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c#drawingsystem.drawing

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


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


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|     ^      |
|     |      |
|     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.


Solution

  • 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); }
    }