Develop Reference

On-the-fly thumbnails in React

I am developing a website with React which has what we called "snippets", basically a modal window displaying some kind of media (audios, videos, slides, text quotations, pdfs). These media have "positions", as a page number, an image number, a playback position, or a scroll position. If she likes the user may store these snippets together with their positions in a "locker" and come back later to whatever is in there. Visually the locker will hold a "thumbnail" of the snippet representing the appearance of the snippet at the time of storing it. My question is how to go about making such a on-the-fly thumbnail. Two approaches come to my mind, however, if you have other ideas I am eager to hear them.
Component approach: Since I already have the component, I could reuse or rather clone it, scale it down, disable it for mouse interaction. Would React.cloneElement() be the way to go?
Advantage: Easy to do.
Disadvantage: Too many duplicates of potentially resource-heavy components may slow down website. Styling may become non-trivial as some embedded media (audio, video) bring their own potentially inaccessible styling with them.
Image generation approach: Since I only need an image, I could take a screenshot of the snippet area, scale it down and use it. Can this be done fully (from generation to usage) on the client side? Is there a good library which does the heavy-work for me?
Advantage: Resource-heavy only during the making of the thumbnail, resource-light in the locker. Accessible for any styling.
Disadvantage: Potentially difficult to do?

After some research I found a solution. Interestingly, it is a mixture of the two approaches I was able to think of. It is possible to access and rasterize the DOM elements which make up the snippets, draw them on a canvas and turn it into an image. The most popular library for this seems to be html2canvas, however, there are a number of others among which rasterizeHTML and html-to-image seem to stand out. Often wrappers for React exist, in the case of html2canvas, for example, use-react-screenshot.

Photoeffects site based on php

I want to know how websites like http://photofunia.com/ and other online photo effects sites are built. For example, using php, i want merge two images frame.png with profile.jpg. I want my frame.png transparent in the center where I would place my profile.jpg.
I have tried this, but it doesn't work:
<?php $dest = imagecreatefromjpeg('dest.jpg');
$src = imagecreatefrompng('logo.png');
$src = imagerotate($src, 90, imageColorAllocateAlpha($src, 0, 0, 0, 127));
$almostblack = imagecolorallocate($src,254,254,254);
$src = imagecolortransparent($src,$almostblack);
imagealphablending($dest, true);
imagesavealpha($dest, 0);
imagecopymerge($dest, $src, 900,600, 1, 1, 90,90, 90);
Thanks in advance. Please help me.

Answering your questions:
Adobe doesn't provide an API for this. However you can use Adobe Creative SDK for your Photo-editing stuff.
Usually a lot of Javascript libraries are used. you can check out top image manipulation libraries at codegeekz
If you insist on using php, your best bet is to go with ImageMagick or with Image processing GD Library. It is the developer who is supposed to make these results 'perfect' as you term it. There are some interesting php image editing libraries that you could check out many of which are maintained till date!
For Merging images, you can hop to the official docs for imagecopymerge or perhaps utilise the Imagick/GD Library. This SO post may give you a headstart.
You could also use Gmagick which is a fork of ImageMagick and faster (see benchmark) in processing images (although at the cost of lesser features). The original project can be found at graphicsmagick. Going strictly by Php way, personally, I'd recommend ImageMagick given its speed, rich feature-set, popularity, support, documentation and examples.
Additional Ref:
Php Image Processing
GD vs ImageMagick vs Gmagick

