How do I prevent a user from seeing a certain parts of the page. My goal was to make a huge maze within the browser (so big that the path is big as the width of the browswer screen); the user has to navigate using the scroll bar or any other scrolling method until they find the end of the maze. Making the maze is not the challenge, but to prevent the user from crossing over the boundaries is where I am having trouble.
My thought process is to make objects/areas on the page that block the user from continuing to move in that particular direction. Maybe the user can see 50px of the block/area before he can not go any further? I have never seen this done and I was curious to know if this is even possible.
Thanks in advance. Any help or advice will be appreciated.
Maybe that won’t be that answer you were looking for, but if you have some experience in graphics, you can try to use three.js library to generate the maze with canvas or webgl. You can use point light to lighten only small part of the maze. Other part can have something like “fog of war”.
If you are not interested in canvas/webgl, then you can try to use an overlay png image with transparent hole in it. Width and height of the image has to be screen.height*2 x screen.width*2 (not sure about that, but that is how I see it). That image should be on top of whole maze. It’ll hide whole maze except for that under transparent area. And your starting point should be in the center of that transparent area. Then you need to move that image along with user input (arrow keys, mouse, whatever). Alternatively, you can move maze itself. This way overlay image can have screen dimetions.
These are two option that came to my mind.
Related
I'm trying to create an image editor that can mask personal identifiable information. We're using konva right now to add black Rect shapes over images, but we would love to use the blur or even pixelate feature. Im not sure I'm going about this right, can anyone help me out? Here's a sandbox
UPDATE
Ok I was able to figure it out. Instead of trying to blur a transparent Rect shape on top of an image (which will just blur the transparent Rect, not the image behind it), I needed to get a little more clever with how this worked. My solution was to keep the original image as is. Keep the black rectangular shapes working the same way, but change their fill to transparent and set a stroke color only while they were selected. These will act as a way for us to set and interact with the redacted parts. Then for each shape that was created, I created a new full-size and blurred version of the image layered on top of the original image with a parent Group that had a clip path set to the bounds of the shape.
Here's a link to the updated sandbox
It's not 100% perfect, for some reason the selection is behaving a little funny (it's working alright in our production app ¯\_(ツ)_/¯). But hopefully this is a solid enough ground for anyone else to get up and running with a redaction tool!
Would love to see if anyone has any suggestions for improvement!
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 am working on a map that is divided into 800x800 150 pixel tiles. These tiles are contained within a jQuery draggable wrapper, which moves the contents of the tiles around inside the parent to achieve a Google Maps style dragging effect. The top left corner is 0,0 and the bottom right is 799x799. I am looking to replicate Google's tiling effect where the user can drag to the left or top of the start point or the right or bottom of the end point and see the tiled (repeated) contents of the DIV in a seamless manner. Using Clone is not an option as it creates duplicates of an already very large (albeit not yet optimised) source which seriously hampered the load times of the page when dragging was performed.
I could best summarise this by saying I need the map itself to have the visual effect and user experience of looping endlessly, but actually only using one instance of the map source. The resulting effect would not be too dissimilar to the repeating background of an image on a page, except with the contents of the map DIV and not an image. When the user drags the map left of anything on the 0 X Axis, it should display X 799, X 798, etc.
I have not had any luck searching for a solution. Is such an effect possible? If so, what would I need to use to achieve it? I am content with simple answers to point me in the right direction; I do not expect somebody to produce a working example that I can cut and paste. Not afraid to research and experiment myself, my problem is I really don't know where to start. I have plenty of experience with Javascript and jQuery but I've never had to do anything quite like this.
I have been trying to understand how they did those effects in http://artofflightmovie.com/ with no success so far. I am not even sure what to google for for help. Could any one ellaborate on it and perhaps put links to plugins\tutorials\other websites doing the same thing?
There is already a similar question, but it didn't help me a bit ^^
Custom scroll bar behavior in Javascript?
All of the answers here so far are spot on and cover various pieces of the execution. Joseph's post about how we 'contained' and 'maneuvered' the site are dead-on, and those mentioning jQuery accurately depict our heavy reliance on it :)
With that said, the other concept of moving along a non-linear path was probably the most difficult part. We literally used an Illustrator file that was setup like a piece of graph paper and drew a bezier path that reflected the movement we wanted from the scrollbar. Then we 'downsampled' the path by converting the curved lines into a bunch of straight lines that represented the curve (similar to downsampling audio waveforms) to keep performance/speed high. We took those coordinates, gave them to our designer, and he created a gigantic design file and literally designed each content section at the designated 'stop' points. Next we mapped each coordinate along the path to a percentage value of the scroll position. We stored these values in a JavaScript array. Lastly we wrote some JS functions that we pipe the scroll position through to determine how to offset the positioning of the site 'container'. (It basically 'tweens' between each coordinate allowing us very fine/precise values at any given scroll percentage) The scroll functionality is handled by a tall div that basically sets our document height to force a scrollbar, and we just read it's position during a Scroll Event and slide the container around to where it should be using the above mentioned functions.
The parallax effect is achieved by applying a percentage of the position offset (what we use to move the container around) and applying it to the sub-containers of the various content sections. This makes the subcontainers move slower or faster than the background, but on the same motion path.
Lastly, the little snowboarders and helicopters (which have CSS3 rotations in addition to x,y movement in some browsers!) are positioned by using a simliar array of 'start' and 'end' positions and tweening between them based on the scroll percentage.
I'll leave it at that to keep this from turning into a book, but I'd be happy to elaborate on specifics if you're interested.
Full disclosure: I was lead developer on the site. I'm not posting to 'toot my own horn' or anything like that, just to be helpful and provide assistance to a fellow tinkerer. I come here a lot to dig through and get insight from others. (many, many thanks to those who have helped us!) Also, shameless plug, but the film is breath-taking... go rent it if you haven't yet, you won't be sorry. :)
That's a pretty cool website ;)
Basically using some javascript you can detect how far a person has scrolled. Considering the amount of scrolling you can move the contents of your webpage around if their position is absolute.
There are a couple of jQuery plugins that allow you to do simular stuff although I'm not sure you can "scroll through" a sequence of coordinates.
Here are a couple of jQuery plugins that helps you get simular effects:
http://johnpolacek.github.com/scrolldeck.js/
http://johnpolacek.github.com/scrollorama/
http://demos.flesler.com/jquery/scrollTo
http://webdev.stephband.info/parallax.html
I just picked a couple I'm familiar with but there are many plugins that are alike.
edit:
Decided to add some more simular websites for your pleasure.
http://www.activatedrinks.com
http://www.beetle.de
http://www.nikebetterworld.com
the whole page is an "overlay" - a full width and height wrapper <div>. sort of how modal windows do their "full page shadow" effect and have a small div float inside. the whole page content is in that wrapper. the scroll path is a script. the script captures the body scroll and moves the contents of the div accordingly to the positions provided by the script. with a body long enough to be scrollable (which cannot be seen since the wrapper covers the whole page), it's as if you are scrolling sideways, upwards etc.
an analogy is a modal window. the wrapper is the full-page shade. the modal window is the content. and notice how modal windows stick to the middle? that's using a script to calculate it's position to stay in the middle by moving the modal window down, relative to the page's top. but in that website's case, they move in different directions.
It doesn't seem too complicated.
Using the .scroll(function() {}) in jQuery you listen for a scroll event. When triggered you set the position style (left, top) of the content div to give the appearance of moving sideways instead of down.
I guess you'll need overflow:none property on the div to prevent users from scrolling over the area you don't want them to see.
Sounds like a lot of effort for a clunky user interface in my opinion.
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.