src/mercenary/main.c

   1 /* main routine
   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 <stdlib.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include "../libsdl/sdl.h"
  26 #include "../libsdl/opengl.h"
  27 #include "../libsdl/print.h"
  28 #include "../libcpu/m68k.h"
  29 #include "../libcpu/execute.h"
  30 #include "../libvideo/video.h"
  31 #include "../libsound/sound.h"
  32 #include "../libjoystick/joystick.h"
  33 #include "../libkeyboard/keyboard.h"
  34 #include "../libdisk/disk.h"
  35 #include "mercenary.h"
  36 #include "render.h"
  37
  38 static int config_amiga_speed = 1;
  39 static const char *config_gamesave_dir = ".mercenary";
  40 static int config_video_filter = 1;
  41 static int config_audio_filter = 1;
  42 static int config_render = 0;
  43 static int config_skip_intro = 0;
  44 static int config_debug_opengl = 0;
  45
  46 #define CPU_SPEED       7093790.0;
  47
  48 #define SOUND_SAMPLERATE 48000
  49 /* - game IRQ rate
  50  * - must be used for sound rendering chunk
  51  */
  52 #define IRQ_RATE        50
  53 /* numbe of buffer chunks to dejitter:
  54  * - SDL render interval
  55  * - sound rendering interval
  56  * - sound card interval
  57  * 4 should be minimum, if video rate is >=50 Hz
  58  */
  59 #define SOUND_CHUNKS    4
  60
  61 /* test sound to check if buffer does not overflow / underrun */
  62 //#define DEBUG_SOUND_BUFFERING
  63
  64 #define IOSIZE          0x1000 /* bytes in io space */
  65 #define MEMORY_SIZE     0x80000
  66 static uint8_t *memory = NULL;
  67 static uint8_t *stop_event = NULL;
  68 static uint8_t *image = NULL;
  69 #define SCREEN_WIDTH    320
  70 #define SCREEN_HEIGHT   200
  71 #define IMAGE_WIDTH     320
  72 #define IMAGE_HEIGHT    200
  73 #define BENSON_AT_LINE  136
  74 #define IMAGE_DIWSTART  0x2c
  75 static uint16_t *chipreg = NULL;
  76 static stereo_t *sound_buffer = NULL; /* sound buffer memory */
  77 static int sound_buffer_size; /* buffer sample size */
  78 static int sound_buffer_writep; /* write pointer at buffer */
  79 static int sound_buffer_readp; /* read pointer at buffer */
  80 static int double_size = 1; /* render in double size, so each pixle is 2*2 pixles wide */
  81 static int render_legacy = 0; /* render original amiga screen, if set */
  82 static int render_improved = 0; /* render improved image, if set */
  83 static int render_debug = 0; /* render both, amiga screen and  improved image, if set */
  84
  85 static const char *home_dir;
  86
  87 static int quit = 0;
  88
  89 int parse_args(int argc, char *argv[])
  90 {
  91         int i = 1;
  92
  93         while (argc > i) {
  94                 if (!strcmp(argv[i], "-h") || !strcmp(argv[i], "--help")) {
  95                         print_info("Usage: %s\n", argv[0]);
  96                         print_info(" -s --amiga-speed original | full\n");
  97                         print_info("        Set speed of rendering to original Amiga or full speed.\n");
  98                         print_info(" -v --video-filter on | off\n");
  99                         print_info("        Set video filter.\n");
 100                         print_info(" -a --audio-filter on | off\n");
 101                         print_info("        Set audio filter.\n");
 102                         print_info(" -r --render original | opegl\n");
 103                         print_info("        Set speed of rendering to original Amiga or full speed.\n");
 104                         print_info(" -i --skip-intro\n");
 105                         print_info("        Skip intro sequence approaching to Eris space port.\n");
 106                         print_info("Debug options:\n");
 107                         print_info(" -o --debug-opengl\n");
 108                         print_info("        Use split screen to debug opengl rendering vs. amiga rendering.\n");
 109                         return -1;
 110                 } else
 111                 if (!strcmp(argv[i], "-s") || !strcmp(argv[i], "--amiga-speed")) {
 112                         i++;
