Fixing audio interrupt handling (unknown if it works)
[mercenary-reloaded.git] / 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 "../libframerate/framerate.h"
31 #include "../libvideo/video.h"
32 #include "../libsound/sound.h"
33 #include "../libjoystick/joystick.h"
34 #include "../libkeyboard/keyboard.h"
35 #include "../libdisk/disk.h"
36 #include "../libtext/text.h"
37 #include "mercenary.h"
38 #include "render.h"
39
40 #define FOV_MIN         10.0
41 #define FOV_NOVAGEN     64.0
42 #define FOV_JOLLY       80.0
43 #define FOV_MAX         170.0
44
45 static int config_ctrl_c = 0;
46 static int config_amiga_speed = 1;
47 #warning fixme: make use of 10 for intro, then be as fast as given
48 static double config_fps = 16.0;
49 static const char *config_gamesave_dir = ".mercenary";
50 static int config_video_filter = 1;
51 static int config_audio_filter = 1;
52 static int config_render = 0;
53 static int config_skip_intro = 0;
54 static int config_multisampling = 16;
55 static double config_fov = FOV_NOVAGEN;
56 static double config_benson_size = 1.0;
57 static int config_debug_transparent = 0;
58 static int config_debug_opengl = 0;
59 /* render improvements */
60 static int config_improve_extend_roads = 1;     /* set to 1 to extend roads */
61
62 #define CPU_SPEED       7093790.0;
63
64 #define SOUND_SAMPLERATE 48000
65 /* - game IRQ rate
66  * - must be used for sound rendering chunk
67  */
68 #define IRQ_RATE        50
69 /* numbe of buffer chunks to dejitter:
70  * - SDL render interval
71  * - sound rendering interval
72  * - sound card interval
73  * 4 should be minimum, if video rate is >=50 Hz
74  */
75 #define SOUND_CHUNKS    4
76
77 /* test sound to check if buffer does not overflow / underrun */
78 //#define DEBUG_SOUND_BUFFERING
79
80 #define IOSIZE          0x1000 /* bytes in io space */
81 #define MEMORY_SIZE     0x80000
82 static uint8_t *memory = NULL;
83 static uint8_t *stop_event = NULL;
84 static uint8_t *image = NULL;
85 static uint8_t *help_osd = NULL;
86 static uint8_t *info_osd = NULL;
87 static int help_view = 1;
88 static int32_t osd_timer = 0;
89 #define SCREEN_WIDTH    320
90 #define SCREEN_HEIGHT   200
91 #define IMAGE_WIDTH     320
92 #define IMAGE_HEIGHT    200
93 #define BENSON_AT_LINE  136
94 #define IMAGE_DIWSTART  0x2c
95 #define HELP_ALPHA      0xd0
96 #define OSD_WIDTH       320
97 #define OSD_HEIGHT      16
98 static uint16_t *chipreg = NULL;
99 static stereo_t *sound_buffer = NULL; /* sound buffer memory */
100 static int sound_buffer_size; /* buffer sample size */
101 static int sound_buffer_writep; /* write pointer at buffer */
102 static int sound_buffer_readp; /* read pointer at buffer */
103 static int double_pixel_size = 1; /* render in double size, so each pixle is 2*2 pixles wide */
104 static double benson_size; /* render size of benson */
105 static int render_legacy = 0; /* render original amiga screen, if set */
106 static int render_improved = 0; /* render improved image, if set */
107 static int debug_opengl = 0; /* render both, amiga screen and  improved image, if set */
108 static int intro_skipped = 0; /* indicated if we already have landed */
109
110 static const char *home_dir;
111
112 static int quit = 0;
113
114 int parse_args(int argc, char *argv[])
115 {
116         int i = 1;
117
118         while (argc > i) {
119                 if (!strcmp(argv[i], "-h") || !strcmp(argv[i], "--help")) {
120                         print_info("Usage: %s\n", argv[0]);
121                         print_info(" -s --render-speed original | fast\n");
122                         print_info("        Set speed of rendering to original Amiga or fast speed.\n");
123                         print_info("    --fps <fps>\n");
124                         print_info("        Set frames per second for fast rate (default = %.1f).\n", config_fps);
125                         print_info(" -v --video-filter on | off\n");
126                         print_info("        Set video filter.\n");
127                         print_info(" -a --audio-filter on | off\n");
128                         print_info("        Set audio filter.\n");
129                         print_info(" -r --render original | opengl\n");
130                         print_info("        Set speed of rendering to original Amiga or OpenGL.\n");
131                         print_info(" -b --benson normal | half\n");
132                         print_info("        Size of 'Benson' (control panel).\n");
133                         print_info(" -m --multisampling <samples>\n");
134                         print_info("        Use multisampling (default = %d) to render the scene.\n", config_multisampling);
135                         print_info(" -f --fov <%.0f..%.0f..%.0f>\n", FOV_MIN, FOV_NOVAGEN, FOV_MAX);
136                         print_info("        Set field-of-view. Default is %.0f.\n", FOV_NOVAGEN);
137                         print_info(" -i --skip-intro\n");
138                         print_info("        Skip intro sequence approaching to Eris space port.\n");
139                         print_info("Debug options:\n");
140                         print_info(" -o --debug-opengl\n");
141                         print_info("        Use split screen to display both Amiga and OpenGL rendering.\n");
142                         print_info("    --debug-transparent\n");
143                         print_info("        Draw all things half transparent.\n");
144                         print_info("    --ctrl-c\n");
145                         print_info("        Use CTRL+C to exit game (used for development)\n");
146                         return -1;
147                 } else
148                 if (!strcmp(argv[i], "-s") || !strcmp(argv[i], "--render-speed")) {
149                         i++;
150                         if (argc == i) {
151 missing_parameter:
152                                 print_info("Missing parameter, use '--help'!\n");
