I'm working with svg files and some processing.js code to create a homepage.
It has some animation and static elements but the idea is to have everything the same but with different colours - Like an alternative homepage. I want this alternative to "peek" through as the mouse moves around. Only a small area around the mouse.
Does anyone have any idea how to do that?
since it isn't an image file it's a bit tricky.
I tried doing it by using the an image and the "drawing" element of processing.js thinking it could paint the alternative homepage, however it repeats the image everywhere the mouse go and what i want is for everything to remain in the same position only show the different colours in that spot.
You might consider superimposing two versions of your site, the "top" one completely covering the "bottom" one (make sure all backgrounds are opaque). Then you could try applying an SVG mask to the top page, making it transparent at a specific area and causing the bottom page to shine through. You could modify the mask as the mouse moves.
The other way round - i.e. clipping the top layer - is also thinkable.
I see the risk that this approach is slow and not consistent across browsers - you'd have to give it a try. Speed may differ depending on whether you clip/mask the top or the bottom layer.
W3C SVG Clipping, Masking and Compositing specs
MDN page on clipping and masking
MDN page on applying SVG effects to HTML content
If one version of the page can be converted to other by swapping out colors, SVG filters might be an option as well.
I have an image and I want to restrict the clickable area on this image. I want user to click only particular area. I want to obtain a darker view out side of this clickable area. How could I achieve this usin java script and/or jquery.
Kind regards
There are many ways to implement the clickable area:
using image map :
http://en.wikipedia.org/wiki/Image_map
Take a look at this website : http://odyniec.net/projects/imgareaselect/
or using divs and z-index.
It might be difficult, but if you use a to determine a clickable area first, you can use jquery to do something like this:
On hover over the mapped area, Show a transparent black div, the same size as the image. (This makes the image darker)
Place another div on top of that, with the same dimensions as the image. (this contains the small map-sized container for the new image)
Place another div INSIDE of the last to be the same size and position as your mapped area. (This will contain the original image - not darkened)
Place the image again INSIDE of the last div and position it so it lines up with the original image.
This should show something like what you're talking about.
If it's more complicated than this, I'm sure we will ALL need an example and all of the outcomes of these images. I don't think there's enough detail to give you a real answer.
I am trying to create an image map, where I define on the images coordinates that are links to the some other pages. Now the problem I am facing is that the position of coordinates is not relative.
If the image is on a different browser or in a different screen size, then the coordinates are not preserved. I mean a link which was at a particular place in the image is now on some other place of image.
Can anyone provide a piece of code where I can have some relative positioning where even the browser size or the image size will change the coordinates position also with it.
I tried to user percentage tags like COORDSCALE "50%,50%" but it seems like a wrong attribute for the Area tag. Even this COORDSCALE="ABSOLUTE|RELATIVE" is also not working.
First of all, are these the right attributes? Is there a possibility of relative positioning? Any CSS, or Javascript code will be great.
Wrap the image with div that has relative position. Inside it use absolutely positioned elements to imitate the same thing imagemap is supposed to do.
Google "CSS image map" to find more information about the technique.
Google has the coolest effects - once it was a Pac-man game, today is apparently the 160th anniversary of the first World Fair, and Google's logo has an image of it. They also turn the mouse into a magnifying glass that can sweep over the picture (the gold ring).
I'm wondering how they do that. It's obviously Javascript, and I looked at the page source, but it's not especially readable (no surprise).
Looking at their source code, it seems they are using rather basic techniques to achieve this.
Ignoring all the embedded nifty animated gif's, there are basically two images - large, and small of the entire scene. The larger image is repeated thrice in the document. Look at the annotated image below to get a better idea of how the zoom works.
The portion inside the magnifying circle is split up in three div's - top, mid, and bottom. The overflow for each div should be hidden. Each div is relatively positioned inside the zoom circle. On mouse move, change the absolute position of the zoom circle to the mouse coordinates. Their example also uses CSS3 for the scaling and adding some animation delays.
Here's a sorta minimal reconstructed example.
Another example where we don't hide the div overflow to reveal the entire thing as a square.
Well, firstly, for anyone who wants to use such an effect, there are loads of jQuery plugins. Here are just a few:
Power Zoomer
Featured Image
Zoomer
Cloud Zoom
Secondly, it's quite easy to achieve. Just load the full-size image, but give it a width smaller than it's actual width, so it is scaled by CSS. Then, use JavaScript+CSS to create a Div (the magnifying glass) with the same image as background, but change the background-position property to the corresponding scaled x,y coordinate that the user's mouse is currently on.
There are other ways of doing it I suppose, and Google might be doing it differently, but this is the most obvious way for me that comes to mind.
Visit http://codeblab.com/glass/ for an real life example and in depth explanation of this technique. Flash and CSS v3 have ample functionality to construct a round magnifying glass.
However, simulate-a-circle-with-overlapping-rectangles works on (many) more platforms.
(DISCLOSURE: codeblab.com is my personal hobby blog with some weak links to my work in The Netherlands.)
There is a full example of magnifying any sort of HTML, including HTML5 at http://www.aplweb.co.uk/blog/js/magnifying-glass/. Works cross-browser too - although rounded corners are a bit iffy on most browsers - so you are going to have to use a box rather than circle.
Here is how to works:
Duplicate the content you want to zoom
Place the duplicated content into another element and set the visible width/height and overflow hidden
Use JavaScript to move the duplicated content so that it moves by the zoom amount * mouse movement. Also move the visible div by the mouse movement.
That is pretty much it too it. There are lots of little things to look out for though to make it work on all browsers.
I don't know how Google does it, since the logo is no longer showing in my area; but this effect can be achieved by clipping the enlarged animated GIF over the regular image using canvas. Alternatively, it is also possible to create create a circular clipping using CSS border-radius (commonly used to implement rounded corners).
EDIT: I've hacked this up together to show the basic technique that you need if you used CSS border-radius: http://jsfiddle.net/yjBuS/
Looks like they're using two images, one for the logo and one for the zoom (the zoomed one is actually sliced, to run the animations separately...?) They probably detect if the mouse is over the normal logo, then show the yellow circle and attach it to the mouse position. Then showing the other image, shifting it opposite of the mouse. Or something similar.
Okay my last question got no response. I think I didn't ask the way I should do.
Basically my requirement is similar to this one Programmatically Clip/Cut image using Javascript
But following that link will result in a rectangle view of any portion of the image but I want to clip it any direction (polygon). Would that be possible?
There is not a good way to make an arbitrary polygon shape with the HTML 4 DOM. If you were using canvas I'd say you could do it that way. Your other option would be to just have a transparent png (and gif for IE6) on top and then the image underneath that and absolute positioned similarly to the other answer you referenced.