 113                         if (argc == i) {
 114 missing_parameter:
 115                                 print_info("Missing parameter, use '--help'!\n");
 116                                 return -1;
 117                         }
 118                         if (!strcmp(argv[i], "original"))
 119                                 config_amiga_speed = 1;
 120                         else
 121                         if (!strcmp(argv[i], "full"))
 122                                 config_amiga_speed = 0;
 123                         else {
 124 illegal_parameter:
 125                                 print_info("Illegal parameter, use '--help'!\n");
 126                                 return -1;
 127                         }
 128                 } else
 129                 if (!strcmp(argv[i], "-v") || !strcmp(argv[i], "--video-filter")) {
 130                         i++;
 131                         if (argc == i)
 132                                 goto missing_parameter;
 133                         if (!strcmp(argv[i], "on"))
 134                                 config_video_filter = 1;
 135                         else
 136                         if (!strcmp(argv[i], "off"))
 137                                 config_video_filter = 0;
 138                         else
 139                                 goto illegal_parameter;
 140                 } else
 141                 if (!strcmp(argv[i], "-a") || !strcmp(argv[i], "--audio-filter")) {
 142                         i++;
 143                         if (argc == i)
 144                                 goto missing_parameter;
 145                         if (!strcmp(argv[i], "on"))
 146                                 config_audio_filter = 1;
 147                         else
 148                         if (!strcmp(argv[i], "off"))
 149                                 config_audio_filter = 0;
 150                         else
 151                                 goto illegal_parameter;
 152                 } else
 153                 if (!strcmp(argv[i], "-r") || !strcmp(argv[i], "--render")) {
 154                         i++;
 155                         if (argc == i)
 156                                 goto missing_parameter;
 157                         if (!strcmp(argv[i], "original"))
 158                                 config_render = 0;
 159                         else
 160                         if (!strcmp(argv[i], "opengl"))
 161                                 config_render = 1;
 162                         else
 163                                 goto illegal_parameter;
 164                 } else
 165                 if (!strcmp(argv[i], "-i") || !strcmp(argv[i], "--skip-intro")) {
 166                         config_skip_intro = 1;
 167                 } else
 168                 if (!strcmp(argv[i], "-o") || !strcmp(argv[i], "--debug-opengl")) {
 169                         config_debug_opengl = 1;
 170                 } else {
 171                         print_info("Illegal option '%s', use '--help'!\n", argv[i]);
 172                         return -1;
 173                 }
 174                 i++;
 175         }
 176
 177         return 0;
 178 }
 179
 180 static void special_event(int event)
 181 {
 182         if (render_improved)
 183                 render_improved_event(event);
 184 }
 185
 186 static void main_loop(void)
 187 {
 188         int had_first_irq = 0;
 189         static uint32_t current_time, last_time = 0, diff;
 190         int i, rc;
 191         int space, length;
 192         int cycle_count, event;
 193         double render_delay = 0.0;
 194         uint32_t palette_address;
 195         uint16_t palette[16];
 196
 197         last_time = SDL_GetTicks();
 198
 199         /* render result on window */
 200         while (!quit) {
 201                 /* handle SDL events */
 202                 rc = event_sdl();
 203                 if (rc)
 204                         break;
 205
 206                 /* clear screen */
 207                 opengl_clear();
 208
