input.c

   1 /*
   2    Cantaveria - action adventure platform game
   3    Copyright (C) 2009 2010 Evan Rinehart
   4
   5    This program is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU General Public License
   7    as published by the Free Software Foundation; either version 2
   8    of the License, or (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to
  17
  18    The Free Software Foundation, Inc.
  19    51 Franklin Street, Fifth Floor
  20    Boston, MA  02110-1301, USA
  21
  22    evanrinehart@gmail.com
  23 */
  24
  25
  26 /*
  27 the input module is an interface to the low level input system
  28 plus a mapper from low level input events to abstract game inputs.
  29 it has several functions:
  30 * generate the next available input, if possible
  31 * save and load input maps
  32 * remap abstract event to last low level event
  33 * convert abstract input to string form
  34 */
  35
  36
  37 #include <SDL/SDL.h>
  38
  39
  40 #include <util.h>
  41 #include <input.h>
  42
  43 #define JOY_MAX 32767
  44 #define JOY_MIN -32768
  45 #define JOY_THRESH 1000
  46
  47 static input NoInput = {NO_INPUT, INVALID_BUTTON, 0};
  48 static input SkipInput = {SKIP_INPUT, INVALID_BUTTON, 0};
  49 static input EndOfProgram = {END_OF_PROGRAM, INVALID_BUTTON, 0};
  50
  51 static SDL_Event last_event;
  52
  53 /* controller mappings */
  54 struct key_map {
  55         SDLKey sym;
  56
  57         int player;
  58         enum input_button button;
  59
  60         struct key_map* next;
  61 };
  62 struct key_map* key_maps = NULL;
  63
  64
  65 struct axis_map {
  66         Uint8 joystick;
  67         Uint8 axis;
  68         Sint16 last_value;
  69
  70         int player;
  71         enum input_button button[2];
  72
  73         struct axis_map* next;
  74 };
  75 struct axis_map* axis_maps = NULL;
  76
  77 struct jbutton_map {
  78         Uint8 joystick;
  79         Uint8 jbutton;
  80
  81         int player;
  82         enum input_button button;
  83
  84         struct jbutton_map* next;
  85 };
  86 struct jbutton_map* jbutton_maps = NULL;
  87
  88
  89 struct key_map* kmfind(SDLKey sym){
  90         struct key_map* ptr = key_maps;
  91         while(ptr){
  92                 if(ptr->sym == sym)
  93                         return ptr;
  94                 else
  95                         ptr = ptr->next;
  96         }
  97         return NULL;
  98 }
  99
 100 struct axis_map* amfind(Uint8 joystick, Uint8 axis){
 101         struct axis_map* ptr = axis_maps;
 102         while(ptr){
 103                 if(ptr->joystick == joystick && ptr->axis == axis)
 104                         return ptr;
 105                 else
 106                         ptr = ptr->next;
 107         }
 108         return NULL;
 109 }
 110
 111 struct jbutton_map* jmfind(Uint8 joystick, Uint8 jbutton){
 112         struct jbutton_map* ptr = jbutton_maps;
 113         while(ptr){
 114                 if(ptr->joystick == joystick && ptr->jbutton == jbutton)
 115                         return ptr;
 116                 else
 117                         ptr = ptr->next;
 118         }
 119         return NULL;
 120 }
 121
 122
 123
 124 enum input_type kmtype(Uint8 type){
 125         switch(type){
 126         case SDL_KEYDOWN: return BUTTON_PRESS;
 127         case SDL_KEYUP: return BUTTON_RELEASE;
 128         default:
 129                 error_msg("input map_key: invalid SDL event type\n");
 130                 return INVALID_INPUT;
 131         }
 132 }
 133
 134 enum input_type jmtype(Uint8 type){
 135         switch(type){
 136         case SDL_JOYBUTTONDOWN: return BUTTON_PRESS;
 137         case SDL_JOYBUTTONUP: return BUTTON_RELEASE;
 138         default:
 139                 error_msg("input map_jbutton: invalid SDL event type\n");
 140                 return INVALID_INPUT;
 141         }
 142 }
 143
 144 enum input_button ambutton(int state, struct axis_map* am){
 145         switch(state){
 146         case -1: return am->button[0];
 147         case 1: return am->button[1];
 148         case 0:
 149                 error_msg("input axis_motion: axis state 0 does not imply a button\n");
 150                 return INVALID_BUTTON;
 151         default:
 152                 error_msg("input axis_motion: invalid axis state (%d)\n", state);
 153                 return INVALID_BUTTON;
 154         }
 155 }
 156
 157 input map_key(SDL_Event* e){
 158         SDLKey sym = e->key.keysym.sym;
 159         struct key_map* km = kmfind(sym);
 160         input in;
 161         if(km){
 162                 in.type = kmtype(e->type);
 163                 in.player = km->player;
 164                 in.button = km->button;
 165                 return in;
 166         }
 167         else{
