6502/CLK
1
0
Fork 0
mirror of https://github.com/TomHarte/CLK.git synced 2025-02-28 22:29:36 +00:00
Code Issues Projects Releases Wiki Activity

Reinstituted the playfield. Probably needs more buffering though. Time to look into delays.

Browse Source
This commit is contained in:
Thomas Harte 2017-01-30 21:38:58 -05:00
parent 2b08758b2b
commit 8545707b54
2 changed files with 33 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
Machines/Atari2600/TIA.cpp
View File

@ -14,17 +14,29 @@ namespace {
const int sync_flag = 0x1;
const int blank_flag = 0x2;
uint8_t reverse_table[256];
}
TIA::TIA() :
horizontal_counter_(0),
output_cursor_(0),
pixel_target_(nullptr),
output_mode_(0)
output_mode_(0),
background_{0, 0},
background_half_mask_(0)
{
crt_.reset(new Outputs::CRT::CRT(cycles_per_line * 2 + 1, 1, Outputs::CRT::DisplayType::NTSC60, 1));
crt_->set_output_device(Outputs::CRT::Television);
set_output_mode(OutputMode::NTSC);
for(int c = 0; c < 256; c++)
{
reverse_table[c] = (uint8_t)(
((c & 0x01) << 7) | ((c & 0x02) << 5) | ((c & 0x04) << 3) | ((c & 0x08) << 1) |
((c & 0x10) >> 1) | ((c & 0x20) >> 3) | ((c & 0x40) >> 5) | ((c & 0x80) >> 7)
);
}
}
void TIA::set_output_mode(Atari2600::TIA::OutputMode output_mode)
@ -125,10 +137,26 @@ void TIA::set_background_colour(uint8_t colour)
void TIA::set_playfield(uint16_t offset, uint8_t value)
{
switch(offset)
{
case 0:
background_[1] = (background_[1] & 0x0ffff) | ((uint32_t)reverse_table[value & 0xf0] << 16);
background_[0] = (background_[0] & 0xffff0) | (uint32_t)(value >> 4);
break;
case 1:
background_[1] = (background_[1] & 0xf00ff) | ((uint32_t)value << 8);
background_[0] = (background_[0] & 0xff00f) | ((uint32_t)reverse_table[value] << 4);
break;
case 2:
background_[1] = (background_[1] & 0xfff00) | reverse_table[value];
background_[0] = (background_[0] & 0x00fff) | ((uint32_t)value << 12);
break;
}
}
void TIA::set_playfield_control_and_ball_size(uint8_t value)
{
background_half_mask_ = value & 1;
}
void TIA::set_playfield_ball_colour(uint8_t colour)
@ -295,7 +323,8 @@ void TIA::output_for_cycles(int number_of_cycles)
{
while(output_cursor_ < horizontal_counter_)
{
pixel_target_[output_cursor_ - 68] = (output_cursor_&1) ? playfield_ball_colour_ : background_colour_;
int offset = (output_cursor_ - 68) >> 2;
pixel_target_[output_cursor_ - pixel_target_origin_] = ((background_[(offset/20)&background_half_mask_] >> (offset%20))&1) ? playfield_ball_colour_ : background_colour_;
output_cursor_++;
}
} else output_cursor_ = horizontal_counter_;

2
Machines/Atari2600/TIA.hpp
View File

@ -77,6 +77,8 @@ class TIA {
uint8_t playfield_ball_colour_;
uint8_t background_colour_;
uint32_t background_[2];
int background_half_mask_;
void output_for_cycles(int number_of_cycles);
void output_line();