3 * (C) 2018 by Andreas Eversberg <jolly@eversberg.eu>
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.
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.
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/>.
25 #include <sys/types.h>
26 #include "../libsdl/sdl.h"
27 #include "../libsdl/opengl.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"
37 static int config_amiga_speed = 1;
38 static const char *config_gamesave_dir = ".mercenary";
39 static int config_video_filter = 0;
40 static int config_audio_filter = 1;
42 #define CPU_SPEED 7093790.0;
44 #define SOUND_SAMPLERATE 48000
46 * - must be used for sound rendering chunk
49 /* numbe of buffer chunks to dejitter:
50 * - SDL render interval
51 * - sound rendering interval
52 * - sound card interval
53 * 4 should be minimum, if video rate is >=50 Hz
55 #define SOUND_CHUNKS 4
57 /* test sound to check if buffer does not overflow / underrun */
58 //#define DEBUG_SOUND_BUFFERING
60 #define IOSIZE 0x1000 /* bytes in io space */
61 #define MEMORY_SIZE 0x80000
62 static uint8_t *memory = NULL;
63 static uint8_t *image = NULL;
64 #define SCREEN_WIDTH (320*3)
65 #define SCREEN_HEIGHT (200*3)
66 #define IMAGE_WIDTH 320
67 #define IMAGE_HEIGHT 200
68 #define BENSON_AT_LINE 136
69 #define IMAGE_DIWSTART 0x2c
70 static uint16_t *chipreg = NULL;
71 static float *sound_buffer = NULL; /* sound buffer memory */
72 static int sound_buffer_size; /* buffer sample size */
73 static int sound_buffer_writep; /* write pointer at buffer */
74 static int sound_buffer_readp; /* read pointer at buffer */
76 static const char *home_dir;
80 static void main_loop(void)
82 int had_first_irq = 0;
83 static uint32_t current_time, last_time = 0, diff;
87 double render_delay = 0.0;
88 uint32_t palette_address;
91 last_time = SDL_GetTicks();
93 /* render result on window */
95 /* STEP 1: let the CPU render/process the game */
96 /* don't render if we still delay */
98 /* execute until the rendered image is ready */
99 cycle_count = execute_cpu(0, mercenary_stop_at);
101 palette_address = mercenary_palette();
102 for (i = 0; i < 16; i++)
103 palette[i] = m68k_read_memory_16(palette_address + i*2);
104 /* for amiga speed: set delay by the number of cycles */
105 if (config_amiga_speed)
106 render_delay = (double)cycle_count / CPU_SPEED;
109 /* STEP 2: render image in memory via OpenGL */
111 /* render game view without benson
112 * because benson is not updated before VBL IRQ, we don't want old image from double buffer
114 emul_video(image, memory, palette, IMAGE_WIDTH, IMAGE_HEIGHT, IMAGE_DIWSTART, chipreg, 0, BENSON_AT_LINE);
119 render_opengl(image, config_video_filter);
122 /* STEP 3: execute interrupt at rate of 50Hz, render sound */
123 current_time = SDL_GetTicks();
124 diff = current_time - last_time;
125 /* in case of timer glitch, execute IRQ only by maximum number of SOUND_CHUNKS */
126 if (diff > 1000 * SOUND_CHUNKS / IRQ_RATE) {
127 diff = 1000 * SOUND_CHUNKS / IRQ_RATE;
128 last_time = current_time - 1000 * SOUND_CHUNKS / IRQ_RATE;
130 while (diff > 1000 / IRQ_RATE) {
131 execute_cpu(3, NULL);
132 execute_cpu(4, NULL);
134 /* render benson without game view
135 * because we only got benson refreshed during VBL IRQ
137 emul_video(image, memory, palette, IMAGE_WIDTH, IMAGE_HEIGHT, IMAGE_DIWSTART, chipreg, BENSON_AT_LINE, IMAGE_HEIGHT);
138 /* render sound to sound buffer
139 * buffer pointer read and write is atomic, so no locking required!