 209                 /* initialize rendering */
 210                 render_debug = config_debug_opengl;
 211                 render_legacy = (!config_render) || render_debug;
 212                 render_improved = config_render || render_debug;
 213                 /* start rendering for improved graphics */
 214                 if (render_improved)
 215                         opengl_viewport_improved(render_debug, (double_size) ? BENSON_AT_LINE * 2 : BENSON_AT_LINE);
 216
 217                 /* STEP 1: let the CPU render/process the game */
 218                 /* don't render if we still delay */
 219                 if (!render_delay) {
 220                         /* execute until the rendered image is ready (wait for VBL) */
 221                         cycle_count = 0;
 222                         do {
 223                                 cycle_count += execute_cpu(0, &event);
 224                                 /* handle special events */
 225                                 if (event != STOP_AT_WAIT_VBL)
 226                                         special_event(event);
 227                         } while (event != STOP_AT_WAIT_VBL);
 228                         /* copy palette */
 229                         palette_address = mercenary_palette();
 230                         for (i = 0; i < 16; i++)
 231                                 palette[i] = m68k_read_memory_16(palette_address + i*2);
 232                         /* for amiga speed: set delay by the number of cycles */
 233                         if (config_amiga_speed)
 234                                 render_delay = (double)cycle_count / CPU_SPEED;
 235                 }
 236
 237                 /* STEP 2: transfer legacy image in memory to OpenGL texture */
 238                 if (had_first_irq) {
 239                         /* render game view without benson
 240                          * because benson is not updated before VBL IRQ, we don't want old image from double buffer
 241                          */
 242                         if (render_legacy)
 243                                 emul_video(image, memory, palette, IMAGE_WIDTH, IMAGE_HEIGHT, IMAGE_DIWSTART, chipreg, 0, BENSON_AT_LINE, double_size);
 244                 }
 245                 /* render benson on improved rendering, if enabled */
 246                 if (render_improved)
 247                         opengl_render_benson(image, config_video_filter, (double_size) ? BENSON_AT_LINE * 2 : BENSON_AT_LINE);
 248                 /* setup viewport for legacy image and render image, if enabled */
 249                 if (render_legacy) {
 250                         opengl_viewport_legacy(render_debug);
 251                         opengl_render_legacy(image, config_video_filter);
 252                 }
 253                 swap_sdl();
 254
 255                 /* STEP 3: execute interrupt at rate of 50Hz, render sound */
 256                 current_time = SDL_GetTicks();
 257                 diff = current_time - last_time;
 258                 /* in case of timer glitch, execute IRQ only by maximum number of SOUND_CHUNKS */
 259                 if (diff > 1000 * SOUND_CHUNKS / IRQ_RATE) {
 260                         diff = 1000 * SOUND_CHUNKS / IRQ_RATE;
 261                         last_time = current_time - 1000 * SOUND_CHUNKS / IRQ_RATE;
 262                 }
 263                 while (diff > 1000 / IRQ_RATE) {
 264                         execute_cpu(3, NULL);
 265                         execute_cpu(4, NULL);
 266                         had_first_irq = 1;
 267                         /* render benson without game view
 268                          * because we only got benson refreshed during VBL IRQ
 269                          */
 270                         emul_video(image, memory, palette, IMAGE_WIDTH, IMAGE_HEIGHT, IMAGE_DIWSTART, chipreg, BENSON_AT_LINE, IMAGE_HEIGHT, double_size);
 271                         /* render sound to sound buffer
 272                          * buffer pointer read and write is atomic, so no locking required!
