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CLK/Machines/Atari2600/Atari2600.cpp

782 lines
25 KiB
C++

//
// Atari2600.cpp
// CLK
//
// Created by Thomas Harte on 14/07/2015.
// Copyright © 2015 Thomas Harte. All rights reserved.
//
#include "Atari2600.hpp"
#include <algorithm>
#include <stdio.h>
using namespace Atari2600;
namespace {
static const unsigned int horizontalTimerPeriod = 228;
static const double NTSC_clock_rate = 1194720;
static const double PAL_clock_rate = 1182298;
}
Machine::Machine() :
horizontal_timer_(0),
last_output_state_duration_(0),
last_output_state_(OutputState::Sync),
rom_(nullptr),
tia_input_value_{0xff, 0xff},
upcoming_events_pointer_(0),
object_counter_pointer_(0),
state_by_time_(state_by_extend_time_[0]),
cycles_since_speaker_update_(0),
is_pal_region_(false)
{
memset(collisions_, 0xff, sizeof(collisions_));
setup_reported_collisions();
for(int vbextend = 0; vbextend < 2; vbextend++)
{
for(int c = 0; c < 57; c++)
{
OutputState state;
// determine which output state will be active in four cycles from now
switch(c)
{
case 0: case 1: case 2: case 3: state = OutputState::Blank; break;
case 4: case 5: case 6: case 7: state = OutputState::Sync; break;
case 8: case 9: case 10: case 11: state = OutputState::ColourBurst; break;
case 12: case 13: case 14:
case 15: case 16: state = OutputState::Blank; break;
case 17: case 18: state = vbextend ? OutputState::Blank : OutputState::Pixel; break;
default: state = OutputState::Pixel; break;
}
state_by_extend_time_[vbextend][c] = state;
}
}
set_clock_rate(NTSC_clock_rate);
}
void Machine::setup_output(float aspect_ratio)
{
speaker_.reset(new Speaker);
crt_.reset(new Outputs::CRT::CRT(228, 1, 263, Outputs::CRT::ColourSpace::YIQ, 228, 1, false, 1));
crt_->set_output_device(Outputs::CRT::Television);
// this is the NTSC phase offset function; see below for PAL
crt_->set_composite_sampling_function(
"float composite_sample(usampler2D texID, vec2 coordinate, vec2 iCoordinate, float phase, float amplitude)"
"{"
"uint c = texture(texID, coordinate).r;"
"uint y = c & 14u;"
"uint iPhase = (c >> 4);"
"float phaseOffset = 6.283185308 * float(iPhase - 1u) / 13.0;"
"return mix(float(y) / 14.0, step(1, iPhase) * cos(phase + phaseOffset), amplitude);"
"}");
speaker_->set_input_rate((float)(get_clock_rate() / 38.0));
}
void Machine::switch_region()
{
// the PAL function
crt_->set_composite_sampling_function(
"float composite_sample(usampler2D texID, vec2 coordinate, vec2 iCoordinate, float phase, float amplitude)"
"{"
"uint c = texture(texID, coordinate).r;"
"uint y = c & 14u;"
"uint iPhase = (c >> 4);"
"uint direction = iPhase & 1u;"
"float phaseOffset = float(7u - direction) + (float(direction) - 0.5) * 2.0 * float(iPhase >> 1);"
"phaseOffset *= 6.283185308 / 12.0;"
"return mix(float(y) / 14.0, step(4, (iPhase + 2u) & 15u) * cos(phase + phaseOffset), amplitude);"
"}");
crt_->set_new_timing(228, 312, Outputs::CRT::ColourSpace::YUV, 228, 1, true);
is_pal_region_ = true;
speaker_->set_input_rate((float)(get_clock_rate() / 38.0));
set_clock_rate(PAL_clock_rate);
}
void Machine::close_output()
{
crt_ = nullptr;
}
Machine::~Machine()
{
delete[] rom_;
close_output();
}
void Machine::update_timers(int mask)
{
unsigned int upcoming_pointer_plus_4 = (upcoming_events_pointer_ + 4)%number_of_upcoming_events;
