//------------------------------------------------------------------------
private void LineClipY(RasterizerCellsAA ras,
int x1, int y1,
int x2, int y2,
uint f1, uint f2)
{
f1 &= 10;
f2 &= 10;
if ((f1 | f2) == 0)
{
// Fully visible
ras.Line(x1, y1, x2, y2);
}
else
{
if (f1 == f2)
{
// Invisible by Y
return;
}
int tx1 = x1;
int ty1 = y1;
int tx2 = x2;
int ty2 = y2;
if ((f1 & 8) != 0) // y1 < clip.y1
{
tx1 = x1 + MulDiv(m_clip_box.Y1 - y1, x2 - x1, y2 - y1);
ty1 = m_clip_box.Y1;
}
if ((f1 & 2) != 0) // y1 > clip.y2
{
tx1 = x1 + MulDiv(m_clip_box.Y2 - y1, x2 - x1, y2 - y1);
ty1 = m_clip_box.Y2;
}
if ((f2 & 8) != 0) // y2 < clip.y1
{
tx2 = x1 + MulDiv(m_clip_box.Y1 - y1, x2 - x1, y2 - y1);
ty2 = m_clip_box.Y1;
}
if ((f2 & 2) != 0) // y2 > clip.y2
{
tx2 = x1 + MulDiv(m_clip_box.Y2 - y1, x2 - x1, y2 - y1);
ty2 = m_clip_box.Y2;
}
ras.Line(tx1, ty1, tx2, ty2);
}
}
public void LineTo(RasterizerCellsAA ras, int x2, int y2)
{
ras.Line(m_x1, m_y1, x2, y2);
m_x1 = x2;
m_y1 = y2;
}
//--------------------------------------------------------------------
public void LineTo(RasterizerCellsAA ras, int x2, int y2)
{
if (m_clipping)
{
uint f2 = LiangBarskyClipper.GetClippingFlags(x2, y2, m_clip_box);
if ((m_f1 & 10) == (f2 & 10) && (m_f1 & 10) != 0)
{
// Invisible by Y
m_x1 = x2;
m_y1 = y2;
m_f1 = f2;
return;
}
int x1 = m_x1;
int y1 = m_y1;
uint f1 = m_f1;
int y3, y4;
uint f3, f4;
switch (((f1 & 5) << 1) | (f2 & 5))
{
case 0: // Visible by X
LineClipY(ras, x1, y1, x2, y2, f1, f2);
break;
case 1: // x2 > clip.x2
y3 = y1 + MulDiv(m_clip_box.X2 - x1, y2 - y1, x2 - x1);
f3 = LiangBarskyClipper.GetClippingFlagsY(y3, m_clip_box);
LineClipY(ras, x1, y1, m_clip_box.X2, y3, f1, f3);
LineClipY(ras, m_clip_box.X2, y3, m_clip_box.X2, y2, f3, f2);
break;
case 2: // x1 > clip.x2
y3 = y1 + MulDiv(m_clip_box.X2 - x1, y2 - y1, x2 - x1);
f3 = LiangBarskyClipper.GetClippingFlagsY(y3, m_clip_box);
LineClipY(ras, m_clip_box.X2, y1, m_clip_box.X2, y3, f1, f3);
LineClipY(ras, m_clip_box.X2, y3, x2, y2, f3, f2);
break;
case 3: // x1 > clip.x2 && x2 > clip.x2
LineClipY(ras, m_clip_box.X2, y1, m_clip_box.X2, y2, f1, f2);
break;
case 4: // x2 < clip.x1
y3 = y1 + MulDiv(m_clip_box.X1 - x1, y2 - y1, x2 - x1);
f3 = LiangBarskyClipper.GetClippingFlagsY(y3, m_clip_box);
LineClipY(ras, x1, y1, m_clip_box.X1, y3, f1, f3);
LineClipY(ras, m_clip_box.X1, y3, m_clip_box.X1, y2, f3, f2);
break;
case 6: // x1 > clip.x2 && x2 < clip.x1
y3 = y1 + MulDiv(m_clip_box.X2 - x1, y2 - y1, x2 - x1);
y4 = y1 + MulDiv(m_clip_box.X1 - x1, y2 - y1, x2 - x1);
f3 = LiangBarskyClipper.GetClippingFlagsY(y3, m_clip_box);
f4 = LiangBarskyClipper.GetClippingFlagsY(y4, m_clip_box);
LineClipY(ras, m_clip_box.X2, y1, m_clip_box.X2, y3, f1, f3);
LineClipY(ras, m_clip_box.X2, y3, m_clip_box.X1, y4, f3, f4);
LineClipY(ras, m_clip_box.X1, y4, m_clip_box.X1, y2, f4, f2);
break;
case 8: // x1 < clip.x1
y3 = y1 + MulDiv(m_clip_box.X1 - x1, y2 - y1, x2 - x1);
f3 = LiangBarskyClipper.GetClippingFlagsY(y3, m_clip_box);
LineClipY(ras, m_clip_box.X1, y1, m_clip_box.X1, y3, f1, f3);
LineClipY(ras, m_clip_box.X1, y3, x2, y2, f3, f2);
break;
case 9: // x1 < clip.x1 && x2 > clip.x2
y3 = y1 + MulDiv(m_clip_box.X1 - x1, y2 - y1, x2 - x1);
y4 = y1 + MulDiv(m_clip_box.X2 - x1, y2 - y1, x2 - x1);
f3 = LiangBarskyClipper.GetClippingFlagsY(y3, m_clip_box);
f4 = LiangBarskyClipper.GetClippingFlagsY(y4, m_clip_box);
LineClipY(ras, m_clip_box.X1, y1, m_clip_box.X1, y3, f1, f3);
LineClipY(ras, m_clip_box.X1, y3, m_clip_box.X2, y4, f3, f4);
LineClipY(ras, m_clip_box.X2, y4, m_clip_box.X2, y2, f4, f2);
break;
case 12: // x1 < clip.x1 && x2 < clip.x1
LineClipY(ras, m_clip_box.X1, y1, m_clip_box.X1, y2, f1, f2);
break;
}
m_f1 = f2;
}
else
{
ras.Line(m_x1, m_y1,
x2, y2);
}
m_x1 = x2;
m_y1 = y2;
}