//传入六边形的一个方向，渲染这个方向相关的Mesh
void Triangulate(HexDirection d, HexCell cell)
{
Vector3 center = cell.Position;
Vector3 v1 = center + HexMetrics.GetFirstSolidCornet(d);
Vector3 v2 = center + HexMetrics.GetSecondSolidCornet(d);
//将三角形细分为三分，以便于更好地随机化
//e1,e2,e3皆为本方顶点
Vector3 e1 = Vector3.Lerp(v1, v2, 0.25f);
Vector3 e2 = Vector3.Lerp(v1, v2, 0.5f);
Vector3 e3 = Vector3.Lerp(v1, v2, 0.75f);
if (cell.HasRiver)
{
if (cell.HasRiverThroughEdge(d))
{
e2.y = cell.StreamBedY;
TriangulateWithRiver(d, cell, center, v1, e1, e2, e3, v2);
}
else
{
TriangulatAdjacentToRiver(d, cell, center, v1, e1, e2, e3, v2);
}
}
else
{
//内部三角形，颜色为纯色
AddTriangle4(center, v1, e1, e2, e3, v2, cell.Color);
}
TriangulateConnection(d, cell, v1, e1, e2, e3, v2);
}
//仅当河道中存在河道时才会调用
//绘制河道
void TriangulateWithRiver(HexDirection direction, HexCell cell,
Vector3 center, Vector3 v1, Vector3 e1, Vector3 e2, Vector3 e3, Vector3 v2)
{
//如果为河流的尽头，则仅仅弯下去一个角，其他角不受影响
if (cell.HasRiverBeginOrEnd)
{
Vector3 centerRiver = center;
centerRiver.y = cell.StreamBedY;
float lerpVal = 0.5f;
Vector3 mL = Vector3.Lerp(v1, center, lerpVal);
Vector3 mR = Vector3.Lerp(v2, center, lerpVal);
Vector3 m1 = Vector3.Lerp(e1, center, lerpVal);
Vector3 m2 = Vector3.Lerp(e2, centerRiver, lerpVal);
Vector3 m3 = Vector3.Lerp(e3, center, lerpVal);
AddTrapezoid(mL, m1, m2, m3, mR, v1, e1, e2, e3, v2, cell.Color);
AddTriangle4(center, mL, m1, m2, m3, mR, cell.Color);
}
//如果是直线穿过的河流，则将六边形中间挖一个类似矩形的空间，会影响几乎所有的角
else if (cell.RiverState == riverState.Dif3)
{
Vector3 cL = center + HexMetrics.GetFirstSolidCornet(direction.Previous()) * 0.25f;
Vector3 cR = center + HexMetrics.GetSecondSolidCornet(direction.Next()) * 0.25f;
center.y = cell.StreamBedY;
float lerpVal = 0.5f;
Vector3 mL = Vector3.Lerp(v1, cL, lerpVal);
Vector3 mR = Vector3.Lerp(v2, cR, lerpVal);
Vector3 m1 = Vector3.Lerp(e1, cL, lerpVal);
Vector3 m2 = Vector3.Lerp(e2, center, lerpVal);
Vector3 m3 = Vector3.Lerp(e3, cR, lerpVal);
AddTrapezoid(mL, m1, m2, m3, mR, v1, e1, e2, e3, v2, cell.Color);
AddTrapezoid(cL, cL, center, cR, cR, mL, m1, m2, m3, mR, cell.Color);
}
//一度只差
else if (cell.RiverState == riverState.Dif1)
{
if (cell.HasRiverThroughEdge(direction.Previous()))
{
Vector3 c1 = Vector3.Lerp(v1, center, 2 / 3f);
c1.y = cell.StreamBedY;
Vector3 c2 = Vector3.Lerp(v1, center, 1 / 3f);
Vector3 c3 = Vector3.Lerp(v1, center, 1 / 5f);
Vector3 leftMid = Vector3.Lerp(v2, center, 0.5f);
Vector3 m1 = Vector3.Lerp(e3, center, 0.5f);
Vector3 m2 = Vector3.Lerp(e2, c1, 0.5f);
Vector3 m3 = Vector3.Lerp(e1, c2, 0.5f);
AddTrapezoid(c3, m3, m2, m1, leftMid, v1, e1, e2, e3, v2, cell.Color);
AddTriangle(m1, leftMid, center, cell.Color);
AddQuad(c1, center, m2, m1, cell.Color);
AddQuad(c2, c1, m3, m2, cell.Color);
AddTriangle(c3, m3, c2, cell.Color);
}
