mirror of
https://github.com/ekeeke/Genesis-Plus-GX.git
synced 2024-09-20 05:09:43 +02:00
467 lines
11 KiB
C
467 lines
11 KiB
C
/*
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dos.c --
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DOS interface code for the emulator
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*/
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#include "osd.h"
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#define FRAMES_PER_SECOND 60
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RGB vdp_palette[3][0x200];
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PALETTE gen_pal;
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BITMAP *gen_bmp;
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volatile int frame_skip = 1;
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volatile int frame_count = 0;
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volatile int frames_rendered = 0;
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volatile int frame_rate = 0;
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volatile int tick_count = 0;
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volatile int old_tick_count = 0;
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volatile int skip = 0;
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int quit = 0;
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int main (int argc, char *argv[])
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{
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if(argc < 2) {
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printf("Genesis Plus - Sega Mega Drive emulator (v1.0)\n");
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printf("(C) 1999, 2000, 2001, 2002, 2003 Charles MacDonald\n");
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printf("Usage %s file.[bin|smd|zip] [-options]\n", argv[0]);
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printf("Type `%s -help' for a list of options.\n", argv[0]);
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exit(1);
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};
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if(stricmp(argv[1], "-help") == 0)
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{
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print_options();
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return (0);
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}
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if(!load_rom(argv[1]))
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{
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printf("File `%s' not found.\n", argv[1]);
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return (0);
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}
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init_machine();
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error_init();
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system_init();
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if(option.sound)
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{
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audio_init(option.sndrate);
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}
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system_reset();
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for(;;)
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{
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frame_count += 1;
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if(quit) break;
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dos_update_input();
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if(frame_count % frame_skip == 0)
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{
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system_frame(0);
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dos_update_video();
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}
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else
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{
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system_frame(1);
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}
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if(option.sound) dos_update_audio();
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}
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trash_machine();
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system_shutdown();
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error_shutdown();
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return (0);
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}
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/* Timer handler */
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void tick_handler(void)
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{
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tick_count += 1;
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if(tick_count % FRAMES_PER_SECOND == 0)
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{
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frame_rate = frames_rendered;
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frames_rendered = 0;
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}
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}
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END_OF_FUNCTION(tick_handler);
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int load_file(char *filename, char *buf, int size)
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{
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FILE *fd = fopen(filename, "rb");
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if(!fd) return (0);
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fread(buf, size, 1, fd);
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fclose(fd);
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return (1);
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}
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int save_file(char *filename, char *buf, int size)
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{
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FILE *fd = NULL;
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if(!(fd = fopen(filename, "wb"))) return (0);
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fwrite(buf, size, 1, fd);
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fclose(fd);
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return (1);
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}
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void dos_update_input(void)
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{
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if(key[KEY_ESC] || key[KEY_END])
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{
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quit = 1;
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}
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input.pad[0] = 0;
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/* Is the joystick being used ? */
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if(option.joy_driver != JOY_TYPE_NONE)
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{
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poll_joystick();
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/* Check player 1 joystick */
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if(joy[0].stick[0].axis[1].d1) input.pad[0] |= INPUT_UP;
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else
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if(joy[0].stick[0].axis[1].d2) input.pad[0] |= INPUT_DOWN;
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if(joy[0].stick[0].axis[0].d1) input.pad[0] |= INPUT_LEFT;
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else
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if(joy[0].stick[0].axis[0].d2) input.pad[0] |= INPUT_RIGHT;
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if(joy[0].button[0].b) input.pad[0] |= INPUT_A;
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if(joy[0].button[1].b) input.pad[0] |= INPUT_B;
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if(joy[0].button[2].b) input.pad[0] |= INPUT_C;
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if(joy[0].button[3].b) input.pad[0] |= INPUT_START;
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if(joy[0].button[4].b) input.pad[0] |= INPUT_X;
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if(joy[0].button[5].b) input.pad[0] |= INPUT_Y;
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if(joy[0].button[6].b) input.pad[0] |= INPUT_Z;
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if(joy[0].button[7].b) input.pad[0] |= INPUT_MODE;
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/* More than one joystick supported ? */
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if(num_joysticks > 2)
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{
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/* Check player 2 joystick */
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if(joy[1].stick[0].axis[1].d1) input.pad[1] |= INPUT_UP;
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else
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if(joy[1].stick[0].axis[1].d2) input.pad[1] |= INPUT_DOWN;
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if(joy[1].stick[0].axis[0].d1) input.pad[1] |= INPUT_LEFT;
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else
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if(joy[1].stick[0].axis[0].d1) input.pad[1] |= INPUT_RIGHT;
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if(joy[1].button[0].b) input.pad[1] |= INPUT_A;
