// Triangulate the center of a cell with a river
void TriangulateWithRiver(HexDirection direction, HexCell cell, Vector3 center, EdgeVertices e)
{
Vector3 centerL, centerR;
if (cell.HasRiverThroughEdge(direction.Opposite()))
{
centerL = center + HexMetrics.GetFirstSolidCorner(direction.Previous()) * 1f / 4f;
centerR = center + HexMetrics.GetSecondSolidCorner(direction.Next()) * 1f / 4f;
}
else if (cell.HasRiverThroughEdge(direction.Next()))
{
centerL = center;
centerR = Vector3.Lerp(center, e.v5, 2f / 3f);
}
else if (cell.HasRiverThroughEdge(direction.Previous()))
{
centerL = Vector3.Lerp(center, e.v1, 2f / 3f);
centerR = center;
}
else if (cell.HasRiverThroughEdge(direction.Next2()))
{
centerL = center;
centerR = center + HexMetrics.GetSolidEdgeMiddle(direction.Next()) * (0.5f * HexMetrics.innerToOutter);
}
else
{
centerL = center + HexMetrics.GetSolidEdgeMiddle(direction.Previous()) * (0.5f * HexMetrics.innerToOutter);
centerR = center;
}
center = Vector3.Lerp(centerL, centerR, 0.5f);
EdgeVertices m = new EdgeVertices(Vector3.Lerp(centerL, e.v1, 0.5f),
Vector3.Lerp(centerR, e.v5, 0.5f),
1f / 6f);
m.v3.y = center.y = e.v3.y;
TriangulateEdgeStrip(m, cell.Color, e, cell.Color);
terrain.AddTriangle(centerL, m.v1, m.v2);
terrain.AddTriangleColor(cell.Color);
terrain.AddTriangle(centerR, m.v4, m.v5);
terrain.AddTriangleColor(cell.Color);
terrain.AddQuad(centerL, center, m.v2, m.v3);
terrain.AddQuadColor(cell.Color);
terrain.AddQuad(center, centerR, m.v3, m.v4);
terrain.AddQuadColor(cell.Color);
if (!cell.IsUnderwater)
{
bool reversed = cell.IncomingRiver == direction;
TriangulateRiverQuad(centerL, centerR, m.v2, m.v4, cell.RiverSurfaceY, 0.4f, reversed);
TriangulateRiverQuad(m.v2, m.v4, e.v2, e.v4, cell.RiverSurfaceY, 0.6f, reversed);
}
}