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Hes_Emu.cpp
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Hes_Emu.cpp
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// Game_Music_Emu 0.5.5. http://www.slack.net/~ant/
#include "Hes_Emu.h"
#include "blargg_endian.h"
#include <string.h>
/* Copyright (C) 2006 Shay Green. This module is free software; you
can redistribute it and/or modify it under the terms of the GNU Lesser
General Public License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version. This
module is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
details. You should have received a copy of the GNU Lesser General Public
License along with this module; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
#include "blargg_source.h"
int const timer_mask = 0x04;
int const vdp_mask = 0x02;
int const i_flag_mask = 0x04;
int const unmapped = 0xFF;
long const period_60hz = 262 * 455L; // scanlines * clocks per scanline
Hes_Emu::Hes_Emu()
{
timer.raw_load = 0;
set_type( gme_hes_type );
static const char* const names [Hes_Apu::osc_count] = {
"Wave 1", "Wave 2", "Wave 3", "Wave 4", "Multi 1", "Multi 2"
};
set_voice_names( names );
static int const types [Hes_Apu::osc_count] = {
wave_type | 0, wave_type | 1, wave_type | 2, wave_type | 3,
mixed_type | 0, mixed_type | 1
};
set_voice_types( types );
set_silence_lookahead( 6 );
set_gain( 1.11 );
}
Hes_Emu::~Hes_Emu() { }
void Hes_Emu::unload()
{
rom.clear();
Music_Emu::unload();
}
// Track info
static byte const* copy_field( byte const* in, char* out )
{
if ( in )
{
int len = 0x20;
if ( in [0x1F] && !in [0x2F] )
len = 0x30; // fields are sometimes 16 bytes longer (ugh)
// since text fields are where any data could be, detect non-text
// and fields with data after zero byte terminator
int i = 0;
for ( i = 0; i < len && in [i]; i++ )
if ( ((in [i] + 1) & 0xFF) < ' ' + 1 ) // also treat 0xFF as non-text
return 0; // non-ASCII found
for ( ; i < len; i++ )
if ( in [i] )
return 0; // data after terminator
Gme_File::copy_field_( out, (char const*) in, len );
in += len;
}
return in;
}
static void copy_hes_fields( byte const* in, track_info_t* out )
{
if ( *in >= ' ' )
{
in = copy_field( in, out->game );
in = copy_field( in, out->author );
in = copy_field( in, out->copyright );
}
}
blargg_err_t Hes_Emu::track_info_( track_info_t* out, int ) const
{
copy_hes_fields( rom.begin() + 0x20, out );
return 0;
}
static blargg_err_t check_hes_header( void const* header )
{
if ( memcmp( header, "HESM", 4 ) )
return gme_wrong_file_type;
return 0;
}
struct Hes_File : Gme_Info_
{
struct header_t {
char header [Hes_Emu::header_size];
char unused [0x20];
byte fields [0x30 * 3];
} h;
Hes_File() { set_type( gme_hes_type ); }
blargg_err_t load_( Data_Reader& in )
{
assert( offsetof (header_t,fields) == Hes_Emu::header_size + 0x20 );
blargg_err_t err = in.read( &h, sizeof h );
if ( err )
return (err == in.eof_error ? gme_wrong_file_type : err);
return check_hes_header( &h );
}
blargg_err_t track_info_( track_info_t* out, int ) const
{
copy_hes_fields( h.fields, out );
return 0;
}
};
static Music_Emu* new_hes_emu () { return BLARGG_NEW Hes_Emu ; }
static Music_Emu* new_hes_file() { return BLARGG_NEW Hes_File; }
static gme_type_t_ const gme_hes_type_ = { "PC Engine", 256, &new_hes_emu, &new_hes_file, "HES", 1 };
gme_type_t const gme_hes_type = &gme_hes_type_;
// Setup
blargg_err_t Hes_Emu::load_( Data_Reader& in )
{
assert( offsetof (header_t,unused [4]) == header_size );
RETURN_ERR( rom.load( in, header_size, &header_, unmapped ) );
RETURN_ERR( check_hes_header( header_.tag ) );
if ( header_.vers != 0 )
set_warning( "Unknown file version" );
if ( memcmp( header_.data_tag, "DATA", 4 ) )
set_warning( "Data header missing" );
if ( memcmp( header_.unused, "\0\0\0\0", 4 ) )
set_warning( "Unknown header data" );
// File spec supports multiple blocks, but I haven't found any, and
// many files have bad sizes in the only block, so it's simpler to
// just try to load the damn data as best as possible.
