private static void InterpolateX(
int y,
RasterizerPoint a, RasterizerPoint b,
int notUsedIndex,
out RasterizerResult result
)
{
int dY = b.Y - a.Y;
var ratio = (y - a.Y) / (float)(dY != 0 ? dY : 1);
var iratio = 1 - ratio;
var x = ratio.Interpolate(a.X, b.X);
switch (notUsedIndex)
{
case 0:
result = new RasterizerResult(x, new Vector3(0, iratio, ratio));
return;
case 1:
result = new RasterizerResult(x, new Vector3(iratio, 0, ratio));
return;
case 2:
result = new RasterizerResult(x, new Vector3(iratio, ratio, 0));
return;
default:
throw new Exception();
}
}
private void AdjustX(ref RasterizerResult r0, ref RasterizerResult r1)
{
if (r0.X > r1.X)
{
Swap(ref r0, ref r1);
}
var rx0 = r0.X;
var rx1 = r1.X;
if (rx0 < xmin || rx0 > xmax || rx1 < xmin || rx1 > xmax)
{
var x0 = rx0.Clamp(xmin, xmax);
var x1 = rx1.Clamp(xmin, xmax);
r0 = new RasterizerResult(x0, Vector3.Lerp(r0.Ratios, r1.Ratios, x0.RatioInRange(rx0, rx1)));
r1 = new RasterizerResult(x1, Vector3.Lerp(r0.Ratios, r1.Ratios, x1.RatioInRange(rx0, rx1)));
}
}
public void RasterizeLine(
RasterizerPoint p0, RasterizerPoint p1, T param
)
{
// ReSharper disable InvocationIsSkipped
Debug.Assert(p0.Y <= p1.Y);
var y0 = p0.Y.Clamp(ymin, ymax);
var y1 = p1.Y.Clamp(ymin, ymax);
for (var y = y0; y < y1; y++)
{
var ratio0 = y.RatioInRange(y0, y1);
var ratio1 = (y + 1).RatioInRange(y0, y1);
var vx0 = ratio0.Interpolate(p0.X, p1.X);
var vx1 = ratio1.Interpolate(p0.X, p1.X) + 1;
var r0 = new RasterizerResult(vx0, new Vector3(ratio0));
var r1 = new RasterizerResult(vx1, new Vector3(ratio1));
AdjustX(ref r0, ref r1);
rowHandler(y, ref r0, ref r1, ref param);
}
}
