I'm using GD2 with PHP 5.2.9.2 and I'm trying to create a dynamic compass type thing. What I'd like is simply an arrow image that will change where it's pointing based on the get variable I pass to it. Problem is that because the image is square, imagerotate (the function I'm using) makes the overall canvas bigger and bigger, to it's maximum size, at any of the 45 degree angles. This is not what I expected, nor what I want, what I'd much prefer is it to stay exactly in it's place and clipping to occur. I understand how I could do this manually, but to do so, I'd need the dimensions of the newly rotated image, in it's current form, rather than how it was. The only function I can see that does something like that, only works for images loaded directly from a file, rather than a resource (which is what imagerotate returns). Is there another function that gives you the same as what getimagesize() does, but for a manipulated resource?

Thanks guys.

for anyone interested, it's the functions imagesx and imagesy that give you the width and height of a resource image.

Why don't you just compute the new size? If the original image is w x w, and you rotate by an angle theta, the new size will be w*(sin(theta) + cos(theta)). I've attached an image that shoes why this formula works. It may be off by a pixel due to rounding error, but is should give you a good enough estimate.

Attached Images

square.jpg (18.4 KB, 10 views)

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