else if (cell.HasRiverThroughEdge(direction.Next()))
{
Vector3 c1 = Vector3.Lerp(v2, center, 2 / 3f);
c1.y = cell.StreamBedY;
Vector3 c2 = Vector3.Lerp(v2, center, 1 / 3f);
Vector3 c3 = Vector3.Lerp(v2, center, 1 / 5f);
Vector3 rightMid = Vector3.Lerp(v1, center, 0.5f);
Vector3 m1 = Vector3.Lerp(e1, center, 0.5f);
Vector3 m2 = Vector3.Lerp(e2, c1, 0.5f);
Vector3 m3 = Vector3.Lerp(e3, c2, 0.5f);
AddTrapezoid(rightMid, m1, m2, m3, c3, v1, e1, e2, e3, v2, cell.Color);
AddTriangle(m1, center, rightMid, cell.Color);
AddQuad(m2, m1, c1, center, cell.Color);
AddQuad(m3, m2, c2, c1, cell.Color);
AddTriangle(c3, c2, m3, cell.Color);
}
}
//两度只差
else if (cell.RiverState == riverState.Dif2)
{
if (cell.HasRiverThroughEdge(direction.Previous2()))
{
Vector3 cL = Vector3.Lerp(center + HexMetrics.GetFirstSolidCornet(direction.Previous()) * 0.5f,
center + HexMetrics.GetSecondSolidCornet(direction.Previous()) * 0.5f, 0.5f);
Vector3 cR = Vector3.Lerp(center + HexMetrics.GetFirstSolidCornet(direction.Next2()) * 0.25f,
center + HexMetrics.GetSecondSolidCornet(direction.Next2()) * 0.25f, 0.5f);
center.y = cell.StreamBedY;
Vector3 mL = Vector3.Lerp(cL, v1, 0.5f);
Vector3 mR = Vector3.Lerp(cR, v2, 0.5f);
Vector3 m1 = Vector3.Lerp(cL, e1, 0.5f);
Vector3 m2 = Vector3.Lerp(center, e2, 0.5f);
Vector3 m3 = Vector3.Lerp(cR, e3, 0.5f);
AddTrapezoid(mL, m1, m2, m3, mR, v1, e1, e2, e3, v2, cell.Color);
AddTrapezoid(cL, cL, center, cR, cR, mL, m1, m2, m3, mR, cell.Color);
}
else if (cell.HasRiverThroughEdge(direction.Next2()))
{
Vector3 cL = Vector3.Lerp(center + HexMetrics.GetFirstSolidCornet(direction.Previous2()) * 0.25f,
center + HexMetrics.GetSecondSolidCornet(direction.Previous2()) * 0.25f, 0.5f);
Vector3 cR = Vector3.Lerp(center + HexMetrics.GetFirstSolidCornet(direction.Next()) * 0.5f,
center + HexMetrics.GetSecondSolidCornet(direction.Next()) * 0.5f, 0.5f);
center.y = cell.StreamBedY;
Vector3 mL = Vector3.Lerp(cL, v1, 0.5f);
Vector3 mR = Vector3.Lerp(cR, v2, 0.5f);
Vector3 m1 = Vector3.Lerp(cL, e1, 0.5f);
Vector3 m2 = Vector3.Lerp(center, e2, 0.5f);
Vector3 m3 = Vector3.Lerp(cR, e3, 0.5f);
AddTrapezoid(mL, m1, m2, m3, mR, v1, e1, e2, e3, v2, cell.Color);
AddTrapezoid(cL, cL, center, cR, cR, mL, m1, m2, m3, mR, cell.Color);
}
}
}
//补全空缺
void TriangulatAdjacentToRiver(HexDirection direction, HexCell cell, Vector3 center,
Vector3 v1, Vector3 e1, Vector3 e2, Vector3 e3, Vector3 v2)
{
//尽头或源头的情况
if (cell.HasRiverBeginOrEnd)
{
if (cell.HasRiverThroughEdge(direction.Previous()))
{
Vector3 leftMid = Vector3.Lerp(center, v1, 0.5f);
TriangulatAdjacentToRiverLeft(center, v1, e1, e2, e3, v2, cell.Color, leftMid);
}
else if (cell.HasRiverThroughEdge(direction.Next()))
{
Vector3 rightMid = Vector3.Lerp(center, v2, 0.5f);
TriangulatAdjacentToRiverRight(center, v1, e1, e2, e3, v2, cell.Color, rightMid);
