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 "sdl.h"
  25 #include "opengl.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 SDL_Window *gl_window = NULL;
  34 static SDL_GLContext gl_context = NULL;
  35 static void (*keyboard_sdl)(int down, enum keycode keycode) = NULL;
  36 static void (*audio_sdl)(float *data, int len) = NULL;
  37
  38 static void audio_cb(void __attribute__((unused)) *userdata, Uint8 *stream, int len)
  39 {
  40         float audio_data[len / sizeof(float)];
  41
  42         SDL_memset(stream, 0, len);
  43         audio_sdl(audio_data, len / sizeof(float) / 2);
  44         SDL_MixAudio(stream, (Uint8 *)audio_data, len, SDL_MIX_MAXVOLUME);
  45 }
  46
  47 int init_sdl(const char *progname, int width, int height, int sound_samplerate, int sound_chunk, void (*keyboard)(int down, enum keycode keycode), void (*audio)(float *data, int len), int multisampling)
  48 {
  49         int rc;
  50
  51         keyboard_sdl = keyboard;
  52         audio_sdl = audio;
  53
  54         /* init SDL library */
  55         rc = SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO);
  56         if (rc < 0) {
  57                 print_error("Failed to init SDL\n");
  58                 goto error;
  59         }
  60         sdl_initialized = 1;
  61
  62         if (multisampling) {
  63                 SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
  64                 SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
  65                 SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
  66                 SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
  67                 SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
  68                 SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1);
  69                 SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, multisampling);
  70         }
  71
  72         /* open window */
  73         gl_window = SDL_CreateWindow(progname, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, width, height, SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);
  74         if (!gl_window) {
  75                 print_error("Failed to open SDL window: %s (try without multisampling)\n", SDL_GetError());
  76                 rc = EIO;
  77                 goto error;
  78         }
  79
  80         /* create GL context */
  81         gl_context = SDL_GL_CreateContext(gl_window);
  82         if (!gl_context) {
  83                 print_error("Failed to create SDL's OpenGL context: %s\n", SDL_GetError());
  84                 rc = EIO;
  85                 goto error;
  86         }
  87
  88         rc = SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
  89         if (rc < 0) {
  90                 print_error("Failed to set SDL's OpenGL context profile\n");
  91                 goto error;
  92         }
  93
  94         rc = SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
  95         if (rc < 0) {
  96                 print_error("Failed to set SDL's OpenGL major version\n");
  97                 goto error;
  98         }
  99         rc = SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
 100         if (rc < 0) {
 101                 print_error("Failed to set SDL's OpenGL minor version\n");
 102                 goto error;
 103         }
 104
 105         rc = SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
 106         if (rc < 0) {
 107                 print_error("Failed to set SDL's OpenGL doublebuffer\n");
 108                 goto error;
 109         }
 110
 111         rc = SDL_GL_SetSwapInterval(1);
 112         if (rc < 0) {
 113                 print_error("Failed to set SDL's OpenGL swap interval to VBLANK\n");
 114                 // continue anyway
 115         }
 116
 117 #ifndef __APPLE__
 118         glewExperimental = GL_TRUE;
 119         if (glewInit() != GLEW_OK) {
 120                 print_error("Failed to init GLEW\n");
 121                 goto error;
 122         }
 123 #endif
 124
 125         /* just in case */
 126         glDisable(GL_DEPTH_TEST);
 127         glDisable(GL_CULL_FACE);
 128         if (multisampling)
 129                 glEnable(GL_MULTISAMPLE);
 130
 131         /* open audio */
 132         SDL_AudioSpec want, have;
 133         SDL_memset(&want, 0, sizeof(want)); /* or SDL_zero(want) */
 134         want.freq = sound_samplerate;
