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Name horizontal events.

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This commit is contained in:
Thomas Harte 2024-12-15 08:46:07 -05:00
parent b76104d145
commit 3d7e016b42
1 changed files with 61 additions and 26 deletions
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87
Machines/Commodore/Plus4/Video.hpp
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@ -202,8 +202,46 @@ public:
interrupts_.apply(Interrupts::Flag::Raster);
}
// List of events.
enum HorizontalEvent {
Begin38Columns = 3,
EndExternalFetchWindow = 288,
LatchCharacterPosition = 290,
EndCharacterFetchWindow = 296,
EndVideoShiftRegister = 304,
End38Columns = 307,
End40Columns = 315,
EndRefresh = 328,
IncrementBlink = 336,
BeginBlank = 344,
BeginSync = 358,
TestRasterInterrupt = 368,
IncrementVerticalLine = 376,
BeginBurst = 384,
EndSync = 390,
BeginExternalFetchWindow = 400,
EndBurst = 408,
EndBlank = 416,
IncrementCharacterPositionReload = 424,
BeginCharacterFetchWindow = 432,
BeginVideoShiftRegister = 440,
Begin40Columns = 451,
EndOfLine = 456,
};
const auto next = Numeric::upper_bound<
0, 3, 288, 290, 296, 304, 307, 315, 328, 336, 344, 358, 368, 376, 384, 390, 400, 416, 424, 432, 440, 451, 465
0, Begin38Columns,
EndExternalFetchWindow, LatchCharacterPosition,
EndCharacterFetchWindow, EndVideoShiftRegister,
End38Columns, End40Columns,
EndRefresh, IncrementBlink,
BeginBlank, BeginSync,
TestRasterInterrupt, IncrementVerticalLine,
BeginBurst, EndSync,
BeginExternalFetchWindow, EndBurst,
EndBlank, IncrementCharacterPositionReload,
BeginCharacterFetchWindow, BeginVideoShiftRegister,
Begin40Columns, EndOfLine
>(horizontal_counter_);
const auto period = std::min(next - horizontal_counter_, ticks_remaining);
@ -258,68 +296,65 @@ public:
horizontal_counter_ += period;
ticks_remaining -= period;
switch(horizontal_counter_) {
case 288: // External fetch window end, refresh single clock start, increment character position end.
case EndExternalFetchWindow:
// TODO: release RDY if it was held.
// TODO: increment character position end.
refresh_ = true;
break;
case 400: // External fetch window start.
case BeginExternalFetchWindow:
// TODO: set RDY line if this is an appropriate row.
break;
case 290: line_character_address_ = character_address_; break; // Latch character position to reload.
case LatchCharacterPosition: line_character_address_ = character_address_; break;
case 296: // Character window end, character window single clock end, increment refresh start.
case EndCharacterFetchWindow:
fetch_characters_ = false;
break;
case 432: // Character window start, character window single clock start, increment character position start.
case BeginCharacterFetchWindow:
fetch_characters_ = true;
break;
case 304: // Video shift register end.
break;
case Begin38Columns: if(!columns_40_) output_pixels_ = true; break;
case End38Columns: if(!columns_40_) output_pixels_ = false; break;
case Begin40Columns: if(columns_40_) output_pixels_ = true; break;
case End40Columns: if(columns_40_) output_pixels_ = false; break;
case 3: if(!columns_40_) output_pixels_ = true; break; // 38-column screen start.
case 307: if(!columns_40_) output_pixels_ = false; break; // 38-column screen stop.
case 451: if(columns_40_) output_pixels_ = true; break; // 40-column screen start.
case 315: if(columns_40_) output_pixels_ = false; break; // 40-column screen end.
case 328: // Refresh single clock end.
case EndRefresh:
refresh_ = false;
break;
case 336: // Increment blink, increment refresh end.
case IncrementBlink:
break;
case 376: // Increment vertical line.
case IncrementVerticalLine:
vertical_counter_ = (vertical_counter_ + 1) & 0x1ff;
break;
case 384: // Burst start, end of screen — clear vertical line, vertical sub and character reload registers.
case BeginBurst:
horizontal_burst_ = true;
// TODO: rest.
break;
case 344: horizontal_blank_ = true; break; // Horizontal blanking start.
case 358: horizontal_sync_ = true; break; // Horizontal sync start.
case 390: horizontal_sync_ = false; break; // Horizontal sync end.
case 408: horizontal_burst_ = false; break; // Burst end.
case 416: horizontal_blank_ = false; break; // Horizontal blanking end.
case BeginBlank: horizontal_blank_ = true; break;
case BeginSync: horizontal_sync_ = true; break;
case EndSync: horizontal_sync_ = false; break;
case EndBurst: horizontal_burst_ = false; break;
case EndBlank: horizontal_blank_ = false; break;
case 368:
case TestRasterInterrupt:
if(raster_interrupt_ == vertical_counter_) {
interrupts_.apply(Interrupts::Flag::Raster);
}
break;
case 424: // Increment character position reload; also interrput time.
case IncrementCharacterPositionReload:
break;
case 440: // Video shift register start.
case BeginVideoShiftRegister:
break;
case 465: // Wraparound.
case EndOfLine:
horizontal_counter_ = 0;
break;
}