full arg parse

src/args.c

@@ -1,16 +1,155 @@
 #include "args.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
-const parameters EMPTY_PARAMS = {
-    0, 0, NULL, 0, 0.0, {0.0, 0.0, 0.0}, {0.0, 0.0, 0.0}};
+void print_help(int status_code) {
+  puts("usage: mg "
+       "[--help] "
+       "[-q] "
+       "[-w=WIDTH] "
+       "[-h=HEIGHT] "
+       "[-o=PATH] "
+       "[-p=PIXEL_SIZE] "
+       "[-s=SLOPE] "
+       "[-c=R,G,B] "
+       "[-v=R,G,B]\n\n"
+       "generates a marble-like pattern bitmap image.\n\n"
+       "options:\n"
+       "  --help             show this help message and exit\n"
+       "  -q, --quiet        do not print to console\n"
+       "  -w, --width        image width (default: 1920)\n"
+       "  -h, --height       image height (default: 1080)\n"
+       "  -o, --output       output file (default: output.bmp)\n"
+       "  -p, --pixel        pixel size (default: random)\n"
+       "  -s, --slope        slope [0-255] (default: random)\n"
+       "  -c, --color        base color [0-255,0-255,0-255] (default: random)\n"
+       "  -v, --variation    base variation [0-255,0-255,0-255] (default: "
+       "random)");
+  exit(status_code);
+}
+
+void invalid_arg(char *arg) {
+  fprintf(stderr, "invalid argument: '%s'\n\n", arg);
+  print_help(1);
+}
+
+void invalid_value(char *arg, char *subarg, char *value) {
+  if (subarg == NULL) {
+    fprintf(stderr, "invalid value for argument '%s': '%s'\n\n", arg, value);
+  } else {
+    fprintf(stderr, "invalid value for argument '%s' %s: '%s'\n\n", arg, subarg,
+            value);
+  }
+  print_help(1);
+}
+
+bool is_arg(char *arg, char *ref) {
+  return strncmp(arg, ref, strlen(ref)) == 0;
+}
+
+char *get_arg_value(char *arg) {
+  strtok(arg, "="); // remove first part
+  return strtok(NULL, "=");
+}
+
+bool is_digit(char c) { return c >= '0' && c <= '9'; }
+
+bool is_number(char *value) {
+  if (value == NULL) {
+    return false;
+  }
+  unsigned long value_len = strlen(value);
+  int i;
+  for (i = 0; i < value_len; i++) {
+    if (!is_digit(value[i])) {
+      return false;
+    }
+  }
+  return value;
+}
+
+void parse_number(char *arg, char *value, unsigned char color[3]) {
+  char *tmp;
+  tmp = strtok(value, ",");
+  if (!is_number(tmp)) {
+    invalid_value(arg, "(R)", tmp);
+  }
+  color[0] = (unsigned char)atoi(tmp);
+  tmp = strtok(NULL, ",");
+  if (!is_number(tmp)) {
+    invalid_value(arg, "(G)", tmp);
+  }
+  color[1] = (unsigned char)atoi(tmp);
+  tmp = strtok(NULL, ",");
+  if (!is_number(tmp)) {
+    invalid_value(arg, "(B)", tmp);
+  }
+  color[2] = (unsigned char)atoi(tmp);
+}
 
 parameters parse_args(int argc, char **argv) {
   parameters params;
 
+  params.quiet = false;
   params.width = 1920;
   params.height = 1080;
   params.file_path = "output.bmp";
+  params.size = 1;       // TODO random
+  params.slope = 128;    // TODO random
+  params.start[0] = 128; // TODO random
+  params.start[1] = 128; // TODO random
+  params.start[2] = 128; // TODO random
+  params.var[0] = 20;    // TODO random
+  params.var[1] = 20;    // TODO random
+  params.var[2] = 20;    // TODO random
 
-  // TODO
+  int i;
+  char *arg;
+  char *value;
+  for (i = 1; i < argc; i++) {
+    arg = argv[i];
+    if (is_arg(arg, "--help")) {
+      print_help(0);
+    } else if (is_arg(arg, "-q") || is_arg(arg, "--quiet")) {
+      params.quiet = true;
+    } else if (is_arg(arg, "-w") || is_arg(arg, "--width")) {
+      value = get_arg_value(arg);
+      if (!is_number(value)) {
+        invalid_value(arg, NULL, value);
+      }
+      params.width = (unsigned long)atol(value);
+    } else if (is_arg(arg, "-h") || is_arg(arg, "--height")) {
+      value = get_arg_value(arg);
+      if (!is_number(value)) {
+        invalid_value(arg, NULL, value);
+      }
+      params.height = (unsigned long)atol(value);
+    } else if (is_arg(arg, "-o") || is_arg(arg, "--output")) {
+      value = get_arg_value(arg);
+      params.file_path = value;
+    } else if (is_arg(arg, "-p") || is_arg(arg, "--pixel")) {
+      value = get_arg_value(arg);
+      if (!is_number(value)) {
+        invalid_value(arg, NULL, value);
+      }
+      params.size = (unsigned char)atoi(value);
+    } else if (is_arg(arg, "-s") || is_arg(arg, "--slope")) {
+      value = get_arg_value(arg);
+      if (!is_number(value)) {
+        invalid_value(arg, NULL, value);
+      }
+      params.size = (unsigned char)atoi(value);
+    } else if (is_arg(arg, "-c") || is_arg(arg, "--color")) {
+      value = get_arg_value(arg);
+      parse_number(arg, value, params.start);
+    } else if (is_arg(arg, "-v") || is_arg(arg, "--variation")) {
+      value = get_arg_value(arg);
+      parse_number(arg, value, params.start);
+    } else {
+      invalid_arg(arg);
+    }
+  }
 
   return params;
 }