joysticks: configurable, working, buttons enable

[vor.git] / args.c

diff --git a/args.c b/args.c
index 5056239..3ff1412 100644 (file)
--- a/args.c
+++ b/args.c
@@ -8,6 +8,10 @@
 // Look and Feel
 int opt_fullscreen;
 int opt_sound;
+int opt_joystick_enabled;
+int opt_joystick_number;
+int opt_joystick_x_axis;
+int opt_joystick_y_axis;
 
 int opt_autopilot;
 
@@ -17,19 +21,108 @@ show_help(void)
        puts("Dodge the rocks until you die.");
        putchar('\n');
        puts("  -f, --full-screen");
-       puts("  -s, --silent               No explosion sounds or music");
-       puts("  -V, --version              Print program version");
-       puts("  -?, --help                 Give this help list");
+       puts("  -s, --silent             No explosion sounds or music");
+       puts("  -j x,y, --joystick=x,y   set the axis numbers. defaults to 0,1");
+       puts("                           press a joystick button to activate that joystick");
+       puts("  -V, --version            Print program version");
+       puts("  -?, --help               Give this help list");
        putchar('\n');
        puts("Report bugs at http://jasonwoof.com/contact.html");
 }
 
+// Advances buf while reading a positive int, terminated by [^0-9]
+// buf is left pointing at first [^0-9]
+// If digits are found, the parsed number is written to *out and 0 is returned.
+// Otherwise *buf and *out are left unchanged, and non-zero is returned.
+int
+parse_next_int(char **buf, int* out) {
+       int ret = 0, mul = 1;
+       if(!*buf) {
+               return 1;
+       }
+       // make sure *buf starts -?[0-9]
+       if(**buf == '-') {
+               mul = -1;
+               if((*buf)[1] < '0' || (*buf)[1] > '9') {
+                       return 2;
+               }
+               *buf += 1;
+       } else {
+               if(**buf < '0' || **buf > '9') {
+                       return 2;
+               }
+       }
+       while(**buf >= '0' && **buf <= '9') {
+               ret *= 10;
+               ret += **buf - '0';
+               *buf += 1;
+       }
+       *out = ret * mul;
+
+       return 0;
+}
+
+// returns 1 on success. return 0 causes usage message
+int
+parse_joystick_opts(char *arg) {
+       char *arg_was = arg;
+       static char* bad_arg = "Error: invalid argument to -j/--joystick.";
+
+       // argument is required
+       if(arg == NULL) {
+               puts(bad_arg);
+               return 0;
+       }
+
+       // read x axis
+       if(parse_next_int(&arg, &opt_joystick_x_axis)) {
+               puts(bad_arg);
+               return 0;
+       }
+
+       // skip comma
+       if(*arg != ',') {
+               puts(bad_arg);
+               return 0;
+       }
+       arg += 1;
+
+       // read y axis
+       if(parse_next_int(&arg, &opt_joystick_y_axis)) {
+               puts(bad_arg);
+               return 0;
+       }
+
+       // optionally joystick number
+       if(*arg == ',') {
+               arg += 1; // skip comma
+               if(parse_next_int(&arg, &opt_joystick_number)) {
+                       puts(bad_arg);
+                       return 0;
+               }
+               opt_joystick_enabled = 1;
+       }
+
+       // end with a comma or end of string
+       if(*arg != 0 && *arg != ',') {
+               puts(bad_arg);
+               return 0;
+       }
+
+       // mark arg as consumed (so it won't be parsed as a commandline switch)
+       arg_was[0] = 0;
+
+       // return success
+       return 1;
+}
 int
 short_opt(char c, char *arg)
 {
        switch(c) {
                case 'f': opt_fullscreen = 1; break;
                case 's': opt_sound = 0; break;
+               case 'j':
+                       return parse_joystick_opts(arg);
                case 'V':
                                  printf("Variations on Rockdodger %s\n", PACKAGE_VERSION);
                                  exit(0);
@@ -50,9 +143,9 @@ parse_short_opts(const char *s, char *arg)
        return short_opt(*s, arg);
 }
 
-static char *long_opts[] = { "full-screen", "silent", "version", "help", "autopilot" };
+static char *long_opts[] = { "full-screen", "silent", "joystick", "version", "help", "autopilot" };
 
-static char short_opts[] = { 'f', 's', 'V', 'h', 'a' };
+static char short_opts[] = { 'f', 's', 'j', 'V', 'h', 'a' };
 
 int
 parse_long_opt(const char *s, char *arg)
@@ -71,6 +164,10 @@ init_opts(void)
 {
        opt_fullscreen = 0;
        opt_sound = 1;
+       opt_joystick_enabled = 0; // can also be enabled by pressing one of its buttons
+       opt_joystick_number = 0;
+       opt_joystick_x_axis = 0;
+       opt_joystick_y_axis = 1;
        opt_autopilot = 0;
 }
 
@@ -83,6 +180,8 @@ parse_opts(int argc, char *argv[])
        init_opts();
        for(i=1; i<argc; i++) {
                char *s, *arg;
+               // args that are consumed as arguments to an option (such as the zero
+               // in: -j 0) have their first byte set to null. So skip them:
                s = argv[i]; if(!*s) continue;
                if(*s++ != '-') {
                        fputs("not an option\n\n", stderr);
@@ -92,7 +191,12 @@ parse_opts(int argc, char *argv[])
 
                arg = NULL;
                for(r=s; *r; r++) if(*r == '=') { *r = 0; arg = r+1; break; }
-               if(!arg && (i+1 < argc)) arg = argv[i+1];
+
+               if(arg == NULL && i + 1 < argc) {
+                       arg = argv[i+1];
+                       // if this is used, it's first byte will be set to null, and
+                       // it'll be skipped. See above.
+               }
 
                if(*s == '-') {
                        if(!parse_long_opt(s+1, arg)) { show_help(); return 0; }