141 space = (sound_buffer_readp - sound_buffer_writep - 1 + sound_buffer_size) % sound_buffer_size;
142 if (space < SOUND_SAMPLERATE / IRQ_RATE) {
143 #ifdef DEBUG_SOUND_BUFFERING
144 fprintf(stderr, "sound buffer overflow\n");
148 length = SOUND_SAMPLERATE / IRQ_RATE;
149 #ifdef DEBUG_SOUND_BUFFERING
150 printf("can write %d, write %d\n", space, length);
153 for (s = 0; s < length; s++) {
154 sound_buffer[(sound_buffer_writep + s) % sound_buffer_size]
155 = sin(2 * M_PI * 999 * cnt / SOUND_SAMPLERATE)
156 * sin(2 * M_PI * 21 * cnt / SOUND_SAMPLERATE)
157 * sin(2 * M_PI * 0.5 * cnt / SOUND_SAMPLERATE);
161 render_sound(memory, sound_buffer, sound_buffer_size, sound_buffer_writep, length, config_audio_filter);
163 sound_buffer_writep = (sound_buffer_writep + length) % sound_buffer_size;
164 diff -= 1000 / IRQ_RATE;
165 last_time += 1000 / IRQ_RATE;
167 /* count down render delay */
169 render_delay -= 1.0 / (double)IRQ_RATE;
170 if (render_delay < 0.0)
177 int main(int __attribute__((unused)) argc, char *argv[])
182 home_dir = getenv("HOME");
187 image = calloc(IMAGE_WIDTH * IMAGE_HEIGHT, 3);
189 fprintf(stderr, "Failed to allocate image buffer\n");
193 if ((SOUND_SAMPLERATE % IRQ_RATE)) {
194 fprintf(stderr, "Sample rate must be a multiple of IRQ rate, please fix!\n");
197 if ((1000 % IRQ_RATE)) {
198 fprintf(stderr, "1000 (Ticks per second) rate must be a multiple of IRQ rate, please fix!\n");
202 /* calculate SDL chunk size for audio
203 * it must be a power of two, but not more than the chunk size for each IRQ!
205 for (sdl_sound_chunk = 2; sdl_sound_chunk <= (SOUND_SAMPLERATE / IRQ_RATE); sdl_sound_chunk <<= 1)
207 sdl_sound_chunk >>= 1;
208 // printf("samples per IRQ = %d, samples per SDL audio = %d\n", SOUND_SAMPLERATE / IRQ_RATE, sdl_sound_chunk); exit(0);
210 /* allocate sound buffers */
211 sound_buffer_size = SOUND_SAMPLERATE / IRQ_RATE * SOUND_CHUNKS;
212 sound_buffer = calloc(sound_buffer_size, sizeof(*sound_buffer));
214 fprintf(stderr, "Failed to allocate image buffer\n");
218 /* allocate memory */
219 memory = calloc(MEMORY_SIZE, 1);
221 fprintf(stderr, "Failed to allocate cpu's memory\n");
224 chipreg = calloc(IOSIZE, 1);
226 fprintf(stderr, "Failed to allocate chip register\n");
231 execute_init(MEMORY_SIZE, memory, chipreg);
236 /* patch some stuff */
239 /* init SDL and OpenGL */
240 rc = init_sdl(argv[0], SCREEN_WIDTH, SCREEN_HEIGHT, SOUND_SAMPLERATE, sdl_sound_chunk);
243 rc = init_opengl(IMAGE_WIDTH, IMAGE_HEIGHT);
246 resize_opengl(SCREEN_WIDTH, SCREEN_HEIGHT);
248 /* init audio filter */
249 sound_init_filter(SOUND_SAMPLERATE);
254 printf("Welcome to Mercenary Reloaded!\n\n");
255 printf("Hold CTRL and use cursor keys to select inventory or pickup/drop item.\n");
256 printf("Press CTRL + f to toggle full screen.\n");
257 printf("Press CTRL + s to toggle rendering speed.\n");
258 printf("Press CTRL + v to toggle video filter.\n");
259 printf("Press CTRL + a to toggle audio filter.\n");
260 printf("Press CTRL + c to exit game.\n");
282 void audio_sdl(float *data, int length)
286 /* read sound from sound buffer
287 * buffer pointer read and write is atomic, so no locking required!
