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Started trying to move some logic out of the inner loop.

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This commit is contained in:
Thomas Harte 2016-01-21 21:28:09 -05:00
parent 48ddd3c497
commit 34640cec93
1 changed files with 49 additions and 57 deletions
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106
Machines/Electron/Electron.cpp
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@ -476,6 +476,8 @@ inline void Machine::update_display()
if(line_position >= 24 && line_position < 104)
{
// determine whether the pixel clock divider has changed; if so write out the old
// data and start a new run
unsigned int newDivider = 0;
switch(_screenMode)
{
@ -491,83 +493,73 @@ inline void Machine::update_display()
_currentLine = _writePointer = (uint8_t *)_crt->get_write_target_for_buffer(0);
}
// TODO: determine whether we need to change divider
// int pixels_to_output = std::max(_frameCycles - _displayOutputPosition, 104 - line_position);
// if(_screenMode >= 4)
// {
// // just shifting wouldn't be enough if both
// if(_displayOutputPosition&1) pixels_to_output++;
// pixels_to_output >>= 1;
// }
//
// swi
if(_currentLine && ((_screenMode < 4) || !(line_position&1)))
int pixels_to_output = std::min(_frameCycles - _displayOutputPosition, 104 - line_position);
_displayOutputPosition += pixels_to_output;
if(_screenMode >= 4)
{
if(_currentScreenAddress&32768)
{
_currentScreenAddress = _screenModeBaseAddress + (_currentScreenAddress&32767);
}
uint8_t pixels = _ram[_currentScreenAddress];
_currentScreenAddress = _currentScreenAddress+8;
// just shifting wouldn't be enough if both
if(_displayOutputPosition&1) pixels_to_output++;
pixels_to_output >>= 1;
}
#define GetNextPixels() \
if(_currentScreenAddress&32768)\
{\
_currentScreenAddress = _screenModeBaseAddress + (_currentScreenAddress&32767);\
}\
uint8_t pixels = _ram[_currentScreenAddress];\
_currentScreenAddress = _currentScreenAddress+8
if(pixels_to_output)
{
switch(_screenMode)
{
case 0:
case 3:
for(int c = 0; c < 8; c++)
default:
case 0: case 3: case 4: case 6:
while(pixels_to_output--)
{
uint8_t colour = (pixels&0x80) >> 4;
_writePointer[c] = _palette[colour];
pixels <<= 1;
GetNextPixels();
for(int c = 0; c < 8; c++)
{
uint8_t colour = (pixels&0x80) >> 4;
_writePointer[c] = _palette[colour];
pixels <<= 1;
}
_writePointer += 8;
}
_writePointer += 8;
break;
case 1:
for(int c = 0; c < 4; c ++)
case 5:
while(pixels_to_output--)
{
uint8_t colour = ((pixels&0x80) >> 4) | ((pixels&0x08) >> 2);
_writePointer[c] = _palette[colour];
pixels <<= 1;
GetNextPixels();
for(int c = 0; c < 4; c ++)
{
uint8_t colour = ((pixels&0x80) >> 4) | ((pixels&0x08) >> 2);
_writePointer[c] = _palette[colour];
pixels <<= 1;
}
_writePointer += 4;
}
_writePointer += 4;
break;
case 2:
for(int c = 0; c < 2; c ++)
while(pixels_to_output--)
{
uint8_t colour = ((pixels&0x80) >> 4) | ((pixels&0x20) >> 3) | ((pixels&0x08) >> 2) | ((pixels&0x02) >> 1);
_writePointer[c] = _palette[colour];
pixels <<= 1;
GetNextPixels();
for(int c = 0; c < 2; c ++)
{
uint8_t colour = ((pixels&0x80) >> 4) | ((pixels&0x20) >> 3) | ((pixels&0x08) >> 2) | ((pixels&0x02) >> 1);
_writePointer[c] = _palette[colour];
pixels <<= 1;
}
_writePointer += 2;
}
_writePointer += 2;
break;
case 5:
for(int c = 0; c < 4; c ++)
{
uint8_t colour = ((pixels&0x80) >> 4) | ((pixels&0x08) >> 2);
_writePointer[c] = _palette[colour];
pixels <<= 1;
}
_writePointer += 4;
break;
default:
case 4:
case 6:
for(int c = 0; c < 8; c ++)
{
uint8_t colour = (pixels&0x80) >> 4;
_writePointer[c] = _palette[colour];
pixels <<= 1;
}
_writePointer += 8;
break;
}
}
_displayOutputPosition++;
}
if(line_position == 104)