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Established the basic timing loop, albeit without clocking delays yet.

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This commit is contained in:
Thomas Harte 2016-05-16 08:01:29 -04:00
parent bf2932cd57
commit 9d92ad659f
3 changed files with 61 additions and 51 deletions
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108
Machines/Atari2600/Atari2600.cpp
View File

@ -11,7 +11,9 @@
#include <stdio.h>
using namespace Atari2600;
static const int horizontalTimerReload = 227;
namespace {
static const unsigned int horizontalTimerPeriod = 228;
}
Machine::Machine() :
_horizontalTimer(0),
@ -185,58 +187,64 @@ void Machine::get_output_pixel(uint8_t *pixel, int offset)
void Machine::output_pixels(unsigned int count)
{
const int32_t start_of_sync = 214;
/* const int32_t start_of_sync = 214;
const int32_t end_of_sync = 198;
const int32_t end_of_colour_burst = 188;
const int32_t end_of_colour_burst = 188;*/
while(count--)
{
OutputState state;
// update hmove
if(!(_horizontalTimer&3)) {
if(_hMoveFlags) {
const uint8_t counterValue = _hMoveCounter ^ 0x7;
for(int c = 0; c < 5; c++) {
if(counterValue == (_objectMotion[c] >> 4)) _hMoveFlags &= ~(1 << c);
if(_hMoveFlags&(1 << c)) increment_object_counter(c);
}
}
if(_hMoveIsCounting) {
_hMoveIsCounting = !!_hMoveCounter;
_hMoveCounter = (_hMoveCounter-1)&0xf;
}
}
// blank is decoded as 68 counts; sync and colour burst as 16 counts
// 4 blank
// 4 sync
// 9 'blank'; colour burst after 4
// 40 pixels
// it'll be about 43 cycles from start of hsync to start of visible frame, so...
// guesses, until I can find information: 26 cycles blank, 16 sync, 40 blank, 160 pixels
if(_horizontalTimer < (_vBlankExtend ? 152 : 160)) {
if(_vBlankEnabled) {
switch(_horizontalTimer >> 2)
{
case 0: case 1: case 2: case 3:
state = OutputState::Blank;
} else {
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 = _vBlankExtend ? OutputState::Blank : OutputState::Pixel;
break;
default:
state = OutputState::Pixel;
}
break;
}
else if(_horizontalTimer < end_of_colour_burst) state = OutputState::Blank;
else if(_horizontalTimer < end_of_sync) state = OutputState::ColourBurst;
else if(_horizontalTimer < start_of_sync) state = OutputState::Sync;
else state = OutputState::Blank;
// logic: if vsync is enabled, output the opposite of the automatic hsync output
if(_vSyncEnabled) {
state = (state = OutputState::Sync) ? OutputState::Blank : OutputState::Sync;
}
// update hmove
// if(!(_horizontalTimer&3)) {
//
// if(_hMoveFlags) {
// const uint8_t counterValue = _hMoveCounter ^ 0x7;
// for(int c = 0; c < 5; c++) {
// if(counterValue == (_objectMotion[c] >> 4)) _hMoveFlags &= ~(1 << c);
// if(_hMoveFlags&(1 << c)) increment_object_counter(c);
// }
// }
//
// if(_hMoveIsCounting) {
// _hMoveIsCounting = !!_hMoveCounter;
// _hMoveCounter = (_hMoveCounter-1)&0xf;
// }
// }
_lastOutputStateDuration++;
if(state != _lastOutputState) {
switch(_lastOutputState) {
@ -250,12 +258,13 @@ void Machine::output_pixels(unsigned int count)
if(state == OutputState::Pixel) {
_outputBuffer = _crt->allocate_write_area(160);
if(_outputBuffer) for(int c = 0; c < 160; c++) _outputBuffer[c] = (uint8_t)rand();
} else {
_outputBuffer = nullptr;
}
}
if(_horizontalTimer < (_vBlankExtend ? 152 : 160)) {
/* if(_horizontalTimer < (_vBlankExtend ? 152 : 160)) {
uint8_t throwaway_pixel;
get_output_pixel(_outputBuffer ? &_outputBuffer[_lastOutputStateDuration] : &throwaway_pixel, 159 - _horizontalTimer);
@ -274,7 +283,9 @@ void Machine::output_pixels(unsigned int count)
_horizontalTimer = (_horizontalTimer&~sign_extension) | (sign_extension&horizontalTimerReload);
if(!_horizontalTimer)
_vBlankExtend = false;
_vBlankExtend = false;*/
_horizontalTimer = (_horizontalTimer + 1) % horizontalTimerPeriod;
}
}
@ -284,24 +295,23 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
uint8_t returnValue = 0xff;
unsigned int cycles_run_for = 1;
const int32_t ready_line_disable_time = 227;//horizontalTimerReload;
if(operation == CPU6502::BusOperation::Ready) {
unsigned int distance_to_end_of_ready = (_horizontalTimer - ready_line_disable_time + horizontalTimerReload + 1)%(horizontalTimerReload + 1);
unsigned int distance_to_end_of_ready = horizontalTimerPeriod - _horizontalTimer;
cycles_run_for = distance_to_end_of_ready / 3;
output_pixels(distance_to_end_of_ready);
} else {
output_pixels(3);
}
if(_hMoveWillCount) {
_hMoveCounter = 0x0f;
_hMoveFlags = 0x1f;
_hMoveIsCounting = true;
_hMoveWillCount = false;
}
// if(_hMoveWillCount) {
// _hMoveCounter = 0x0f;
// _hMoveFlags = 0x1f;
// _hMoveIsCounting = true;
// _hMoveWillCount = false;
// }
if(_horizontalTimer == ready_line_disable_time)
if(!_horizontalTimer)
set_ready_line(false);
if(operation != CPU6502::BusOperation::Ready) {

2
Machines/Atari2600/Atari2600.hpp
View File

@ -66,7 +66,7 @@ class Machine: public CPU6502::Processor<Machine> {
uint8_t _ballGraphicsEnableDelay;
// graphics output
int32_t _horizontalTimer;
unsigned int _horizontalTimer;
bool _vSyncEnabled, _vBlankEnabled;
bool _vBlankExtend;
uint8_t _hMoveCounter;

2
Outputs/CRT/Internals/Shaders/IntermediateShader.cpp
View File

@ -269,7 +269,7 @@ std::unique_ptr<IntermediateShader> IntermediateShader::make_chroma_filter_shade
"), vec3(1.0))"
");"
"vec3 lumaChromaColourInRange = (lumaChromaColour - vec3(0.0, 0.5, 0.5)) * vec3(1.0, 4.0, 4.0);"
"vec3 lumaChromaColourInRange = (lumaChromaColour - vec3(0.0, 0.5, 0.5)) * vec3(1.0, 2.0, 2.0);"
"fragColour = lumaChromaToRGB * lumaChromaColourInRange;"
"}", false, false);
}