public UpdateContext OffsetUpdateContext(UpdateContext context)
{
if (CanScroll())
{
if (context.LeftButton == ButtonState.Pressed)
{
if (LastPressedOrigin.HasValue)
{
int maxOffset = (int)(Size.X * Scale.X - WindowSize.X);
int newOffset = Offset + (LastPressedOrigin.Value - context.CursorPosition.Value.X);
Offset = Math.Max(0, Math.Min(maxOffset, newOffset));
Transformation = Matrix.CreateScale(Scale.X) * Matrix.CreateTranslation(-Offset, 0, 0);
}
LastPressedOrigin = context.CursorPosition.Value.X;
}
else
{
LastPressedOrigin = null;
}
}
if (context.CursorPosition.HasValue)
{
var cursorPosition = context.CursorPosition.Value;
return(context.Clone(cursorPosition: new Point((int)((cursorPosition.X + Offset) / Scale.X), (int)(cursorPosition.Y / Scale.Y))));
}
else
{
return(context);
}
}
