } else {
+    return false;
+  }
+
+  if (value) {
+    if (candidate) {
+      *value = candidate;
+    } else if (*i < argc - 1) {
+      ++*i;
+      *value = argv[*i];
+    } else {
+      fprintf(stderr, "Expected a value for %s\n", arg);
+      *error = true;
+      return false;
+    }
+  } else if (candidate) {
+    fprintf(stderr, "Unexpected value for %s: `%s'\n",
+            actual_form, candidate);
+    *error = true;
+    return false;
+  }
+
+  return true;
+}
+
+static bool
+str_to_uint(const char *str, unsigned int *value)
+{
+  char *endptr;
+  long result = strtol(str, &endptr, 10);
+  if (*str == '\0' || *endptr != '\0') {
+    return false;
+  }
+  if (result < 0 || result > UINT_MAX) {
+    return false;
+  }
+
+  *value = result;
+  return true;
+}
+
+static void
+strcatinc(char **destp, const char *src)
+{
+  strcpy(*destp, src);
+  *destp += strlen(src);
+}
+
+typedef enum {
+  COLORIZE_NORMAL,
+  COLORIZE_AT,
+  COLORIZE_BANG,
+  COLORIZE_STAR,
+  COLORIZE_SHORT_OPTION,
+  COLORIZE_LONG_OPTION,
+} colorize_state_t;
+
+static void
+print_colorized(FILE *file, bool tty, const char *format, ...)
+{
+  const char *bold = tty ? "\033[1m" : "";
+  const char *red = tty ? "\033[1;31m" : "";
+  const char *green = tty ? "\033[1;32m" : "";
+  const char *normal = tty ? "\033[0m" : "";
+
+  size_t size = strlen(format) + 1;
+  char colorized[16*size];
+  char *builder = colorized;
+
+  colorize_state_t state = COLORIZE_NORMAL;
+  for (size_t i = 0; i < size; ++i) {
+    char c = format[i];
+
+    if (c == '\\') {
+      *builder++ = format[++i];
+      continue;
+    }
+
+    switch (state) {
+    case COLORIZE_AT:
+      if (c == '@') {
+        strcatinc(&builder, normal);
+        state = COLORIZE_NORMAL;
+      } else {
+        *builder++ = c;
+      }
+      break;
+
+    case COLORIZE_BANG:
+      if (c == '!') {
+        strcatinc(&builder, normal);
+        state = COLORIZE_NORMAL;
+      } else {
+        *builder++ = c;
+      }
+      break;
+
+    case COLORIZE_STAR:
+      if (c == '*') {
+        strcatinc(&builder, normal);
+        state = COLORIZE_NORMAL;
+      } else {
+        *builder++ = c;
+      }
+      break;
+
+    case COLORIZE_SHORT_OPTION:
+      *builder++ = c;
+      strcatinc(&builder, normal);
+      state = COLORIZE_NORMAL;
+      break;
+
+    case COLORIZE_LONG_OPTION:
+      if (!isalpha(c) && c != '-') {
+        strcatinc(&builder, normal);
+        state = COLORIZE_NORMAL;
+      }
+      *builder++ = c;
+      break;
+
+    default:
+      switch (c) {
+      case '@':
+        state = COLORIZE_AT;
+        strcatinc(&builder, green);
+        break;
+
+      case '!':
+        state = COLORIZE_BANG;
+        strcatinc(&builder, bold);
+        break;
+
+      case '*':
+        state = COLORIZE_STAR;
+        strcatinc(&builder, red);
+        break;
+
+      case '-':
+        if (c == '-') {
+          if (format[i + 1] == '-') {
+            state = COLORIZE_LONG_OPTION;
+          } else {
+            state = COLORIZE_SHORT_OPTION;
+          }
+          strcatinc(&builder, red);
+        }
+        *builder++ = c;
+        break;
+
+      default:
+        *builder++ = c;
+        break;
+      }
+      break;
+    }
+  }
+
+  va_list args;
+  va_start(args, format);
+  vprintf(colorized, args);
+  va_end(args);
+}
+
+void
+print_usage(FILE *file, const char *command)
+{
+#if __unix__
+  bool tty = isatty(fileno(file));
+#else
+  bool tty = false;
+#endif
+
+  size_t length = strlen(command);
+  char whitespace[length + 1];
+  memset(whitespace, ' ', length);
+  whitespace[length] = '\0';
+
+#define usage(...) print_colorized(file, tty, __VA_ARGS__)
+  usage("Usage:\n");
+  usage("  !$! *%s* [-b|--bit-depth @DEPTH@]\n", command);
+  usage("    %s [-s|--hue-sort] [-r|--random]\n", whitespace);
+  usage("    %s [-c|--color-space @RGB@|@Lab@|@Luv@]\n", whitespace);
+  usage("    %s [-a|--animate]\n", whitespace);
+  usage("    %s [-o|--output @PATH@]\n", whitespace);
+  usage("    %s [-e|--seed @SEED@]\n", whitespace);
+  usage("    %s [-h|--help]\n", whitespace);
+  usage("\n");
+  usage("  -b, --bit-depth @DEPTH@:\n");
+  usage("          Use all @DEPTH@\\-bit colors (!default!: @24@)\n\n");
+  usage("  -s, --hue-sort:\n");
+  usage("          Sort colors by hue first (!default!)\n");
+  usage("  -r, --random:\n");
+  usage("          Randomize colors first\n\n");
+  usage("  -c, --color-space @RGB@|@Lab@|@Luv@:\n");