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if(joy[1].button[1].b) input.pad[1] |= INPUT_B;
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if(joy[1].button[2].b) input.pad[1] |= INPUT_C;
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if(joy[1].button[3].b) input.pad[1] |= INPUT_START;
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if(joy[1].button[4].b) input.pad[1] |= INPUT_X;
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if(joy[1].button[5].b) input.pad[1] |= INPUT_Y;
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if(joy[1].button[6].b) input.pad[1] |= INPUT_Z;
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if(joy[1].button[7].b) input.pad[1] |= INPUT_MODE;
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}
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}
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if(key[KEY_UP]) input.pad[0] |= INPUT_UP;
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else
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if(key[KEY_DOWN]) input.pad[0] |= INPUT_DOWN;
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if(key[KEY_LEFT]) input.pad[0] |= INPUT_LEFT;
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else
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if(key[KEY_RIGHT]) input.pad[0] |= INPUT_RIGHT;
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if(key[KEY_A]) input.pad[0] |= INPUT_A;
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if(key[KEY_S]) input.pad[0] |= INPUT_B;
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if(key[KEY_D]) input.pad[0] |= INPUT_C;
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if(key[KEY_F]) input.pad[0] |= INPUT_START;
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if(key[KEY_Z]) input.pad[0] |= INPUT_X;
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if(key[KEY_X]) input.pad[0] |= INPUT_Y;
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if(key[KEY_C]) input.pad[0] |= INPUT_Z;
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if(key[KEY_V]) input.pad[0] |= INPUT_MODE;
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if(check_key(KEY_TAB))
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system_reset();
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if(check_key(KEY_F1)) frame_skip = 1;
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if(check_key(KEY_F2)) frame_skip = 2;
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if(check_key(KEY_F3)) frame_skip = 3;
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if(check_key(KEY_F4)) frame_skip = 4;
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}
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void dos_update_audio(void)
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{
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osd_play_streamed_sample_16(option.swap ^ 0, snd.buffer[0], snd.buffer_size * 2, option.sndrate, FRAMES_PER_SECOND, -100);
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osd_play_streamed_sample_16(option.swap ^ 1, snd.buffer[1], snd.buffer_size * 2, option.sndrate, FRAMES_PER_SECOND, 100);
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}
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void dos_update_palette(void)
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{
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if(is_border_dirty)
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{
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uint16 data = *(uint16 *)&cram[(border << 1)];
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RGB *color;
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is_border_dirty = 0;
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if(reg[12] & 8)
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{
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int j;
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for(j = 0; j < 3; j += 1)
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{
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color = &vdp_palette[j][data];
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set_color((j << 6), color);
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}
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}
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else
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{
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color = &vdp_palette[1][data];
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set_color(0x00, color);
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set_color(0x40, color);
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set_color(0x80, color);
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}
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}
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if(is_color_dirty)
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{
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int i;
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uint16 *p = (uint16 *)&cram[0];
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is_color_dirty = 0;
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for(i = 0; i < 64; i += 1)
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{
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if((color_dirty[i]) && ((i & 0x0F) != 0x00))
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{
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RGB *color;
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color_dirty[i] = 0;
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if(reg[12] & 8)
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{
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int j;
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for(j = 0; j < 3; j += 1)
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{
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color = &vdp_palette[j][p[i]];
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set_color((j << 6) | i, color);
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}
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}
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else
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{
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color = &vdp_palette[1][p[i]];
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set_color(0x00 | i, color);
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set_color(0x40 | i, color);
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set_color(0x80 | i, color);
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}
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}
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}
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}
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}
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void dos_update_video(void)
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{
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int width = (reg[12] & 1) ? 320 : 256;
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int height = (reg[1] & 8) ? 240 : 224;
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int center_x = (SCREEN_W - width) / 2;
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int center_y = (SCREEN_H / (option.scanlines ? 4 : 2)) - (height / 2);
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/* Wait for VSync */
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if(option.vsync) vsync();
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if(bitmap.viewport.changed)
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{
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bitmap.viewport.changed = 0;
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if(bitmap.remap)
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{
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clear(screen);
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}
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else
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{
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clear_to_color(screen, 0xFF);
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}
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}
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if(bitmap.remap == 0)
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{
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dos_update_palette();
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}
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if(option.scanlines)
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{
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int y;
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for(y = 0; y < height; y += 1)
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{
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blit(gen_bmp, screen, 0x20, y, center_x, (center_y + y) << 1, width, 1);
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}
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}
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else
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{
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blit(gen_bmp, screen, 0x20, 0, center_x, center_y, width, height);
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}
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}
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void init_machine(void)
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{
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do_config("gen.cfg");
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if(option.sound)
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{
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msdos_init_sound(&option.sndrate, option.sndcard);
