src/libsdl/sdl.c

   1 /* SDL handling
   2  *
   3  * (C) 2018 by Andreas Eversberg <jolly@eversberg.eu>
   4  * All Rights Reserved
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <stdio.h>
  21 #include <stdint.h>
  22 #include <errno.h>
  23 #include "print.h"
  24 #include "../../include/keycodes.h"
  25 #include "sdl.h"
  26
  27 #include <SDL2/SDL.h>
  28 #define GL3_PROTOTYPES 1
  29 #include <GL/glew.h>
  30
  31 static int sdl_initialized = 0;
  32 static int audio_initialized = 0;
  33 static const char *device_string = NULL;
  34 static SDL_AudioDeviceID audio_devid = 0;
  35 static SDL_Window *gl_window = NULL;
  36 static SDL_GLContext gl_context = NULL;
  37 static SDL_Joystick *sdl_joystick = NULL;
  38 static void (*keyboard_sdl)(int down, enum keycode keycode) = NULL;
  39 static void (*joystick_sdl)(double x, double y, int fire) = NULL;
  40 static void (*audio_sdl)(float *data, int len) = NULL;
  41 static void (*resize_window_sdl)(int width, int height) = NULL;
  42 static int joystick_y_axis_sdl = 1, joystick_x_axis_sdl = 0, joystick_fire_button_sdl = -1;
  43
  44 static void audio_cb(void __attribute__((unused)) *userdata, Uint8 *stream, int len)
  45 {
  46         float audio_data[len / sizeof(float)];
  47
  48         SDL_memset(stream, 0, len);
  49         audio_sdl(audio_data, len / sizeof(float) / 2);
  50         SDL_MixAudioFormat(stream, (Uint8 *)audio_data, AUDIO_F32, len, SDL_MIX_MAXVOLUME / 2.0);
  51 }
  52
  53 void sdl_list_joysticks(void)
  54 {
  55         int num, i, rc;
  56
  57         rc = SDL_Init(SDL_INIT_JOYSTICK);
  58         if (rc < 0) {
  59                 print_error("Failed to init SDL\n");
  60                 return;
  61         }
  62
  63         num = SDL_NumJoysticks();
  64         for (i = 0; i < num; i++)
  65                 printf("#%d: %s\n", i, SDL_JoystickNameForIndex(i));
  66
  67         SDL_Quit();
  68 }
  69
  70 int init_sdl(const char *progname, int width, int height, int sound_samplerate, int sound_chunk, void (*keyboard)(int down, enum keycode keycode), int joysticknum, int joystick_x_axis, int joystick_y_axis, int joystick_fire_button, void (*joystick)(double x, double y, int fire), void (*audio)(float *data, int len), void (*resize_window)(int width, int height), int multisampling, int vbl_sync, int rift)
  71 {
  72         int rc = -EINVAL;
  73
  74         keyboard_sdl = keyboard;
  75         joystick_sdl = joystick;
  76         audio_sdl = audio;
  77         resize_window_sdl = resize_window;
  78         if (joystick_x_axis >= 0)
  79                 joystick_x_axis_sdl = joystick_x_axis;
  80         if (joystick_y_axis >= 0)
  81                 joystick_y_axis_sdl = joystick_y_axis;
  82         if (joystick_fire_button >= 0)
  83                 joystick_fire_button_sdl = joystick_fire_button;
  84
  85         /* init SDL library */
  86         rc = SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_JOYSTICK);
  87         if (rc < 0) {
  88                 print_error("Failed to init SDL\n");
  89                 goto error;
  90         }
  91         sdl_initialized = 1;
  92
  93         SDL_JoystickEventState(SDL_ENABLE);
  94         sdl_joystick = SDL_JoystickOpen((joysticknum < 0) ? 0 : joysticknum);
  95         if (!sdl_joystick && joysticknum >= 0) {
  96                 rc = -EIO;
  97                 print_error("Failed to open joystick #%d, see help!\n", joysticknum);
  98                 goto error;
  99         }
 100
 101 retry_without_multisampling:
 102         if (multisampling > 1) {
 103                 SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
 104                 SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
 105                 SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
 106                 SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
 107                 SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
 108                 SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1);
 109                 SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, multisampling);
 110         }
 111
 112         /* open window */
 113         gl_window = SDL_CreateWindow(progname, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, width, height, SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);
 114         if (!gl_window) {
 115                 if (multisampling) {
 116                         print_info("Failed to open SDL window: %s (retrying without multisampling)\n", SDL_GetError());
 117                         SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 0);
 118                         SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, 0);
 119                         multisampling = 0;
 120                         goto retry_without_multisampling;
 121                 }
 122                 print_error("Failed to open SDL window: %s\n", SDL_GetError());
 123                 SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1);
 124                 SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, multisampling);
 125                 rc = EIO;
 126                 goto error;
 127         }
 128
 129         /* create GL context */
 130         gl_context = SDL_GL_CreateContext(gl_window);
 131         if (!gl_context) {
 132                 print_error("Failed to create SDL's OpenGL context: %s\n", SDL_GetError());
 133                 rc = EIO;
 134                 goto error;
 135         }
 136
 137         rc = SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
 138         if (rc < 0) {
 139                 print_error("Failed to set SDL's OpenGL context profile\n");
 140                 goto error;
 141         }
 142
 143         rc = SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
 144         if (rc < 0) {
 145                 print_error("Failed to set SDL's OpenGL major version\n");
 146                 goto error;
 147         }
 148         rc = SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
 149         if (rc < 0) {
 150                 print_error("Failed to set SDL's OpenGL minor version\n");
 151                 goto error;
 152         }
 153
 154         rc = SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
 155         if (rc < 0) {
 156                 print_error("Failed to set SDL's OpenGL doublebuffer\n");
 157                 goto error;
 158         }
 159
 160         rc = SDL_GL_SetSwapInterval((vbl_sync) ? 1 : 0);
 161         if (rc < 0) {
 162                 print_error("Failed to set SDL's OpenGL swap interval to VBLANK\n");
 163                 // continue anyway
 164         }
 165
 166 // seems like a hack to me. do we need this?