}
else
{
AddTriangle4(center, v1, e1, e2, e3, v2, cell.Color);
}
}
//平直流过
else if (cell.RiverState == riverState.Dif3)
{
if (cell.HasRiverThroughEdge(direction.Previous()))
{
Vector3 centerX = center + HexMetrics.GetSecondSolidCornet(direction) * 0.25f;
Vector3 leftMid = Vector3.Lerp(centerX, v1, 0.5f);
TriangulatAdjacentToRiverLeft(centerX, v1, e1, e2, e3, v2, cell.Color, leftMid);
}
else if (cell.HasRiverThroughEdge(direction.Next()))
{
Vector3 centerX = center + HexMetrics.GetFirstSolidCornet(direction) * 0.25f;
Vector3 rightMid = Vector3.Lerp(centerX, v2, 0.5f);
TriangulatAdjacentToRiverRight(centerX, v1, e1, e2, e3, v2, cell.Color, rightMid);
}
}
//锐角转弯
else if (cell.RiverState == riverState.Dif1)
{
if (cell.HasRiverThroughEdge(direction.Previous()))
{
Vector3 leftMid = Vector3.Lerp(center, v1, 0.5f);
TriangulatAdjacentToRiverLeft(center, v1, e1, e2, e3, v2, cell.Color, leftMid);
}
else if (cell.HasRiverThroughEdge(direction.Next()))
{
Vector3 rightMid = Vector3.Lerp(center, v2, 0.5f);
TriangulatAdjacentToRiverRight(center, v1, e1, e2, e3, v2, cell.Color, rightMid);
}
else
{
AddTriangle4(center, v1, e1, e2, e3, v2, cell.Color);
}
}
//平缓转弯
else if (cell.RiverState == riverState.Dif2)
{
if (cell.HasRiverThroughEdge(direction.Previous()) && cell.HasRiverThroughEdge(direction.Next()))
{
Vector3 centerX = Vector3.Lerp(center + HexMetrics.GetFirstSolidCornet(direction) * 0.5f,
center + HexMetrics.GetSecondSolidCornet(direction) * 0.5f, 0.5f);
Vector3 mL = Vector3.Lerp(v1, centerX, 0.5f);
Vector3 m1 = Vector3.Lerp(e1, centerX, 0.5f);
Vector3 m2 = Vector3.Lerp(e2, centerX, 0.5f);
Vector3 m3 = Vector3.Lerp(e3, centerX, 0.5f);
Vector3 mR = Vector3.Lerp(v2, centerX, 0.5f);
AddTriangle4(centerX, mL, m1, m2, m3, mR, cell.Color);
AddTrapezoid(mL, m1, m2, m3, mR, v1, e1, e2, e3, v2, cell.Color);
}
else if (cell.HasRiverThroughEdge(direction.Previous()))
{
Vector3 centerX = Vector3.Lerp(center + HexMetrics.GetFirstSolidCornet(direction.Next()) * 0.25f,
center + HexMetrics.GetSecondSolidCornet(direction.Next()) * 0.25f, 0.5f);
Vector3 leftMid = Vector3.Lerp(v1, centerX, 0.5f);
TriangulatAdjacentToRiverLeft(centerX, v1, e1, e2, e3, v2, cell.Color, leftMid);
}
else if (cell.HasRiverThroughEdge(direction.Next()))
{
Vector3 centerX = Vector3.Lerp(center + HexMetrics.GetFirstSolidCornet(direction.Previous()) * 0.25f,
center + HexMetrics.GetSecondSolidCornet(direction.Previous()) * 0.25f, 0.5f);
Vector3 rightMid = Vector3.Lerp(v2, centerX, 0.5f);
TriangulatAdjacentToRiverRight(centerX, v1, e1, e2, e3, v2, cell.Color, rightMid);
}
else
{
Vector3 centerX = Vector3.Lerp(center + HexMetrics.GetFirstSolidCornet(direction) * 0.25f,
center + HexMetrics.GetSecondSolidCornet(direction) * 0.25f, 0.5f);
AddTriangle4(centerX, v1, e1, e2, e3, v2, cell.Color);
}
}
}