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Made an attempt to unify my variable storage (and, technically, to get beam size correct across the frame).

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This commit is contained in:
Thomas Harte 2015-08-02 19:30:45 -04:00
parent 6e52e5df1c
commit 55017b78a5
2 changed files with 31 additions and 43 deletions
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70
Outputs/CRT.cpp
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@ -37,30 +37,18 @@ void CRT::set_new_timing(int cycles_per_line, int height_of_display)
_sync_capacitor_charge_threshold = (syncCapacityLineChargeThreshold * _cycles_per_line) >> 1;
_horizontal_retrace_time = (millisecondsHorizontalRetraceTime * _cycles_per_line) >> 6;
const int vertical_retrace_time = scanlinesVerticalRetraceTime * _cycles_per_line;
const float halfLineWidth = (float)_height_of_display * 1.0f;
_scanSpeed.x = kCRTFixedPointRange / _cycles_per_line;
_scanSpeed.y = kCRTFixedPointRange / (_height_of_display * _cycles_per_line);
_retraceSpeed.x = kCRTFixedPointRange / _horizontal_retrace_time;
_retraceSpeed.y = kCRTFixedPointRange / vertical_retrace_time;
for(int c = 0; c < 4; c++)
{
_scanSpeed[c].x = (c&kRetraceXMask) ? -(kCRTFixedPointRange / _horizontal_retrace_time) : (kCRTFixedPointRange / _cycles_per_line);
_scanSpeed[c].y = (c&kRetraceYMask) ? -(kCRTFixedPointRange / vertical_retrace_time) : (kCRTFixedPointRange / (_height_of_display * _cycles_per_line));
// precompute the lengths of all four combinations of scan direction, for fast triangle
// strip generation later
float scanSpeedXfl = 1.0f / (float)_cycles_per_line;
float scanSpeedYfl = 1.0f / (float)(_height_of_display * _cycles_per_line);
float retraceSpeedXfl = 1.0f / (float)_horizontal_retrace_time;
float retraceSpeedYfl = 1.0f / (float)(vertical_retrace_time);
float lengths[4];
lengths[0] = sqrtf(scanSpeedXfl*scanSpeedXfl + scanSpeedYfl*scanSpeedYfl);
lengths[kRetraceXMask] = sqrtf(retraceSpeedXfl*retraceSpeedXfl + scanSpeedYfl*scanSpeedYfl);
lengths[kRetraceXMask | kRetraceYMask] = sqrtf(retraceSpeedXfl*retraceSpeedXfl + retraceSpeedYfl*retraceSpeedYfl);
lengths[kRetraceYMask] = sqrtf(scanSpeedXfl*scanSpeedXfl + retraceSpeedYfl*retraceSpeedYfl);
// width should be 1.0 / _height_of_display, rotated to match the direction
float angle = atan2f(scanSpeedYfl, scanSpeedXfl);
float halfLineWidth = (float)_height_of_display * 1.0f;
_widths[0][0] = (sinf(angle) / halfLineWidth) * kCRTFixedPointRange;
_widths[0][1] = (cosf(angle) / halfLineWidth) * kCRTFixedPointRange;
// width should be 1.0 / _height_of_display, rotated to match the direction
float angle = atan2f(_scanSpeed[c].y, _scanSpeed[c].x);
_beamWidth[c].x = (sinf(angle) / halfLineWidth) * kCRTFixedPointRange;
_beamWidth[c].y = (cosf(angle) / halfLineWidth) * kCRTFixedPointRange;
}
}
CRT::CRT(int cycles_per_line, int height_of_display, int number_of_buffers, ...)
@ -115,14 +103,14 @@ CRT::SyncEvent CRT::get_next_vertical_sync_event(bool vsync_is_charging, int cyc
// have we overrun the maximum permitted number of horizontal syncs for this frame?
if (!_is_in_vsync) {
int time_until_end_of_frame = (kCRTFixedPointRange - _rasterPosition.y) / _scanSpeed.y;
int time_until_end_of_frame = (kCRTFixedPointRange - _rasterPosition.y) / _scanSpeed[0].y;
if(time_until_end_of_frame < proposedSyncTime) {
proposedSyncTime = time_until_end_of_frame;
proposedEvent = SyncEvent::StartVSync;
}
} else {
int time_until_start_of_frame = _rasterPosition.y / _retraceSpeed.y;
int time_until_start_of_frame = _rasterPosition.y / _scanSpeed[kRetraceYMask].y;
if(time_until_start_of_frame < proposedSyncTime) {
proposedSyncTime = time_until_start_of_frame;
@ -133,7 +121,7 @@ CRT::SyncEvent CRT::get_next_vertical_sync_event(bool vsync_is_charging, int cyc
// will an acceptable vertical sync be triggered?
if (vsync_is_charging && !_is_in_vsync) {
if (_sync_capacitor_charge_level < _sync_capacitor_charge_threshold && _sync_capacitor_charge_level + proposedSyncTime >= _sync_capacitor_charge_threshold) {
uint32_t proposed_sync_y = _rasterPosition.y + (_sync_capacitor_charge_threshold - _sync_capacitor_charge_level) * _scanSpeed.y;
uint32_t proposed_sync_y = _rasterPosition.y + (_sync_capacitor_charge_threshold - _sync_capacitor_charge_level) * _scanSpeed[0].y;
if(proposed_sync_y >= (kCRTFixedPointRange * 7) >> 3) {