 168                 in.type = kmtype(e->type);
 169                 in.player = 0;
 170                 in.button = NONDESCRIPT_BUTTON;
 171                 return in;
 172         }
 173 }
 174
 175 input map_jbutton(SDL_Event* e){
 176         Uint8 which = e->jbutton.which;
 177         Uint8 jbutton = e->jbutton.button;
 178         struct jbutton_map* jm = jmfind(which, jbutton);
 179         input in;
 180
 181         if(jm){
 182                 in.type = jmtype(e->type);
 183                 in.player = jm->player;
 184                 in.button = jm->button;
 185                 return in;
 186         }
 187         else{
 188                 in.type = jmtype(e->type);
 189                 in.player = 0;
 190                 in.button = NONDESCRIPT_BUTTON;
 191                 return in;
 192         }
 193 }
 194
 195 int axis_state(Sint16 x){
 196         if(x < -JOY_THRESH) return -1;
 197         else if(x > JOY_THRESH) return 1;
 198         else return 0;
 199 }
 200
 201 input axis_motion(Sint16 value, struct axis_map* am){
 202         int state0 = axis_state(am->last_value);
 203         int state1 = axis_state(value);
 204         int diff = state1 - state0;
 205         input in;
 206
 207         if(abs(diff) == 2){
 208                 /*stuck FIXME ?
 209                 set a flag in the am which tells get_input
 210                 to do a button press
 211                 note that without this fix, it wont get stuck,
 212                 the input system will just be slightly inconsistent*/
 213                 error_msg("input axis_motion: (FIXME) joystick almost got stuck\n");
 214         }
 215
 216         if(diff == 0){
 217                 return SkipInput;
 218         }
 219         else if(state0 != 0){
 220                 in.type = BUTTON_RELEASE;
 221                 in.player = am->player;
 222                 in.button = ambutton(state0, am);
 223                 return in;
 224         }
 225         else{ /*(state1 != 0)*/
 226                 in.type = BUTTON_PRESS;
 227                 in.player = am->player;
 228                 in.button = ambutton(state1, am);
 229                 return in;
 230         }
 231 }
 232
 233 input map_jaxis(SDL_Event* e){
 234         Uint8 which = e->jaxis.which;
 235         Uint8 axis = e->jaxis.axis;
 236         Sint16 value = e->jaxis.value;
 237         struct axis_map* am = amfind(which, axis);
 238         if(am){
 239                 return axis_motion(value, am);
 240         }
 241         else{
 242                 return SkipInput;
 243         }
 244 }
 245
 246
 247
 248 void kmadd(int player, enum input_button button, SDLKey sym){
 249         struct key_map* km = malloc(sizeof(struct key_map));
 250         struct key_map* ptr = key_maps;;
 251         km->player = player;
 252         km->button = button;
 253         km->sym = sym;
 254         km->next = NULL;
 255
 256         if(!ptr){
 257                 key_maps = km;
 258                 return;
 259         }
 260
 261         while(ptr->next) ptr = ptr->next;
 262
 263         ptr->next = km;
 264 }
 265
 266
 267 /* *** */
 268 input get_input(){
 269         SDL_Event e;
 270         input in;
 271
 272         while(SDL_PollEvent(&e) != 0){
 273                 last_event = e;
 274                 switch(e.type){
 275                         case SDL_KEYDOWN:
 276                         case SDL_KEYUP:
 277                                 return map_key(&e);
 278
 279                         case SDL_JOYBUTTONDOWN:
 280                         case SDL_JOYBUTTONUP:
 281                                 return map_jbutton(&e);
 282
 283                         case SDL_JOYAXISMOTION:
 284                                 in = map_jaxis(&e);
 285                                 if(in.type == SKIP_INPUT)
 286                                         return in;
 287                                 else
 288                                         break;
 289
 290                         case SDL_QUIT:
 291                                 return EndOfProgram;
 292                 }
 293         }
 294
 295         return NoInput;
 296 }
 297
 298
 299 void remap_last_input(enum input_button button, int player){
 300         SDL_Event e = last_event;
 301         switch(e.type){
 302                 case SDL_KEYDOWN:
 303                 case SDL_KEYUP:
 304                         kmadd(player, button, e.key.keysym.sym);
 305                         break;
 306                 case SDL_JOYBUTTONDOWN:
 307                 case SDL_JOYBUTTONUP:
 308                         //jmadd(player, button, e.jbutton.button);
 309                         break;
 310                 case SDL_JOYAXISMOTION:
 311                         //amadd...