You've received a more technical answer already so I'm going to focus on the creative aspect of things. You've also mentioned familiarity with the associated php libraries and even previous attempts to create similar compositions that seemed to lack luster in the end.
In my opinion, this endeavor is far more reliant on artistry, creativity and, most importantly, prepared assets. By manually preparing these images you will have more finesse over the final result as well as leave only the simple compositing to php. Not the entire editing process.
Frankly, such detailed results are not achievable via an API. This project will require hours of manual labor and editing. Paying attention to lighting, transparency and colors.
The most impressive effects are the ones where objects in the photo overlap the user-added image. Ie:
While this example is rather simple, the same logic applies to more complex compositions.
You need to start with a high resolution image. Especially if you will be offering physical prints to your users.
The high resolution is also quite necessary as you will have to edit and prep these in a program like Photoshop beforehand.
For best results these will require complex, compound masks in Photoshop. Think sharp and smooth alpha transitions. Don't just cut everything with hard lines.
When considering the example above, you would be able to get away with only one layer in photoshop. Simply cut a hole where photos will be placed and export as png.
For other examples I would recommend separate background and foreground layers, with the user-added image sandwiched in between.
This is another great example where resolution is of utmost importance. The leaves are way too small to be effectively masked out at a tiny resolution. Some of the leaves may also be blurred and out of focus; again, don't cut them with hard lines. For best results, use a soft brush when masking them in Photoshop.
And last but not least, here's a very simple hands-on example.
Note how the background image has a smooth mask while the leaf has a hard one. Frankly, parts of the leaf are out of focus and can be further refined. The investment of time you make here will make the world of difference in how convincing your final results are.
Save out each layer as a png and composite within php. I would recommend making sure each png has the same dimension. Don't try to position a tiny png over a larger one. Give them the same dimensions to make alignment a breeze.

If I understood the Question, Then it does'nt need to be js, Css will do the trick. Look into alpha and opacity and z-index
#img1{position:absolute;top:0px;}
#img2{position:absolute;top:50px;opacity:.6;}
<img src="http://lorempixel.com/400/200/sports/1" id="img1">
<img src="http://lorempixel.com/50/50/sports/2" id="img2">

Full width video background: A non-HTML5, purely jQuery solution...maybe

Long time Stack Overflow creeper. This community has come up with some incredibly elegant solutions to rather perplexing questions.
I'm more of a CSS3 or PHP kinda guy when it comes to handling dynamically displayed content. Ideally someone with a solid knowledge base of jQuery and/or Javascript would be able to answer this one best. Here is the idea, along with the thought process behind it:
Create a Full Screen (width:100%; height:auto; background:cover;) Video background. But instead of going about using HTML5's video tag, a flash fallback, iFrame, or even .GIF, create a series of images, much like the animation render output of say Cinema4D, that if put together in sequential order create a seamless pseudo-video experience.
In Before "THAT's JUST A .GIF, YOU'RE AN IDIOT" Guy.
I believe jQuery/Javascript could solve this. Would it or would it not be possible to write a script that essentially recognizes (or even adds) the div class of an image, then sets that image to display for say .0334ms (29.7 frame rate) then sets this image back in z space while at the same time firing in the next image within the sequential class order to display for another .0336ms; and so on and so forth until all of the images (or "frames") play out seamlessly fluid, so the user would assume he/she is actually seeing a video. Not a knowing it's actually a .GIF on steroids.
Here's a more verbose way of explaining the intended result:
You have a 1 second super awesome 1080p video clip (video format doesn't matter for helping to answer this question, just assume its lossless and really pretty k?). It's recorded at 29.97 frames per second. Break each frame into it's own massive image file, leaving you with essentially 30 images. 24 frames a second would mean you'd have 24 images, 60 frames per second would mean you'd have 60 images, etc., etc., excedera.
If you have ever used Cinema4D, the output I am looking to recreate is reflexive to that of an animation render, where you are left with a .TIFF per frame, placed side by side so that when uploaded into Photoshop or viewed in Quicktime you get a "slideshow" of images displaying so fast it look likes a video.
HTML would look something like this:
<div id="incredible-video">
<div class="image-1">
<img source=url('../movie/scene-one.tiff');/>
</div>
<div class="image-2">
<img source=url('../movie/scene-two.tiff');/>
</div>
<div class="image-3">
<img source=url('../movie/scene-three.tiff');/>
</div>
<div class="image-4">
<img source=url('../movie/scene-four.tiff');/>
</div>
<div class="image-5">
<img source=url('../movie/scene-five.tiff');/>
</div>
....etc.....
....etc.....
....etc.....
</div>
jQuery/Javascript could handle appending the sequential image classes instead of writting it all out by hand for each "frame".
CSS would look like:
#incredible-video img {
position:absolute;
width:100%;
height:auto;
background:cover;
}
But what would the jQuery/Javascript need to be to pull the off/can it be done? It would need to happen right after window load, and run on an infinite loop. Ofcourse audio is not happening in this example, but say we don't need it. Say we just want our End User to have a visually appealing page, with a minimal design implemented in the UI.
I love video animation, and really love sites built with Full Screen Backgrounds. But a site out with this visual setup and keeping it responsive is proving to strenuous a challenge. HTML5 will only get you so far, and makes mobile compatibility null and void (data usage protection). .GIF files are MASSIVE compared to calling in a .mp4, .Webm, or .OGG so that option is out.
I've actually recently played around with Adobe Edge Animate. Using the Edge Hero .js library I was able to reproduce a similar project to this: http://www.edgehero.com/tutorials/starwars-crawl-tutorial
I found it worked on ALL devices. Very cool. Made me think that maybe it's possibly to use this program or hit jQuery/Javascript directly to achieve the desired effect.
Thanks for taking a look at this one guys.
-Cheers,
Branden Dane