object_counter_pointer_ = (object_counter_pointer_ + 1)%number_of_recorded_counters;
ObjectCounter *oneClockAgo = object_counter_[(object_counter_pointer_ - 1 + number_of_recorded_counters)%number_of_recorded_counters];
ObjectCounter *twoClocksAgo = object_counter_[(object_counter_pointer_ - 2 + number_of_recorded_counters)%number_of_recorded_counters];
ObjectCounter *now = object_counter_[object_counter_pointer_];
// grab the background now, for application in four clocks
if(mask & (1 << 5) && !(horizontal_timer_&3))
{
unsigned int offset = 4 + horizontal_timer_ - (horizontalTimerPeriod - 160);
upcoming_events_[upcoming_pointer_plus_4].updates |= Event::Action::Playfield;
upcoming_events_[upcoming_pointer_plus_4].playfield_pixel = playfield_[(offset >> 2)%40];
}
if(mask & (1 << 4))
{
// the ball becomes visible whenever it hits zero, regardless of whether its status
// is the result of a counter rollover or a programmatic reset, and there's a four
// clock delay on that triggering the start signal
now[4].count = (oneClockAgo[4].count + 1)%160;
now[4].pixel = oneClockAgo[4].pixel + 1;
if(!now[4].count) now[4].pixel = 0;
}
else
{
now[4] = oneClockAgo[4];
}
// check for player and missle triggers
for(int c = 0; c < 4; c++)
{
if(mask & (1 << c))
{
// update the count
now[c].count = (oneClockAgo[c].count + 1)%160;
uint8_t repeatMask = player_and_missile_size_[c&1] & 7;
ObjectCounter *rollover;
ObjectCounter *equality;
if(c < 2)
{
// update the pixel
now[c].broad_pixel = oneClockAgo[c].broad_pixel + 1;
switch(repeatMask)
{
default: now[c].pixel = oneClockAgo[c].pixel + 1; break;
case 5: now[c].pixel = oneClockAgo[c].pixel + (now[c].broad_pixel&1); break;
case 7: now[c].pixel = oneClockAgo[c].pixel + (((now[c].broad_pixel | (now[c].broad_pixel >> 1))^1)&1); break;
}
// check for a rollover six clocks ago or equality five clocks ago
rollover = twoClocksAgo;
equality = oneClockAgo;
}
else
{
// update the pixel
now[c].pixel = oneClockAgo[c].pixel + 1;
// check for a rollover five clocks ago or equality four clocks ago
rollover = oneClockAgo;
equality = now;
}
if(
(rollover[c].count == 159) ||
(has_second_copy_[c&1] && equality[c].count == 16) ||
(has_third_copy_[c&1] && equality[c].count == 32) ||
(has_fourth_copy_[c&1] && equality[c].count == 64)
)
{
now[c].pixel = 0;
now[c].broad_pixel = 0;
}
}
else
{
now[c] = oneClockAgo[c];
}
}
}
uint8_t Machine::get_output_pixel()
{
ObjectCounter *now = object_counter_[object_counter_pointer_];
// get the playfield pixel
unsigned int offset = horizontal_timer_ - (horizontalTimerPeriod - 160);
uint8_t playfieldColour = ((playfield_control_&6) == 2) ? player_colour_[offset / 80] : playfield_colour_;
// ball pixel
uint8_t ballPixel = 0;
if(now[4].pixel < ball_size_) {
ballPixel = ball_graphics_enable_[ball_graphics_selector_];
}
// determine the player and missile pixels
uint8_t playerPixels[2] = { 0, 0 };
uint8_t missilePixels[2] = { 0, 0 };
for(int c = 0; c < 2; c++)
{
if(player_graphics_[c] && now[c].pixel < 8) {
playerPixels[c] = (player_graphics_[player_graphics_selector_[c]][c] >> (now[c].pixel ^ player_reflection_mask_[c])) & 1;
}
if(!missile_graphics_reset_[c] && now[c+2].pixel < missile_size_[c]) {
missilePixels[c] = missile_graphics_enable_[c];
