internal ScanlineSubPixelRasterizer()
{
//default
_currentLcdLut = s_g4_1_2LcdLut;
}
void BlendScanline(byte[] destImgBuffer, int destStride, int y, int srcW, int srcStride, byte[] grayScaleLineBuffer)
{
LcdDistributionLut lcdLut = _currentLcdLut;
_forwardBuffer.Reset();
int srcIndex = 0;
//start pixel
int destImgIndex = 0;
int destX = 0;
//-----------------
byte color_alpha = _color.alpha;
byte color_c0 = _color.red;
byte color_c1 = _color.green;
byte color_c2 = _color.blue;
//-----------------
//single line
srcIndex = 0;
destImgIndex = (destStride * y) + (destX * 4); //4 color component
_forwardBuffer.Reset();
int nwidth = srcW;
while (nwidth > 3)
{
//------------
//TODO: add release mode code (optimized version)
//1. convert from original grayscale value from lineBuff to lcd level
//and
//2.
//from single grey scale value,
//it is expanded*** into 5 color-components
byte e_0, e_1, e_2; //energy 0,1,2
{
byte write0 = lcdLut.Convert255ToLevel(grayScaleLineBuffer[srcIndex]);
byte write1 = lcdLut.Convert255ToLevel(grayScaleLineBuffer[srcIndex + 1]);
byte write2 = lcdLut.Convert255ToLevel(grayScaleLineBuffer[srcIndex + 2]);
//0
_forwardBuffer.WriteAccumAndReadBack(
lcdLut.Tertiary(write0),
lcdLut.Secondary(write0),
lcdLut.Primary(write0),
out e_0);
//1
_forwardBuffer.WriteAccumAndReadBack(
lcdLut.Tertiary(write1),
lcdLut.Secondary(write1),
lcdLut.Primary(write1),
out e_1);
//2
_forwardBuffer.WriteAccumAndReadBack(
lcdLut.Tertiary(write2),
lcdLut.Secondary(write2),
lcdLut.Primary(write2),
out e_2);
}
//4. blend 3 pixels
byte exc0 = destImgBuffer[destImgIndex]; //existing color
byte exc1 = destImgBuffer[destImgIndex + 1]; //existing color
byte exc2 = destImgBuffer[destImgIndex + 2]; //existing color
//--------------------------------------------------------
//note: that we swap e_2 and e_0 on the fly***
//--------------------------------------------------------
destImgBuffer[destImgIndex] = (byte)((((color_c0 - exc0) * (e_2 * color_alpha)) + (exc0 << 16)) >> 16); //swap on the fly
destImgBuffer[destImgIndex + 1] = (byte)((((color_c1 - exc1) * (e_1 * color_alpha)) + (exc1 << 16)) >> 16);
destImgBuffer[destImgIndex + 2] = (byte)((((color_c2 - exc2) * (e_0 * color_alpha)) + (exc2 << 16)) >> 16); //swap on the fly
//---------------------------------------------------------
destImgIndex += 4;
srcIndex += 3;
nwidth -= 3;
}
//---------
//when finish each line
//we must draw extened 4 pixels
//---------
{
//get remaining energy from _forward buffer
byte ec_r1, ec_r2, ec_r3, ec_r4;
_forwardBuffer.ReadRemaining4(out ec_r1, out ec_r2, out ec_r3, out ec_r4);
//we need 2 pixels,
int remaining_dest = Math.Min((srcStride - (destImgIndex + 4)), 5);
if (remaining_dest < 1)
{
return;
}
switch (remaining_dest)
{
default: throw new NotSupportedException();
case 5:
{
//1st round
byte exc0 = destImgBuffer[destImgIndex]; //existing color
byte exc1 = destImgBuffer[destImgIndex + 1]; //existing color
byte exc2 = destImgBuffer[destImgIndex + 2]; //existing color
//--------------------------------------------------------
//note: that we swap ec_r3 and ec_r1 on the fly***
destImgBuffer[destImgIndex] = (byte)((((color_c0 - exc0) * (ec_r3 * color_alpha)) + (exc0 << 16)) >> 16); //swap on the fly
destImgBuffer[destImgIndex + 1] = (byte)((((color_c1 - exc1) * (ec_r2 * color_alpha)) + (exc1 << 16)) >> 16);
destImgBuffer[destImgIndex + 2] = (byte)((((color_c2 - exc2) * (ec_r1 * color_alpha)) + (exc2 << 16)) >> 16); //swap on the fly
destImgIndex += 4;
srcIndex += 3;
//--------------------------------------------------------
//2nd round
exc0 = destImgBuffer[destImgIndex]; //existing color
destImgBuffer[destImgIndex] = (byte)((((color_c0 - exc0) * (ec_r4 * color_alpha)) + (exc0 << 16)) >> 16);
}
break;
case 4:
{
//1st round
byte ec0 = destImgBuffer[destImgIndex]; //existing color
byte ec1 = destImgBuffer[destImgIndex + 1]; //existing color
byte ec2 = destImgBuffer[destImgIndex + 2]; //existing color
//--------------------------------------------------------
//note: that we swap e_2 and e_0 on the fly
destImgBuffer[destImgIndex] = (byte)((((color_c0 - ec0) * (ec_r3 * color_alpha)) + (ec0 << 16)) >> 16); //swap on the fly
destImgBuffer[destImgIndex + 1] = (byte)((((color_c1 - ec1) * (ec_r2 * color_alpha)) + (ec1 << 16)) >> 16);
destImgBuffer[destImgIndex + 2] = (byte)((((color_c2 - ec2) * (ec_r1 * color_alpha)) + (ec2 << 16)) >> 16); //swap on the fly
destImgIndex += 4;
srcIndex += 3;
}
break;
case 3:
case 2:
case 1:
case 0:
//just return
break;
}
}
}