long addr = get_le32( header_.addr );
long size = get_le32( header_.size );
long const rom_max = 0x100000;
if ( addr & ~(rom_max - 1) )
{
set_warning( "Invalid address" );
addr &= rom_max - 1;
}
if ( (unsigned long) (addr + size) > (unsigned long) rom_max )
set_warning( "Invalid size" );
if ( size != rom.file_size() )
{
if ( size <= rom.file_size() - 4 && !memcmp( rom.begin() + size, "DATA", 4 ) )
set_warning( "Multiple DATA not supported" );
else if ( size < rom.file_size() )
set_warning( "Extra file data" );
else
set_warning( "Missing file data" );
}
rom.set_addr( addr );
set_voice_count( apu.osc_count );
apu.volume( gain() );
return setup_buffer( 7159091 );
}
void Hes_Emu::update_eq( blip_eq_t const& eq )
{
apu.treble_eq( eq );
}
void Hes_Emu::set_voice( int i, Blip_Buffer* center, Blip_Buffer* left, Blip_Buffer* right )
{
apu.osc_output( i, center, left, right );
}
// Emulation
void Hes_Emu::recalc_timer_load()
{
timer.load = timer.raw_load * timer_base + 1;
}
void Hes_Emu::set_tempo_( double t )
{
play_period = hes_time_t (period_60hz / t);
timer_base = int (1024 / t);
recalc_timer_load();
}
blargg_err_t Hes_Emu::start_track_( int track )
{
RETURN_ERR( Classic_Emu::start_track_( track ) );
memset( ram, 0, sizeof ram ); // some HES music relies on zero fill
memset( sgx, 0, sizeof sgx );
apu.reset();
cpu::reset();
for ( unsigned i = 0; i < sizeof header_.banks; i++ )
set_mmr( i, header_.banks [i] );
set_mmr( page_count, 0xFF ); // unmapped beyond end of address space
irq.disables = timer_mask | vdp_mask;
irq.timer = future_hes_time;
irq.vdp = future_hes_time;
timer.enabled = false;
timer.raw_load= 0x80;
timer.count = timer.load;
timer.fired = false;
timer.last_time = 0;
vdp.latch = 0;
vdp.control = 0;
vdp.next_vbl = 0;
ram [0x1FF] = (idle_addr - 1) >> 8;
ram [0x1FE] = (idle_addr - 1) & 0xFF;
r.sp = 0xFD;
r.pc = get_le16( header_.init_addr );
r.a = track;
recalc_timer_load();
last_frame_hook = 0;
return 0;
}
// Hardware
void Hes_Emu::cpu_write_vdp( int addr, int data )
{
switch ( addr )
{
case 0:
vdp.latch = data & 0x1F;
break;
case 2:
if ( vdp.latch == 5 )
{
if ( data & 0x04 )
set_warning( "Scanline interrupt unsupported" );
run_until( time() );
vdp.control = data;
irq_changed();
}
else
{
debug_printf( "VDP not supported: $%02X <- $%02X\n", vdp.latch, data );
}
break;
case 3:
debug_printf( "VDP MSB not supported: $%02X <- $%02X\n", vdp.latch, data );
break;
}
}
void Hes_Emu::cpu_write_( hes_addr_t addr, int data )
{
if ( unsigned (addr - apu.start_addr) <= apu.end_addr - apu.start_addr )
{
GME_APU_HOOK( this, addr - apu.start_addr, data );
// avoid going way past end when a long block xfer is writing to I/O space
hes_time_t t = min( time(), end_time() + 8 );
apu.write_data( t, addr, data );
return;
}
hes_time_t time = this->time();
switch ( addr )
{
case 0x0000:
case 0x0002:
case 0x0003:
cpu_write_vdp( addr, data );
return;
case 0x0C00: {
run_until( time );
timer.raw_load = (data & 0x7F) + 1;
recalc_timer_load();
timer.count = timer.load;
break;
}
case 0x0C01:
data &= 1;
if ( timer.enabled == data )
return;
run_until( time );
timer.enabled = data;
if ( data )
timer.count = timer.load;
break;
case 0x1402:
run_until( time );
irq.disables = data;
if ( (data & 0xF8) && (data & 0xF8) != 0xF8 ) // flag questionable values
debug_printf( "Int mask: $%02X\n", data );
break;
case 0x1403:
run_until( time );
if ( timer.enabled )
timer.count = timer.load;
timer.fired = false;
break;
#ifndef NDEBUG
case 0x1000: // I/O port
case 0x0402: // palette
case 0x0403:
case 0x0404:
case 0x0405:
return;
default:
debug_printf( "unmapped write $%04X <- $%02X\n", addr, data );
return;
#endif
}
irq_changed();
}
int Hes_Emu::cpu_read_( hes_addr_t addr )
{
hes_time_t time = this->time();
addr &= page_size - 1;
switch ( addr )
{
case 0x0000:
if ( irq.vdp > time )
return 0;
irq.vdp = future_hes_time;
run_until( time );
irq_changed();
return 0x20;
case 0x0002:
case 0x0003:
debug_printf( "VDP read not supported: %d\n", addr );
return 0;
case 0x0C01:
//return timer.enabled; // TODO: remove?
