public void FillTriangle(Vertex v1, Vertex v2, Vertex v3)
{
var verts = SortVertex(v1, v2, v3);
if (MathUtility.IsEqual(verts[1].pos.y, verts[2].pos.y))
{
FillBottomFlatTriangle(verts[0], verts[1], verts[2]);
}
else if (verts[0].pos.y == verts[1].pos.y)
{
FillTopFlatTriangle(verts[0], verts[1], verts[2]);
}
else //将三角面切割成平顶平底两个三角面绘制
{
float t = (verts[1].pos.y - verts[0].pos.y) / (verts[2].pos.y - verts[0].pos.y);
Vertex v4 = TransformUtility.LerpVertexInScreenSpace(verts[0], verts[2], t);
v4.color = ColorUtility.Lerp(verts[0], verts[1], verts[2], v4);
float y = verts[1].pos.y;
float x = (int)(verts[0].pos.x + (((float)verts[1].pos.y - verts[0].pos.y) / ((float)verts[2].pos.y - verts[0].pos.y)) *
(verts[2].pos.x - verts[0].pos.x));
v4.pos = new Vector(x, y, verts[1].pos.z);
FillBottomFlatTriangle(verts[0], verts[1], v4);
FillTopFlatTriangle(verts[1], v4, verts[2]);
//测试用
//DrawTriangleLine(v1.pos, v2.pos, v3.pos, Color.Black);
}
}
public void FillTriangle(Vector v1, Vector v2, Vector v3, Color color = default(Color))
{
int lineState = CheckInSameLineState(v1, v2, v3);
if (lineState != 0)
{
var vertPoint = SortPoint(v1, v2, v3, lineState == -1);
DrawLine(vertPoint[0], vertPoint[2], color);
return;
}
var verts = SortPoint(v1, v2, v3);
if (MathUtility.IsEqual(verts[1].y, verts[2].y))
{
FillBottomFlatTriangle(verts[0], verts[1], verts[2], color);
}
else if (verts[0].y == verts[1].y)
{
FillTopFlatTriangle(verts[0], verts[1], verts[2], color);
}
else //将三角面切割成平顶平底两个三角面绘制
{
Vector v4 = Vector.Zero;
v4.y = verts[1].y;
v4.x = (int)(verts[0].x + (((float)verts[1].y - verts[0].y) / ((float)verts[2].y - verts[0].y)) *
(verts[2].x - verts[0].x));
FillBottomFlatTriangle(verts[0], verts[1], v4, color);
FillTopFlatTriangle(verts[1], v4, verts[2], color);
DrawTriangleLine(v1, v2, v3, Color.Black);
}
}
public static bool operator !=(Vector a, Vector b)
{
return(!MathUtility.IsEqual(a.x, b.x) ||
!MathUtility.IsEqual(a.y, b.y) ||
!MathUtility.IsEqual(a.z, b.z)
);
}
public static bool operator ==(Vector a, Vector b)
{
return(MathUtility.IsEqual(a.x, b.x) &&
MathUtility.IsEqual(a.y, b.y) &&
MathUtility.IsEqual(a.z, b.z)
);
}
// -1 : 同行 ， 0 ：不等 1 ：同列
public int CheckInSameLineState(Vector v1, Vector v2, Vector v3)
{
if (MathUtility.IsEqual(v1.y - v2.y - v3.y, 0))
{
return(1);
}
else if (MathUtility.IsEqual(v1.x - v2.x - v3.x, 0))
{
return(-1);
}
return(0);
}
public List <Vertex> SortVertex(Vertex v1, Vertex v2, Vertex v3, bool sortByX = false)
{
List <Vertex> result = new List <Vertex>()
{
v1, v2, v3
};
result.Sort((a, b) =>
{
float value1 = sortByX ? a.pos.x : a.pos.y;
float value2 = sortByX ? b.pos.x : b.pos.y;
if (value1 > value2)
{
return(1);
}
else if (MathUtility.IsEqual(value1, value2))
{
return(0);
}
return(-1);
});
return(result);
}
public List <Vector> SortPoint(Vector v1, Vector v2, Vector v3, bool sortByX = false)
{
List <Vector> result = new List <Vector>()
{
v1, v2, v3
};
result.Sort((a, b) =>
{
float value1 = sortByX ? a.x : a.y;
float value2 = sortByX ? b.x : b.y;
if (value1 > value2)
{
return(1);
}
else if (MathUtility.IsEqual(value1, value2))
{
return(0);
}
return(-1);
});
return(result);
}