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Genesis-Plus-GX/source/gx/main.c

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/****************************************************************************
* main.c
*
* Genesis Plus GX
*
* Copyright Eke-Eke (2007-2012), based on original work from Softdev (2006)
*
* Redistribution and use of this code or any derivative works are permitted
* provided that the following conditions are met:
*
* - Redistributions may not be sold, nor may they be used in a commercial
* product or activity.
*
* - Redistributions that are modified from the original source must include the
* complete source code, including the source code for all components used by a
* binary built from the modified sources. However, as a special exception, the
* source code distributed need not include anything that is normally distributed
* (in either source or binary form) with the major components (compiler, kernel,
* and so on) of the operating system on which the executable runs, unless that
* component itself accompanies the executable.
*
* - Redistributions must reproduce the above copyright notice, this list of
* conditions and the following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************************/
#include "shared.h"
#include "font.h"
#include "gui.h"
#include "menu.h"
#include "history.h"
#include "file_slot.h"
#include "file_load.h"
#include "filesel.h"
#include "cheats.h"
#include <fat.h>
/* audio "exact" samplerate, measured on real hardware */
#ifdef HW_RVL
#define SAMPLERATE_48KHZ 48000
#else
#define SAMPLERATE_48KHZ 48044
#endif
u32 Shutdown = 0;
u32 ConfigRequested = 1;
u32 frameticker;
#ifdef LOG_TIMING
u64 prevtime;
u32 frame_cnt;
u32 delta_time[LOGSIZE];
u32 delta_samp[LOGSIZE];
#endif
#ifdef HW_RVL
/****************************************************************************
* Power Button callback
***************************************************************************/
static void PowerOff_cb(void)
{
Shutdown = 1;
ConfigRequested = 1;
}
#endif
/****************************************************************************
* Reset Button callback
***************************************************************************/
static void Reset_cb(void)
{
if (system_hw & SYSTEM_MD)
{
/* Soft Reset */
gen_reset(0);
}
else if (system_hw == SYSTEM_SMS)
{
/* assert RESET input (Master System model 1 only) */
io_reg[0x0D] &= ~IO_RESET_HI;
}
}
/***************************************************************************
* Genesis Plus Virtual Machine
*
***************************************************************************/
static void init_machine(void)
{
/* allocate cartridge ROM here (10 MB) */
cart.rom = memalign(32, MAXROMSIZE);
/* mark all BIOS as unloaded */
config.bios &= 0x03;
/* Genesis BOOT ROM support (2KB max) */
memset(boot_rom, 0xFF, 0x800);
FILE *fp = fopen(MD_BIOS, "rb");
if (fp != NULL)
{
/* read BOOT ROM */
fread(boot_rom, 1, 0x800, fp);
fclose(fp);
/* check BOOT ROM */
if (!strncmp((char *)(boot_rom + 0x120),"GENESIS OS", 10))
{
/* mark Genesis BIOS as loaded */
config.bios |= SYSTEM_MD;
}
}
/* allocate global work bitmap */
memset(&bitmap, 0, sizeof (bitmap));
bitmap.width = 720;
bitmap.height = 576;
bitmap.pitch = bitmap.width * 2;
bitmap.viewport.w = 256;
bitmap.viewport.h = 224;
bitmap.viewport.x = 0;
bitmap.viewport.y = 0;
bitmap.data = texturemem;
}
static void run_emulation(void)
{
/* main emulation loop */
while (1)
{
/* emulated system */
if ((system_hw & SYSTEM_PBC) == SYSTEM_MD)
{
/* Mega Drive type hardware */
while (!ConfigRequested)
{
/* automatic frame skipping (only needed when running Virtua Racing on Gamecube) */
if (frameticker > 1)
{
/* skip frame */
system_frame_gen(1);
frameticker = 1;
}
else
{
/* render frame */
frameticker = 0;
system_frame_gen(0);
/* update video */
gx_video_Update();
}
/* update audio */
gx_audio_Update();
/* check interlaced mode change */
if (bitmap.viewport.changed & 4)
{
/* VSYNC "original" mode */
if (!config.render && (gc_pal == vdp_pal))
{
/* framerate has changed, reinitialize audio timings */
audio_init(SAMPLERATE_48KHZ, get_framerate());
/* reinitialize sound chips */
sound_restore();
}
/* clear flag */
bitmap.viewport.changed &= ~4;
}
/* wait for next frame */
