CODEWITHSUNDEEP
math
sgtfrankieboy
sgtfrankieboy

Reputation: 1030

Calculate zoom level of tiles

I'm trying to calculate a variable based on a zoom level.

For example I have a 4x4 grid of tiles at zoom level 1. Now I zoom in once it will become 8 * 8 at zoom level 2. Zoom in once again and it will be 16 * 16 at zoom level 3. etc.

Now the only thing I store are the two numbers from zoom level 1 which can change to for example 5x4 or even 1x1.

So my question is how do I calculate the width and height of zoom level's 2 and 3 and beyond with just those two numbers and the zoom level?

Thanks in advance.

Upvotes: 2

Views: 479

Answers (2)

jmstoker
jmstoker

Reputation: 3475

A slicker way of doing the same thing is to use bit shifting since you're always multiplying by a power of 2 with each zoom level.

var x = this.data.Size.X;
var y = this.data.Size.Y;

x = x << (zoom-1);
y = y << (zoom-1);

Upvotes: 1

sgtfrankieboy
sgtfrankieboy

Reputation: 1030

Thanks to jmstoker I've figured out how to get it working properly

var x = this.data.Size.X;
var y = this.data.Size.Y;
for (var i = 1; i < zoom; i++) {
    x += x;
    y += y;
}

I just get the count of tiles on each side and go through the amount of zoom levels excluding level 1 and adding the count to itself for each zoom level.

Upvotes: 0

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