 167 #ifndef __APPLE__
 168 #if !defined(_WIN32)
 169         glewExperimental = GL_TRUE;
 170         if (glewInit() != GLEW_OK) {
 171                 print_error("Failed to init GLEW\n");
 172                 goto error;
 173         }
 174 #endif
 175 #endif
 176
 177         /* just in case */
 178         glDisable(GL_DEPTH_TEST);
 179         glDisable(GL_CULL_FACE);
 180         if (multisampling > 1)
 181                 glEnable(GL_MULTISAMPLE);
 182
 183         if (rift) {
 184                 int i, count;
 185                 count = SDL_GetNumAudioDevices(0);
 186                 const char *string;
 187                 for(i = 0; i < count; i++) {
 188                         string = SDL_GetAudioDeviceName(i, 0);
 189                         if (strstr(string, "Rift"))
 190                                 device_string = string;
 191                 }
 192                 if (!device_string)
 193                         print_error("Oculus Rift headset not found, falling back to default audio device.\n");
 194         }
 195
 196         /* open audio */
 197         SDL_AudioSpec want, have;
 198         SDL_memset(&want, 0, sizeof(want)); /* or SDL_zero(want) */
 199         want.freq = sound_samplerate;
 200         want.format = AUDIO_F32; /* we always use float in this project */
 201         want.channels = 2;
 202         want.samples = sound_chunk; /* must be a power of two */
 203         want.callback = audio_cb;
 204         audio_devid = SDL_OpenAudioDevice(device_string, 0, &want, &have, SDL_AUDIO_ALLOW_ANY_CHANGE);
 205         if (audio_devid <= 0) {
 206                 print_error("Failed to open audio! (No speaker connected?)\n");
 207                 rc = -EIO;
 208                 goto error;
 209         } else if (have.format != want.format) {
 210                 print_error("Failed to open audio with desired audio format (want %d, got %d)\n", want.format, have.format);
 211                 rc = -EIO;
 212                 goto error;
 213         } else if (have.freq != want.freq) {
 214                 print_error("Failed to open audio with desired sample rate (want %d, got %d)\n", want.freq, have.freq);
 215                 rc = -EIO;
 216                 goto error;
 217         } else if (have.channels != want.channels) {
 218                 print_error("Failed to open audio with desired number of channels (want %d, got %d)\n", want.channels, have.channels);
 219                 rc = -EIO;
 220                 goto error;
 221         } else {
 222                 SDL_PauseAudioDevice(audio_devid, 0);
 223                 audio_initialized = 1;
 224         }
 225
 226         return 0;
 227
 228 error:
 229         exit_sdl();
 230         return rc;
 231 }
 232
 233 static enum keycode sdl2keycode(SDL_Keycode sym)
 234 {
 235         switch (sym) {
 236         case SDLK_LCTRL: return KEYCODE_LCTRL;
 237         case SDLK_RCTRL: return KEYCODE_RCTRL;
 238         case SDLK_LSHIFT: return KEYCODE_LSHIFT;
 239         case SDLK_RSHIFT: return KEYCODE_RSHIFT;
 240         case SDLK_LALT: return KEYCODE_LALT;
 241         case SDLK_RALT: return KEYCODE_RALT;
 242         case SDLK_PAUSE: return KEYCODE_PAUSE;
 243         case SDLK_LEFT: return KEYCODE_LEFT;
 244         case SDLK_RIGHT: return KEYCODE_RIGHT;
 245         case SDLK_UP: return KEYCODE_UP;
 246         case SDLK_DOWN: return KEYCODE_DOWN;
 247         case SDLK_END: return KEYCODE_END;
 248         case SDLK_a: return KEYCODE_a;
 249         case SDLK_b: return KEYCODE_b;
 250         case SDLK_c: return KEYCODE_c;
 251         case SDLK_d: return KEYCODE_d;
 252         case SDLK_e: return KEYCODE_e;
 253         case SDLK_f: return KEYCODE_f;
 254         case SDLK_g: return KEYCODE_g;
 255         case SDLK_h: return KEYCODE_h;
 256         case SDLK_i: return KEYCODE_i;
 257         case SDLK_j: return KEYCODE_j;
 258         case SDLK_k: return KEYCODE_k;
 259         case SDLK_l: return KEYCODE_l;
 260         case SDLK_m: return KEYCODE_m;