 273                          */
 274                         space = (sound_buffer_readp - sound_buffer_writep - 1 + sound_buffer_size) % sound_buffer_size;
 275                         if (space < SOUND_SAMPLERATE / IRQ_RATE) {
 276 #ifdef DEBUG_SOUND_BUFFERING
 277                                 fprintf(stderr, "sound buffer overflow\n");
 278 #endif
 279                                 length = space;
 280                         } else
 281                                 length = SOUND_SAMPLERATE / IRQ_RATE;
 282 #ifdef DEBUG_SOUND_BUFFERING
 283                         printf("can write %d, write %d\n", space, length);
 284                         static int cnt = 0;
 285                         int s;
 286                         for (s = 0; s < length; s++) {
 287                                 sound_buffer[(sound_buffer_writep + s) % sound_buffer_size].left =
 288                                 sound_buffer[(sound_buffer_writep + s) % sound_buffer_size].right
 289                                         = sin(2 * M_PI * 999 * cnt / SOUND_SAMPLERATE)
 290                                         * sin(2 * M_PI * 21 * cnt / SOUND_SAMPLERATE)
 291                                         * sin(2 * M_PI * 0.5 * cnt / SOUND_SAMPLERATE);
 292                                  cnt++;
 293                         }
 294 #else
 295                         render_sound(memory, sound_buffer, sound_buffer_size, sound_buffer_writep, length, config_audio_filter);
 296 #endif
 297                         sound_buffer_writep = (sound_buffer_writep + length) % sound_buffer_size;
 298                         diff -= 1000 / IRQ_RATE;
 299                         last_time += 1000 / IRQ_RATE;
 300
 301                         /* count down render delay */
 302                         if (render_delay) {
 303                                 render_delay -= 1.0 / (double)IRQ_RATE;
 304                                 if (render_delay < 0.0)
 305                                         render_delay = 0.0;
 306                         }
 307                 }
 308         }
 309 }
 310
 311 static uint16_t io_read(uint32_t address)
 312 {
 313         uint16_t value = 0xffff;
 314
 315         /* joystick and fire button */
 316         if (address == 0xbfe000 || address == 0xdff00c)
 317                 value &= emulate_joystick_read(address);
 318         /* keyboard */
 319         if (address == 0xbfec00 || address == 0xbfed00 || address == 0xbfee00)
 320                 value &= emulate_keyboard_read(address);
 321         /* diskette */
 322         if (address == 0xbfd100 || address == 0xbfe000 || address == 0xdff01a || address == 0xdff01e)
 323                 value &= emulate_disk_read(address);
 324
 325         return value;
 326 }
 327
 328 static void io_write(uint32_t address, uint16_t value)
 329 {
 330         /* dmacon and sound registers */
 331         if (address == 0xdff096 || (address >= 0xdff0a0 && address <= 0xdff0df))
 332                 emulate_sound_write(address, value, SOUND_SAMPLERATE);
 333         if (address == 0xbfd100 || (address >= 0xdff020 && address <= 0xdff024))
 334                 emulate_disk_write(address, value);
 335 }
 336
 337 /* two tracks with 0x1820 words of length */
 338 static uint8_t game_save[2][0x1820 << 1];
 339 static int last_track = 0;
 340
 341 /* game reads track with saved game */
 342 static void disk_read(int track, int __attribute__((unused)) side, uint32_t data, uint16_t length)
 343 {
 344         if (length > sizeof(game_save[0])) {
 345                 print_error("loading game state failed, because length exceeds game save data size, please fix!\n");
 346                 return;
 347         }
 348
 349         /* if even track is selected, load game */
 350         if (!(track & 1)) {
 351                 char filename[256];
 352                 int gamesave_num = (track - 2) >> 1;
 353                 int got;
 354                 FILE *fp;
 355
 356                 memset(game_save, 0, sizeof(game_save)); /* clear so make the game fail, if we fail */
 357 #if defined(_WIN32)
 358                 filename[0] = '\0';
 359 #else
 360                 sprintf(filename, "%s/%s/", home_dir, config_gamesave_dir);
 361                 mkdir(filename, 0777);
 362 #endif
 363                 sprintf(filename + strlen(filename), "%d%s", gamesave_num, mercenary_gamesavesuffix);
 364                 fp = fopen(filename, "r");
 365                 if (!fp) {
 366 fail:
 367                         print_error("failed to load game from '%s'\n", filename);
 368                         goto copy;
 369                 }
 370                 got = fread(game_save, sizeof(game_save[0]), 2, fp);
 371                 fclose(fp);
 372                 if (got != 2)
 373                         goto fail;
 374         }
 375
 376 copy:
 377         /* copy track */