}
}
// accumulate collisions
int pixel_mask = playerPixels[0] | (playerPixels[1] << 1) | (missilePixels[0] << 2) | (missilePixels[1] << 3) | (ballPixel << 4) | (playfield_output_ << 5);
collisions_[0] |= reported_collisions_[pixel_mask][0];
collisions_[1] |= reported_collisions_[pixel_mask][1];
collisions_[2] |= reported_collisions_[pixel_mask][2];
collisions_[3] |= reported_collisions_[pixel_mask][3];
collisions_[4] |= reported_collisions_[pixel_mask][4];
collisions_[5] |= reported_collisions_[pixel_mask][5];
collisions_[6] |= reported_collisions_[pixel_mask][6];
collisions_[7] |= reported_collisions_[pixel_mask][7];
// apply appropriate priority to pick a colour
uint8_t playfield_pixel = playfield_output_ | ballPixel;
uint8_t outputColour = playfield_pixel ? playfieldColour : background_colour_;
if(!(playfield_control_&0x04) || !playfield_pixel) {
if(playerPixels[1] || missilePixels[1]) outputColour = player_colour_[1];
if(playerPixels[0] || missilePixels[0]) outputColour = player_colour_[0];
}
// return colour
return outputColour;
}
void Machine::setup_reported_collisions()
{
for(int c = 0; c < 64; c++)
{
memset(reported_collisions_[c], 0, 8);
int playerPixels[2] = { c&1, (c >> 1)&1 };
int missilePixels[2] = { (c >> 2)&1, (c >> 3)&1 };
int ballPixel = (c >> 4)&1;
int playfield_pixel = (c >> 5)&1;
if(playerPixels[0] | playerPixels[1]) {
reported_collisions_[c][0] |= ((missilePixels[0] & playerPixels[1]) << 7) | ((missilePixels[0] & playerPixels[0]) << 6);
reported_collisions_[c][1] |= ((missilePixels[1] & playerPixels[0]) << 7) | ((missilePixels[1] & playerPixels[1]) << 6);
reported_collisions_[c][2] |= ((playfield_pixel & playerPixels[0]) << 7) | ((ballPixel & playerPixels[0]) << 6);
reported_collisions_[c][3] |= ((playfield_pixel & playerPixels[1]) << 7) | ((ballPixel & playerPixels[1]) << 6);
reported_collisions_[c][7] |= ((playerPixels[0] & playerPixels[1]) << 7);
}
if(playfield_pixel | ballPixel) {
reported_collisions_[c][4] |= ((playfield_pixel & missilePixels[0]) << 7) | ((ballPixel & missilePixels[0]) << 6);
reported_collisions_[c][5] |= ((playfield_pixel & missilePixels[1]) << 7) | ((ballPixel & missilePixels[1]) << 6);
reported_collisions_[c][6] |= ((playfield_pixel & ballPixel) << 7);
}
if(missilePixels[0] & missilePixels[1])
reported_collisions_[c][7] |= (1 << 6);
}
}
void Machine::output_pixels(unsigned int count)
{
while(count--)
{
if(upcoming_events_[upcoming_events_pointer_].updates)
{
// apply any queued changes and flush the record
if(upcoming_events_[upcoming_events_pointer_].updates & Event::Action::HMoveSetup)
{
// schedule an extended left border
state_by_time_ = state_by_extend_time_[1];
// clear any ongoing moves
if(hmove_flags_)
{
for(int c = 0; c < number_of_upcoming_events; c++)
{
upcoming_events_[c].updates &= ~(Event::Action::HMoveCompare | Event::Action::HMoveDecrement);
}
}
// schedule new moves
hmove_flags_ = 0x1f;
hmove_counter_ = 15;
// follow-through into a compare immediately
upcoming_events_[upcoming_events_pointer_].updates |= Event::Action::HMoveCompare;
}
if(upcoming_events_[upcoming_events_pointer_].updates & Event::Action::HMoveCompare)
{
for(int c = 0; c < 5; c++)
{
if(((object_motions_[c] >> 4)^hmove_counter_) == 7)
{
hmove_flags_ &= ~(1 << c);
}
}
if(hmove_flags_)
