private void TriangulateWithRiver(VoronoiCell cell, VoronoiDirection direction, Vector3 center, EdgeVertices e)
{
Vector3 centerR;
Vector3 centerL = centerR = center;
// 4 sided straight
if (cell.HasRiverThroughEdge(direction.Next2(cell)) && cell.HasRiverThroughEdge(direction.Previous2(cell)))
{
centerL = center + VoronoiMetrics.GetSolidEdgeMiddle(cell, direction.Previous(cell)) *
(0.25f * VoronoiMetrics.InnerToOuter(cell, direction.Previous(cell)));
centerR = center + VoronoiMetrics.GetSolidEdgeMiddle(cell, direction.Next(cell)) *
(0.25f * VoronoiMetrics.InnerToOuter(cell, direction.Next(cell)));
// 1 step turn
}
else if (cell.HasRiverThroughEdge(direction.Next(cell)))
{
centerL = center;
centerR = Vector3.Lerp(center, e.V5, 2 / 3f);
// 1 step turn
}
else if (cell.HasRiverThroughEdge(direction.Previous(cell)))
{
centerL = Vector3.Lerp(center, e.V1, 2 / 3f);
centerR = center;
// 2 step turn
}
else if (cell.HasRiverThroughEdge(direction.Next2(cell)))
{
centerL = center;
centerR = center + VoronoiMetrics.GetSolidEdgeMiddle(cell, direction.Next(cell)) *
(0.5f * VoronoiMetrics.InnerToOuter(cell, direction.Next(cell)));
// 2 step turn
}
else if (cell.HasRiverThroughEdge(direction.Previous2(cell)))
{
centerL = center + VoronoiMetrics.GetSolidEdgeMiddle(cell, direction.Previous(cell)) *
(0.5f * VoronoiMetrics.InnerToOuter(cell, direction.Previous(cell)));
centerR = center;
// 6 sided straight
}
else if (cell.HasRiverThroughEdge(direction.Next3(cell)) &&
cell.HasRiverThroughEdge(direction.Previous3(cell)))
{
centerL = center + VoronoiMetrics.GetFirstSolidCorner(cell, direction.Previous(cell)) * 0.25f;
centerR = center + VoronoiMetrics.GetSecondSolidCorner(cell, direction.Next(cell)) * 0.25f;
// 7 sided straight
}
else if (cell.HasRiverThroughEdge(direction.Previous3(cell)) &&
cell.HasRiverThroughEdge(direction.Next4(cell)) &&
cell.Neighbors.Count > 4)
{
centerL = center + VoronoiMetrics.GetFirstSolidCorner(cell, direction.Previous(cell)) * 0.25f;
centerR = center + VoronoiMetrics.GetSolidEdgeMiddle(cell, direction.Next2(cell)) * 0.25f;
// 7 sided straight
}
else if (cell.HasRiverThroughEdge(direction.Previous4(cell)) &&
cell.HasRiverThroughEdge(direction.Next3(cell)) &&
cell.Neighbors.Count > 4)
{
centerL = center + VoronoiMetrics.GetSolidEdgeMiddle(cell, direction.Previous2(cell)) * 0.25f;
centerR = center + VoronoiMetrics.GetSecondSolidCorner(cell, direction.Next(cell)) * 0.25f;
// 8 sided straight
}
else if (cell.HasRiverThroughEdge(direction.Previous4(cell)) &&
cell.HasRiverThroughEdge(direction.Next4(cell)) &&
cell.Neighbors.Count > 4)
{
centerL = center + VoronoiMetrics.GetSolidEdgeMiddle(cell, direction.Previous2(cell)) * 0.25f;
centerR = center + VoronoiMetrics.GetSolidEdgeMiddle(cell, direction.Next2(cell)) * 0.25f;
// 3 step turn
}
else if (cell.HasRiverThroughEdge(direction.Previous3(cell)) &&
cell.HasRiverThroughEdge(direction.Next5(cell)) &&
cell.Neighbors.Count > 5)
{
centerR = center + VoronoiMetrics.GetSecondSolidCorner(cell, direction.Next2(cell)) * 0.25f;
centerL = center + VoronoiMetrics.GetFirstSolidCorner(cell, direction.Previous(cell)) * 0.25f;
// 3 step turn
}
else if (cell.HasRiverThroughEdge(direction.Previous5(cell)) &&
cell.HasRiverThroughEdge(direction.Next3(cell)) &&
cell.Neighbors.Count > 5)
{
centerL = center + VoronoiMetrics.GetFirstSolidCorner(cell, direction.Previous2(cell)) * 0.25f;
centerR = center + VoronoiMetrics.GetSecondSolidCorner(cell, direction.Next(cell)) * 0.25f;
}
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),
1 / 6f
);
m.V3 = Vector3.ClampMagnitude(m.V3, cell.StreamBedElevation);
center = Vector3.ClampMagnitude(center, cell.StreamBedElevation);
TriangulateEdgeStrip(m, cell.Color, e, cell.Color);
Terrain.AddTriangle(centerL, m.V1, m.V2);
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);
Terrain.AddTriangle(centerR, m.V4, m.V5);
Terrain.AddTriangleColor(cell.Color);
bool reversed = cell.IncomingRiver == direction;
TriangulateRiverQuad(centerL, centerR, m.V2, m.V4, cell.RiverSurfaceElevation, 0.4f, reversed);
TriangulateRiverQuad(m.V2, m.V4, e.V2, e.V4, cell.RiverSurfaceElevation, 0.6f, reversed);
}