CODEWITHSUNDEEP
c#math
Loren Shaw
Loren Shaw

Reputation: 466

Convert any number range to -1/1 scale

I need to convert any range to a -1 to 1 scale. I have multiple ranges that I am using and therefore need this equation to be dynamic. Below is my current equation. It works great for ranges where 0 is the centerpoint. I.E. 200 to -200. I have another range however that isn't converting nicely. 6000 to 4000. I've also tested 0 to 360 and it works.

var offset = -1 + ((2 / yMax) * (point.Y));

One of the major issues that I may have is that sometimes I'll get a value that is outside the range, and as such, the converted value needs to also be outside the -1 to 1 range.

What this is for is to take a value that is a real world value, and I need to be able to plot it into an OpenGL point. I'm using .NET 4.0 and the Tao Framework.

Upvotes: 1

Views: 1038

Answers (1)

Ben Voigt
Ben Voigt

Reputation: 283614

rescaled = -1 + 2 * (point.Y - yMin) / (yMax - yMin);

However, in OpenGL you can do this with a projection matrix (or matrix multiply inside a shader). Read about glTranslatef and glScalef for how to use them or how to duplicate them with matrix multiply.

Upvotes: 4

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