Blend lerp implemented.

src/engine/InterestManagement/HeightMap.java

@@ -13,6 +13,7 @@ import engine.gameManager.ConfigManager;
 import engine.gameManager.DbManager;
 import engine.gameManager.ZoneManager;
 import engine.math.Bounds;
+import engine.math.FastMath;
 import engine.math.Vector2f;
 import engine.math.Vector3fImmutable;
 import engine.objects.Zone;
@@ -231,13 +232,12 @@ public class HeightMap {
         // Interpolate height for this position using pixel array.
 
         float interpolatedTerrainHeight = heightMapZone.getHeightMap().getInterpolatedTerrainHeight(zoneLoc);
+        worldHeight = interpolatedTerrainHeight + heightMapZone.worldAltitude;
 
         // Heightmap blending is based on distance to edge of zone.
 
-        if (Bounds.collide(worldLoc, heightMapZone.maxBlend) == true) {
-            worldHeight = interpolatedTerrainHeight + heightMapZone.worldAltitude;
+        if (Bounds.collide(worldLoc, heightMapZone.maxBlend) == true)
             return worldHeight;
-        }
 
         // We will need the parent height if we got this far into the method
 
@@ -253,12 +253,21 @@ public class HeightMap {
             zoneLoc.y = abs(zoneLoc.x);
             blendBounds.setBounds(new Vector2f(heightMapZone.absX, heightMapZone.absZ), zoneLoc, 0.0f);
 
+            float childArea = (blendBounds.getHalfExtents().x * 2) *
+                    (blendBounds.getHalfExtents().y * 2);
+            float parentArea = (parentZone.minBlend.getHalfExtents().x * 2) *
+                    (parentZone.minBlend.getHalfExtents().y * 2);
+
+            float areaDelta = childArea / parentArea;
+
+            interpolatedTerrainHeight = FastMath.LERP(interpolatedTerrainHeight, parentHeight, areaDelta);
+            return interpolatedTerrainHeight + heightMapZone.worldAltitude;
 
         }
 
-        // Position returned from Heightmap engine is relative to zone world height
+        // Past min blend we just return the parent height.
 
-        return interpolatedTerrainHeight + heightMapZone.worldAltitude;
+        return parentHeight + heightMapZone.worldAltitude;
 
     }