{
if(hmove_counter_) hmove_counter_--;
upcoming_events_[(upcoming_events_pointer_+4)%number_of_upcoming_events].updates |= Event::Action::HMoveCompare;
upcoming_events_[(upcoming_events_pointer_+2)%number_of_upcoming_events].updates |= Event::Action::HMoveDecrement;
}
}
if(upcoming_events_[upcoming_events_pointer_].updates & Event::Action::HMoveDecrement)
{
update_timers(hmove_flags_);
}
if(upcoming_events_[upcoming_events_pointer_].updates & Event::Action::ResetCounter)
{
object_counter_[object_counter_pointer_][upcoming_events_[upcoming_events_pointer_].counter].count = 0;
}
// zero out current update event
upcoming_events_[upcoming_events_pointer_].updates = 0;
}
// progress to next event
upcoming_events_pointer_ = (upcoming_events_pointer_ + 1)%number_of_upcoming_events;
// determine which output state is currently active
OutputState primary_state = state_by_time_[horizontal_timer_ >> 2];
OutputState effective_state = primary_state;
// update pixel timers
if(primary_state == OutputState::Pixel) update_timers(~0);
// update the background chain
if(horizontal_timer_ >= 64 && horizontal_timer_ <= 160+64 && !(horizontal_timer_&3))
{
playfield_output_ = next_playfield_output_;
next_playfield_output_ = playfield_[(horizontal_timer_ - 64) >> 2];
}
// if vsync is enabled, output the opposite of the automatic hsync output;
// also honour the vertical blank flag
if(vsync_enabled_) {
effective_state = (effective_state = OutputState::Sync) ? OutputState::Blank : OutputState::Sync;
} else if(vblank_enabled_ && effective_state == OutputState::Pixel) {
effective_state = OutputState::Blank;
}
// decide what that means needs to be communicated to the CRT
last_output_state_duration_++;
if(effective_state != last_output_state_) {
switch(last_output_state_) {
case OutputState::Blank: crt_->output_blank(last_output_state_duration_); break;
case OutputState::Sync: crt_->output_sync(last_output_state_duration_); break;
case OutputState::ColourBurst: crt_->output_colour_burst(last_output_state_duration_, 96, 0); break;
case OutputState::Pixel: crt_->output_data(last_output_state_duration_, 1); break;
}
last_output_state_duration_ = 0;
last_output_state_ = effective_state;
if(effective_state == OutputState::Pixel) {
output_buffer_ = crt_->allocate_write_area(160);
} else {
output_buffer_ = nullptr;
}
}
// decide on a pixel colour if that's what's happening
if(effective_state == OutputState::Pixel)
{
uint8_t colour = get_output_pixel();
if(output_buffer_)
{
*output_buffer_ = colour;
output_buffer_++;
}
}
// advance horizontal timer, perform reset actions if desired
horizontal_timer_ = (horizontal_timer_ + 1) % horizontalTimerPeriod;
if(!horizontal_timer_)
{
// switch back to a normal length left border
state_by_time_ = state_by_extend_time_[0];
set_ready_line(false);
}
}
}
unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uint16_t address, uint8_t *value)
{
uint8_t returnValue = 0xff;
unsigned int cycles_run_for = 3;
// this occurs as a feedback loop — the 2600 requests ready, then performs the cycles_run_for
// leap to the end of ready only once ready is signalled — because on a 6502 ready doesn't take
// effect until the next read; therefore it isn't safe to assume that signalling ready immediately
// skips to the end of the line.