289 fill = (sound_buffer_writep - sound_buffer_readp + sound_buffer_size) % sound_buffer_size;
291 #ifdef DEBUG_SOUND_BUFFERING
292 fprintf(stderr, "sound buffer underrun\n");
294 /* correct read pointer as if the buffer would have 'length' of samples stored inside */
295 sound_buffer_readp = (sound_buffer_readp + fill - length + sound_buffer_size) % sound_buffer_size;
297 for (s = 0; s < length; s++)
298 *data++ = sound_buffer[(sound_buffer_readp + s) % sound_buffer_size];
299 #ifdef DEBUG_SOUND_BUFFERING
300 printf("fill %d = %.4f\n", length, sound_buffer[sound_buffer_readp]);
302 sound_buffer_readp =(sound_buffer_readp + length) % sound_buffer_size;
305 static int shift = 0, ctrl = 0;
307 void keyboard_sdl(int down, SDL_Keycode sym)
316 config_video_filter ^= 1;
317 printf("audio filter: %d\n", config_audio_filter);
322 config_audio_filter ^= 1;
323 printf("video filter: %d\n", config_video_filter);
328 printf("amiga speed: %d\n", config_amiga_speed);
329 config_amiga_speed ^= 1;
340 set_key("LSH", down);
344 set_key("RSH", down);
350 set_joystick(-1, -1, -1, -1, -1);
354 set_joystick(down, -1, -1, -1, -1);
359 set_joystick(-1, -1, -1, -1, -1);
363 set_joystick(-1, down, -1, -1, -1);
368 set_joystick(-1, -1, -1, -1, -1);
372 set_joystick(-1, -1, down, -1, -1);
377 set_joystick(-1, -1, -1, -1, -1);
381 set_joystick(-1, -1, -1, down, -1);
384 set_joystick(-1, -1, -1, -1, down);
387 case SDLK_a: set_key("A", down); break;
388 case SDLK_b: set_key("B", down); break;
389 case SDLK_c: set_key("C", down); break;
390 case SDLK_d: set_key("D", down); break;
391 case SDLK_e: set_key("E", down); break;
392 case SDLK_f: set_key("F", down); break;
393 case SDLK_g: set_key("G", down); break;
394 case SDLK_h: set_key("H", down); break;
395 case SDLK_i: set_key("I", down); break;
396 case SDLK_j: set_key("J", down); break;
397 case SDLK_k: set_key("K", down); break;
398 case SDLK_l: set_key("L", down); break;
399 case SDLK_m: set_key("M", down); break;
400 case SDLK_n: set_key("N", down); break;
401 case SDLK_o: set_key("O", down); break;
402 case SDLK_p: set_key("P", down); break;
403 case SDLK_q: set_key("Q", down); break;
404 case SDLK_r: set_key("R", down); break;
405 case SDLK_s: set_key("S", down); break;
406 case SDLK_t: set_key("T", down); break;
407 case SDLK_u: set_key("U", down); break;
408 case SDLK_v: set_key("V", down); break;
409 case SDLK_w: set_key("W", down); break;
410 case SDLK_x: set_key("X", down); break;
411 case SDLK_y: set_key("Y", down); break;
412 case SDLK_z: set_key("Z", down); break;
414 case SDLK_0: set_key("0", down); break;
415 case SDLK_1: set_key("1", down); break;
416 case SDLK_2: set_key("2", down); break;
417 case SDLK_3: set_key("3", down); break;
418 case SDLK_4: set_key("4", down); break;
419 case SDLK_5: set_key("5", down); break;
420 case SDLK_6: set_key("6", down); break;
421 case SDLK_7: set_key("7", down); break;
422 case SDLK_8: set_key("8", down); break;
423 case SDLK_9: set_key("9", down); break;
425 case SDLK_KP_0: set_key("NP0", down); break;
426 case SDLK_KP_1: set_key("NP1", down); break;
427 case SDLK_KP_2: set_key("NP2", down); break;
428 case SDLK_KP_3: set_key("NP3", down); break;
429 case SDLK_KP_4: set_key("NP4", down); break;
430 case SDLK_KP_5: set_key("NP5", down); break;
431 case SDLK_KP_6: set_key("NP6", down); break;
432 case SDLK_KP_7: set_key("NP7", down); break;
433 case SDLK_KP_8: set_key("NP8", down); break;
434 case SDLK_KP_9: set_key("NP9", down); break;
435 case SDLK_KP_DIVIDE: set_key("NPDIV", down); break;
436 case SDLK_KP_MULTIPLY: set_key("NPMUL", down); break;
437 case SDLK_KP_MINUS: set_key("NPSUB", down); break;
438 case SDLK_KP_PLUS: set_key("NPADD", down); break;
439 case SDLK_KP_PERIOD: set_key("NPDEL", down); break;
440 // NPLPAREN and NPRPAREN are not emulated
