private Rectangle GetVisibleTiles(ArrayGrid <Sprite> grid, Vector2 cameraPosition, Point viewportSize,
Vector2 layerOffset)
{
var gridPosition = grid.Position + layerOffset;
Rectangle visibleCoordinates;
Point offset;
switch (grid.Perspective)
{
case Perspective.Standard:
visibleCoordinates = GetVisibleCartesianCoordinates(cameraPosition, viewportSize, grid.TileSize, 1);
offset = Projector.PixelsToCartesian(gridPosition, grid.TileSize).ToPoint();
break;
case Perspective.Isometric:
visibleCoordinates = GetVisibleIsometricCoordinates(cameraPosition, viewportSize, grid.TileSize, 1);
offset = Projector.PixelsToIsometric(gridPosition, grid.TileSize).ToPoint();
break;
default:
throw new InvalidOperationException($"Can not process {grid.Perspective} perspective.");
}
visibleCoordinates.Location -= offset; // Is this right?
return(visibleCoordinates);
}
/// <summary>
/// Gets the range of coordinates currently in camera view.
/// </summary>
/// <returns>A rectangle containing all visible coordinates.</returns>
protected static Rectangle GetVisibleCartesianCoordinates(Vector2 cameraPosition, Point viewportSize, Vector2 unit,
int padding = 0)
{
var location = Projector.PixelsToCartesian(cameraPosition.ToPoint(), unit) - new Point(padding);
var size = Projector.PixelsToCartesian(viewportSize, unit) + new Point(padding * 2);
return(new Rectangle(location, size));
}