if(operation == CPU6502::BusOperation::Ready) {
unsigned int distance_to_end_of_ready = horizontalTimerPeriod - horizontal_timer_;
cycles_run_for = distance_to_end_of_ready;
}
output_pixels(cycles_run_for);
cycles_since_speaker_update_ += cycles_run_for;
if(operation != CPU6502::BusOperation::Ready) {
// check for a paging access
if(rom_size_ > 4096 && ((address & 0x1f00) == 0x1f00)) {
uint8_t *base_ptr = rom_pages_[0];
uint8_t first_paging_register = (uint8_t)(0xf8 - (rom_size_ >> 14)*2);
const uint8_t paging_register = address&0xff;
if(paging_register >= first_paging_register) {
const uint16_t selected_page = paging_register - first_paging_register;
if(selected_page * 4096 < rom_size_) {
base_ptr = &rom_[selected_page * 4096];
}
}
if(base_ptr != rom_pages_[0]) {
rom_pages_[0] = base_ptr;
rom_pages_[1] = base_ptr + 1024;
rom_pages_[2] = base_ptr + 2048;
rom_pages_[3] = base_ptr + 3072;
}
}
// check for a ROM read
if((address&0x1000) && isReadOperation(operation)) {
returnValue &= rom_pages_[(address >> 10)&3][address&1023];
}
// check for a RAM access
if((address&0x1280) == 0x80) {
if(isReadOperation(operation)) {
returnValue &= mos6532_.get_ram(address);
} else {
mos6532_.set_ram(address, *value);
}
}
// check for a TIA access
if(!(address&0x1080)) {
if(isReadOperation(operation)) {
const uint16_t decodedAddress = address & 0xf;
switch(decodedAddress) {
case 0x00: // missile 0 / player collisions
case 0x01: // missile 1 / player collisions
case 0x02: // player 0 / playfield / ball collisions
case 0x03: // player 1 / playfield / ball collisions
case 0x04: // missile 0 / playfield / ball collisions
case 0x05: // missile 1 / playfield / ball collisions
case 0x06: // ball / playfield collisions
case 0x07: // player / player, missile / missile collisions
returnValue &= collisions_[decodedAddress];
break;
case 0x08:
case 0x09:
case 0x0a:
case 0x0b:
// TODO: pot ports
break;
case 0x0c:
case 0x0d:
returnValue &= tia_input_value_[decodedAddress - 0x0c];
break;
}
} else {
const uint16_t decodedAddress = address & 0x3f;
switch(decodedAddress) {
case 0x00:
vsync_enabled_ = !!(*value & 0x02);
break;
case 0x01: vblank_enabled_ = !!(*value & 0x02); break;
case 0x02:
if(horizontal_timer_) set_ready_line(true);
break;
case 0x03:
// Reset is delayed by four cycles.
horizontal_timer_ = horizontalTimerPeriod - 4;
// TODO: audio will now be out of synchronisation — fix
break;
case 0x04:
case 0x05: {
int entry = decodedAddress - 0x04;
player_and_missile_size_[entry] = *value;
missile_size_[entry] = 1 << ((*value >> 4)&3);
uint8_t repeatMask = (*value)&7;
has_second_copy_[entry] = (repeatMask == 1) || (repeatMask == 3);
has_third_copy_[entry] = (repeatMask == 2) || (repeatMask == 3) || (repeatMask == 6);
has_fourth_copy_[entry] = (repeatMask == 4) || (repeatMask == 6);
} break;
case 0x06:
case 0x07: player_colour_[decodedAddress - 0x06] = *value; break;
case 0x08: playfield_colour_ = *value; break;
case 0x09: background_colour_ = *value; break;
case 0x0a: {
uint8_t old_playfield_control = playfield_control_;
playfield_control_ = *value;
ball_size_ = 1 << ((playfield_control_ >> 4)&3);
// did the mirroring bit change?
