Added options loading

options_load loads the config file at ~/.m4kc/m4kc.conf and is called within
options_init. Entering in adbormal values for parameters causes the second page
to segfault. Will attempt fix in next commit.

src/options.c

@@ -1,3 +1,6 @@
+#include <stdio.h>
+#include "data.h"
+#include "string.h"
 #include "options.h"
 
 Options options = { 0 };
@@ -19,5 +22,44 @@ int options_init (void) {
                 }
         };
 
+        int err = options_load();
+        return err;
+}
+
+/* options_load
+ * Loads options from the configuration file into the options struct. Returns 0
+ * on success, non-zero on failure.
+ */
+int options_load (void) {
+        const char *path = data_getOptionsFileName();
+
+        // If the file doesn't exist, calmly exit the function and just use
+        // default values
+        FILE *file = fopen(path, "r");
+        if (file == NULL) { return 0; }
+
+        int version;
+        fscanf(file, "%i", &version);
+        if (version != 0) { return 1; }
+
+        char parameter[16];
+        while (1) {
+                if (fscanf(file, "%15s", parameter) == EOF) { break; }
+
+                #define PARAMETER(what, how, where) \
+                        else if (strcmp(parameter, #what) == 0) { \
+                                fscanf(file, how, where); \
+                        }
+                PARAMETER(fogType,      "%i",  &options.fogType)
+                PARAMETER(drawDistance, "%i",  &options.drawDistance)
+                PARAMETER(trapMouse,    "%i",  &options.trapMouse)
+                PARAMETER(fov,          "%lf", &options.fov)
+                PARAMETER(username,     "%7s", username)
+                #undef PARAMETER
+        }
+
+        options.username.cursor = strlen(username);
+
+        fclose(file);
         return 0;
 }

src/options.h

@@ -12,3 +12,4 @@ typedef struct {
 extern Options options;
 
 int options_init (void);
+int options_load (void);