Implement terrain merging in TerrainChannel.

Modify archiver to use terrain merging when loading oars.
This makes displacement AND rotation properly work on terrain when loading oars.
Especially useful when loading legacy region oars into large varregions.

1 files changed, 72 insertions, 0 deletions

diff --git a/OpenSim/Region/Framework/Scenes/TerrainChannel.cs b/OpenSim/Region/Framework/Scenes/TerrainChannel.cs
index b4b1823..24709dc 100644
--- a/OpenSim/Region/Framework/Scenes/TerrainChannel.cs
+++ b/OpenSim/Region/Framework/Scenes/TerrainChannel.cs
@@ -36,6 +36,8 @@ using OpenSim.Data;
 using OpenSim.Framework;
 using OpenSim.Region.Framework.Interfaces;
 
+using OpenMetaverse;
+
 using log4net;
 
 namespace OpenSim.Region.Framework.Scenes
@@ -212,6 +214,76 @@ namespace OpenSim.Region.Framework.Scenes
             sr.Close();
         }
 
+        // ITerrainChannel.Merge
+        public void Merge(ITerrainChannel newTerrain, Vector3 displacement, float radianRotation, Vector2 rotationDisplacement)
+        {
+            for (int xx = 0; xx < newTerrain.Width; xx++)
+            {
+                for (int yy = 0; yy < newTerrain.Height; yy++)
+                {
+                    int dispX = (int)displacement.X;
+                    int dispY = (int)displacement.Y;
+                    float newHeight = (float)newTerrain[xx, yy] + displacement.Z;
+                    if (radianRotation == 0)
+                    {
+                        // If no rotation, place the new height in the specified location
+                        dispX += xx;
+                        dispY += yy;
+                        if (dispX >= 0 && dispX < m_terrainData.SizeX && dispY >= 0 && dispY < m_terrainData.SizeY)
+                        {
+                            m_terrainData[dispX, dispY] = newHeight;
+                        }
+                    }
+                    else
+                    {
+                        // If rotating, we have to smooth the result because the conversion
+                        //    to ints will mean heightmap entries will not get changed
+                        // First compute the rotation location for the new height.
+                        dispX += (int)(rotationDisplacement.X
+                            + ((float)xx - rotationDisplacement.X) * Math.Cos(radianRotation)
+                            - ((float)yy - rotationDisplacement.Y) * Math.Sin(radianRotation) );
+
+                        dispY += (int)(rotationDisplacement.Y
+                            + ((float)xx - rotationDisplacement.X) * Math.Sin(radianRotation)
+                            + ((float)yy - rotationDisplacement.Y) * Math.Cos(radianRotation) );
+
+                        if (dispX >= 0 && dispX < m_terrainData.SizeX && dispY >= 0 && dispY < m_terrainData.SizeY)
+                        {
+                            float oldHeight = m_terrainData[dispX, dispY];
+                            // Smooth the heights around this location if the old height is far from this one
+                            for (int sxx = dispX - 2; sxx < dispX + 2; sxx++)
+                            {
+                                for (int syy = dispY - 2; syy < dispY + 2; syy++)
+                                {
+                                    if (sxx >= 0 && sxx < m_terrainData.SizeX && syy >= 0 && syy < m_terrainData.SizeY)
+                                    {
+                                        if (sxx == dispX && syy == dispY)
+                                        {
+                                            // Set height for the exact rotated point
+                                            m_terrainData[dispX, dispY] = newHeight;
+                                        }
+                                        else
+                                        {
+                                            if (Math.Abs(m_terrainData[sxx, syy] - newHeight) > 1f)
+                                            {
+                                                // If the adjacent height is far off, force it to this height
+                                                m_terrainData[sxx, syy] = newHeight;
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
+
+                        if (dispX >= 0 && dispX < m_terrainData.SizeX && dispY >= 0 && dispY < m_terrainData.SizeY)
+                        {
+                            m_terrainData[dispX, dispY] = (float)newTerrain[xx, yy];
+                        }
+                    }
+                }
+            }
+        }
+
         #endregion
 
         public TerrainChannel Copy()