I need to draw a custom shape and fill it with a solid colour or a pattern. I have already achieved the shape and been able to change the fill colour with a 2d html5 canvas and javascript.
However I abandoned the canvas approach as it's a web app for phones and I found have several canvases on one page ran really slowly on older phones in particular.
Can anyone advise on an alternative approach that would work, keeping in mind speed is important? I have been considering:
Drawing with css, but it seems like a lot of markup and messing around to create a relatively simple shape.
SVG - didn't know this existed until last night. This example http://www.w3schools.com/svg/tryit.asp?filename=trysvg_polygon4 seems a lot like canvas, does it have any performance implications?
Overlay some sort of webkit css mask, like this http://www.webkit.org/blog/181/css-masks/ but with a background colour or pattern. Seems like it might be problematic if the page has a background image not a solid colour.
Apologies for the long winded post, I just don't know the best approach to this after canvas proved to be out of the question. I would love to be pointed in the right direction.
Thanks
Check out Raphaël, it's based on SVG and is supported by the following browsers:
Firefox 3.0+, Safari 3.0+, Chrome 5.0+, Opera 9.5+ and Internet Explorer 6.0+.
http://raphaeljs.com/
With SVG you can use CSS to style the fill, which makes it really easy to set the fill to either a pattern or a solid color.
Here's an example of patterns in svg.
Related
So I'm looking at a specific application for a web browser which requires me to express color as a straight alpha channel with a black and white alpha channel as a separate element. (an example of both types
I know many moons ago, IE supported some perverse filter options, but since I'm doing css3 transforms, I need this to work in a modern browser, preferably Chrome.
Basically what I'd like to do is have an element with CSS transforms applied, specifically rotation most likely, then I'd like to take that and copy it to another equivalently sized element which has the black / white transformation applied. An additional bonus would be setting the original element to use straight alpha, but I can live without that for now.
I haven't been able to find any routes with which to start investigating. If you have one, I'd be super grateful. My last resort is to start doing things in WebGL or Canvas and modifying the output there.
Two or three different elements stacked on top of each other using absolute positioning and z-index? This would require you to save two different images which I'm guessing you're trying to avoid.
You can do CSS 3D transforms. Browser support is basically there in newer IE, Chrome, Firefox, iOS and Android.
where can you use them
how to use them
MDN
I've actually figured out the answer... it's CSS Shaders.
https://dvcs.w3.org/hg/FXTF/raw-file/tip/custom/index.html
Not yet available, but soon.
The reason not to use Canvas is for simplicity in authoring. (Long story.)
I'm trying to make a wheel, which will be sliced into different coloured sections (kinda like a pie chart) but they may have extra elements on top of them, e.g., a stitched border across the borders at the side and an icon at the edge of each, etc.
So my question is do I just use css3 (examples: http://www.css3shapes.com/)
and then use something like http://css3pie.com/ for Internet explorer 6-9?
Or am I just better off doing it in Photoshop and slapping it on a div as a background image? And use absolute positioning for extra elements?
Which is the best practice?
I would (and do) use PHP's GD extension to create a pie chart based on input data, save the image generated by that, and optionally generate an imagemap so parts of the chart can be highlighted, have tooltips, etc.
I really wouldn't use CSS for drawing shapes. It's hacky at best, and can get really messy. Quite a few of the examples in the cssshapes site you linked to don't even work in Firefox 3.6 - which is still quite heavily used - let alone other older browsers, and in IE you'd really struggle; css3pie won't give you the kind of fine-grained control you'd need for a pie chart.
If you want to draw stuff on the browser using on the client side, there are a number of ways to do so without resorting to hacks like CSS shapes.
Both SVG and Canvas are relatively new technologies for placing and manipulating graphics on the browser. SVG draws vector graphics and Canvas is for pixel-based graphics.
Both of them are supported on a wide variety of browsers. The obvious exception being IE8 and earlier. However, IE does support an alternative graphics format called VML, and there are javascript tools for IE which allow it to convert both SVG and Canvas into VML, so you can use either of them and they will work in IE using these tools, which makes both SVG and Canvas effectively cross-browser compatible.
But if you're drawing pie charts, or similar sorts of things, my personal recommendation would be to use the Raphael library. This is a javascript library which works in all browsers, and can be used to draw and animate pretty much anything, including graphs and charts (it even has a separate graphing add-on library. See the demos on those two sites to see what it's capable of; I think you'll be impressed. (I certainly was)
Hope that helps.
I'm trying to create a trapeze like shape using any number of techinques so that it will be as much as possible. the shape i'm trying to create a shape like this:
(there will be content inside the shape [imgs & txt])
so far, the possible ways of doing that are: masking (webkit) and SVG effects on html content (firefox). but I cant seem to find any way to make this work with IE and opera.
So if anyone could show me how to do this, it will be greatly appreciated.
There are a few options for creating non-rectangular shapes using CSS, but they are all hacks. This isn't something that you'd normally expect to do using CSS.
The most well known technique is triangles made using borders. It is very much a hack, and would require using multiple elements for a single shape. I wouldn't suggest using it on a production site.
The other CSS solution I can think of would be to use an extreme border-radius setting to modify the shape of the box. This is less hacky, but won't work in IE8 and lower, so fails your criteria.
You say you've tried the SVG approach and given up on it because it doesn't work in IE8. It's worth pointing out that while IE doesn't support SVG, it does support VML, which is a competing vector graphics format. SVG is now standardised, so VML will fade away, but older IEs will continue to support it.
Therefore the solution I'd go with would be to use SVG by default, and VML instead on IE7/8. The good news is that there are several Javascript solutions which make this easy.
One is Raphael, which allows you to draw SVG/VML images using Javascript. Commonly used for real-time graphs, etc.
There are also a number of solutions which simply convert SVG to VML. For example http://code.google.com/p/svg2vml/. But there are several others available.
Hope that helps.
As you suggest, masking and SVG are the way to go. These will be supported in future browsers. If you must be backwards compatible with IE, look into the IE "filter" for CSS (google "ie filter").
Be forewarned: It's very unintuitive (compared to CSS3) and generally a bitch to work with. If your goal is to make the page look identical to the CSS3 version, it will be difficult and you're probably better off using images.
Is there any way to make ie (7,8) display a gradient AND a background-image on the same div?
The only way I got it working (but only almost) was by using two filters, one for the gradient and one using the AlphaImageLoader - but of course, then you can't position the image.
Declaring a background-image and gradient filter doesn't work, because it simply won't render the image - only the gradient.
Is there any (preferably non-js) solution to this?
If not, I'll have to resort to using a background image for the gradient as well, which isn't quite as nice but won't make much of a difference either...
I would say that adding a little unnecessary markup is the lesser of the evils here. Either that, or let IE-users live without the gradient.
Oftentimes getting your design to work is a trade-off between semantics, performance, standards and pixel perfection. Accepting that fact was hard for me, but it's made me a better front-end developer - I can work faster, and I can make decisions about what metric is important in a given case.
I want to use a diagonal gradient in my background.
I have read this, and I found that it has just only horizontal gradient and vertical gradient in IE.
Is it possible to make the gradient in IE show in the diagonal like Firefox?
You can do it using CSS, but it's kind of a hacked together solution involving two layers. You can read about the details of it here.
Yes, you have to use a background-image though so there may be a limited element size depending on how much you want a page to cost, and you will need to use a separate image.
HTML5 brings along SVG images though which are scalable and take up little space.