public static bool TryGetBackendViewportBounds(this PRIMITIVE2D dc, out BRECT bounds)
{
bounds = BRECT.Empty;
if (!(dc is IServiceProvider srv))
{
return(false);
}
if (!(srv.GetService(typeof(IRenderTargetInfo)) is IRenderTargetInfo vinfo))
{
return(false);
}
if (!(dc is ITransformer2D xform))
{
return(false);
}
var w = vinfo.PixelsWidth;
var h = vinfo.PixelsHeight;
Span <POINT2> points = stackalloc POINT2[4];
points[0] = (0, 0);
points[1] = (w, 0);
points[2] = (0, h);
points[3] = (w, h);
xform.TransformInverse(points); // from screen space to dc space.
bool first = true;
foreach (var p in points)
{
var other = new BRECT(p.X, p.Y, 0, 0);
bounds = first ? other : BRECT.Union(bounds, other);
first = false;
}
return(true);
}