Files
OpenRA/OpenRA.Game/Map/ProjectedCellRegion.cs

125 lines
3.5 KiB
C#

#region Copyright & License Information
/*
* Copyright 2007-2015 The OpenRA Developers (see AUTHORS)
* This file is part of OpenRA, which is free software. It is made
* available to you under the terms of the GNU General Public License
* as published by the Free Software Foundation. For more information,
* see COPYING.
*/
#endregion
using System.Collections;
using System.Collections.Generic;
namespace OpenRA
{
// Represents a (on-screen) rectangular collection of tiles.
// TopLeft and BottomRight are inclusive
public class ProjectedCellRegion : IEnumerable<PPos>
{
// Corners of the region
public readonly PPos TopLeft;
public readonly PPos BottomRight;
// Corners of the bounding map region that contains all the cells that
// may be projected within this region.
readonly MPos mapTopLeft;
readonly MPos mapBottomRight;
public ProjectedCellRegion(Map map, PPos topLeft, PPos bottomRight)
{
TopLeft = topLeft;
BottomRight = bottomRight;
// The projection from MPos -> PPos cannot produce a larger V coordinate
// so the top edge of the MPos region is the same as the PPos region.
// (in fact the cells are identical if height == 0)
mapTopLeft = (MPos)topLeft;
// The bottom edge is trickier: cells at MPos.V > bottomRight.V may have
// been projected into this region if they have height > 0.
// Each height step is equivalent to 512 WRange units, which is one MPos
// step for isometric cells, but only half a MPos step for classic cells. Doh!
var maxHeight = map.Grid.MaximumTerrainHeight;
var heightOffset = map.Grid.Type == MapGridType.RectangularIsometric ? maxHeight : maxHeight / 2;
// Use the MapHeight data array to clamp the bottom coordinate so it doesn't overflow the map
mapBottomRight = map.MapHeight.Value.Clamp(new MPos(bottomRight.U, bottomRight.V + heightOffset));
}
public bool Contains(PPos puv)
{
return puv.U >= TopLeft.U && puv.U <= BottomRight.U && puv.V >= TopLeft.V && puv.V <= BottomRight.V;
}
/// <summary>
/// The region in map coordinates that contains all the cells that
/// may be projected inside this region. For increased performance,
/// this does not validate whether individual map cells are actually
/// projected inside the region.
/// </summary>
public MapCoordsRegion CandidateMapCoords { get { return new MapCoordsRegion(mapTopLeft, mapBottomRight); } }
public ProjectedCellRegionEnumerator GetEnumerator()
{
return new ProjectedCellRegionEnumerator(this);
}
IEnumerator<PPos> IEnumerable<PPos>.GetEnumerator()
{
return GetEnumerator();
}
IEnumerator IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
public sealed class ProjectedCellRegionEnumerator : IEnumerator<PPos>
{
readonly ProjectedCellRegion r;
// Current position, in projected map coordinates
int u, v;
PPos current;
public ProjectedCellRegionEnumerator(ProjectedCellRegion region)
{
r = region;
Reset();
}
public bool MoveNext()
{
u += 1;
// Check for column overflow
if (u > r.BottomRight.U)
{
v += 1;
u = r.TopLeft.U;
// Check for row overflow
if (v > r.BottomRight.V)
return false;
}
current = new PPos(u, v);
return true;
}
public void Reset()
{
// Enumerator starts *before* the first element in the sequence.
u = r.TopLeft.U - 1;
v = r.TopLeft.V;
}
public PPos Current { get { return current; } }
object IEnumerator.Current { get { return Current; } }
public void Dispose() { }
}
}
}