public override void OnMouseMove(MouseEventArgs e)
{
if (TilesetSelection == Rectangle.Empty)
{
return;
}
Point location = RelativePoint(e.Location);
// don't need to do anything if the position hasn't changed
if (lastMouseMove == location)
{
return;
}
// calculated the center offset of the selection.
Point selectionOffset = new Point(
(int)Math.Floor((float)(TilesetSelection.Width / TileSize.Width) / 2.0f),
(int)Math.Floor((float)(TilesetSelection.Height / TileSize.Height) / 2.0f)
);
// set the brush preview location relative to the world
brushRect.Location = location.Minus(selectionOffset).Minus(World.ViewportOffset).Multiplied(TileSize).Plus(World.ViewportPadding);
// paint onto the world if the left button is down.
// we render a line to ensure there are no
// skips when moving the mouse quickly
if (e.Button == MouseButtons.Left)
{
renderLine(lastMouseMove, location);
}
// redraw the canvas to show changes
World.InvalidateCanvas();
lastMouseMove = location;
}