153                                 return -1;
154                         }
155                         if (!strcmp(argv[i], "original"))
156                                 config_amiga_speed = 1;
157                         else
158                         if (!strcmp(argv[i], "fast"))
159                                 config_amiga_speed = 0;
160                         else {
161 illegal_parameter:
162                                 print_info("Illegal parameter, use '--help'!\n");
163                                 return -1;
164                         }
165                 } else
166                 if (!strcmp(argv[i], "--fps")) {
167                         i++;
168                         if (argc == i)
169                                 goto missing_parameter;
170                         config_fps = atof(argv[i]);
171                         if (config_fov <= 0.0)
172                                 goto illegal_parameter;
173                 } else
174                 if (!strcmp(argv[i], "-v") || !strcmp(argv[i], "--video-filter")) {
175                         i++;
176                         if (argc == i)
177                                 goto missing_parameter;
178                         if (!strcmp(argv[i], "on"))
179                                 config_video_filter = 1;
180                         else
181                         if (!strcmp(argv[i], "off"))
182                                 config_video_filter = 0;
183                         else
184                                 goto illegal_parameter;
185                 } else
186                 if (!strcmp(argv[i], "-a") || !strcmp(argv[i], "--audio-filter")) {
187                         i++;
188                         if (argc == i)
189                                 goto missing_parameter;
190                         if (!strcmp(argv[i], "on"))
191                                 config_audio_filter = 1;
192                         else
193                         if (!strcmp(argv[i], "off"))
194                                 config_audio_filter = 0;
195                         else
196                                 goto illegal_parameter;
197                 } else
198                 if (!strcmp(argv[i], "-r") || !strcmp(argv[i], "--render")) {
199                         i++;
200                         if (argc == i)
201                                 goto missing_parameter;
202                         if (!strcmp(argv[i], "original"))
203                                 config_render = 0;
204                         else
205                         if (!strcmp(argv[i], "opengl"))
206                                 config_render = 1;
207                         else
208                                 goto illegal_parameter;
209                 } else
210                 if (!strcmp(argv[i], "-b") || !strcmp(argv[i], "--benson")) {
211                         i++;
212                         if (argc == i)
213                                 goto missing_parameter;
214                         if (!strcmp(argv[i], "normal"))
215                                 config_benson_size = 1.0;
216                         else
217                         if (!strcmp(argv[i], "half")) {
218                                 config_benson_size = 0.5;
219                                 if (config_fov == FOV_NOVAGEN)
220                                         config_fov = FOV_JOLLY;
221                         } else
222                                 goto illegal_parameter;
223                 } else
224                 if (!strcmp(argv[i], "-m") || !strcmp(argv[i], "--multisampling")) {
225                         i++;
226                         if (argc == i)
227                                 goto missing_parameter;
228                         config_multisampling = atoi(argv[i]);
229                 } else
230                 if (!strcmp(argv[i], "-f") || !strcmp(argv[i], "--fov")) {
231                         i++;
232                         if (argc == i)
233                                 goto missing_parameter;
234                         config_fov = atof(argv[i]);
235                         if (config_fov < 1.0 || config_fov > 179.0)
236                                 goto illegal_parameter;
237                 } else
238                 if (!strcmp(argv[i], "-i") || !strcmp(argv[i], "--skip-intro")) {
239                         config_skip_intro = 1;
240                 } else
241                 if (!strcmp(argv[i], "-o") || !strcmp(argv[i], "--debug-opengl")) {
242                         config_debug_opengl = 1;
243                 } else
244                 if (!strcmp(argv[i], "--debug-transparent")) {
245                         config_debug_transparent = 1;
246                 } else
247                 if (!strcmp(argv[i], "--ctrl-c")) {
248                         config_ctrl_c = 1;
249                 } else {
250                         print_info("Illegal option '%s', use '--help'!\n", argv[i]);
251                         return -1;
252                 }
253                 i++;
254         }
255
256         return 0;
257 }
258
259 static void skip_intro(void)
260 {
261         int event;
262         double render_delay = 0.0;
263         double cycle_count;
264
265         if (intro_skipped)
266                 return;
267
268         print_info("*** Skipping intro, fast forwarding... ***\n\n");
269         do {
270                 /* render, if not delayed */
271                 if (render_delay <= 0.0) {
272                         cycle_count = 0;
273                         do {
274                                 cycle_count += execute_cpu(0, &event);
275                         } while (event != STOP_AT_WAIT_VBL && event != STOP_AT_CLEAR_SCREEN1);
276                         render_delay += (double)cycle_count / CPU_SPEED;
277                 }