 261         case SDLK_n: return KEYCODE_n;
 262         case SDLK_o: return KEYCODE_o;
 263         case SDLK_p: return KEYCODE_p;
 264         case SDLK_q: return KEYCODE_q;
 265         case SDLK_r: return KEYCODE_r;
 266         case SDLK_s: return KEYCODE_s;
 267         case SDLK_t: return KEYCODE_t;
 268         case SDLK_u: return KEYCODE_u;
 269         case SDLK_v: return KEYCODE_v;
 270         case SDLK_w: return KEYCODE_w;
 271         case SDLK_x: return KEYCODE_x;
 272         case SDLK_y: return KEYCODE_y;
 273         case SDLK_z: return KEYCODE_z;
 274         case SDLK_0: return KEYCODE_0;
 275         case SDLK_1: return KEYCODE_1;
 276         case SDLK_2: return KEYCODE_2;
 277         case SDLK_3: return KEYCODE_3;
 278         case SDLK_4: return KEYCODE_4;
 279         case SDLK_5: return KEYCODE_5;
 280         case SDLK_6: return KEYCODE_6;
 281         case SDLK_7: return KEYCODE_7;
 282         case SDLK_8: return KEYCODE_8;
 283         case SDLK_9: return KEYCODE_9;
 284         case SDLK_KP_0: return KEYCODE_KP_0;
 285         case SDLK_KP_1: return KEYCODE_KP_1;
 286         case SDLK_KP_2: return KEYCODE_KP_2;
 287         case SDLK_KP_3: return KEYCODE_KP_3;
 288         case SDLK_KP_4: return KEYCODE_KP_4;
 289         case SDLK_KP_5: return KEYCODE_KP_5;
 290         case SDLK_KP_6: return KEYCODE_KP_6;
 291         case SDLK_KP_7: return KEYCODE_KP_7;
 292         case SDLK_KP_8: return KEYCODE_KP_8;
 293         case SDLK_KP_9: return KEYCODE_KP_9;
 294         case SDLK_KP_DIVIDE: return KEYCODE_KP_DIVIDE;
 295         case SDLK_KP_MULTIPLY: return KEYCODE_KP_MULTIPLY;
 296         case SDLK_KP_MINUS: return KEYCODE_KP_MINUS;
 297         case SDLK_KP_PLUS: return KEYCODE_KP_PLUS;
 298         case SDLK_KP_PERIOD: return KEYCODE_KP_PERIOD;
 299         case SDLK_KP_ENTER: return KEYCODE_KP_ENTER;
 300         case SDLK_F1: return KEYCODE_F1;
 301         case SDLK_F2: return KEYCODE_F2;
 302         case SDLK_F3: return KEYCODE_F3;
 303         case SDLK_F4: return KEYCODE_F4;
 304         case SDLK_F5: return KEYCODE_F5;
 305         case SDLK_F6: return KEYCODE_F6;
 306         case SDLK_F7: return KEYCODE_F7;
 307         case SDLK_F8: return KEYCODE_F8;
 308         case SDLK_F9: return KEYCODE_F9;
 309         case SDLK_F10: return KEYCODE_F10;
 310         case SDLK_SPACE: return KEYCODE_SPACE;
 311         case SDLK_BACKSPACE: return KEYCODE_BACKSPACE;
 312         case SDLK_TAB: return KEYCODE_TAB;
 313         case SDLK_RETURN: return KEYCODE_RETURN;
 314         case SDLK_ESCAPE: return KEYCODE_ESCAPE;
 315         case SDLK_DELETE: return KEYCODE_DELETE;
 316         case SDLK_INSERT: return KEYCODE_INSERT;
 317         case SDLK_COMMA: return KEYCODE_COMMA;
 318         case SDLK_PERIOD: return KEYCODE_PERIOD;
 319         default: return KEYCODE_UNDEFINED;
 320         }
 321 }
 322
 323 static double joystick_x = 0, joystick_y = 0;
 324 static int joystick_fire = 0;
 325
 326 static void joystick_event(int axis, int value)
 327 {
 328         double v = (double)value  / 32767.0;
 329
 330         switch (axis) {
 331         case 0: joystick_y = v; break;
 332         case 1: joystick_x = v; break;
 333         case 2: joystick_fire = value; break;
 334         }
 335
 336         joystick_sdl(joystick_x, joystick_y, joystick_fire);
 337 }
 338
 339 static int key_ctrl = 0, key_f = 0, fullscreen = 0;
 340
 341 int event_sdl(void)
 342 {
 343         int quit = 0;
 344         SDL_Event event;
 345
 346         while (SDL_PollEvent(&event)) {
 347                 switch (event.type) {
 348                 case SDL_QUIT:
 349                         quit = 1;
 350                         break;
 351                 case SDL_WINDOWEVENT:
 352                         if (event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)
 353                                 resize_window_sdl(event.window.data1, event.window.data2);
 354                         break;
 355                 case SDL_KEYDOWN:
 356                         switch (event.key.keysym.sym) {
 357                         case SDLK_f:
 358                                 if (key_ctrl && !key_f) {
 359                                         if (fullscreen) {
 360                                                 fullscreen = 0;
 361                                                 SDL_SetWindowFullscreen(gl_window, 0);
 362                                                 SDL_ShowCursor(SDL_ENABLE);
 363                                         } else {
 364                                                 SDL_SetWindowFullscreen(gl_window, SDL_WINDOW_FULLSCREEN_DESKTOP);
 365                                                 SDL_ShowCursor(SDL_DISABLE);
 366                                                 fullscreen = 1;
 367                                         }
 368                                 }
 369                                 key_f = 1;
 370                                 break;
 371                         case SDLK_LCTRL:
 372                         case SDLK_RCTRL:
 373                                 key_ctrl = 1;
 374                                 break;
 375                         }
 376                         keyboard_sdl(1, sdl2keycode(event.key.keysym.sym));
 377                         break;
 378                 case SDL_KEYUP:
 379                         switch (event.key.keysym.sym) {
 380                         case SDLK_LCTRL:
 381                         case SDLK_RCTRL:
 382                                 key_ctrl = 0;
 383                                 break;
 384                         case SDLK_f:
 385                                 key_f = 0;
 386                                 break;
 387                         }
 388                         keyboard_sdl(0, sdl2keycode(event.key.keysym.sym));
 389                         break;
 390                 case SDL_JOYAXISMOTION:
 391                         if (event.jaxis.axis == joystick_y_axis_sdl)
 392                                 joystick_event(0, event.jaxis.value);
 393                         if (event.jaxis.axis == joystick_x_axis_sdl)
 394                                 joystick_event(1, event.jaxis.value);
 395                         break;
 396                 case SDL_JOYBUTTONDOWN:
 397                         if (joystick_fire_button_sdl < 0 || event.jbutton.button == joystick_fire_button_sdl)
 398                                 joystick_event(2, 1);
 399                         break;
 400                 case SDL_JOYBUTTONUP:
 401                         if (joystick_fire_button_sdl < 0 || event.jbutton.button == joystick_fire_button_sdl)
 402                                 joystick_event(2, 0);
 403                         break;
 404                 }
 405         }
 406
 407         return quit;
 408 }
 409
 410 void swap_sdl(void)
 411 {
 412         SDL_GL_SwapWindow(gl_window);
 413 }
 414
 415 void exit_sdl(void)
 416 {
 417         /* close joystick */
 418         if (sdl_joystick) {
 419                 SDL_JoystickClose(sdl_joystick);
 420                 sdl_joystick = NULL;
 421         }
 422         /* close window */
 423         if (gl_window) {
 424                 SDL_DestroyWindow(gl_window);
 425                 gl_window = NULL;
 426         }
 427
 428         /* clear OpenGL context */
 429         if (gl_context) {
 430                 SDL_GL_DeleteContext(gl_context);
 431                 gl_context = NULL;
 432         }
 433
 434         /* exit SDL library */
 435         if (audio_initialized) {
 436                 SDL_PauseAudioDevice(audio_devid, 1);
 437                 audio_initialized = 0;
 438         }
 439         if (audio_devid > 0) {
 440                 SDL_CloseAudioDevice(audio_devid);
 441                 audio_devid = 0;
 442         }
 443         if (sdl_initialized) {
 444                 SDL_Quit();
 445                 sdl_initialized = 0;
 446         }
 447 }
 448
 449 uint32_t ticks_sdl(void)
 450 {
 451         return SDL_GetTicks();
 452 }