.Net equivalent for ScaleHeight and Scalewidth

Question

Basically what I am trying to do is make my drawing job easier.

Back in the days of VB6 there was something called Scalewidth and Scaleheight and I could set them to custom values. Ex. 100.

Then when I needed to draw a point at the center of the available space i would just draw it at 50,50.

Is there any way in .Net that I can get similar functionality?

So that no matter what the size of drawing canvas I get, I can draw on it using absolute co-ordinates.

Answer 1

I don't know if there's a way to achieve this in .NET, but you could easily implement this yourself:

// Unscaled coordinates = x, y; canvas size = w, h;
// Scaled coordinates = sx, sy; Scalewidth, Scaleheight = sw, sh;
x = (sx / sw) * w;
y = (sy / sh) * h;

// Or the other way round
sx = (x / w) * sw;
sy = (y / h) * sh;

Answer 2

Schnaader had the right idea... Ultimately I implemented four functions to do this. The functions are below

private float cnvX(double x)
{
    return (float)((Width / 100.00) * x);
}

private float rcnvX(double x)
{
    return (float)(x / Width) * 100;
}

private float rcnvY(double y)
{
    return (float)((y / Height) * 100);
}

private float cnvY(double y)
{
    return (float)((Height / 100.00) * y);
}

Answer 3

First, why don't you use Graphics.ScaleTransform instead of handling all the scaling yourself? Something like:

e.Graphics.ScaleTransform( 
  100.0 / this.ClientSize.Width, 
  100.0 / this.ClientSize.Height );

Your code will end up much clearer, and I'd bet a beer this would be a little faster.

Second, if you stick with your cnvX/rcnvX functions, make sure to use this.ClientSize.Width (and the same for height) instead of "this.Width".