442 case SDLK_F1: set_key("F1", down); break;
443 case SDLK_F2: set_key("F2", down); break;
444 case SDLK_F3: set_key("F3", down); break;
445 case SDLK_F4: set_key("F4", down); break;
446 case SDLK_F5: set_key("F5", down); break;
447 case SDLK_F6: set_key("F6", down); break;
448 case SDLK_F7: set_key("F7", down); break;
449 case SDLK_F8: set_key("F8", down); break;
450 case SDLK_F9: set_key("F9", down); break;
451 case SDLK_F10: set_key("F10", down); break;
453 case SDLK_SPACE: set_key("SPC", down); break;
454 case SDLK_BACKSPACE: set_key("BS", down); break;
455 case SDLK_TAB: set_key("TAB", down); break;
456 case SDLK_KP_ENTER: set_key("ENT", down); break;
457 case SDLK_RETURN: set_key("RET", down); break;
458 case SDLK_ESCAPE: set_key("ESC", down); break;
459 case SDLK_DELETE: set_key("DEL", down); break;
460 case SDLK_INSERT: set_key("HELP", down); break;
465 uint16_t emulate_io_read(uint32_t address)
467 uint16_t value = 0xffff;
469 /* joystick and fire button */
470 if (address == 0xbfe000 || address == 0xdff00c)
471 value &= emulate_joystick_read(address);
473 if (address == 0xbfec00 || address == 0xbfed00 || address == 0xbfee00)
474 value &= emulate_keyboard_read(address);
476 if (address == 0xbfd100 || address == 0xbfe000 || address == 0xdff01a || address == 0xdff01e)
477 value &= emulate_disk_read(address);
482 void emulate_io_write(uint32_t address, uint16_t value)
484 /* dmacon and sound registers */
485 if (address == 0xdff096 || (address >= 0xdff0a0 && address <= 0xdff0df))
486 emulate_sound_write(address, value, SOUND_SAMPLERATE);
487 if (address == 0xbfd100 || (address >= 0xdff020 && address <= 0xdff024))
488 emulate_disk_write(address, value);
491 /* two tracks with 0x1820 words of length */
492 static uint8_t game_save[2][0x1820 << 1];
493 static int last_track = 0;
495 /* game reads track with saved game */
496 void disk_read(int track, int __attribute__((unused)) side, uint32_t data, uint16_t length)
498 if (length > sizeof(game_save[0])) {
499 fprintf(stderr, "loading game state failed, because length exceeds game save data size, please fix!\n");
503 /* if even track is selected, load game */
506 int gamesave_num = (track - 2) >> 1;
510 memset(game_save, 0, sizeof(game_save)); /* clear so make the game fail, if we fail */
511 sprintf(filename, "%s/%s/%d.gamesave", home_dir, config_gamesave_dir, gamesave_num);
512 fp = fopen(filename, "r");
515 fprintf(stderr, "failed to load game from '%s'\n", filename);
518 got = fread(game_save, sizeof(game_save[0]), 2, fp);
526 memcpy(memory + data, game_save[track & 1], length /* sizeof(game_save[0])*/);
529 /* game writes track with saved game */
530 void disk_write(int track, int __attribute__((unused)) side, uint32_t data, uint16_t length)
532 /* skip sync info that is provided by game and only relevant for a real disk track */
536 if (length != sizeof(game_save[0])) {
537 fprintf(stderr, "saving game state failed, because length of data does not match, please fix!\n");
541 /* don't save if last track is the same, because disk is written on both sides with the same data */
542 if (track == last_track) {
543 if (memcmp(memory + data, game_save[track & 1], length)) {
544 fprintf(stderr, "saving game data on other side of the disk is different, please fix!\n");
551 memcpy(game_save[track & 1], memory + data, length);
553 /* if done with saving */
556 int gamesave_num = (track - 2) >> 1;
560 sprintf(filename, "%s/%s", home_dir, config_gamesave_dir);
561 mkdir(filename, 0777);
562 sprintf(filename + strlen(filename), "/%d.gamesave", gamesave_num);
563 fp = fopen(filename, "w");
566 fprintf(stderr, "failed to save game to '%s'\n", filename);
569 printf("Game state saved to '%s'\n", filename);
570 wrote = fwrite(game_save, sizeof(game_save[0]), 2, fp);