 378         memcpy(memory + data, game_save[track & 1], length /* sizeof(game_save[0])*/);
 379 }
 380
 381 /* game writes track with saved game */
 382 static void disk_write(int track, int __attribute__((unused)) side, uint32_t data, uint16_t length)
 383 {
 384         /* skip sync info that is provided by game and only relevant for a real disk track */
 385         data += 0x200;
 386         length -= 0x200;
 387
 388         if (length != sizeof(game_save[0])) {
 389                 print_error("saving game state failed, because length of data does not match, please fix!\n");
 390                 return;
 391         }
 392
 393         /* don't save if last track is the same, because disk is written on both sides with the same data */
 394         if (track == last_track) {
 395                 if (memcmp(memory + data, game_save[track & 1], length)) {
 396                         print_error("saving game data on other side of the disk is different, please fix!\n");
 397                 }
 398                 return;
 399         }
 400         last_track = track;
 401
 402         /* save game data */
 403         memcpy(game_save[track & 1], memory + data, length);
 404
 405         /* if done with saving */
 406         if ((track & 1)) {
 407                 char filename[256];
 408                 int gamesave_num = (track - 2) >> 1;
 409                 int wrote;
 410                 FILE *fp;
 411
 412 #if defined(_WIN32)
 413                 filename[0] = '\0';
 414 #else
 415                 sprintf(filename, "%s/%s/", home_dir, config_gamesave_dir);
 416                 mkdir(filename, 0777);
 417 #endif
 418                 sprintf(filename + strlen(filename), "%d%s", gamesave_num, mercenary_gamesavesuffix);
 419                 fp = fopen(filename, "w");
 420                 if (!fp) {
 421 fail:
 422                         print_error("failed to save game to '%s'\n", filename);
 423                         return;
 424                 }
 425                 print_info("Game state saved to '%s'\n", filename);
 426                 wrote = fwrite(game_save, sizeof(game_save[0]), 2, fp);
 427                 fclose(fp);
 428                 if (wrote != 2)
 429                         goto fail;
 430         }
 431 }
 432
 433 static int shift = 0, ctrl = 0;
 434
 435 static void keyboard_sdl(int down, SDL_Keycode sym)
 436 {
 437         switch (sym) {
 438         case SDLK_LCTRL:
 439         case SDLK_RCTRL:
 440                 ctrl = down;
 441                 break;
 442         case SDLK_v:
 443                 if (down && ctrl) {
 444                         config_video_filter ^= 1;
 445                         print_info("video filter: %s\n", (config_video_filter) ? "on" : "off");
 446                 }
 447                 break;
 448         case SDLK_a:
 449                 if (down && ctrl) {
 450                         config_audio_filter ^= 1;
 451                         print_info("audio filter: %s\n", (config_audio_filter) ? "on" : "off");
 452                 }
 453                 break;
 454         case SDLK_s:
 455                 if (down && ctrl) {
 456                         config_amiga_speed ^= 1;
 457                         print_info("amiga speed: %s\n", (config_amiga_speed) ? "original" : "full");
 458                 }
 459                 break;
 460         case SDLK_r:
 461                 if (down && ctrl) {
 462                         config_render ^= 1;
 463                         printf("render: %s\n", (config_render) ? "opengl" : "original");
 464                 }
 465                 break;
 466         case SDLK_c:
 467                 if (down)
 468                         quit = 1;
 469                 break;
 470         }
 471
 472         switch (sym) {
 473         case SDLK_LSHIFT:
 474                 set_key("LSH", down);
 475                 shift = down;
 476                 break;
 477         case SDLK_RSHIFT:
 478                 set_key("RSH", down);
 479                 shift = down;
 480                 break;
 481         case SDLK_LEFT:
 482                 if (shift && down) {
 483                         set_key("LF", down);
 484                         set_joystick(-1, -1, -1, -1, -1);
 485                         break;
 486                 }
 487                 set_key("LF", 0);
 488                 set_joystick(down, -1, -1, -1, -1);
 489                 break;
 490         case SDLK_RIGHT:
 491                 if (shift && down) {
 492                         set_key("RT", down);
 493                         set_joystick(-1, -1, -1, -1, -1);
 494                         break;
 495                 }
 496                 set_key("RT", 0);
 497                 set_joystick(-1, down, -1, -1, -1);
 498                 break;
 499         case SDLK_UP:
 500                 if (shift && down) {
 501                         set_key("UP", down);
