Logical position

[Andreik]

I want to create a custom slider but seems I have some troubles with calculate coordinate from a logical position and then calculate from coordinate a logical position. To understand better I attached 2 images:

Let's say slider start at (105,100) and finish at (290,100):

Case#1:

Case#2:

In case#2 seems to work this formula but just when logical values are positives.

For example: min=0 and max=10

105+(290-105)/(10-0)*x

Edited April 14, 2011 by Andreik

[jchd]

It's a simple ratio.

In case #1, you have the proportion:

((x - 105) / (290 - 105)) = ((0 - (-10)) / (10 - (-10)))

which gives that (x - 105) = ((0 - (-10)) / (10 - (-10))) * (290 - 105)

reducing to x - 105 = (10 / 20) * 185 = 185 / 2 = 92.5

hence x = 105 + 92.5 = 197.5

In case #2 you have another equation to solve:

((197.5 - 105) / (290 - 105)) = (((x - (-10)) / (10 - (-10)))

giving that ((197.5 - 105) / (290 - 105)) * (10 - (-10)) = (x - (-10))

reduces to (92.5 / 185) * 20 = (1 / 2) * 20 = x + 10

hence x = 20 / 2 - 10 = 0

Is that clear now?

[Andreik]

Thanks, it's clear now.