public override bool write(laszip_point item)
{
int diff_l = 0;
int diff_h = 0;
uint sym = 0;
bool rl = (last_item[0] & 0x00FF) != (item.rgb[0] & 0x00FF); if (rl)
{
sym |= 1;
}
bool rh = (last_item[0] & 0xFF00) != (item.rgb[0] & 0xFF00); if (rh)
{
sym |= 2;
}
bool gl = (last_item[1] & 0x00FF) != (item.rgb[1] & 0x00FF); if (gl)
{
sym |= 4;
}
bool gh = (last_item[1] & 0xFF00) != (item.rgb[1] & 0xFF00); if (gh)
{
sym |= 8;
}
bool bl = (last_item[2] & 0x00FF) != (item.rgb[2] & 0x00FF); if (bl)
{
sym |= 16;
}
bool bh = (last_item[2] & 0xFF00) != (item.rgb[2] & 0xFF00); if (bh)
{
sym |= 32;
}
bool allColors = ((item.rgb[0] & 0x00FF) != (item.rgb[1] & 0x00FF)) || ((item.rgb[0] & 0x00FF) != (item.rgb[2] & 0x00FF)) ||
((item.rgb[0] & 0xFF00) != (item.rgb[1] & 0xFF00)) || ((item.rgb[0] & 0xFF00) != (item.rgb[2] & 0xFF00));
if (allColors)
{
sym |= 64;
}
enc.encodeSymbol(m_byte_used, sym);
if (rl)
{
diff_l = ((int)(item.rgb[0] & 255)) - (last_item[0] & 255);
enc.encodeSymbol(m_rgb_diff_0, (byte)MyDefs.U8_FOLD(diff_l));
}
if (rh)
{
diff_h = ((int)(item.rgb[0] >> 8)) - (last_item[0] >> 8);
enc.encodeSymbol(m_rgb_diff_1, (byte)MyDefs.U8_FOLD(diff_h));
}
if (allColors)
{
if (gl)
{
int corr = ((int)(item.rgb[1] & 255)) - MyDefs.U8_CLAMP(diff_l + (last_item[1] & 255));
enc.encodeSymbol(m_rgb_diff_2, (byte)MyDefs.U8_FOLD(corr));
}
if (bl)
{
diff_l = (diff_l + (item.rgb[1] & 255) - (last_item[1] & 255)) / 2;
int corr = ((int)(item.rgb[2] & 255)) - MyDefs.U8_CLAMP(diff_l + (last_item[2] & 255));
enc.encodeSymbol(m_rgb_diff_4, (byte)MyDefs.U8_FOLD(corr));
}
if (gh)
{
int corr = ((int)(item.rgb[1] >> 8)) - MyDefs.U8_CLAMP(diff_h + (last_item[1] >> 8));
enc.encodeSymbol(m_rgb_diff_3, (byte)MyDefs.U8_FOLD(corr));
}
if (bh)
{
diff_h = (diff_h + (item.rgb[1] >> 8) - (last_item[1] >> 8)) / 2;
int corr = ((int)(item.rgb[2] >> 8)) - MyDefs.U8_CLAMP(diff_h + (last_item[2] >> 8));
enc.encodeSymbol(m_rgb_diff_5, (byte)MyDefs.U8_FOLD(corr));
}
}
last_item[0] = item.rgb[0];
last_item[1] = item.rgb[1];
last_item[2] = item.rgb[2];
return(true);
}
public override void read(laszip_point item)
{
int corr;
int diff = 0;
uint sym = dec.decodeSymbol(m_byte_used);
if ((sym & (1 << 0)) != 0)
{
corr = (int)dec.decodeSymbol(m_rgb_diff_0);
item.rgb[0] = (ushort)MyDefs.U8_FOLD(corr + (last_item[0] & 255));
}
else
{
item.rgb[0] = (ushort)(last_item[0] & 0xFF);
}
if ((sym & (1 << 1)) != 0)
{
corr = (int)dec.decodeSymbol(m_rgb_diff_1);
item.rgb[0] |= (ushort)((MyDefs.U8_FOLD(corr + (last_item[0] >> 8))) << 8);
}
else
{
item.rgb[0] |= (ushort)(last_item[0] & 0xFF00);
}
if ((sym & (1 << 6)) != 0)
{
diff = (item.rgb[0] & 0x00FF) - (last_item[0] & 0x00FF);
if ((sym & (1 << 2)) != 0)
{
corr = (int)dec.decodeSymbol(m_rgb_diff_2);
item.rgb[1] = (ushort)MyDefs.U8_FOLD(corr + MyDefs.U8_CLAMP(diff + (last_item[1] & 255)));
}
else
{
item.rgb[1] = (ushort)(last_item[1] & 0xFF);
}
if ((sym & (1 << 4)) != 0)
{
corr = (int)dec.decodeSymbol(m_rgb_diff_4);
diff = (diff + ((item.rgb[1] & 0x00FF) - (last_item[1] & 0x00FF))) / 2;
item.rgb[2] = (ushort)MyDefs.U8_FOLD(corr + MyDefs.U8_CLAMP(diff + (last_item[2] & 255)));
}
else
{
item.rgb[2] = (ushort)(last_item[2] & 0xFF);
}
diff = (item.rgb[0] >> 8) - (last_item[0] >> 8);
if ((sym & (1 << 3)) != 0)
{
corr = (int)dec.decodeSymbol(m_rgb_diff_3);
item.rgb[1] |= (ushort)((MyDefs.U8_FOLD(corr + MyDefs.U8_CLAMP(diff + (last_item[1] >> 8)))) << 8);
}
else
{
item.rgb[1] |= (ushort)(last_item[1] & 0xFF00);
}
if ((sym & (1 << 5)) != 0)
{
corr = (int)dec.decodeSymbol(m_rgb_diff_5);
diff = (diff + ((item.rgb[1] >> 8) - (last_item[1] >> 8))) / 2;
item.rgb[2] |= (ushort)((MyDefs.U8_FOLD(corr + MyDefs.U8_CLAMP(diff + (last_item[2] >> 8)))) << 8);
}
else
{
item.rgb[2] |= (ushort)(last_item[2] & 0xFF00);
}
}
else
{
item.rgb[1] = item.rgb[0];
item.rgb[2] = item.rgb[0];
}
last_item[0] = item.rgb[0];
last_item[1] = item.rgb[1];
last_item[2] = item.rgb[2];
}