[whatwg] [canvas] rotate.

Andrew Fedoniouk news at terrainformatica.com
Thu May 18 14:57:35 PDT 2006

Thanks, Ian,

----- Original Message ----- 
From: "Ian Hickson" <ian at hixie.ch>
Subject: Re: [whatwg] [canvas] rotate.

| >
| > Coordinate system of the <canvas> is x-axis : top-to-bottom and y-axis
| > is left-to-right. Let's say we have some vector of the length 1 and
| > angle 0. How it is located in respect of the axis?
| The canvas API doesn't have vectors. The only two functions that take
| angles are (a) the arc() method, whose definition defines its
| interpretation as radians clockwise from the positive x-axis, and (b) the
| rotate() method, whose definition again defines its interpretation as
| radians clockwise.

Yep. That was may second question: angle direction.
Usualy in y-to-top and x-to-right systems direction of angle rotation is 
Seems like here we have strictly mirrored (around x-axis) coordinate system.

That I guess needs to be defined somewhere ...

Andrew Fedoniouk.

More information about the whatwg mailing list