278                 /* VBL */
279                 execute_cpu(3, NULL);
280                 /* count down render delay */
281                 if (render_delay) {
282                         render_delay -= 1.0 / (double)IRQ_RATE;
283                         if (render_delay < 0.0)
284                                 render_delay = 0.0;
285                 }
286         } while (event != STOP_AT_CLEAR_SCREEN1);
287
288         intro_skipped = 1;
289 }
290
291 static void special_event(int event)
292 {
293         if (render_improved)
294                 render_capture_event(event);
295 }
296
297 static void main_loop(void)
298 {
299         double frame_step, frame_time = 0.0, frame_render = 1;
300         int had_first_irq = 0;
301         static uint32_t current_time, last_time = 0, diff;
302         int i, rc;
303         int space, length;
304         int cycle_count, event = STOP_AT_END;
305         double render_delay = 0.0;
306         uint32_t palette_address;
307         uint16_t palette[16];
308
309         last_time = SDL_GetTicks();
310
311         /* render result on window */
312         while (!quit) {
313 #warning oder ganz anders: bevor landung machen wir amiga-rate als interpolation
314                 /* if we are in interstellar fligt, we use 50 Hz */
315                 /* if we are approaching to Eris Space Port, we use 10 Hz */
316                 /* else we use whatever frame rate the user wants */
317                 if (render_capture_is_interstellar())
318                         frame_step = vbl_duration * 50.0;
319                 else
320                         frame_step = vbl_duration * config_fps;
321                 if (frame_step > 1.0)
322                         frame_step = 1.0;
323                 /* handle SDL events */
324                 rc = event_sdl();
325                 if (rc)
326                         break;
327
328                 /* clear screen */
329                 opengl_clear();
330
331                 /* initialize rendering */
332                 debug_opengl = config_debug_opengl;
333                 benson_size = config_benson_size;
334                 render_legacy = (!config_render) || debug_opengl;
335                 render_improved = config_render || debug_opengl;
336                 if (!render_improved) {
337                         /* be sure to clean all capture history, so we don't get glichtes when turning on improved rendering again */
338                         render_capture_reset();
339                 }
340                 if (render_improved) {
341                         opengl_viewport_improved(debug_opengl, (double_pixel_size) ? BENSON_AT_LINE * 2 : BENSON_AT_LINE, config_fov, benson_size);
342                         opengl_copy_last();
343                 }
344                 /* STEP 1: let the CPU render/process the game, also improve rendering via OpenGL, if enabled */
345                 /* amgia speed: don't render if we still delay */
346                 /* non amiga speed: render if we need a new frame */
347                 /* NOTE: at input event we must render after every VBL, so we do this in every loop */
348                 /* in case of help view: stop cpu after first IRQ, regardless of other options */
349                 /* NOTE: We need initial IRQ, so we have out copper list initialized */
350                 if (((frame_render && !config_amiga_speed)
351                   || (config_amiga_speed && render_delay <= 0.0)
352                   || event == STOP_AT_WAIT_INPUT)
353                 && !(had_first_irq && help_view)) {
354                         frame_render = 0;
355                         /* start capturing for improved graphics */
356                         if (render_improved)
357                                 render_capture_start(config_fov, config_improve_extend_roads, config_debug_transparent);
358
359                         /* execute until the rendered image is ready (wait for VBL) */
360                         cycle_count = 0;
361                         do {
362                                 cycle_count += execute_cpu(0, &event);
363                                 /* handle special events */
364                                 special_event(event);
365                                 if (event == STOP_AT_CLEAR_SCREEN1)
366                                         intro_skipped = 1;
367                         } while (event != STOP_AT_WAIT_VBL && event != STOP_AT_WAIT_INPUT);
368                         /* stop capturing for improved graphics */
369                         if (render_improved)
370                                 render_capture_stop();
371                         /* copy palette */
372                         palette_address = mercenary_palette_view();
373                         for (i = 0; i < 16; i++)
374                                 palette[i] = m68k_read_memory_16(palette_address + i*2);
375                         /* for amiga speed: set delay by the number of cycles */
376                         if (config_amiga_speed)
377                                 render_delay += (double)cycle_count / CPU_SPEED;
378                 }
379                 /* render improved graphics, interpolate, if required */
380                 if (render_improved)
381                         render_all_items((config_amiga_speed) ? 1.0 : frame_time);
382                 /* advance frame time, if we are not in help view  */
383                 if (!(had_first_irq && help_view)) {
384 //printf("frame rate: %.6f, frame-step=%.5f frame-time=%.5f\n", 1.0 / vbl_duration, frame_step,frame_time);
385                         frame_time += frame_step;
386                         if (frame_time >= 1.0) {
387                                 frame_time -= 1.0;
388                                 frame_render = 1;
389                         }
390                 }
391
