Make +y UP, Move Origin C# System.Drawing.Graphics

Question

I want the origin to be at the center of my window.

______________
|     ^      |
|     |      |
|     o----->|
|            |
|____________|

.NET wants it to be in the top left hand corner.

_____________>
|            |
|            |
|            |
|            |
V____________|

Dot net and I are trying to get along..

Does anyone know how to do this in C# just using the Graphics object?

Graphics.TranslateTransform doesn't do it since it leaves the coordinates flipped upside down. Combining this Graphics.ScaleTransform(1,-1) isn't satisfactory either since that makes text appear upside down.

Answer 1

Try creating the graphics object with a negative height. I don't know the C# library specifically, but this trick works in recent versions of GDI.

Answer 2

One solution would be to use the TranslateTransform property. Then, instead of using the Point/PointF structs you could create a FlippedPoint/FlippedPointF structs of your own that have implicit casts to Point/PointF (but by casting them the coords get flipped):

public struct FlippedPoint
{
    public int X { get; set; }
    public int Y { get; set; }

    public FlippedPoint(int x, int y) : this()
    { X = x; Y = y; }

    public static implicit operator Point(FlippedPoint point)
    { return new Point(-point.X, -point.Y); }

    public static implicit operator FlippedPoint(Point point)
    { return new FlippedPoint(-point.X, -point.Y); }
}