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Made a first attempt at switching to a model that respects blank and sync.

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This commit is contained in:
Thomas Harte 2017-01-30 07:19:19 -05:00
parent 92754ace7a
commit 764b528891
2 changed files with 50 additions and 30 deletions
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78
Machines/Atari2600/TIA.cpp
View File

@ -20,7 +20,6 @@ TIA::TIA() :
horizontal_counter_(0),
output_cursor_(0),
pixel_target_(nullptr),
requested_output_mode_(0),
output_mode_(0)
{
crt_.reset(new Outputs::CRT::CRT(cycles_per_line * 2 + 1, 1, Outputs::CRT::DisplayType::NTSC60, 1));
@ -102,12 +101,12 @@ void TIA::run_for_cycles(int number_of_cycles)
void TIA::set_sync(bool sync)
{
requested_output_mode_ = (requested_output_mode_ & ~sync_flag) | (sync ? sync_flag : 0);
output_mode_ = (output_mode_ & ~sync_flag) | (sync ? sync_flag : 0);
}
void TIA::set_blank(bool blank)
{
requested_output_mode_ = (requested_output_mode_ & ~blank_flag) | (blank ? blank_flag : 0);
output_mode_ = (output_mode_ & ~blank_flag) | (blank ? blank_flag : 0);
}
void TIA::reset_horizontal_counter()
@ -237,37 +236,58 @@ void TIA::output_for_cycles(int number_of_cycles)
8 cycles: blank or pixels, depending on whether the blank extend bit is set
152 cycles: pixels
*/
// if(output_mode_ != requested_output_mode_)
// {
// // flush the old output
// }
horizontal_counter_ += number_of_cycles;
if(!output_cursor_ && horizontal_counter_ >= 16)
{
crt_->output_blank(32);
output_cursor_ = 16;
#define Period(function, target) \
if(output_cursor_ < target) \
{ \
if(horizontal_counter_ <= target) \
{ \
crt_->function((unsigned int)((horizontal_counter_ - output_cursor_) * 2)); \
output_cursor_ = horizontal_counter_; \
return; \
} \
else \
{ \
crt_->function((unsigned int)((target - output_cursor_) * 2)); \
output_cursor_ = target; \
} \
}
if(output_cursor_ == 16 && horizontal_counter_ >= 32)
switch(output_mode_)
{
crt_->output_sync(32);
output_cursor_ = 32;
default:
Period(output_blank, 16)
Period(output_sync, 32)
Period(output_default_colour_burst, 48)
Period(output_blank, 68)
break;
case sync_flag:
case sync_flag | blank_flag:
Period(output_sync, 16)
Period(output_blank, 32)
Period(output_default_colour_burst, 48)
Period(output_sync, 228)
break;
}
if(output_cursor_ == 32 && horizontal_counter_ >= 48)
if(output_mode_ & blank_flag)
{
crt_->output_default_colour_burst(32);
output_cursor_ = 48;
}
if(output_cursor_ == 48 && horizontal_counter_ >= 68)
{
crt_->output_blank(40);
output_cursor_ = 68;
}
if(horizontal_counter_ > 68)
{
if(output_cursor_ == 68)
if(pixel_target_)
{
pixel_target_ = crt_->allocate_write_area(160);
crt_->output_data((unsigned int)((horizontal_counter_ - pixel_target_origin_) * 2), 2);
pixel_target_ = nullptr;
}
int duration = std::min(228, horizontal_counter_) - output_cursor_;
crt_->output_blank((unsigned int)(duration * 2));
output_cursor_ += duration;
}
else
{
if(!pixel_target_)
{
pixel_target_ = crt_->allocate_write_area((unsigned int)(228 - output_cursor_));
pixel_target_origin_ = output_cursor_;
}
if(pixel_target_)
{
@ -279,17 +299,17 @@ void TIA::output_for_cycles(int number_of_cycles)
} else output_cursor_ = horizontal_counter_;
if(horizontal_counter_ == cycles_per_line)
{
crt_->output_data(320, 2);
crt_->output_data((unsigned int)((horizontal_counter_ - pixel_target_origin_) * 2), 2);
pixel_target_ = nullptr;
}
}
horizontal_counter_ %= cycles_per_line;
output_cursor_ %= cycles_per_line;
}
void TIA::output_line()
{
output_mode_ = requested_output_mode_;
switch(output_mode_)
{
default:

2
Machines/Atari2600/TIA.hpp
View File

@ -71,9 +71,9 @@ class TIA {
int output_cursor_;
int output_mode_;
int requested_output_mode_;
uint8_t *pixel_target_;
int pixel_target_origin_;
void output_for_cycles(int number_of_cycles);
void output_line();