private static void DrawGridHex(Graphics g, TmxMap tmxMap)
{
// Our collection of points to render
HashSet <Point> points = new HashSet <Point>();
// Note: borrowed heavily from Tiled source (HexagonalRenderer::drawGrid)
int tileWidth = tmxMap.TileWidth & ~1;
int tileHeight = tmxMap.TileHeight & ~1;
int sideLengthX = tmxMap.StaggerAxis == TmxMap.MapStaggerAxis.X ? tmxMap.HexSideLength : 0;
int sideLengthY = tmxMap.StaggerAxis == TmxMap.MapStaggerAxis.Y ? tmxMap.HexSideLength : 0;
int sideOffsetX = (tmxMap.TileWidth - sideLengthX) / 2;
int sideOffsetY = (tmxMap.TileHeight - sideLengthY) / 2;
int columnWidth = sideOffsetX + sideLengthX;
int rowHeight = sideOffsetY + sideLengthY;
bool staggerX = tmxMap.StaggerAxis == TmxMap.MapStaggerAxis.X;
// Determine the tile and pixel coordinates to start at
Point startTile = new Point(0, 0);
Point startPos = TmxMath.TileCornerInScreenCoordinates(tmxMap, startTile.X, startTile.Y);
Point[] oct = new Point[8]
{
new Point(0, tileHeight - sideOffsetY),
new Point(0, sideOffsetY),
new Point(sideOffsetX, 0),
new Point(tileWidth - sideOffsetX, 0),
new Point(tileWidth, sideOffsetY),
new Point(tileWidth, tileHeight - sideOffsetY),
new Point(tileWidth - sideOffsetX, tileHeight),
new Point(sideOffsetX, tileHeight)
};
if (staggerX)
{
// Odd row shifting is applied in the rendering loop, so un-apply it here
if (TmxMath.DoStaggerX(tmxMap, startTile.X))
{
startPos.Y -= rowHeight;
}
for (; startTile.X < GetMaxTilesWide(tmxMap); startTile.X++)
{
Point rowTile = startTile;
Point rowPos = startPos;
if (TmxMath.DoStaggerX(tmxMap, startTile.X))
{
rowPos.Y += rowHeight;
}
for (; rowTile.Y < GetMaxTilesHigh(tmxMap); rowTile.Y++)
{
points.Add(TmxMath.AddPoints(rowPos, oct[1]));
points.Add(TmxMath.AddPoints(rowPos, oct[2]));
points.Add(TmxMath.AddPoints(rowPos, oct[3]));
points.Add(TmxMath.AddPoints(rowPos, oct[4]));
bool isStaggered = TmxMath.DoStaggerX(tmxMap, startTile.X);
bool lastRow = rowTile.Y == tmxMap.Height - 1;
bool lastColumn = rowTile.X == tmxMap.Width - 1;
bool bottomLeft = rowTile.X == 0 || (lastRow && isStaggered);
bool bottomRight = lastColumn || (lastRow && isStaggered);
if (bottomRight)
{
points.Add(TmxMath.AddPoints(rowPos, oct[5]));
points.Add(TmxMath.AddPoints(rowPos, oct[6]));
}
if (lastRow)
{
points.Add(TmxMath.AddPoints(rowPos, oct[6]));
points.Add(TmxMath.AddPoints(rowPos, oct[7]));
}
if (bottomLeft)
{
points.Add(TmxMath.AddPoints(rowPos, oct[7]));
points.Add(TmxMath.AddPoints(rowPos, oct[0]));
}
rowPos.Y += tileHeight + sideLengthY;
}
startPos.X += columnWidth;
}
}
else
{
// Odd row shifting is applied in the rendering loop, so un-apply it here
if (TmxMath.DoStaggerY(tmxMap, startTile.Y))
{
startPos.X -= columnWidth;
}
for (; startTile.Y < tmxMap.Height; startTile.Y++)
{
Point rowTile = startTile;
Point rowPos = startPos;
if (TmxMath.DoStaggerY(tmxMap, startTile.Y))
{
rowPos.X += columnWidth;
}
for (; rowTile.X < tmxMap.Width; rowTile.X++)
{
points.Add(TmxMath.AddPoints(rowPos, oct[0]));
points.Add(TmxMath.AddPoints(rowPos, oct[1]));
points.Add(TmxMath.AddPoints(rowPos, oct[2]));
points.Add(TmxMath.AddPoints(rowPos, oct[3]));
points.Add(TmxMath.AddPoints(rowPos, oct[4]));
bool isStaggered = TmxMath.DoStaggerY(tmxMap, startTile.Y);
bool lastRow = rowTile.Y == tmxMap.Height - 1;
bool lastColumn = rowTile.Y == tmxMap.Width - 1;
bool bottomLeft = lastRow || (rowTile.X == 0 && !isStaggered);
bool bottomRight = lastRow || (lastColumn && isStaggered);
if (lastColumn)
{
points.Add(TmxMath.AddPoints(rowPos, oct[4]));
points.Add(TmxMath.AddPoints(rowPos, oct[5]));
}
if (bottomRight)
{
points.Add(TmxMath.AddPoints(rowPos, oct[5]));
points.Add(TmxMath.AddPoints(rowPos, oct[6]));
}
if (bottomLeft)
{
points.Add(TmxMath.AddPoints(rowPos, oct[7]));
points.Add(TmxMath.AddPoints(rowPos, oct[0]));
}
rowPos.X += tileWidth + sideLengthX;
}
startPos.Y += rowHeight;
}
}
foreach (var p in points)
{
RectangleF rc = new RectangleF(p.X, p.Y, PreviewImage.GridSize, PreviewImage.GridSize);
rc.Offset(-PreviewImage.GridSize * 0.5f, -PreviewImage.GridSize * 0.5f);
g.DrawRectangle(Pens.Black, rc.X, rc.Y, rc.Width, rc.Height);
}
}