 502                         set_joystick(-1, -1, -1, -1, -1);
 503                         break;
 504                 }
 505                 set_key("UP", 0);
 506                 set_joystick(-1, -1, down, -1, -1);
 507                 break;
 508         case SDLK_DOWN:
 509                 if (shift && down) {
 510                         set_key("DN", down);
 511                         set_joystick(-1, -1, -1, -1, -1);
 512                         break;
 513                 }
 514                 set_key("DN", 0);
 515                 set_joystick(-1, -1, -1, down, -1);
 516                 break;
 517         case SDLK_END:
 518                 set_joystick(-1, -1, -1, -1, down);
 519                 break;
 520
 521         case SDLK_a: set_key("A", down); break;
 522         case SDLK_b: set_key("B", down); break;
 523         case SDLK_c: set_key("C", down); break;
 524         case SDLK_d: set_key("D", down); break;
 525         case SDLK_e: set_key("E", down); break;
 526         case SDLK_f: set_key("F", down); break;
 527         case SDLK_g: set_key("G", down); break;
 528         case SDLK_h: set_key("H", down); break;
 529         case SDLK_i: set_key("I", down); break;
 530         case SDLK_j: set_key("J", down); break;
 531         case SDLK_k: set_key("K", down); break;
 532         case SDLK_l: set_key("L", down); break;
 533         case SDLK_m: set_key("M", down); break;
 534         case SDLK_n: set_key("N", down); break;
 535         case SDLK_o: set_key("O", down); break;
 536         case SDLK_p: set_key("P", down); break;
 537         case SDLK_q: set_key("Q", down); break;
 538         case SDLK_r: set_key("R", down); break;
 539         case SDLK_s: set_key("S", down); break;
 540         case SDLK_t: set_key("T", down); break;
 541         case SDLK_u: set_key("U", down); break;
 542         case SDLK_v: set_key("V", down); break;
 543         case SDLK_w: set_key("W", down); break;
 544         case SDLK_x: set_key("X", down); break;
 545         case SDLK_y: set_key("Y", down); break;
 546         case SDLK_z: set_key("Z", down); break;
 547
 548         case SDLK_0: set_key("0", down); break;
 549         case SDLK_1: set_key("1", down); break;
 550         case SDLK_2: set_key("2", down); break;
 551         case SDLK_3: set_key("3", down); break;
 552         case SDLK_4: set_key("4", down); break;
 553         case SDLK_5: set_key("5", down); break;
 554         case SDLK_6: set_key("6", down); break;
 555         case SDLK_7: set_key("7", down); break;
 556         case SDLK_8: set_key("8", down); break;
 557         case SDLK_9: set_key("9", down); break;
 558
 559         case SDLK_KP_0: set_key("NP0", down); break;
 560         case SDLK_KP_1: set_key("NP1", down); break;
 561         case SDLK_KP_2: set_key("NP2", down); break;
 562         case SDLK_KP_3: set_key("NP3", down); break;
 563         case SDLK_KP_4: set_key("NP4", down); break;
 564         case SDLK_KP_5: set_key("NP5", down); break;
 565         case SDLK_KP_6: set_key("NP6", down); break;
 566         case SDLK_KP_7: set_key("NP7", down); break;
 567         case SDLK_KP_8: set_key("NP8", down); break;
 568         case SDLK_KP_9: set_key("NP9", down); break;
 569         case SDLK_KP_DIVIDE: set_key("NPDIV", down); break;
 570         case SDLK_KP_MULTIPLY: set_key("NPMUL", down); break;
 571         case SDLK_KP_MINUS: set_key("NPSUB", down); break;
 572         case SDLK_KP_PLUS: set_key("NPADD", down); break;
 573         case SDLK_KP_PERIOD: set_key("NPDEL", down); break;
 574         // NPLPAREN and NPRPAREN are not emulated
 575
 576         case SDLK_F1: set_key("F1", down); break;
 577         case SDLK_F2: set_key("F2", down); break;
 578         case SDLK_F3: set_key("F3", down); break;
 579         case SDLK_F4: set_key("F4", down); break;
 580         case SDLK_F5: set_key("F5", down); break;
 581         case SDLK_F6: set_key("F6", down); break;
 582         case SDLK_F7: set_key("F7", down); break;
 583         case SDLK_F8: set_key("F8", down); break;
 584         case SDLK_F9: set_key("F9", down); break;
 585         case SDLK_F10: set_key("F10", down); break;
 586
 587         case SDLK_SPACE: set_key("SPC", down); break;
 588         case SDLK_BACKSPACE: set_key("BS", down); break;
 589         case SDLK_TAB: set_key("TAB", down); break;
 590         case SDLK_KP_ENTER: set_key("ENT", down); break;
 591         case SDLK_RETURN: set_key("RET", down); break;
 592         case SDLK_ESCAPE: set_key("ESC", down); break;
 593         case SDLK_DELETE: set_key("DEL", down); break;
 594         case SDLK_INSERT: set_key("HELP", down); break;
 595
 596         }
 597 }
 598
 599 void audio_sdl(float *data, int length)
 600 {
 601         int fill, s;
 602
 603         /* read sound from sound buffer
 604          * buffer pointer read and write is atomic, so no locking required!
