X-Git-Url: http://gitweb.fperrin.net/?p=GpsPrune.git;a=blobdiff_plain;f=src%2Ftim%2Fprune%2Fthreedee%2FTerrainCache.java;fp=src%2Ftim%2Fprune%2Fthreedee%2FTerrainCache.java;h=5f5733f72be4a0fa1eb2c954375d3900fb2d54ec;hp=0000000000000000000000000000000000000000;hb=ce6f2161b8596f7018d6a76bff79bc9e571f35fd;hpb=2d8cb72e84d5cc1089ce77baf1e34ea3ea2f8465

diff --git a/src/tim/prune/threedee/TerrainCache.java b/src/tim/prune/threedee/TerrainCache.java
new file mode 100644
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+++ b/src/tim/prune/threedee/TerrainCache.java
@@ -0,0 +1,57 @@
+package tim.prune.threedee;
+
+import tim.prune.DataStatus;
+import tim.prune.data.Track;
+
+/**
+ * This abstract class acts as a singleton to store a single
+ * terrain model (as a Track) for a given data status and terrain definition.
+ * When the data or the definition changes, this track becomes invalid.
+ */
+public abstract class TerrainCache
+{
+	/** The data status at the time this terrain was generated */
+	private static DataStatus _dataStatus = null;
+	/** The definition (grid size) for this terrain */
+	private static TerrainDefinition _terrainDef = null;
+	/** The generated grid of points with altitudes */
+	private static Track _terrainTrack = null;
+
+
+	/**
+	 * Get the stored terrain track if it's still valid
+	 * @param inCurrStatus current data status
+	 * @param inTerrainDef currently selected terrain definition
+	 * @return stored terrain track if it's valid, null otherwise
+	 */
+	public static Track getTerrainTrack(DataStatus inCurrStatus, TerrainDefinition inTerrainDef)
+	{
+		if (_dataStatus == null || _terrainDef == null || _terrainTrack == null)
+		{
+			return null; // nothing stored
+		}
+		if (inCurrStatus == null || inTerrainDef == null || !inTerrainDef.getUseTerrain())
+		{
+			return null; // nonsense requested
+		}
+		if (inCurrStatus.hasDataChanged(_dataStatus) || !inTerrainDef.equals(_terrainDef))
+		{
+			return null; // stored track is out of date
+		}
+		// we have a match
+		return _terrainTrack;
+	}
+
+	/**
+	 * Now that a terrain track has been generated, store it for possible reuse
+	 * @param inTrack terrain track to store
+	 * @param inCurrStatus current data status
+	 * @param inTerrainDef terrain definition
+	 */
+	public static void storeTerrainTrack(Track inTrack, DataStatus inCurrStatus, TerrainDefinition inTerrainDef)
+	{
+		_terrainTrack = inTrack;
+		_dataStatus = inCurrStatus;
+		_terrainDef = inTerrainDef;
+	}
+}