 312                         break;
 313         }
 314 }
 315
 316
 317
 318 void input_init(const char* filename){
 319         /* set up mappings */
 320         // A -> Left
 321         // D -> Right
 322         // W -> Up
 323         kmadd(0, LEFT_BUTTON, SDLK_a);
 324         kmadd(0, RIGHT_BUTTON, SDLK_d);
 325         kmadd(0, UP_BUTTON, SDLK_w);
 326         kmadd(0, DOWN_BUTTON, SDLK_s);
 327
 328         kmadd(0, JUMP_BUTTON, SDLK_k);
 329         kmadd(0, FIRE_BUTTON, SDLK_j);
 330         kmadd(0, INVENTORY_BUTTON, SDLK_i);
 331         kmadd(0, SPECIAL_BUTTON, SDLK_l);
 332
 333         kmadd(0, L_BUTTON, SDLK_u);
 334         kmadd(0, R_BUTTON, SDLK_o);
 335
 336         kmadd(0, START_BUTTON, SDLK_q);
 337         kmadd(0, SELECT_BUTTON, SDLK_e);
 338
 339         kmadd(0, ESCAPE_KEY, SDLK_ESCAPE);
 340         kmadd(0, PAUSE_KEY, SDLK_PAUSE);
 341 }
 342
 343 void save_input(const char* filename){
 344
 345 }
 346
 347
 348 const char* input_str(input in){
 349         switch(in.button){
 350                 case START_BUTTON: return "START";
 351                 case SELECT_BUTTON: return "SELECT";
 352                 case L_BUTTON: return "L";
 353                 case R_BUTTON: return "R";
 354
 355                 case LEFT_BUTTON: return "LEFT";
 356                 case RIGHT_BUTTON: return "RIGHT";
 357                 case UP_BUTTON: return "UP";
 358                 case DOWN_BUTTON: return "DOWN";
 359
 360                 case FIRE_BUTTON: return "FIRE";
 361                 case JUMP_BUTTON: return "JUMP";
 362                 case INVENTORY_BUTTON: return "INVENTORY";
 363                 case SPECIAL_BUTTON: return "SPECIAL";
 364
 365                 case ESCAPE_KEY: return "ESCAPE";
 366                 case PAUSE_KEY: return "PAUSE";
 367                 case INVALID_BUTTON: return "INVALID";
 368                 case NONDESCRIPT_BUTTON: return "NONDESCRIPT";
 369                 default: return "ERROR";
 370         }
 371 }
 372
 373
 374 void print_last_raw(char* buf, int size){
 375         SDL_Event e = last_event;
 376         switch(e.type){
 377                 case SDL_KEYDOWN:
 378                 case SDL_KEYUP:
 379                         snprintf(
 380                                 buf,size,"%s",
 381                                 SDL_GetKeyName(e.key.keysym.sym)
 382                         );
 383                         break;
 384
 385                 case SDL_JOYBUTTONDOWN:
 386                 case SDL_JOYBUTTONUP:
 387                         snprintf(
 388                                 buf, size,
 389                                 "J%d_B%d",
 390                                 e.jbutton.which,
 391                                 e.jbutton.button
 392                         );
 393                         break;
 394
 395                 case SDL_JOYAXISMOTION:
 396                         snprintf(
 397                                 buf,size,
 398                                 "J%d_AXIS%d",
 399                                 e.jaxis.which,
 400                                 e.jaxis.axis
 401                         );
 402                         break;
 403
 404                 default:
 405                         snprintf(buf, size, "???");
 406                         break;
 407         }
 408 }