while (frameticker < 1) usleep(1);
}
}
else
{
/* Master System type hardware */
while (!ConfigRequested)
{
/* render frame (no frameskipping needed) */
frameticker = 0;
system_frame_sms(0);
/* update video */
gx_video_Update();
/* update audio */
gx_audio_Update();
/* check interlaced mode change */
if (bitmap.viewport.changed & 4)
{
/* "original" mode */
if (!config.render)
{
/* framerate has changed, reinitialize audio timings */
audio_init(SAMPLERATE_48KHZ, get_framerate());
/* reinitialize sound chips */
sound_restore();
}
/* clear flag */
bitmap.viewport.changed &= ~4;
}
/* wait for next frame */
while (frameticker < 1) usleep(1);
}
}
/* stop video & audio */
gx_audio_Stop();
gx_video_Stop();
#ifdef LOG_TIMING
if (cart.romsize)
{
FILE *f;
char filename[64];
memset(filename, 0, 64);
strcpy(filename,"timings-");
if (!config.vsync || (config.tv_mode == !vdp_pal))
{
strcat(filename,"no_");
}
else
{
if (gc_pal)
{
strcat(filename,"50hz_");
}
else
{
strcat(filename,"60hz_");
}
}
strcat(filename,"vsync-");
if (vdp_pal)
{
strcat(filename,"pal-");
}
else
{
strcat(filename,"ntsc-");
}
if (config.render == 2)
{
strcat(filename,"prog.txt");
}
else
{
if (!config.render && !interlaced)
{
strcat(filename,"no_");
}
strcat(filename,"int.txt");
}
f = fopen(filename,"a");
if (f != NULL)
{
int i;
u32 min,max;
double total = 0;
double nsamples = 0;
if (delta_time[LOGSIZE - 1] != 0)
{
frame_cnt = LOGSIZE;
}
min = max = delta_time[0];
for (i=0; i<frame_cnt; i++)
{
fprintf(f,"%d ns - %d samples (%5.8f samples/sec)\n", delta_time[i], delta_samp[i], 1000000000.0*(double)delta_samp[i]/(double)delta_time[i]/4.0);
total += delta_time[i];
nsamples += delta_samp[i] / 4.0;
if (min > delta_time[i]) min = delta_time[i];
if (max < delta_time[i]) max = delta_time[i];
}
fprintf(f,"\n");
fprintf(f,"min = %d ns\n", min);
fprintf(f,"max = %d ns\n", max);
fprintf(f,"avg = %8.5f ns (%5.8f samples/sec, %5.8f samples/frame)\n\n\n", total/(double)i, nsamples/total*1000000000.0, nsamples/(double)i);
fclose(f);
}
}
memset(delta_time,0,LOGSIZE);
memset(delta_samp,0,LOGSIZE);
frame_cnt = prevtime = 0;
#endif
/* show menu */
ConfigRequested = 0;
mainmenu();
/* restart video & audio */
gx_video_Start();
gx_audio_Start();
frameticker = 1;
}
}
/*********************************************************************************************************************************************************
Output exact framerate (used for sound chips emulation -- see sound.c)
*********************************************************************************************************************************************************/
double get_framerate(void)
{
/* VSYNC is forced OFF or AUTO with TV mode not matching emulated video mode: emulation is synchronized with audio hardware (DMA interrupt) */
if (!config.vsync || (config.tv_mode == !vdp_pal))
{
/* emulator will use original VDP framerate, which (theorically) provides more accurate frequencies but occasional video desynchronization */
return 0.0;
}
/* VSYNC is forced ON or AUTO with TV mode matching emulated video mode: emulation is synchronized with video hardware (VSYNC) */
/* emulator use exact output framerate for perfect video synchronization and (theorically) no sound skipping */
if (vdp_pal)
{
/* 288p -> 13500000 pixels/sec, 864 pixels/line, 312 lines/field -> fps = 13500000/864/312 = 50.08 hz */
/* 288i,576i -> 13500000 pixels/sec, 864 pixels/line, 312.5 lines/field (two fields = one frame = 625 lines) -> fps = 13500000/864/312.5 = 50.00 hz */
return (config.render || interlaced) ? (27000000.0/864.0/625.0) : (13500000.0/864.0/312.0);
}
else
{
/* 240p -> 13500000 pixels/sec, 858 pixels/line, 263 lines/field -> fps = 13500000/858/263 = 59.83 hz */
/* 240i,480i -> 13500000 pixels/sec, 858 pixels/line, 262.5 lines/field (two fields = one frame = 525 lines) -> fps = 13500000/858/262.5 = 59.94 hz */
/* 480p -> 27000000 pixels/sec, 858 pixels/line, 525 lines/field -> fps = 27000000/858/525 = 59.94 hz */
return (config.render || interlaced) ? (27000000.0/858.0/525.0) : (13500000.0/858.0/263.0);
}
}
/*******************************************
Restart emulation when loading a new game
********************************************/
void reloadrom(void)
{
