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mirror of https://github.com/TomHarte/CLK.git synced 2024-07-04 18:29:40 +00:00

Slightly relaxed time it takes to recognise vertical sync; considered what to do about reviving proper vertical sync but then gave up.

This commit is contained in:
Thomas Harte 2015-07-24 23:56:25 -04:00
parent 78a91b67c5
commit dd428c5d4d

View File

@ -14,25 +14,25 @@ using namespace Outputs;
CRT::CRT(int cycles_per_line, int height_of_display, int number_of_buffers, ...)
{
const int syncCapacityLineChargeThreshold = 3;
const int syncCapacityLineChargeThreshold = 5;
const int millisecondsHorizontalRetraceTime = 7; // source: Dictionary of Video and Television Technology, p. 234
const int scanlinesVerticalRetraceTime = 10; // source: ibid
_time_multiplier = (1000 + cycles_per_line - 1) / cycles_per_line;
// store fundamental display configuration properties
_height_of_display = height_of_display;
_height_of_display = height_of_display;// + (height_of_display / 10);
_cycles_per_line = cycles_per_line * _time_multiplier;
// generate timing values implied by the given arbuments
_hsync_error_window = _cycles_per_line >> 5;
_sync_capacitor_charge_threshold = syncCapacityLineChargeThreshold * _cycles_per_line;
_sync_capacitor_charge_threshold = (syncCapacityLineChargeThreshold * _cycles_per_line) >> 1;
_horizontal_retrace_time = (millisecondsHorizontalRetraceTime * _cycles_per_line) >> 6;
_vertical_retrace_time = scanlinesVerticalRetraceTime * _cycles_per_line;
_scanSpeed.x = UINT32_MAX / _cycles_per_line;
_scanSpeed.y = UINT32_MAX / (height_of_display * _cycles_per_line);
_scanSpeed.y = UINT32_MAX / (_height_of_display * _cycles_per_line);
_retraceSpeed.x = UINT32_MAX / _horizontal_retrace_time;
_retraceSpeed.y = UINT32_MAX / _vertical_retrace_time;
@ -85,7 +85,7 @@ CRT::SyncEvent CRT::next_vertical_sync_event(bool vsync_is_charging, int cycles_
// have we overrun the maximum permitted number of horizontal syncs for this frame?
// if (!_vretrace_counter)
// {
// float raster_distance = _scanSpeed.y * (float)proposedSyncTime;
// float raster_distance = _scanSpeed.y * proposedSyncTime;
// if(_rasterPosition.y < 1.02f && _rasterPosition.y + raster_distance >= 1.02f) {
// proposedSyncTime = (int)(1.02f - _rasterPosition.y) / _scanSpeed.y;
// proposedEvent = SyncEvent::StartVSync;