private static void ComputeFieldOfViewInDodecantZero( int radius, int observerHeight, Func<HexCoords, bool> isOnBoard, Func<HexCoords, int> targetHeight, Func<HexCoords, int> terrainHeight, Action<HexCoords> setFieldOfView) { #if TraceFOV radius = 16; DebugTracing.EnabledFags |= TraceFlag.FieldOfView; #endif var currentCoords = HexCoords.NewCanonCoords(0, 1); if (!isOnBoard(currentCoords)) return; if (radius > 0) setFieldOfView(currentCoords); var queue = new FovQueue(); var current = new FovCone( 2, new IntVector2D(1, 2), new IntVector2D(0, 1), new RiseRun(terrainHeight(currentCoords) - observerHeight, 1)); while (current.Range <= radius) { current = ComputeFoVForRange( observerHeight, current, isOnBoard, targetHeight, terrainHeight, setFieldOfView, queue); } }
/// <summary></summary> /// <param name="observerHeight"></param> /// <param name="cone"></param> /// <param name="isOnBoard"></param> /// <param name="targetHeight"></param> /// <param name="terrainHeight"></param> /// <param name="setFieldOfView"></param> /// <param name="queue"></param> /// <returns></returns> ///<remarks> /// This method: /// (1) marks points inside the cone-arc that are within the radius of the field /// of view; and /// (2) computes which portions of the following column are in the field of view, /// queueing them for later processing. /// /// This algorithm is "center-to-center"; a more sophisticated algorithm /// would say that a cell is visible if there is *any* straight line segment that /// passes through *any* portion of the origin cell and any portion of the target /// cell, passing through only transparent cells along the way. This is the /// "Permissive Field Of View" algorithm, and it is much harder to implement. /// /// Search for transitions from opaque to transparent or transparent to opaque and /// use those to determine what portions of the *next* column are visible from the /// origin. ///</remarks> private static FovCone ComputeFoVForRange( int observerHeight, FovCone cone, Func<HexCoords, bool> isOnBoard, Func<HexCoords, int> targetHeight, Func<HexCoords, int> terrainHeight, Action<HexCoords> setFieldOfView, FovQueue queue) { Action<FovCone> enqueue = queue.Enqueue; var range = cone.Range; var topVector = cone.VectorTop; var topRiseRun = cone.RiseRun; var bottomVector = cone.VectorBottom; // track the overlap-cone between adjacent hexes as we move down. var overlapVector = cone.VectorTop; var hexX = XFromVector(range, topVector); #if TraceFOV TraceFlag.FieldOfView.Trace(false, "DQ: ({0}) from {1}", cone, hexX); #endif do { while (overlapVector.GT(bottomVector)) { var coordsCurrent = HexCoords.NewCanonCoords(hexX, range); var hexVectorBottom = VectorHexBottom(coordsCurrent); if (isOnBoard(coordsCurrent)) { #region Set current hex parameters var hexVectorTop = VectorHexTop(coordsCurrent); var hexElevation = targetHeight(coordsCurrent); var hexHeight = terrainHeight(coordsCurrent); var hexRiseRun = new RiseRun(hexHeight - observerHeight, range); #endregion #region Check visibility of current hex var riseRun = new RiseRun(hexElevation - observerHeight, GetRange(coordsCurrent)); if (riseRun >= cone.RiseRun && bottomVector.LE(coordsCurrent.Canon) && coordsCurrent.Canon.LE(topVector) ) { setFieldOfView(coordsCurrent); #if TraceFOV TraceFlag.FieldOfView.Trace(false," Set visible: {0} / {1}; {2} >= {3}", MapCoordsDodecant(coordsCurrent), coordsCurrent.ToString(), riseRun, cone.RiseRun); #endif } #endregion #region Check hex transition if (hexRiseRun > topRiseRun) { topVector = LogAndEnqueue(enqueue, range, topVector, hexVectorTop, topRiseRun, 0); topRiseRun = hexRiseRun; } else if (hexRiseRun > cone.RiseRun) { topVector = LogAndEnqueue(enqueue, range, topVector, overlapVector, topRiseRun, 1); topRiseRun = hexRiseRun; } else if (hexRiseRun < cone.RiseRun) { topVector = LogAndEnqueue(enqueue, range, topVector, overlapVector, topRiseRun, 2); topRiseRun = cone.RiseRun; } #endregion } overlapVector = VectorMax(hexVectorBottom, bottomVector); if (hexVectorBottom.GT(bottomVector)) --hexX; } #region Dequeue next cone if (queue.Count == 0) { topVector = LogAndEnqueue(enqueue, range, topVector, bottomVector, topRiseRun, 3); cone = queue.Dequeue(); break; } else { cone = queue.Dequeue(); if (cone.Range != range) { topVector = LogAndEnqueue(enqueue, range, topVector, bottomVector, topRiseRun, 4); break; } #if TraceFOV TraceFlag.FieldOfView.Trace(false, "DQ: ({0}) from {1}", cone, hexX); #endif } #endregion #region Check cone transition if (cone.RiseRun > topRiseRun) { topVector = LogAndEnqueue(enqueue, range, topVector, cone.VectorTop, topRiseRun, 5); topRiseRun = cone.RiseRun; } else if (cone.RiseRun < topRiseRun) { topVector = LogAndEnqueue(enqueue, range, topVector, overlapVector, topRiseRun, 6); topRiseRun = cone.RiseRun; // TODO Why is this commented out? } #endregion overlapVector = topVector; bottomVector = cone.VectorBottom; } while (true); // Pick-up any cone portion at bottom of range still unprocessed if (topVector.GT(bottomVector)) LogAndEnqueue(enqueue, range, topVector, bottomVector, cone.RiseRun, 7); return cone; }