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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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72
Machines/Atari2600/TIA.cpp
View File

@ -20,7 +20,6 @@ TIA::TIA() :
horizontal_counter_(0), horizontal_counter_(0),
output_cursor_(0), output_cursor_(0),
pixel_target_(nullptr), pixel_target_(nullptr),
requested_output_mode_(0),
output_mode_(0) output_mode_(0)
{ {
crt_.reset(new Outputs::CRT::CRT(cycles_per_line * 2 + 1, 1, Outputs::CRT::DisplayType::NTSC60, 1)); 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) 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) 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() 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 8 cycles: blank or pixels, depending on whether the blank extend bit is set
152 cycles: pixels 152 cycles: pixels
*/ */
// if(output_mode_ != requested_output_mode_)
// {
// // flush the old output
// }
horizontal_counter_ += number_of_cycles; horizontal_counter_ += number_of_cycles;
if(!output_cursor_ && horizontal_counter_ >= 16) #define Period(function, target) \
{ if(output_cursor_ < target) \
crt_->output_blank(32); { \
output_cursor_ = 16; 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); default:
output_cursor_ = 32; 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); if(pixel_target_)
output_cursor_ = 48; {
crt_->output_data((unsigned int)((horizontal_counter_ - pixel_target_origin_) * 2), 2);
pixel_target_ = nullptr;
} }
if(output_cursor_ == 48 && horizontal_counter_ >= 68) int duration = std::min(228, horizontal_counter_) - output_cursor_;
{ crt_->output_blank((unsigned int)(duration * 2));
crt_->output_blank(40); output_cursor_ += duration;
output_cursor_ = 68;
} }
if(horizontal_counter_ > 68) else
{ {
if(output_cursor_ == 68) if(!pixel_target_)
{ {
pixel_target_ = crt_->allocate_write_area(160); pixel_target_ = crt_->allocate_write_area((unsigned int)(228 - output_cursor_));
pixel_target_origin_ = output_cursor_;
} }
if(pixel_target_) if(pixel_target_)
{ {
@ -279,17 +299,17 @@ void TIA::output_for_cycles(int number_of_cycles)
} else output_cursor_ = horizontal_counter_; } else output_cursor_ = horizontal_counter_;
if(horizontal_counter_ == cycles_per_line) 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; pixel_target_ = nullptr;
} }
} }
horizontal_counter_ %= cycles_per_line; horizontal_counter_ %= cycles_per_line;
output_cursor_ %= cycles_per_line; output_cursor_ %= cycles_per_line;
} }
void TIA::output_line() void TIA::output_line()
{ {
output_mode_ = requested_output_mode_;
switch(output_mode_) switch(output_mode_)
{ {
default: default:

2
Machines/Atari2600/TIA.hpp
View File

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