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Minor simplifications and improvements. Still trying to figure out what's causing the non-linear edge addressing.

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This commit is contained in:
Thomas Harte 2016-05-25 21:12:25 -04:00
parent b01b474e36
commit 40c2c0bd2d
2 changed files with 33 additions and 24 deletions
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33
Machines/Atari2600/Atari2600.cpp
View File

@ -83,24 +83,19 @@ void Machine::update_timers(int mask)
unsigned int upcomingPointerPlus5 = (_upcomingEventsPointer + 5)%number_of_upcoming_events;
unsigned int upcomingPointerPlus6 = (_upcomingEventsPointer + 6)%number_of_upcoming_events;
// grab the background now, for display in four clocks
if(mask & (1 << 5))
{
if(!(_horizontalTimer&3))
// grab the background now, for application in four clocks
if(mask & (1 << 5) && !(_horizontalTimer&3))
{
unsigned int offset = 4 + _horizontalTimer - (horizontalTimerPeriod - 160);
_upcomingEvents[upcomingPointerPlus4].updates |= Event::Action::Playfield;
_upcomingEvents[upcomingPointerPlus4].playfieldPixel = _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
if(!_objectCounter[4].count) _upcomingEvents[upcomingPointerPlus4].pixelCounterResetMask &= ~(1 << 4);
_objectCounter[4].count = (_objectCounter[4].count + 1)%160;
_objectCounter[4].pixel ++;
}
// check for player and missle triggers
@ -138,23 +133,25 @@ void Machine::update_timers(int mask)
{
if(mask&(1 << c))
{
int last_broad_pixel = _objectCounter[c].broad_pixel;
_objectCounter[c].broad_pixel++;
uint8_t repeatMask = _playerAndMissileSize[c] & 7;
switch(repeatMask)
{
default: _objectCounter[c].pixel ++; break;
case 5: _objectCounter[c].pixel += ((last_broad_pixel ^ _objectCounter[c].broad_pixel) >> 1)&1; break;
case 7: _objectCounter[c].pixel += ((last_broad_pixel ^ _objectCounter[c].broad_pixel) >> 2)&1; break;
case 5: _objectCounter[c].pixel += _objectCounter[c].broad_pixel&1; break;
case 7: _objectCounter[c].pixel += ((_objectCounter[c].broad_pixel | (_objectCounter[c].broad_pixel >> 1))^1)&1; break;
}
_objectCounter[c].count = (_objectCounter[c].count + 1)%160;
}
}
if(mask & (1 << (c + 2)))
for(int c = 2; c < 5; c++)
{
_objectCounter[c+2].count = (_objectCounter[c+2].count + 1)%160;
_objectCounter[c+2].pixel ++;
if(mask&(1 << c))
{
_objectCounter[c].count = (_objectCounter[c].count + 1)%160;
_objectCounter[c].pixel ++;
}
}
}
@ -244,9 +241,13 @@ void Machine::output_pixels(unsigned int count)
case 16: case 17: state = _vBlankExtend ? OutputState::Blank : OutputState::Pixel; break;
default: state = OutputState::Pixel; break;
}
// update pixel timers
if(state == OutputState::Pixel)
{
update_timers(~0);
_upcomingEvents[(_upcomingEventsPointer+4)%number_of_upcoming_events].updates |= Event::Action::ClockPixels;
}
// if vsync is enabled, output the opposite of the automatic hsync output
if(_vSyncEnabled) {
@ -298,6 +299,10 @@ void Machine::output_pixels(unsigned int count)
update_timers(_hMoveFlags);
}
if(_upcomingEvents[_upcomingEventsPointer].updates & Event::Action::ClockPixels)
{
}
// apply any resets
_objectCounter[0].pixel *= (_upcomingEvents[_upcomingEventsPointer].pixelCounterResetMask >> 0) & 1;
_objectCounter[0].broad_pixel *= (_upcomingEvents[_upcomingEventsPointer].pixelCounterResetMask >> 0) & 1;
@ -387,8 +392,6 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
output_pixels(additional_pixels + cycles_run_for * 3);
// printf("/%d/", _horizontalTimer);
if(operation != CPU6502::BusOperation::Ready) {
// check for a paging access

16
Machines/Atari2600/Atari2600.hpp
View File

@ -61,9 +61,11 @@ class Machine: public CPU6502::Processor<Machine> {
struct Event {
enum Action {
Playfield = 1 << 0,
HMoveSetup = 1 << 1,
HMoveCompare = 1 << 2,
HMoveDecrement = 1 << 3,
ClockPixels = 1 << 1,
HMoveSetup = 1 << 2,
HMoveCompare = 1 << 3,
HMoveDecrement = 1 << 4,
};
int updates;
@ -71,6 +73,8 @@ class Machine: public CPU6502::Processor<Machine> {
int pixelCounterResetMask;
uint8_t playfieldPixel;
int pixelCounters[5];
Event() : updates(0), pixelCounterResetMask(~0), playfieldPixel(0) {}
} _upcomingEvents[number_of_upcoming_events];
unsigned int _upcomingEventsPointer;
@ -105,8 +109,10 @@ class Machine: public CPU6502::Processor<Machine> {
// object counters
struct {
int count, pixel, broad_pixel;
uint8_t motion;
int count; // the counter value, multiplied by four, counting phase
int pixel; // for non-sprite objects, a count of cycles since the last counter reset; for sprite objects a count of pixels so far elapsed
int broad_pixel; // for sprite objects, a count of cycles since the last counter reset; otherwise unused
uint8_t motion; // the value stored to this counter's motion register
} _objectCounter[5];
// joystick state