if((playfield_control_^old_playfield_control)&1) {
if(playfield_control_&1) {
for(int c = 0; c < 20; c++) playfield_[c+20] = playfield_[19-c];
} else {
memcpy(&playfield_[20], playfield_, 20);
}
}
} break;
case 0x0b:
case 0x0c: player_reflection_mask_[decodedAddress - 0x0b] = (*value)&8 ? 0 : 7; break;
case 0x0d:
playfield_[0] = ((*value) >> 4)&1;
playfield_[1] = ((*value) >> 5)&1;
playfield_[2] = ((*value) >> 6)&1;
playfield_[3] = (*value) >> 7;
if(playfield_control_&1) {
for(int c = 0; c < 4; c++) playfield_[39-c] = playfield_[c];
} else {
memcpy(&playfield_[20], playfield_, 4);
}
break;
case 0x0e:
playfield_[4] = (*value) >> 7;
playfield_[5] = ((*value) >> 6)&1;
playfield_[6] = ((*value) >> 5)&1;
playfield_[7] = ((*value) >> 4)&1;
playfield_[8] = ((*value) >> 3)&1;
playfield_[9] = ((*value) >> 2)&1;
playfield_[10] = ((*value) >> 1)&1;
playfield_[11] = (*value)&1;
if(playfield_control_&1) {
for(int c = 0; c < 8; c++) playfield_[35-c] = playfield_[c+4];
} else {
memcpy(&playfield_[24], &playfield_[4], 8);
}
break;
case 0x0f:
playfield_[19] = (*value) >> 7;
playfield_[18] = ((*value) >> 6)&1;
playfield_[17] = ((*value) >> 5)&1;
playfield_[16] = ((*value) >> 4)&1;
playfield_[15] = ((*value) >> 3)&1;
playfield_[14] = ((*value) >> 2)&1;
playfield_[13] = ((*value) >> 1)&1;
playfield_[12] = (*value)&1;
if(playfield_control_&1) {
for(int c = 0; c < 8; c++) playfield_[27-c] = playfield_[c+12];
} else {
memcpy(&playfield_[32], &playfield_[12], 8);
}
break;
case 0x10: case 0x11: case 0x12: case 0x13:
case 0x14:
upcoming_events_[(upcoming_events_pointer_ + 4)%number_of_upcoming_events].updates |= Event::Action::ResetCounter;
upcoming_events_[(upcoming_events_pointer_ + 4)%number_of_upcoming_events].counter = decodedAddress - 0x10;
break;
case 0x15: case 0x16:
update_audio();
speaker_->set_control(decodedAddress - 0x15, *value);
break;
case 0x17: case 0x18:
update_audio();
speaker_->set_divider(decodedAddress - 0x17, *value);
break;
case 0x19: case 0x1a:
update_audio();
speaker_->set_volume(decodedAddress - 0x19, *value);
break;
case 0x1c:
ball_graphics_enable_[1] = ball_graphics_enable_[0];
case 0x1b: {
int index = decodedAddress - 0x1b;
player_graphics_[0][index] = *value;
player_graphics_[1][index^1] = player_graphics_[0][index^1];
} break;
case 0x1d:
case 0x1e:
missile_graphics_enable_[decodedAddress - 0x1d] = ((*value) >> 1)&1;
// printf("e:%02x <- %c\n", decodedAddress - 0x1d, ((*value)&1) ? 'E' : '-');
break;
case 0x1f:
ball_graphics_enable_[0] = ((*value) >> 1)&1;
break;
case 0x20:
case 0x21:
case 0x22:
case 0x23:
case 0x24:
object_motions_[decodedAddress - 0x20] = *value;
break;
case 0x25: player_graphics_selector_[0] = (*value)&1; break;
case 0x26: player_graphics_selector_[1] = (*value)&1; break;
case 0x27: ball_graphics_selector_ = (*value)&1; break;
case 0x28:
case 0x29:
{
// TODO: this should properly mean setting a flag and propagating later, I think?