392                 /* STEP 2: transfer legacy image (or just benson) in memory to OpenGL texture */
393                 if (had_first_irq) {
394                         /* render game view without benson
395                          * because benson is not updated before VBL IRQ, we don't want old image from double buffer
396                          */
397                         if (render_legacy)
398                                 emul_video(image, memory, palette, IMAGE_WIDTH, IMAGE_HEIGHT, IMAGE_DIWSTART, chipreg, 0, BENSON_AT_LINE, double_pixel_size);
399                 }
400                 /* render benson + osd ontop of improved opengl rendering, if enabled */
401                 if (render_improved) {
402                         opengl_blit_benson(image, config_video_filter, (double_pixel_size) ? BENSON_AT_LINE * 2 : BENSON_AT_LINE, config_fov, benson_size, (double_pixel_size) ? 2 : 1);
403                         if (help_view)
404                                 opengl_blit_osd(0, help_osd, config_video_filter, (double_pixel_size) ? BENSON_AT_LINE * 2 : BENSON_AT_LINE, config_fov, benson_size, 1.0, 1.0, 0.0, 0.0);
405                         if (osd_timer) {
406                                 opengl_blit_osd(1, info_osd, config_video_filter, (double_pixel_size) ? BENSON_AT_LINE * 2 : BENSON_AT_LINE, config_fov, benson_size, 0.5, 0.04, 0.5, -0.95);
407                                 if (osd_timer - (int32_t)SDL_GetTicks() < 0)
408                                         osd_timer = 0;
409                         }
410                 }
411                 /* setup viewport for legacy image and render image, if enabled */
412                 if (render_legacy) {
413                         opengl_viewport_legacy(debug_opengl);
414                         opengl_blit_legacy(image, config_video_filter);
415                         if (help_view)
416                                 opengl_blit_osd(0, help_osd, config_video_filter, 0, 0.0, 0, 1.0, 1.0, 0.0, 0.0);
417                         if (osd_timer) {
418                                 opengl_blit_osd(1, info_osd, config_video_filter, 0, 0.0, 0, 0.5, 0.04, 0.5, -0.95);
419                                 if (osd_timer - (int32_t)SDL_GetTicks() < 0)
420                                         osd_timer = 0;
421                         }
422                 }
423
424                 /* at this point we are ready with our image, so we display */
425                 swap_sdl();
426                 /* measure frame rate */
427                 framerate_measure();
428
429                 /* STEP 3: execute interrupt at rate of 50Hz, render sound */
430                 /* only do this, if we are not in help view */
431                 /* NOTE: We need initial IRQ, so we have out copper list initialized */
432                 if (!(had_first_irq && help_view)) {
433                         current_time = SDL_GetTicks();
434                         diff = current_time - last_time;
435                         /* in case of timer glitch, execute IRQ only by maximum number of SOUND_CHUNKS */
436                         if (diff > 1000 * SOUND_CHUNKS / IRQ_RATE) {
437                                 diff = 1000 * SOUND_CHUNKS / IRQ_RATE;
438                                 last_time = current_time - 1000 * SOUND_CHUNKS / IRQ_RATE;
439                         }
440                         while (diff > 1000 / IRQ_RATE) {
441                                 /* trigger and execute IRQ 3 = VBL */
442                                 execute_cpu(3, NULL);
443                                 had_first_irq = 1;
444                                 /* transfer benson without game view
445                                  * because we only got benson refreshed during VBL IRQ
446                                  */
447                                 emul_video(image, memory, palette, IMAGE_WIDTH, IMAGE_HEIGHT, IMAGE_DIWSTART, chipreg, BENSON_AT_LINE, IMAGE_HEIGHT, double_pixel_size);
448                                 /* render sound to sound buffer
449                                  * buffer pointer read and write is atomic, so no locking required!
450                                  */
451                                 space = (sound_buffer_readp - sound_buffer_writep - 1 + sound_buffer_size) % sound_buffer_size;
452                                 if (space < SOUND_SAMPLERATE / IRQ_RATE) {
453 #ifdef DEBUG_SOUND_BUFFERING
454                                         fprintf(stderr, "sound buffer overflow\n");
455 #endif
456                                         length = space;
457                                 } else
458                                         length = SOUND_SAMPLERATE / IRQ_RATE;
459 #ifdef DEBUG_SOUND_BUFFERING
460                                 printf("can write %d, write %d\n", space, length);
461                                 static int cnt = 0;
462                                 int s;
463                                 for (s = 0; s < length; s++) {
464                                         sound_buffer[(sound_buffer_writep + s) % sound_buffer_size].left =
465                                         sound_buffer[(sound_buffer_writep + s) % sound_buffer_size].right
466                                                 = sin(2 * M_PI * 999 * cnt / SOUND_SAMPLERATE)
467                                                 * sin(2 * M_PI * 21 * cnt / SOUND_SAMPLERATE)
468                                                 * sin(2 * M_PI * 0.5 * cnt / SOUND_SAMPLERATE);
469                                          cnt++;
470                                 }
471 #else
472                                 render_sound(memory, sound_buffer, sound_buffer_size, sound_buffer_writep, length, config_audio_filter);
473 #endif
474                                 sound_buffer_writep = (sound_buffer_writep + length) % sound_buffer_size;