 605          */
 606         fill = (sound_buffer_writep - sound_buffer_readp + sound_buffer_size) % sound_buffer_size;
 607         if (fill < length) {
 608 #ifdef DEBUG_SOUND_BUFFERING
 609                 fprintf(stderr, "sound buffer underrun\n");
 610 #endif
 611                 /* correct read pointer as if the buffer would have 'length' of samples stored inside */
 612                 sound_buffer_readp = (sound_buffer_readp + fill - length + sound_buffer_size) % sound_buffer_size;
 613         }
 614         for (s = 0; s < length; s++) {
 615                 *data++ = sound_buffer[(sound_buffer_readp + s) % sound_buffer_size].left;
 616                 *data++ = sound_buffer[(sound_buffer_readp + s) % sound_buffer_size].right;
 617         }
 618 #ifdef DEBUG_SOUND_BUFFERING
 619         printf("fill %d = %.4f\n", length, sound_buffer[sound_buffer_readp][0]);
 620 #endif
 621         sound_buffer_readp =(sound_buffer_readp + length) % sound_buffer_size;
 622 }
 623
 624 int main(int argc, char *argv[])
 625 {
 626         int rc;
 627         int sdl_sound_chunk;
 628
 629         home_dir = getenv("HOME");
 630         if (!home_dir)
 631                 home_dir = "";
 632
 633         rc = parse_args(argc, argv);
 634         if (rc)
 635                 return 0;
 636
 637         /* allocate image */
 638         image = calloc(IMAGE_WIDTH * IMAGE_HEIGHT * ((double_size) ? 4 : 1), 3);
 639         if (!image) {
 640                 print_error("Failed to allocate image buffer\n");
 641                 goto done;
 642         }
 643
 644         if ((SOUND_SAMPLERATE % IRQ_RATE)) {
 645                 print_error("Sample rate must be a multiple of IRQ rate, please fix!\n");
 646                 goto done;
 647         }
 648         if ((1000 % IRQ_RATE)) {
 649                 print_error("1000 (Ticks per second) rate must be a multiple of IRQ rate, please fix!\n");
 650                 goto done;
 651         }
 652
 653         /* calculate SDL chunk size for audio
 654          * it must be a power of two, but not more than the chunk size for each IRQ!