/* Cartridge Hot Swap (make sure system has already been inited once) */
if (config.hot_swap == 3)
{
/* Initialize cartridge hardware only */
if ((system_hw & SYSTEM_PBC) == SYSTEM_MD)
{
md_cart_init();
md_cart_reset(1);
}
else
{
sms_cart_init();
sms_cart_reset();
}
}
else
{
/* Initialize audio emulation */
/* To prevent any sound skipping, sound chips must run at the exact same speed as the rest of emulation (see sound.c) */
interlaced = 0;
audio_init(SAMPLERATE_48KHZ, get_framerate());
/* Switch virtual system on */
system_init();
system_reset();
/* Allow hot swap */
config.hot_swap |= 2;
}
/* Auto-Load SRAM file */
if (config.s_auto & 1)
{
slot_autoload(0,config.s_device);
}
/* Auto-Load State file */
if (config.s_auto & 2)
{
slot_autoload(config.s_default,config.s_device);
}
/* Load Cheat file */
CheatLoad();
}
/**************************************************
Shutdown everything properly
***************************************************/
void shutdown(void)
{
/* save current config */
config_save();
/* save current game state */
if (config.s_auto & 2)
{
slot_autosave(config.s_default,config.s_device);
}
/* shutdown emulation */
system_shutdown();
audio_shutdown();
free(cart.rom);
gx_audio_Shutdown();
gx_video_Shutdown();
#ifdef HW_RVL
DI_Close();
#endif
}
/***************************************************************************
* M A I N
*
***************************************************************************/
int main (int argc, char *argv[])
{
#ifdef HW_RVL
/* enable 64-byte fetch mode for L2 cache */
L2Enhance();
/* initialize DI interface */
DI_UseCache(0);
DI_Init();
#endif
/* initialize video engine */
gx_video_Init();
#ifndef HW_RVL
/* initialize DVD interface */
DVD_Init();
#endif
/* initialize input engine */
gx_input_Init();
/* initialize FAT devices */
int retry = 0;
int fatMounted = 0;
/* try to mount FAT devices during 3 seconds */
while (!fatMounted && (retry < 12))
{
fatMounted = fatInitDefault();
usleep(250000);
retry++;
}
if (fatMounted)
{
/* base directory */
char pathname[MAXPATHLEN];
sprintf (pathname, DEFAULT_PATH);
DIR *dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
/* default SRAM & Savestate files directories */
sprintf (pathname, "%s/saves",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
sprintf (pathname, "%s/saves/md",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
sprintf (pathname, "%s/saves/ms",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
sprintf (pathname, "%s/saves/gg",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
sprintf (pathname, "%s/saves/sg",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
/* default Snapshot files directories */
sprintf (pathname, "%s/snaps",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
sprintf (pathname, "%s/snaps/md",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
sprintf (pathname, "%s/snaps/ms",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
sprintf (pathname, "%s/snaps/gg",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
sprintf (pathname, "%s/snaps/sg",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
/* default Cheat files directories */
sprintf (pathname, "%s/cheats",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
sprintf (pathname, "%s/cheats/md",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
sprintf (pathname, "%s/cheats/ms",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
sprintf (pathname, "%s/cheats/gg",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
sprintf (pathname, "%s/cheats/sg",DEFAULT_PATH);
dir = opendir(pathname);
if (dir) closedir(dir);
else mkdir(pathname,S_IRWXU);
}
/* initialize sound engine */
gx_audio_Init();
/* initialize genesis plus core */
legal();
config_default();
history_default();
init_machine();
/* auto-load last ROM file */
if (config.autoload)
{
SILENT = 1;
if (OpenDirectory(TYPE_RECENT, -1))
{
if (LoadFile(0))
{
reloadrom();
gx_video_Start();
gx_audio_Start();
frameticker = 1;
ConfigRequested = 0;
}
}
SILENT = 0;
}
#ifdef HW_RVL
/* power button callback */
SYS_SetPowerCallback(PowerOff_cb);
#endif
/* reset button callback */
SYS_SetResetCallback(Reset_cb);
/* main emulation loop */
run_emulation();
/* we should never return anyway */
return 0;
}
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