475                                 diff -= 1000 / IRQ_RATE;
476                                 last_time += 1000 / IRQ_RATE;
477
478                                 /* count down render delay */
479                                 if (render_delay) {
480                                         render_delay -= 1.0 / (double)IRQ_RATE;
481                                         if (render_delay < 0.0)
482                                                 render_delay = 0.0;
483                                 }
484                         }
485                 }
486         }
487 }
488
489 static uint16_t io_read(uint32_t address)
490 {
491         uint16_t value = 0xffff;
492
493         /* joystick and fire button */
494         if (address == 0xbfe000 || address == 0xdff00c)
495                 value &= emulate_joystick_read(address);
496         /* keyboard */
497         if (address == 0xbfec00 || address == 0xbfed00 || address == 0xbfee00)
498                 value &= emulate_keyboard_read(address);
499         /* diskette */
500         if (address == 0xbfd100 || address == 0xbfe000 || address == 0xdff01a || address == 0xdff01e)
501                 value &= emulate_disk_read(address);
502
503         return value;
504 }
505
506 static void io_write(uint32_t address, uint16_t value)
507 {
508         /* dmacon and sound registers */
509         if (address == 0xdff096 || address == 0xdff09a || (address >= 0xdff0a0 && address <= 0xdff0df))
510                 emulate_sound_write(address, value, SOUND_SAMPLERATE);
511         if (address == 0xbfd100 || (address >= 0xdff020 && address <= 0xdff024))
512                 emulate_disk_write(address, value);
513 }
514
515 /* two tracks with 0x1820 words of length */
516 static uint8_t game_save[2][0x1820 << 1];
517 static int last_track = 0;
518
519 /* game reads track with saved game */
520 static void disk_read(int track, int __attribute__((unused)) side, uint32_t data, uint16_t length)
521 {
522         if (length > sizeof(game_save[0])) {
523                 print_error("loading game state failed, because length exceeds game save data size, please fix!\n");
524                 return;
525         }
526
527         /* if even track is selected, load game */
528         if (!(track & 1)) {
529                 char filename[256];
530                 int gamesave_num = (track - 2) >> 1;
531                 int got;
532                 FILE *fp;
533
534                 memset(game_save, 0, sizeof(game_save)); /* clear so make the game fail, if we fail */
535 #if defined(_WIN32)
536                 filename[0] = '\0';
537 #else
538                 sprintf(filename, "%s/%s/", home_dir, config_gamesave_dir);
539                 mkdir(filename, 0777);
540 #endif
541                 sprintf(filename + strlen(filename), "%d%s", gamesave_num, mercenary_gamesavesuffix);
542                 fp = fopen(filename, "r");
543                 if (!fp) {
544 fail:
545                         print_error("failed to load game from '%s'\n", filename);
546                         goto copy;
547                 }
548                 got = fread(game_save, sizeof(game_save[0]), 2, fp);
549                 fclose(fp);
550                 if (got != 2)
551                         goto fail;
552         }
553
554 copy:
555         /* copy track */
556         memcpy(memory + data, game_save[track & 1], length /* sizeof(game_save[0])*/);
557 }
558
559 /* game writes track with saved game */
560 static void disk_write(int track, int __attribute__((unused)) side, uint32_t data, uint16_t length)
561 {
562         /* skip sync info that is provided by game and only relevant for a real disk track */
563         data += 0x200;
564         length -= 0x200;
565
566         if (length != sizeof(game_save[0])) {
567                 print_error("saving game state failed, because length of data does not match, please fix!\n");
568                 return;
569         }
570
571         /* don't save if last track is the same, because disk is written on both sides with the same data */
572         if (track == last_track) {
573                 if (memcmp(memory + data, game_save[track & 1], length)) {
574                         print_error("saving game data on other side of the disk is different, please fix!\n");
575                 }
576                 return;
577         }
578         last_track = track;
579
580         /* save game data */
581         memcpy(game_save[track & 1], memory + data, length);
582
583         /* if done with saving */
584         if ((track & 1)) {
585                 char filename[256];
586                 int gamesave_num = (track - 2) >> 1;
587                 int wrote;
588                 FILE *fp;
589
590 #if defined(_WIN32)
591                 filename[0] = '\0';
592 #else
593                 sprintf(filename, "%s/%s/", home_dir, config_gamesave_dir);
594                 mkdir(filename, 0777);
595 #endif
596                 sprintf(filename + strlen(filename), "%d%s", gamesave_num, mercenary_gamesavesuffix);
597                 fp = fopen(filename, "w");
598                 if (!fp) {
599 fail:
600                         print_error("failed to save game to '%s'\n", filename);
601                         return;
602                 }
603                 print_info("Game state saved to '%s'\n", filename);
604                 wrote = fwrite(game_save, sizeof(game_save[0]), 2, fp);
605                 fclose(fp);
606                 if (wrote != 2)
607                         goto fail;
608         }
609 }
610
611 static void osd_info(const char *param, const char *value)
612 {
613         char line[41] = "                                        ";
614
615         if (param[0]) {
616                 strncpy(line + 21 - strlen(param), param, strlen(param));
617                 line[22] = ':';
618         }
619         if (strlen(value) > 15) {
620                 print_error("string too long\n");