proposedSyncTime = _sync_capacitor_charge_threshold - _sync_capacitor_charge_level;
@ -203,9 +191,7 @@ void CRT::advance_cycles(int number_of_cycles, bool hsync_requested, const bool
int next_run_length = std::min(time_until_vertical_sync_event, time_until_horizontal_sync_event);
uint16_t *next_run = (is_output_run && _current_frame_builder && next_run_length) ? _current_frame_builder->get_next_run() : nullptr;
// int lengthMask = (_is_in_hsync ? kRetraceXMask : 0) | ((_vretrace_counter > 0) ? kRetraceXMask : 0);
// uint32_t *width = _widths[lengthMask];
uint32_t *width = _widths[0];
int lengthMask = (_is_in_hsync ? kRetraceXMask : 0) | (_is_in_vsync ? kRetraceXMask : 0);
#define position_x(v) next_run[kCRTSizeOfVertex*v + kCRTVertexOffsetOfPosition + 0]
#define position_y(v) next_run[kCRTSizeOfVertex*v + kCRTVertexOffsetOfPosition + 1]
@ -216,10 +202,10 @@ void CRT::advance_cycles(int number_of_cycles, bool hsync_requested, const bool
if(next_run)
{
// set the type, initial raster position and type of this run
position_x(0) = position_x(4) = (kCRTFixedPointOffset + _rasterPosition.x + width[0]) >> 16;
position_y(0) = position_y(4) = (kCRTFixedPointOffset + _rasterPosition.y + width[1]) >> 16;
position_x(1) = (kCRTFixedPointOffset + _rasterPosition.x - width[0]) >> 16;
position_y(1) = (kCRTFixedPointOffset + _rasterPosition.y - width[1]) >> 16;
position_x(0) = position_x(4) = (kCRTFixedPointOffset + _rasterPosition.x + _beamWidth[lengthMask].x) >> 16;
position_y(0) = position_y(4) = (kCRTFixedPointOffset + _rasterPosition.y + _beamWidth[lengthMask].y) >> 16;
position_x(1) = (kCRTFixedPointOffset + _rasterPosition.x - _beamWidth[lengthMask].x) >> 16;
position_y(1) = (kCRTFixedPointOffset + _rasterPosition.y - _beamWidth[lengthMask].y) >> 16;
tex_x(0) = tex_x(1) = tex_x(4) = tex_x;
@ -230,23 +216,27 @@ void CRT::advance_cycles(int number_of_cycles, bool hsync_requested, const bool
}
// advance the raster position as dictated by current sync status
int64_t end_position[2];
end_position[0] = (int64_t)_rasterPosition.x + (int64_t)number_of_cycles * (int32_t)_scanSpeed[lengthMask].x;
end_position[1] = (int64_t)_rasterPosition.y + (int64_t)number_of_cycles * (int32_t)_scanSpeed[lengthMask].y;
if (_is_in_hsync)
_rasterPosition.x = (uint32_t)std::max((int64_t)0, (int64_t)_rasterPosition.x - number_of_cycles * (int64_t)_retraceSpeed.x);
_rasterPosition.x = (uint32_t)std::max((int64_t)0, end_position[0]);
else
_rasterPosition.x = (uint32_t)std::min((int64_t)kCRTFixedPointRange, (int64_t)_rasterPosition.x + number_of_cycles * (int64_t)_scanSpeed.x);
_rasterPosition.x = (uint32_t)std::min((int64_t)kCRTFixedPointRange, end_position[0]);
if (_is_in_vsync)
_rasterPosition.y = (uint32_t)std::max((int64_t)0, (int64_t)_rasterPosition.y - number_of_cycles * (int64_t)_retraceSpeed.y);
_rasterPosition.y = (uint32_t)std::max((int64_t)0, end_position[0]);
else
_rasterPosition.y = (uint32_t)std::min((int64_t)kCRTFixedPointRange, (int64_t)_rasterPosition.y + number_of_cycles * (int64_t)_scanSpeed.y);
_rasterPosition.y = (uint32_t)std::min((int64_t)kCRTFixedPointRange, end_position[1]);
if(next_run)
{
// store the final raster position
position_x(2) = position_x(3) = (kCRTFixedPointOffset + _rasterPosition.x - width[0]) >> 16;
position_y(2) = position_y(3) = (kCRTFixedPointOffset + _rasterPosition.y - width[1]) >> 16;
position_x(5) = (kCRTFixedPointOffset + _rasterPosition.x + width[0]) >> 16;
position_y(5) = (kCRTFixedPointOffset + _rasterPosition.y + width[1]) >> 16;
position_x(2) = position_x(3) = (kCRTFixedPointOffset + _rasterPosition.x - _beamWidth[lengthMask].x) >> 16;
position_y(2) = position_y(3) = (kCRTFixedPointOffset + _rasterPosition.y - _beamWidth[lengthMask].y) >> 16;
position_x(5) = (kCRTFixedPointOffset + _rasterPosition.x + _beamWidth[lengthMask].x) >> 16;
position_y(5) = (kCRTFixedPointOffset + _rasterPosition.y + _beamWidth[lengthMask].y) >> 16;
// if this is a data run then advance the buffer pointer
if(type == Type::Data) tex_x += next_run_length / _time_multiplier;

4
Outputs/CRT.hpp
View File

@ -83,9 +83,7 @@ class CRT {
// the current scanning position
struct Vector {
uint32_t x, y;
} _rasterPosition, _scanSpeed, _retraceSpeed;
uint32_t _widths[4][2];
} _rasterPosition, _scanSpeed[4], _beamWidth[4];
// the run delegate and the triple buffer
CRTFrameBuilder *_frame_builders[kCRTNumberOfFrames];