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();
}
}
public void RasterizeTriangle(
RasterizerPoint p0, RasterizerPoint p1, RasterizerPoint p2, T param
)
{
// ReSharper disable InvocationIsSkipped
Debug.Assert(p0.Y <= p1.Y);
Debug.Assert(p1.Y <= p2.Y);
if (p0.Y > ymax)
{
return;
}
var y0 = p0.Y.Clamp(ymin, ymax);
var y1 = p1.Y;
var y2 = p2.Y.Clamp(ymin, ymax);
RasterizerResult r0, r1;
for (var y = y0; y <= y2; y++)
{
InterpolateX(y, p0, p2, 1, out r0);
if (y <= y1)
{
InterpolateX(y, p0, p1, 2, out r1);
}
else
{
InterpolateX(y, p1, p2, 0, out r1);
}
AdjustX(ref r0, ref r1);
rowHandler(y, ref r0, ref r1, ref param);
}
}
public static void RasterizeTriangle <T>(
RasterizerPoint p0, RasterizerPoint p1, RasterizerPoint p2,
T param, RasterizeDelegate <T> rowHandler,
int ymin = int.MinValue, int ymax = int.MaxValue, int xmin = int.MinValue, int xmax = int.MaxValue
)
{
new TriangleRasterizer <T>(rowHandler, ymin, ymax, xmin, xmax).RasterizeTriangle(p0, p1, p2, param);
}
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);
}
}