case 0x0C00:
run_until( time );
debug_printf( "Timer count read\n" );
return (unsigned) (timer.count - 1) / timer_base;
case 0x1402:
return irq.disables;
case 0x1403:
{
int status = 0;
if ( irq.timer <= time ) status |= timer_mask;
if ( irq.vdp <= time ) status |= vdp_mask;
return status;
}
#ifndef NDEBUG
case 0x1000: // I/O port
case 0x180C: // CD-ROM
case 0x180D:
break;
default:
debug_printf( "unmapped read $%04X\n", addr );
#endif
}
return unmapped;
}
// see hes_cpu_io.h for core read/write functions
// Emulation
void Hes_Emu::run_until( hes_time_t present )
{
while ( vdp.next_vbl < present )
vdp.next_vbl += play_period;
hes_time_t elapsed = present - timer.last_time;
if ( elapsed > 0 )
{
if ( timer.enabled )
{
timer.count -= elapsed;
if ( timer.count <= 0 )
timer.count += timer.load;
}
timer.last_time = present;
}
}
void Hes_Emu::irq_changed()
{
hes_time_t present = time();
if ( irq.timer > present )
{
irq.timer = future_hes_time;
if ( timer.enabled && !timer.fired )
irq.timer = present + timer.count;
}
if ( irq.vdp > present )
{
irq.vdp = future_hes_time;
if ( vdp.control & 0x08 )
irq.vdp = vdp.next_vbl;
}
hes_time_t time = future_hes_time;
if ( !(irq.disables & timer_mask) ) time = irq.timer;
if ( !(irq.disables & vdp_mask) ) time = min( time, irq.vdp );
set_irq_time( time );
}
int Hes_Emu::cpu_done()
{
check( time() >= end_time() ||
(!(r.status & i_flag_mask) && time() >= irq_time()) );
if ( !(r.status & i_flag_mask) )
{
hes_time_t present = time();
if ( irq.timer <= present && !(irq.disables & timer_mask) )
{
timer.fired = true;
irq.timer = future_hes_time;
irq_changed(); // overkill, but not worth writing custom code
#if GME_FRAME_HOOK_DEFINED
{
unsigned const threshold = period_60hz / 30;
unsigned long elapsed = present - last_frame_hook;
if ( elapsed - period_60hz + threshold / 2 < threshold )
{
last_frame_hook = present;
GME_FRAME_HOOK( this );
}
}
#endif
return 0x0A;
}
if ( irq.vdp <= present && !(irq.disables & vdp_mask) )
{
// work around for bugs with music not acknowledging VDP
//run_until( present );
//irq.vdp = future_hes_time;
//irq_changed();
#if GME_FRAME_HOOK_DEFINED
last_frame_hook = present;
GME_FRAME_HOOK( this );
#endif
return 0x08;
}
}
return 0;
}
static void adjust_time( blargg_long& time, hes_time_t delta )
{
if ( time < future_hes_time )
{
time -= delta;
if ( time < 0 )
time = 0;
}
}
blargg_err_t Hes_Emu::run_clocks( blip_time_t& duration_, int )
{
blip_time_t const duration = duration_; // cache
if ( cpu::run( duration ) )
set_warning( "Emulation error (illegal instruction)" );
check( time() >= duration );
//check( time() - duration < 20 ); // Txx instruction could cause going way over
run_until( duration );
// end time frame
timer.last_time -= duration;
vdp.next_vbl -= duration;
#if GME_FRAME_HOOK_DEFINED
last_frame_hook -= duration;
#endif
cpu::end_frame( duration );
::adjust_time( irq.timer, duration );
::adjust_time( irq.vdp, duration );
apu.end_frame( duration );
return 0;
}

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