621                 return;
622         }
623         strncpy(line + 25, value, strlen(value));
624         text_render(info_osd, OSD_WIDTH, OSD_HEIGHT, line, 0x00, 4, 0, 0, 1);
625         osd_timer = SDL_GetTicks() + 2500;
626 }
627
628 static int shift = 0, ctrl = 0;
629
630 static void keyboard_sdl(int down, SDL_Keycode sym)
631 {
632         switch (sym) {
633         case SDLK_LCTRL:
634         case SDLK_RCTRL:
635                 ctrl = down;
636                 break;
637         }
638
639         if (ctrl && down) {
640                 switch (sym) {
641                 case SDLK_h:
642                         help_view ^= 1;
643                         break;
644                 case SDLK_v:
645                         config_video_filter ^= 1;
646                         osd_info("video filter", (config_video_filter) ? "on" : "off");
647                         break;
648                 case SDLK_a:
649                         config_audio_filter ^= 1;
650                         osd_info("audio filter", (config_audio_filter) ? "on" : "off");
651                         break;
652                 case SDLK_s:
653                         config_amiga_speed ^= 1;
654                         osd_info("render speed", (config_amiga_speed) ? "original" : "fast");
655                         break;
656                 case SDLK_r:
657                         config_render ^= 1;
658                         osd_info("render mode", (config_render) ? "OpenGL" : "original");
659                         break;
660                 case SDLK_b:
661                         if (!config_render) {
662                                 osd_info("", "not applicable");
663                                 break;
664                         }
665                         if (config_benson_size == 0.5) {
666                                 config_benson_size = 1.0;
667                                 config_fov = FOV_NOVAGEN;
668                         } else {
669                                 config_benson_size = 0.5;
670                                 config_fov = FOV_JOLLY;
671                         }
672                         osd_info("Benson size", (config_benson_size == 0.5) ? "half" : "normal");
673                         break;
674                 case SDLK_i:
675                         if (!intro_skipped)
676                                 skip_intro();
677                         else
678                                 osd_info("", "not applicable");
679                         break;
680                 case SDLK_c:
681                         if (config_ctrl_c)
682                                 quit = 1;
683                         break;
684                 case SDLK_KP_PLUS:
685                         if (config_fov / 1.2 >= FOV_MIN)
686                                 config_fov /= 1.2;
687                         disp_fov:
688                         {
689                                 char text[16];
690                                 sprintf(text, "%.2f", config_fov);
691                                 osd_info("FOV", text);
692                         }
693                         break;
694                 case SDLK_KP_MINUS:
695                         if (config_fov * 1.2 <= FOV_MAX)
696                                 config_fov *= 1.2;
697                         goto disp_fov;
698                 }
699                 /* do not pass keys to game while holding CTRL */
700                 return;
701         }
702
703         if (sym == SDLK_PAUSE && down)
704                 help_view ^= 1;
705
706         /* in help view we don't need to forward keypresses */
707         if (help_view)
708                 return;
709
710         switch (sym) {
711         case SDLK_LSHIFT:
712                 set_key("LSH", down);
713                 shift = down;
714                 break;
715         case SDLK_RSHIFT:
716                 set_key("RSH", down);
717                 shift = down;
718                 break;
719         case SDLK_LEFT:
720                 if (shift && down) {
721                         set_key("LF", down);
722                         set_joystick(-1, -1, -1, -1, -1);
723                         break;
724                 }
725                 set_key("LF", 0);
726                 set_joystick(down, -1, -1, -1, -1);
727                 break;
728         case SDLK_RIGHT:
729                 if (shift && down) {
730                         set_key("RT", down);
731                         set_joystick(-1, -1, -1, -1, -1);
732                         break;
733                 }
734                 set_key("RT", 0);
735                 set_joystick(-1, down, -1, -1, -1);
736                 break;
737         case SDLK_UP:
738                 if (shift && down) {
739                         set_key("UP", down);
740                         set_joystick(-1, -1, -1, -1, -1);
741                         break;
742                 }
743                 set_key("UP", 0);
744                 set_joystick(-1, -1, down, -1, -1);
745                 break;
746         case SDLK_DOWN:
747                 if (shift && down) {
748                         set_key("DN", down);
749                         set_joystick(-1, -1, -1, -1, -1);
750                         break;
751                 }
752                 set_key("DN", 0);
753                 set_joystick(-1, -1, -1, down, -1);
754                 break;
755         case SDLK_END:
756                 set_joystick(-1, -1, -1, -1, down);
757                 break;
758
759         case SDLK_a: set_key("A", down); break;
760         case SDLK_b: set_key("B", down); break;
761         case SDLK_c: set_key("C", down); break;
762         case SDLK_d: set_key("D", down); break;
763         case SDLK_e: set_key("E", down); break;
764         case SDLK_f: set_key("F", down); break;
765         case SDLK_g: set_key("G", down); break;