 135         want.format = AUDIO_F32; /* we always use float in this project */
 136         want.channels = 2;
 137         want.samples = sound_chunk; /* must be a power of two */
 138         want.callback = audio_cb;
 139         rc = SDL_OpenAudio(&want, &have);
 140         if (rc < 0) {
 141                 print_error("Failed to open audio! (No speaker connected?)\n");
 142                 goto error;
 143         } else if (have.format != want.format) {
 144                 print_error("Failed to open audio with desired audio format\n");
 145                 SDL_CloseAudio();
 146                 rc = -EIO;
 147                 goto error;
 148         } else if (have.freq != want.freq) {
 149                 print_error("Failed to open audio with desired sample rate\n");
 150                 SDL_CloseAudio();
 151                 rc = -EIO;
 152                 goto error;
 153         } else if (have.channels != want.channels) {
 154                 print_error("Failed to open audio with desired channels (got %d)\n", have.channels);
 155                 SDL_CloseAudio();
 156                 rc = -EIO;
 157                 goto error;
 158         } else {
 159                 SDL_PauseAudio(0);
 160                 audio_initialized = 1;
 161         }
 162
 163         return 0;
 164
 165 error:
 166         exit_sdl();
 167         return rc;
 168 }
 169
 170 static enum keycode sdl2keycode(SDL_Keycode sym)
 171 {
 172         switch (sym) {
 173         case SDLK_LCTRL: return KEYCODE_LCTRL;
 174         case SDLK_RCTRL: return KEYCODE_RCTRL;
 175         case SDLK_LSHIFT: return KEYCODE_LSHIFT;
 176         case SDLK_RSHIFT: return KEYCODE_RSHIFT;
 177         case SDLK_PAUSE: return KEYCODE_PAUSE;
 178         case SDLK_LEFT: return KEYCODE_LEFT;
 179         case SDLK_RIGHT: return KEYCODE_RIGHT;
 180         case SDLK_UP: return KEYCODE_UP;
 181         case SDLK_DOWN: return KEYCODE_DOWN;
 182         case SDLK_END: return KEYCODE_END;
 183         case SDLK_a: return KEYCODE_a;
 184         case SDLK_b: return KEYCODE_b;
 185         case SDLK_c: return KEYCODE_c;
 186         case SDLK_d: return KEYCODE_d;
 187         case SDLK_e: return KEYCODE_e;
 188         case SDLK_f: return KEYCODE_f;
 189         case SDLK_g: return KEYCODE_g;
 190         case SDLK_h: return KEYCODE_h;
 191         case SDLK_i: return KEYCODE_i;
 192         case SDLK_j: return KEYCODE_j;
 193         case SDLK_k: return KEYCODE_k;
 194         case SDLK_l: return KEYCODE_l;
 195         case SDLK_m: return KEYCODE_m;
 196         case SDLK_n: return KEYCODE_n;
 197         case SDLK_o: return KEYCODE_o;
 198         case SDLK_p: return KEYCODE_p;
 199         case SDLK_q: return KEYCODE_q;
 200         case SDLK_r: return KEYCODE_r;
 201         case SDLK_s: return KEYCODE_s;
 202         case SDLK_t: return KEYCODE_t;
 203         case SDLK_u: return KEYCODE_u;
 204         case SDLK_v: return KEYCODE_v;
 205         case SDLK_w: return KEYCODE_w;
 206         case SDLK_x: return KEYCODE_x;
 207         case SDLK_y: return KEYCODE_y;
 208         case SDLK_z: return KEYCODE_z;
 209         case SDLK_0: return KEYCODE_0;
 210         case SDLK_1: return KEYCODE_1;
 211         case SDLK_2: return KEYCODE_2;
 212         case SDLK_3: return KEYCODE_3;
 213         case SDLK_4: return KEYCODE_4;
 214         case SDLK_5: return KEYCODE_5;
 215         case SDLK_6: return KEYCODE_6;
 216         case SDLK_7: return KEYCODE_7;
 217         case SDLK_8: return KEYCODE_8;
 218         case SDLK_9: return KEYCODE_9;
 219         case SDLK_KP_0: return KEYCODE_KP_0;
 220         case SDLK_KP_1: return KEYCODE_KP_1;
 221         case SDLK_KP_2: return KEYCODE_KP_2;
 222         case SDLK_KP_3: return KEYCODE_KP_3;
 223         case SDLK_KP_4: return KEYCODE_KP_4;
 224         case SDLK_KP_5: return KEYCODE_KP_5;
 225         case SDLK_KP_6: return KEYCODE_KP_6;
 226         case SDLK_KP_7: return KEYCODE_KP_7;
 227         case SDLK_KP_8: return KEYCODE_KP_8;
 228         case SDLK_KP_9: return KEYCODE_KP_9;
 229         case SDLK_KP_DIVIDE: return KEYCODE_KP_DIVIDE;
 230         case SDLK_KP_MULTIPLY: return KEYCODE_KP_MULTIPLY;
 231         case SDLK_KP_MINUS: return KEYCODE_KP_MINUS;
 232         case SDLK_KP_PLUS: return KEYCODE_KP_PLUS;
 233         case SDLK_KP_PERIOD: return KEYCODE_KP_PERIOD;