int index = decodedAddress - 0x28;
if(!(*value&0x02) && missile_graphics_reset_[index])
{
object_counter_[object_counter_pointer_][index + 2].count = object_counter_[object_counter_pointer_][index].count;
uint8_t repeatMask = player_and_missile_size_[index] & 7;
int extra_offset;
switch(repeatMask)
{
default: extra_offset = 3; break;
case 5: extra_offset = 6; break;
case 7: extra_offset = 10; break;
}
object_counter_[object_counter_pointer_][index + 2].count = (object_counter_[object_counter_pointer_][index + 2].count + extra_offset)%160;
}
missile_graphics_reset_[index] = !!((*value) & 0x02);
// printf("r:%02x <- %c\n", decodedAddress - 0x28, ((*value)&2) ? 'R' : '-');
}
break;
case 0x2a: {
// justification for +5: "we need to wait at least 71 [clocks] before the HMOVE operation is complete";
// which will take 16*4 + 2 = 66 cycles from the first compare, implying the first compare must be
// in five cycles from now
// int start_pause = ((horizontal_timer_ + 3)&3) + 4;
upcoming_events_[(upcoming_events_pointer_ + 5)%number_of_upcoming_events].updates |= Event::Action::HMoveSetup;
} break;
case 0x2b:
object_motions_[0] =
object_motions_[1] =
object_motions_[2] =
object_motions_[3] =
object_motions_[4] = 0;
break;
case 0x2c:
collisions_[0] = collisions_[1] = collisions_[2] =
collisions_[3] = collisions_[4] = collisions_[5] = 0x3f;
collisions_[6] = 0x7f;
collisions_[7] = 0x3f;
break;
}
}
}
// check for a PIA access
if((address&0x1280) == 0x280) {
if(isReadOperation(operation)) {
returnValue &= mos6532_.get_register(address);
} else {
mos6532_.set_register(address, *value);
}
}
if(isReadOperation(operation)) {
*value = returnValue;
}
}
mos6532_.run_for_cycles(cycles_run_for / 3);
return cycles_run_for / 3;
}
void Machine::set_digital_input(Atari2600DigitalInput input, bool state)
{
switch (input) {
case Atari2600DigitalInputJoy1Up: mos6532_.update_port_input(0, 0x10, state); break;
case Atari2600DigitalInputJoy1Down: mos6532_.update_port_input(0, 0x20, state); break;
case Atari2600DigitalInputJoy1Left: mos6532_.update_port_input(0, 0x40, state); break;
case Atari2600DigitalInputJoy1Right: mos6532_.update_port_input(0, 0x80, state); break;
case Atari2600DigitalInputJoy2Up: mos6532_.update_port_input(0, 0x01, state); break;
case Atari2600DigitalInputJoy2Down: mos6532_.update_port_input(0, 0x02, state); break;
case Atari2600DigitalInputJoy2Left: mos6532_.update_port_input(0, 0x04, state); break;
case Atari2600DigitalInputJoy2Right: mos6532_.update_port_input(0, 0x08, state); break;
// TODO: latching
case Atari2600DigitalInputJoy1Fire: if(state) tia_input_value_[0] &= ~0x80; else tia_input_value_[0] |= 0x80; break;
case Atari2600DigitalInputJoy2Fire: if(state) tia_input_value_[1] &= ~0x80; else tia_input_value_[1] |= 0x80; break;
default: break;
}
}
void Machine::set_switch_is_enabled(Atari2600Switch input, bool state)
{
switch(input) {
case Atari2600SwitchReset: mos6532_.update_port_input(1, 0x01, state); break;
case Atari2600SwitchSelect: mos6532_.update_port_input(1, 0x02, state); break;
case Atari2600SwitchColour: mos6532_.update_port_input(1, 0x08, state); break;
case Atari2600SwitchLeftPlayerDifficulty: mos6532_.update_port_input(1, 0x40, state); break;
case Atari2600SwitchRightPlayerDifficulty: mos6532_.update_port_input(1, 0x80, state); break;
}
}
void Machine::configure_as_target(const StaticAnalyser::Target &target)
{
if(!target.cartridges.front()->get_segments().size()) return;
Storage::Cartridge::Cartridge::Segment segment = target.cartridges.front()->get_segments().front();
size_t length = segment.data.size();
rom_size_ = 1024;
while(rom_size_ < length && rom_size_ < 32768) rom_size_ <<= 1;
delete[] rom_;
rom_ = new uint8_t[rom_size_];
size_t offset = 0;
const size_t copy_step = std::min(rom_size_, length);
while(offset < rom_size_)
{
size_t copy_length = std::min(copy_step, rom_size_ - offset);
memcpy(&rom_[offset], &segment.data[0], copy_length);
offset += copy_length;
}
size_t romMask = rom_size_ - 1;
rom_pages_[0] = rom_;
rom_pages_[1] = &rom_[1024 & romMask];
rom_pages_[2] = &rom_[2048 & romMask];
rom_pages_[3] = &rom_[3072 & romMask];
}
#pragma mark - Audio
void Machine::update_audio()
{
unsigned int audio_cycles = cycles_since_speaker_update_ / 114;
speaker_->run_for_cycles(audio_cycles);
cycles_since_speaker_update_ %= 114;
}
void Machine::synchronise()
{
update_audio();
}