1
0
mirror of https://github.com/TomHarte/CLK.git synced 2024-12-24 12:30:17 +00:00

Limited CRT calls.

This commit is contained in:
Thomas Harte 2016-10-30 16:21:20 -04:00
parent 1ff9b474bf
commit 58f888c6ad

View File

@ -54,16 +54,19 @@ void VideoOutput::run_for_cycles(int number_of_cycles)
// Vertical: 039: pixels; otherwise blank; 4853 sync, 5456 colour burst
// Horizontal: 0223: pixels; otherwise blank; 256259 sync
#define clamp(action) \
if(cycles_run_for <= number_of_cycles) { action; } else cycles_run_for = number_of_cycles;
while(number_of_cycles)
{
int h_counter =_counter & 63;
int cycles_run_for = 0;
if(_counter >= _v_sync_start_position && _counter <= _v_sync_end_position)
if(_counter >= _v_sync_start_position && _counter < _v_sync_end_position)
{
// this is a sync line
cycles_run_for = std::min(64 - h_counter, number_of_cycles);
_crt->output_sync((unsigned int)cycles_run_for * 6);
cycles_run_for = _v_sync_end_position - _counter;
clamp(_crt->output_sync((unsigned int)(_v_sync_end_position - _v_sync_start_position) * 6));
}
else if(_counter < 224*64 && h_counter < 40)
{
@ -90,6 +93,9 @@ void VideoOutput::run_for_cycles(int number_of_cycles)
cycles_run_for = std::min(40 - h_counter, number_of_cycles);
int columns = cycles_run_for;
int pixel_base_address = 0xa000 + (_counter >> 6) * 40;
int character_base_address = 0xbb80 + (_counter >> 9) * 40;
uint8_t blink_mask = (_blink_text && (_frame_counter&32)) ? 0x00 : 0xff;
while(columns--)
{
@ -97,18 +103,18 @@ void VideoOutput::run_for_cycles(int number_of_cycles)
if(_is_graphics_mode && _counter < 200*64)
{
control_byte = pixels = _ram[0xa000 + (_counter >> 6) * 40 + h_counter];
control_byte = pixels = _ram[pixel_base_address + h_counter];
}
else
{
int address = 0xbb80 + (_counter >> 9) * 40 + h_counter;
int address = character_base_address + h_counter;
control_byte = _ram[address];
int line = _use_double_height_characters ? ((_counter >> 7) & 7) : ((_counter >> 6) & 7);
pixels = _ram[_character_set_base_address + (control_byte&127) * 8 + line];
}
uint8_t inverse_mask = (control_byte & 0x80) ? 0x77 : 0x00;
if(_blink_text && (_frame_counter&32)) pixels = 0;
pixels &= blink_mask;
if(control_byte & 0x60)
{
@ -178,23 +184,26 @@ void VideoOutput::run_for_cycles(int number_of_cycles)
// this is a blank line (or the equivalent part of a pixel line)
if(h_counter < 48)
{
cycles_run_for = std::min(48 - h_counter, number_of_cycles);
_crt->output_blank((unsigned int)cycles_run_for * 6);
cycles_run_for = 48 - h_counter;
clamp(
int period = (_counter < 224*64) ? 8 : 48;
_crt->output_blank((unsigned int)period * 6);
);
}
else if(h_counter < 54)
{
cycles_run_for = std::min(54 - h_counter, number_of_cycles);
_crt->output_sync((unsigned int)cycles_run_for * 6);
cycles_run_for = 54 - h_counter;
clamp(_crt->output_sync(6 * 6));
}
else if(h_counter < 56)
{
cycles_run_for = std::min(56 - h_counter, number_of_cycles);
_crt->output_colour_burst((unsigned int)cycles_run_for * 6, _phase, 128);
cycles_run_for = 56 - h_counter;
clamp(_crt->output_colour_burst(2 * 6, _phase, 128));
}
else
{
cycles_run_for = std::min(64 - h_counter, number_of_cycles);
_crt->output_blank((unsigned int)cycles_run_for * 6);
cycles_run_for = 64 - h_counter;
clamp(_crt->output_blank(8 * 6));
}
}