766         case SDLK_h: set_key("H", down); break;
767         case SDLK_i: set_key("I", down); break;
768         case SDLK_j: set_key("J", down); break;
769         case SDLK_k: set_key("K", down); break;
770         case SDLK_l: set_key("L", down); break;
771         case SDLK_m: set_key("M", down); break;
772         case SDLK_n: set_key("N", down); break;
773         case SDLK_o: set_key("O", down); break;
774         case SDLK_p: set_key("P", down); break;
775         case SDLK_q: set_key("Q", down); break;
776         case SDLK_r: set_key("R", down); break;
777         case SDLK_s: set_key("S", down); break;
778         case SDLK_t: set_key("T", down); break;
779         case SDLK_u: set_key("U", down); break;
780         case SDLK_v: set_key("V", down); break;
781         case SDLK_w: set_key("W", down); break;
782         case SDLK_x: set_key("X", down); break;
783         case SDLK_y: set_key("Y", down); break;
784         case SDLK_z: set_key("Z", down); break;
785
786         case SDLK_0: set_key("0", down); break;
787         case SDLK_1: set_key("1", down); break;
788         case SDLK_2: set_key("2", down); break;
789         case SDLK_3: set_key("3", down); break;
790         case SDLK_4: set_key("4", down); break;
791         case SDLK_5: set_key("5", down); break;
792         case SDLK_6: set_key("6", down); break;
793         case SDLK_7: set_key("7", down); break;
794         case SDLK_8: set_key("8", down); break;
795         case SDLK_9: set_key("9", down); break;
796
797         case SDLK_KP_0: set_key("NP0", down); break;
798         case SDLK_KP_1: set_key("NP1", down); break;
799         case SDLK_KP_2: set_key("NP2", down); break;
800         case SDLK_KP_3: set_key("NP3", down); break;
801         case SDLK_KP_4: set_key("NP4", down); break;
802         case SDLK_KP_5: set_key("NP5", down); break;
803         case SDLK_KP_6: set_key("NP6", down); break;
804         case SDLK_KP_7: set_key("NP7", down); break;
805         case SDLK_KP_8: set_key("NP8", down); break;
806         case SDLK_KP_9: set_key("NP9", down); break;
807         case SDLK_KP_DIVIDE: set_key("NPDIV", down); break;
808         case SDLK_KP_MULTIPLY: set_key("NPMUL", down); break;
809         case SDLK_KP_MINUS: set_key("NPSUB", down); break;
810         case SDLK_KP_PLUS: set_key("NPADD", down); break;
811         case SDLK_KP_PERIOD: set_key("NPDEL", down); break;
812         // NPLPAREN and NPRPAREN are not emulated
813
814         case SDLK_F1: set_key("F1", down); break;
815         case SDLK_F2: set_key("F2", down); break;
816         case SDLK_F3: set_key("F3", down); break;
817         case SDLK_F4: set_key("F4", down); break;
818         case SDLK_F5: set_key("F5", down); break;
819         case SDLK_F6: set_key("F6", down); break;
820         case SDLK_F7: set_key("F7", down); break;
821         case SDLK_F8: set_key("F8", down); break;
822         case SDLK_F9: set_key("F9", down); break;
823         case SDLK_F10: set_key("F10", down); break;
824
825         case SDLK_SPACE: set_key("SPC", down); break;
826         case SDLK_BACKSPACE: set_key("BS", down); break;
827         case SDLK_TAB: set_key("TAB", down); break;
828         case SDLK_KP_ENTER: set_key("ENT", down); break;
829         case SDLK_RETURN: set_key("RET", down); break;
830         case SDLK_ESCAPE: set_key("ESC", down); break;
831         case SDLK_DELETE: set_key("DEL", down); break;
832         case SDLK_INSERT: set_key("HELP", down); break;
833
834         }
835 }
836
837 void audio_sdl(float *data, int length)
838 {
839         int fill, s;
840
841         /* read sound from sound buffer
842          * buffer pointer read and write is atomic, so no locking required!
843          */
844         fill = (sound_buffer_writep - sound_buffer_readp + sound_buffer_size) % sound_buffer_size;
845         if (fill < length) {
846 #ifdef DEBUG_SOUND_BUFFERING
847                 fprintf(stderr, "sound buffer underrun\n");
848 #endif
849                 /* correct read pointer as if the buffer would have 'length' of samples stored inside */
850                 sound_buffer_readp = (sound_buffer_readp + fill - length + sound_buffer_size) % sound_buffer_size;
851         }
852         for (s = 0; s < length; s++) {
853                 *data++ = sound_buffer[(sound_buffer_readp + s) % sound_buffer_size].left;
854                 *data++ = sound_buffer[(sound_buffer_readp + s) % sound_buffer_size].right;
855         }
856 #ifdef DEBUG_SOUND_BUFFERING
857         printf("fill %d = %.4f\n", length, sound_buffer[sound_buffer_readp][0]);
858 #endif
859         sound_buffer_readp =(sound_buffer_readp + length) % sound_buffer_size;
860 }
861
862 void sound_irq(void)
863 {
864         /* trigger and execute IRQ 4 = sound */
865         execute_cpu(4, NULL);
866 }
867
868 int main(int argc, char *argv[])
869 {
870         int rc;
871         int sdl_sound_chunk;
872
873         home_dir = getenv("HOME");
874         if (!home_dir)
875                 home_dir = "";
876
877         rc = parse_args(argc, argv);
878         if (rc)
879                 return 0;
880
881         /* allocate image */
882         image = calloc(IMAGE_WIDTH * IMAGE_HEIGHT * ((double_pixel_size) ? 4 : 1), 3);
883         if (!image) {
884                 print_error("Failed to allocate image buffer\n");
885                 goto done;
886         }
887
888         if ((SOUND_SAMPLERATE % IRQ_RATE)) {
889                 print_error("Sample rate must be a multiple of IRQ rate, please fix!\n");
890                 goto done;
891         }
892         if ((1000 % IRQ_RATE)) {
893                 print_error("1000 (Ticks per second) rate must be a multiple of IRQ rate, please fix!\n");
894                 goto done;
895         }
896
897         /* calculate SDL chunk size for audio
898          * it must be a power of two, but not more than the chunk size for each IRQ!