 234         case SDLK_F1: return KEYCODE_F1;
 235         case SDLK_F2: return KEYCODE_F2;
 236         case SDLK_F3: return KEYCODE_F3;
 237         case SDLK_F4: return KEYCODE_F4;
 238         case SDLK_F5: return KEYCODE_F5;
 239         case SDLK_F6: return KEYCODE_F6;
 240         case SDLK_F7: return KEYCODE_F7;
 241         case SDLK_F8: return KEYCODE_F8;
 242         case SDLK_F9: return KEYCODE_F9;
 243         case SDLK_F10: return KEYCODE_F10;
 244         case SDLK_SPACE: return KEYCODE_SPACE;
 245         case SDLK_BACKSPACE: return KEYCODE_BACKSPACE;
 246         case SDLK_TAB: return KEYCODE_TAB;
 247         case SDLK_KP_ENTER: return KEYCODE_KP_ENTER;
 248         case SDLK_RETURN: return KEYCODE_RETURN;
 249         case SDLK_ESCAPE: return KEYCODE_ESCAPE;
 250         case SDLK_DELETE: return KEYCODE_DELETE;
 251         case SDLK_INSERT: return KEYCODE_INSERT;
 252         default: return KEYCODE_UNDEFINED;
 253         }
 254 }
 255
 256 static int key_ctrl = 0, key_f = 0, fullscreen = 0;
 257
 258 int event_sdl(void)
 259 {
 260         int quit = 0;
 261         SDL_Event event;
 262
 263         while (SDL_PollEvent(&event)) {
 264                 if (event.type == SDL_QUIT)
 265                         quit = 1;
 266                 if (event.type == SDL_WINDOWEVENT) {
 267                         if (event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)
 268                                 resize_opengl(event.window.data1, event.window.data2);
 269                 }
 270                 if (event.type == SDL_KEYDOWN) {
 271                         switch (event.key.keysym.sym) {
 272                         case SDLK_f:
 273                                 if (key_ctrl && !key_f) {
 274                                         if (fullscreen) {
 275                                                 fullscreen = 0;
 276                                                 SDL_SetWindowFullscreen(gl_window, 0);
 277                                                 SDL_ShowCursor(SDL_ENABLE);
 278                                         } else {
 279                                                 SDL_SetWindowFullscreen(gl_window, SDL_WINDOW_FULLSCREEN_DESKTOP);
 280                                                 SDL_ShowCursor(SDL_DISABLE);
 281                                                 fullscreen = 1;
 282                                         }
 283                                 }
 284                                 key_f = 1;
 285                                 break;
 286                         case SDLK_LCTRL:
 287                         case SDLK_RCTRL:
 288                                 key_ctrl = 1;
 289                                 break;
 290                         }
 291                         keyboard_sdl(1, sdl2keycode(event.key.keysym.sym));
 292                 }
 293                 if (event.type == SDL_KEYUP) {
 294                         switch (event.key.keysym.sym) {
 295                         case SDLK_LCTRL:
 296                         case SDLK_RCTRL:
 297                                 key_ctrl = 0;
 298                                 break;
 299                         case SDLK_f:
 300                                 key_f = 0;
 301                                 break;
 302                         }
 303                         keyboard_sdl(0, sdl2keycode(event.key.keysym.sym));
 304                 }
 305         }
 306
 307         return quit;
 308 }
 309
 310 void swap_sdl(void)
 311 {
 312         SDL_GL_SwapWindow(gl_window);
 313 }
 314
 315 void exit_sdl(void)
 316 {
 317         /* close window */
 318         if (gl_window) {
 319                 SDL_DestroyWindow(gl_window);
 320                 gl_window = NULL;
 321         }
 322
 323         /* clear OpenGL context */
 324         if (gl_context) {
 325                 SDL_GL_DeleteContext(gl_context);
 326                 gl_context = NULL;
 327         }
 328
 329         /* exit SDL library */
 330         if (audio_initialized) {
 331                 SDL_PauseAudio(1);
 332                 SDL_CloseAudio();
 333                 audio_initialized = 0;
 334         }
 335         if (sdl_initialized) {
 336                 SDL_Quit();
 337                 sdl_initialized = 0;
 338         }
 339 }
 340
 341 uint32_t ticks_sdl(void)
 342 {
 343         return SDL_GetTicks();
 344 }