 655          */
 656         for (sdl_sound_chunk = 2; sdl_sound_chunk <= (SOUND_SAMPLERATE / IRQ_RATE); sdl_sound_chunk <<= 1)
 657                 ;
 658         sdl_sound_chunk >>= 1;
 659 //      printf("samples per IRQ = %d, samples per SDL audio = %d\n", SOUND_SAMPLERATE / IRQ_RATE, sdl_sound_chunk); exit(0);
 660
 661         /* allocate sound buffers */
 662         sound_buffer_size = SOUND_SAMPLERATE / IRQ_RATE * SOUND_CHUNKS;
 663         sound_buffer = calloc(sound_buffer_size, sizeof(*sound_buffer));
 664         if (!sound_buffer) {
 665                 print_error("Failed to allocate image buffer\n");
 666                 goto done;
 667         }
 668
 669         /* allocate memory */
 670         memory = calloc(MEMORY_SIZE, 1);
 671         if (!memory) {
 672                 print_error("Failed to allocate cpu's memory\n");
 673                 goto done;
 674         }
 675         stop_event = calloc(MEMORY_SIZE, 1);
 676         if (!stop_event) {
 677                 print_error("Failed to allocate cpu's stop_event memory\n");
 678                 goto done;
 679         }
 680         chipreg = calloc(IOSIZE, 1);
 681         if (!chipreg) {
 682                 print_error("Failed to allocate chip register\n");
 683                 goto done;
 684         }
 685
 686         /* init cpu code */
 687         execute_init(MEMORY_SIZE, memory, stop_event, chipreg, io_read, io_write, mercenary_stop_at);
 688
 689         /* init disk emulation */
 690         disk_init(disk_read, disk_write);
 691
 692         /* load binary */
 693         mercenary_load();
 694
 695         /* patch some stuff */
 696         mercenary_patch();
 697
 698         /* init SDL and OpenGL */
 699         rc = init_sdl(argv[0], (config_debug_opengl) ? SCREEN_WIDTH * 2 : SCREEN_WIDTH * 3, (config_debug_opengl) ? SCREEN_HEIGHT * 4 : SCREEN_HEIGHT * 3, SOUND_SAMPLERATE, sdl_sound_chunk, keyboard_sdl, audio_sdl);
 700         if (rc < 0)
 701                 goto done;
 702         rc = init_opengl((double_size) ? IMAGE_WIDTH * 2 : IMAGE_WIDTH, (double_size) ? IMAGE_HEIGHT * 2 : IMAGE_HEIGHT);
 703         if (rc < 0)
 704                 goto done;
 705         resize_opengl((config_debug_opengl) ? SCREEN_WIDTH * 2 : SCREEN_WIDTH * 3, (config_debug_opengl) ? SCREEN_HEIGHT * 4 : SCREEN_HEIGHT * 3);
 706
 707         /* init audio filter */
 708         sound_init_filter(SOUND_SAMPLERATE);
 709
 710         /* start cpu */
 711         reset_cpu();
 712
 713         if (config_skip_intro) {
 714                 int event;
 715
 716                 print_info("*** Skipping intro, fast forwarding... ***\n\n");
 717                 do {
 718                         execute_cpu(0, &event);
 719                 } while (event != STOP_AT_CLEAR_SCREEN1);
 720                 do {
 721                         execute_cpu(0, &event);
 722                 } while (event != STOP_AT_WAIT_VBL);
 723         }
 724
 725         print_info("**********************************\n");
 726         print_info("* Welcome to Mercenary Reloaded! *\n");
 727         print_info("**********************************\n\n");
 728         print_info("Press CTRL + cursor keys to select inventory or pickup/drop item.\n");
 729         print_info("Press CTRL + f to toggle full screen.\n");
 730         print_info("Press CTRL + s to toggle rendering speed.\n");
 731         print_info("Press CTRL + v to toggle video filter.\n");
 732         print_info("Press CTRL + a to toggle audio filter.\n");
 733         print_info("Press CTRL + r to toggle rendering with opengl or orignal code.\n");
 734         print_info("Press CTRL + c to exit game.\n\n");
 735         print_info("Use '--help' as command line option for configuration settings.\n\n");
 736
 737         /* run game */
 738         main_loop();
 739
 740 done:
 741         exit_opengl();
 742         exit_sdl();
 743
 744         if (chipreg)
 745                 free(chipreg);
 746         if (stop_event)
 747                 free(stop_event);
 748         if (memory)
 749                 free(memory);
 750         if (sound_buffer)
 751                 free(sound_buffer);
 752         if (image)
 753                 free(image);
 754
 755         return 0;
 756 }
 757