+  usage("          Use the given color space (!default!: @Lab@)\n\n");
+  usage("  -a, --animate:\n");
+  usage("          Generate frames of an animation\n\n");
+  usage("  -o, --output @PATH@:\n");
+  usage("          Output a PNG file at @PATH@ (!default!: @kd\\-forest.png@)\n\n");
+  usage("          If -a/--animate is specified, this is treated as a directory which\n");
+  usage("          will hold many frames\n\n");
+  usage("  -e, --seed @SEED@:\n");
+  usage("          Seed the random number generator (!default!: @0@)\n\n");
+  usage("  -h, --help:\n");
+  usage("          Show this message\n");
+#undef usage
+}
+
+bool
+parse_options(options_t *options, int argc, char *argv[])
+{
+  // Set defaults
+  options->bit_depth = 24;
+  options->mode = MODE_HUE_SORT;
+  options->seed = 0;
+  options->color_space = COLOR_SPACE_LAB;
+  options->animate = false;
+  options->filename = NULL;
+  options->help = false;
+
+  bool result = true;
+
+  for (int i = 1; i < argc; ++i) {
+    const char *value;
+    bool error = false;
+
+    if (parse_arg(argc, argv, "-b", "--bit-depth", &value, &i, &error)) {
+      if (!str_to_uint(value, &options->bit_depth)
+          || options->bit_depth <= 1
+          || options->bit_depth > 24) {
+        fprintf(stderr, "Invalid bit depth: `%s'\n", value);
+        error = true;
+      }
+    } else if (parse_arg(argc, argv, "-s", "--hue-sort", NULL, &i, &error)) {
+      options->mode = MODE_HUE_SORT;
+    } else if (parse_arg(argc, argv, "-r", "--random", NULL, &i, &error)) {
+      options->mode = MODE_RANDOM;
+    } else if (parse_arg(argc, argv, "-e", "--seed", &value, &i, &error)) {
+      if (!str_to_uint(value, &options->seed)) {
+        fprintf(stderr, "Invalid random seed: `%s'\n", value);
+        error = true;
+      }
+    } else if (parse_arg(argc, argv, "-a", "--animate", NULL, &i, &error)) {
+      options->animate = true;
+    } else if (parse_arg(argc, argv, "-o", "--output", &value, &i, &error)) {
+      options->filename = value;
+    } else if (parse_arg(argc, argv, "-c", "--color-space", &value, &i, &error)) {
+      if (strcmp(value, "RGB") == 0) {
+        options->color_space = COLOR_SPACE_RGB;
+      } else if (strcmp(value, "Lab") == 0) {
+        options->color_space = COLOR_SPACE_LAB;
+      } else if (strcmp(value, "Luv") == 0) {
+        options->color_space = COLOR_SPACE_LUV;
+      } else {
+        fprintf(stderr, "Invalid color space: `%s'\n", value);
+      }
+    } else if (parse_arg(argc, argv, "-h", "--help", NULL, &i, &error)) {
+      options->help = true;
+    } else if (!error) {
+      fprintf(stderr, "Unexpected argument `%s'\n", argv[i]);
+      error = true;
+    }
+
+    if (error) {
+      result = false;
+    }
+  }
+
+  // Default filename depends on -a flag
+  if (!options->filename) {
+    options->filename = options->animate ? "frames" : "kd-forest.png";
+  }
+
+  return result;
+}
diff --git a/options.h b/options.h
new file mode 100644
index 0000000..6f1b2f8
--- /dev/null
+++ b/options.h
@@ -0,0 +1,45 @@
+/*********************************************************************
+ * kd-forest                                                         *
+ * Copyright (C) 2014 Tavian Barnes <tavianator@tavianator.com>      *
+ *                                                                   *
+ * This program is free software. It comes without any warranty, to  *
+ * the extent permitted by applicable law. You can redistribute it   *
+ * and/or modify it under the terms of the Do What The Fuck You Want *
+ * To Public License, Version 2, as published by Sam Hocevar. See    *
+ * the COPYING file or http://www.wtfpl.net/ for more details.       *
+ *********************************************************************/
+
+#ifndef OPTIONS_H
+#define OPTIONS_H
+
+#include <stdbool.h>
+#include <stdio.h>
+
+// Possible generation modes
+typedef enum {
+  MODE_HUE_SORT,
+  MODE_RANDOM,
+} mode_t;
+
+// Possible color spaces
+typedef enum {
+  COLOR_SPACE_RGB,
+  COLOR_SPACE_LAB,
+  COLOR_SPACE_LUV,
+} color_space_t;
+
+// Command-line options
+typedef struct {
+  unsigned int bit_depth;
+  mode_t mode;
+  color_space_t color_space;
+  bool animate;
+  const char *filename;
+  unsigned int seed;
+  bool help;
+} options_t;
+
+bool parse_options(options_t *options, int argc, char *argv[]);
+void print_usage(FILE *file, const char *command);
+
+#endif // OPTIONS_H