899          */
900         for (sdl_sound_chunk = 2; sdl_sound_chunk <= (SOUND_SAMPLERATE / IRQ_RATE); sdl_sound_chunk <<= 1)
901                 ;
902         sdl_sound_chunk >>= 1;
903 //      printf("samples per IRQ = %d, samples per SDL audio = %d\n", SOUND_SAMPLERATE / IRQ_RATE, sdl_sound_chunk); exit(0);
904
905         /* allocate sound buffers */
906         sound_buffer_size = SOUND_SAMPLERATE / IRQ_RATE * SOUND_CHUNKS;
907         sound_buffer = calloc(sound_buffer_size, sizeof(*sound_buffer));
908         if (!sound_buffer) {
909                 print_error("Failed to allocate image buffer\n");
910                 goto done;
911         }
912
913         /* allocate memory */
914         memory = calloc(MEMORY_SIZE, 1);
915         if (!memory) {
916                 print_error("Failed to allocate cpu's memory\n");
917                 goto done;
918         }
919         stop_event = calloc(MEMORY_SIZE, 1);
920         if (!stop_event) {
921                 print_error("Failed to allocate cpu's stop_event memory\n");
922                 goto done;
923         }
924         chipreg = calloc(IOSIZE, 1);
925         if (!chipreg) {
926                 print_error("Failed to allocate chip register\n");
927                 goto done;
928         }
929
930         /* init cpu code */
931         execute_init(MEMORY_SIZE, memory, stop_event, chipreg, io_read, io_write, mercenary_stop_at);
932
933         /* init disk emulation */
934         disk_init(disk_read, disk_write);
935
936         /* load binary */
937         mercenary_load();
938
939         /* patch some stuff */
940         mercenary_patch();
941
942         /* init SDL and OpenGL */
943         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, config_multisampling);
944         if (rc < 0)
945                 goto done;
946         rc = init_opengl((double_pixel_size) ? IMAGE_WIDTH * 2 : IMAGE_WIDTH, (double_pixel_size) ? IMAGE_HEIGHT * 2 : IMAGE_HEIGHT);
947         if (rc < 0)
948                 goto done;
949         resize_opengl((config_debug_opengl) ? SCREEN_WIDTH * 2 : SCREEN_WIDTH * 3, (config_debug_opengl) ? SCREEN_HEIGHT * 4 : SCREEN_HEIGHT * 3);
950
951         /* init osd */
952         rc = init_osd(0, IMAGE_WIDTH * 2, IMAGE_HEIGHT * 2);
953         if (rc < 0)
954                 goto done;
955         rc = init_osd(1, OSD_WIDTH, OSD_HEIGHT);
956         if (rc < 0)
957                 goto done;
958         help_osd = text_alloc(IMAGE_WIDTH * 2, IMAGE_HEIGHT * 2, HELP_ALPHA);
959         if (!help_osd)
960                 goto done;
961         text_render(help_osd, IMAGE_WIDTH * 2, IMAGE_HEIGHT * 2, mercenary_name, HELP_ALPHA, 3, (double)(80 - strlen(mercenary_name)) / 2.0, 1, 1);
962         text_render(help_osd, IMAGE_WIDTH * 2, IMAGE_HEIGHT * 2,
963                 "Emulation:\n"
964                 "        Press `PAUSE' to toggle this help screen on or off.\n"
965                 "        Press `CTRL' + `F' to toggle between full screen / window mode.\n"
966                 "        Press `CTRL' + `R' to toggle between original / OpenGL rendering.\n"
967                 "        Press `CTRL' + `S' to toggle between original / fast rendering.\n"
968                 "        Press `CTRL' + `B' to toggle between large / small Benson.\n"
969                 "        Press `CTRL' + `V' to toggle video filter on / off.\n"
970                 "        Press `CTRL' + `A' to toggle audio filter on / off.\n"
971                 "        Press `CTRL' + `+' or `-' to change field-of-view (OpenGL).\n"
972                 "        Press `CTRL' + `I' to skip intro (approaching to Eris).\n"
973                 "\n"
974                 "Answer to a Question:\n"
975                 "        Press `O' (not Zero) for OK and other key for NO.\n"
976                 "\n"
977                 "Walking / Driving / Flying:\n"
978                 "        Use cursor keys as joystick, to move player / craft.\n"
979                 "        Press `R' for running, 'W' for walking speed.\n"
980                 "        Press `B' to board, `L' to leave.\n"
981                 "        Press `1'...`0' to drive / fly (slow...fast), `+' or `-' to adjust.\n"
982                 "        Press `F1'...`F0' to drive / fly backwards (slow...fast).\n"
983                 "        Press `SPACE' to stop craft.\n"
984                 "        Press `ESCAPE' to activate escape sequence on crafts.\n"
985                 "        Press `T' for turbo on certain craft.\n"
986                 "        Press `END' as joystick's fire button.\n"
987                 "\n"
988                 "Elevator:\n"
989                 "        Press `1'...`9' to select floor, 'G' for ground, `B' for basement.\n"
990                 "\n"
991                 "Inside a transporter:\n"
992                 "        Press `1'...`0' to select destination.\n"
993                 "\n"
994                 "Items:\n"
995                 "        Press `SHFIT' + cursor left / right keys to choose item.\n"
996                 "        Press `SHFIT' + cursor up / down keys to pickup / drop item.\n"
997                 "        Press `NUMPAD Enter' to select certain items.\n"
998                 "        Press `NUMPAD +' / `NUMPAD -' to select entries.\n"
999                 "        Press `NUMPAD *' to read entry\n"
1000                 "Saving / Loading / Pause:\n"
1001                 "        Press `INSERT' to loading and saving options.\n"
1002                 "        Press `ENTER' to pause game, other key to continue.\n"
1003                 ,HELP_ALPHA, 1, 2, 5, 0);
1004         info_osd = text_alloc(OSD_WIDTH, OSD_HEIGHT, 0x00);
1005         if (!info_osd)
1006                 goto done;
1007
1008         /* init audio */
1009         sound_init(SOUND_SAMPLERATE, sound_irq);
1010
1011         /* start cpu */
1012         reset_cpu();
1013
1014         if (config_skip_intro)
1015                 skip_intro();
1016
1017         /* run game */
1018         main_loop();
1019
1020 done:
1021         exit_opengl();
1022         exit_sdl();
1023
1024         if (chipreg)
1025                 free(chipreg);
1026         if (stop_event)
1027                 free(stop_event);
1028         if (memory)
1029                 free(memory);
1030         if (sound_buffer)
1031                 free(sound_buffer);
1032         if (image)
1033                 free(image);
1034         if (help_osd)
1035                 free(help_osd);
1036         if (info_osd)
1037                 free(info_osd);
1038
1039         return 0;
1040 }
1041