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}
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allegro_init();
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install_keyboard();
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install_joystick(option.joy_driver);
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install_timer();
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LOCK_FUNCTION(tick_handler);
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LOCK_VARIABLE(tick_count);
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LOCK_VARIABLE(frame_rate);
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install_int_ex(tick_handler, BPS_TO_TIMER(FRAMES_PER_SECOND));
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set_color_depth(option.video_depth);
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gen_bmp = create_bitmap(512, 512);
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clear(gen_bmp);
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memset(&bitmap, 0, sizeof(bitmap));
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bitmap.data = (uint8 *)&gen_bmp->line[0][0];
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bitmap.width = gen_bmp->w;
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bitmap.height = gen_bmp->h;
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bitmap.depth = option.video_depth;
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switch(option.video_depth)
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{
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case 8:
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bitmap.granularity = 1;
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break;
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case 15:
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bitmap.granularity = 2;
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break;
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case 16:
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bitmap.granularity = 2;
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break;
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case 32:
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bitmap.granularity = 4;
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break;
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}
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bitmap.pitch = (bitmap.width * bitmap.granularity);
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bitmap.viewport.w = 256;
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bitmap.viewport.h = 224;
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bitmap.viewport.x = 0x20;
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bitmap.viewport.y = 0x00;
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bitmap.remap = 0;
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if(option.remap) bitmap.remap = 1;
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else
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if(bitmap.depth > 8) bitmap.remap = 1;
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make_vdp_palette();
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memcpy(gen_pal, black_palette, sizeof(PALETTE));
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gen_pal[0xFE].r = \
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gen_pal[0xFE].g = \
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gen_pal[0xFE].b = 0x3F;
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dos_change_mode();
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}
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void trash_machine(void)
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{
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if(option.sound)
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{
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msdos_shutdown_sound();
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}
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clear(screen);
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destroy_bitmap(gen_bmp);
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set_gfx_mode(GFX_TEXT, 0, 0, 0, 0);
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}
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void make_vdp_palette(void)
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{
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uint8 lut[3][8] =
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{
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{0x00, 0x04, 0x08, 0x0C, 0x10, 0x14, 0x18, 0x1C},
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{0x00, 0x08, 0x10, 0x18, 0x20, 0x28, 0x30, 0x38},
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{0x20, 0x24, 0x28, 0x2C, 0x30, 0x34, 0x38, 0x3C},
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};
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int j;
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for(j = 0; j < 0x600; j += 1)
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{
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int r = (j >> 6) & 7;
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int g = (j >> 3) & 7;
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int b = (j >> 0) & 7;
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int i = (j >> 9) & 3;
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vdp_palette[i][j & 0x1FF].r = lut[i][r];
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vdp_palette[i][j & 0x1FF].g = lut[i][g];
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vdp_palette[i][j & 0x1FF].b = lut[i][b];
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}
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}
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void dos_change_mode(void)
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{
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int ret;
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int width = option.video_width;
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int height = option.video_height;
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if(option.scanlines) height *= 2;
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ret = set_gfx_mode(option.video_driver, width, height, 0, 0);
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if(ret != 0)
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{
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set_gfx_mode(GFX_TEXT, 0, 0, 0, 0);
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printf("Error setting graphics mode (%dx%d %dbpp).\nAllegro says: `%s'\n", width, height, option.video_depth, allegro_error);
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exit(1);
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}
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if(bitmap.depth == 8)
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{
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if(bitmap.remap)
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{
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int i;
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for(i = 0; i < 0x100; i += 1)
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{
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gen_pal[i].r = ((i >> 5) & 7) << 3;
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gen_pal[i].g = ((i >> 2) & 7) << 3;
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gen_pal[i].b = ((i >> 0) & 3) << 4;
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}
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set_palette(gen_pal);
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}
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else
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{
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clear_to_color(screen, 0xFF);
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gen_pal[0xfe].r = 0xff;
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gen_pal[0xfe].g = 0xff;
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gen_pal[0xfe].b = 0xff;
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set_palette(gen_pal);
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inp(0x3DA);
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outp(0x3C0, 0x31);
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outp(0x3C0, 0xFF);
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}
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}
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else
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{
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clear(screen);
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}
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}
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/* Check if a key is pressed */
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int check_key(int code)
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{
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static char lastbuf[0x100] = {0};
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if((!key[code]) && (lastbuf[code] == 1))
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lastbuf[code] = 0;
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if((key[code]) && (lastbuf[code] == 0))
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{
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lastbuf[code] = 1;
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return (1);
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}
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return (0);
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}
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