private void DrawParentTileBitmap(ICanvas canvas, Point point, Tile tile)
{
Tile cachedParentTile = GetCachedParentTile(tile, 4);
if (cachedParentTile != null)
{
IBitmap bitmap = this.tileCache.GetImmediately(CreateJob(cachedParentTile));
if (bitmap != null)
{
int tileSize = this.displayModel.TileSize;
long translateX = tile.GetShiftX(cachedParentTile) * tileSize;
long translateY = tile.GetShiftY(cachedParentTile) * tileSize;
sbyte zoomLevelDiff = (sbyte)(tile.ZoomLevel - cachedParentTile.ZoomLevel);
float scaleFactor = (float)Math.Pow(2, zoomLevelDiff);
int x = (int)Math.Round(point.X);
int y = (int)Math.Round(point.Y);
this.matrix.Reset();
this.matrix.Translate(x - translateX, y - translateY);
this.matrix.Scale(scaleFactor, scaleFactor);
canvas.SetClip(x, y, this.displayModel.TileSize, this.displayModel.TileSize);
canvas.DrawBitmap(bitmap, this.matrix);
canvas.ResetClip();
bitmap.DecrementRefCount();
}
}
}
public override void Draw(BoundingBox boundingBox, sbyte zoomLevel, ICanvas canvas, Point topLeftPoint)
{
IList <TilePosition> tilePositions = LayerUtil.GetTilePositions(boundingBox, zoomLevel, topLeftPoint, this.displayModel.TileSize);
// In a rotation situation it is possible that drawParentTileBitmap sets the
// clipping bounds to portrait, while the device is just being rotated into
// landscape: the result is a partially painted screen that only goes away
// after zooming (which has the effect of resetting the clip bounds if drawParentTileBitmap
// is called again).
// Always resetting the clip bounds here seems to avoid the problem,
// I assume that this is a pretty cheap operation, otherwise it would be better
// to hook this into the onConfigurationChanged call chain.
canvas.ResetClip();
if (!isTransparent)
{
canvas.FillColor(this.displayModel.BackgroundColor);
}
ISet <Job> jobs = new HashSet <Job>();
foreach (TilePosition tilePosition in tilePositions)
{
jobs.Add(CreateJob(tilePosition.Tile));
}
this.tileCache.WorkingSet = jobs;
for (int i = tilePositions.Count - 1; i >= 0; --i)
{
TilePosition tilePosition = tilePositions[i];
Point point = tilePosition.Point;
Tile tile = tilePosition.Tile;
T job = CreateJob(tile);
ITileBitmap bitmap = this.tileCache.GetImmediately(job);
if (bitmap == null)
{
if (this.hasJobQueue && !this.tileCache.ContainsKey(job))
{
this.jobQueue.Add(job);
}
DrawParentTileBitmap(canvas, point, tile);
}
else
{
if (IsTileStale(tile, bitmap) && this.hasJobQueue && !this.tileCache.ContainsKey(job))
{
this.jobQueue.Add(job);
}
RetrieveLabelsOnly(job);
canvas.DrawBitmap(bitmap, (int)Math.Round(point.X), (int)Math.Round(point.Y));
bitmap.DecrementRefCount();
}
}
if (this.hasJobQueue)
{
this.jobQueue.NotifyWorkers();
}
}