I found a viable solution to what I was looking to do. It's actually rather interesting. The answer it's introduces many interesting ideas on how we can display any kind of content dynamically on a site, in an app, or even a a full fledged software application.
The answer came about while diving hard into WebGl, canvas animation (both 2d and 3d), 2D video games techniques, and 3D video game techniques. Instead of looking for that "perfect" workflow, if you are someone interested in creating visually effective design and really seeing what the bleeding edge can do for your thoughts on development, skip the GUI's. Ignore the ads with software promising to make things doable in 5 min. It's not. However we are getting there. 3 major events we have to look forward too in just a few months are
1.) the universal agreement to implment WebGL natively in Opera, Chrome and Firefox (ofcourse), Safari will move to ship with webGL enabled, compered to the user having to enable it manually, and even IE is going to try and give her a go (in IE 12).
2.) Unity 3D, an industry standard in game development, has announced that next month it will release version 5, and with it a complete, intuitive workflow from start to exporting in Javascript (not JSON actual JavaScript). The Three.JS library more specifically as it is one of the most popular of the seemingly endless games engines out today.
How does this answer my initial question?:
Though WebGL has been around for about 3 years now, we are only now starting to see it shine. It's far more than a simple video game engine. With ThreeJS We have a full working JavaScript library, capable of rendering in WebGL, to the Canvas, or EVEN with a few CSS3 magic. Can't use your great movie as a mobile background? It ruining the overall UI? Cheer up. ThreeJS can working with both 2D and 3D javascript draw function, though not at the same time. Hover other libraries exist that allow you to bypass this rule.
AND DRUM ROLL. It is, or can be very easily made in a responsive or adaptive way.
The answer to my question came from looking at custom preloaders. Realizing I can create incredible looping animations in AE, and export them as GIFs offered the quality I wanted, but not control, no optimization, now sound. However, PNG Sequences CAN be exported. Then the epiphany hit. Before I just say what I am using to solve my problem, I'd like to leave a list of material anyone looking to move beyond easy development and challenge limits can use as a reference guide. This will be in order with what I began to where I am now. I hope it helps someone. The time to find it all out would be very much worth it.
1.) WebGL-Three.JS
WebGL opened my eyes to a new world. It's a technology quickly evolving and is here to stay. In a nutshell, all live applications you create now have access to more than just a CPU, but also the Graphics card as well. With GPU's getting more and more powerful, and not so unreasonably priced, the possibilities are endless. The idea we could be playing Crysis 3 "in-browser" without the need of a 3rd party client is no fiction. It's the future. Apply that to websites. Mind blown.
2.) First Cinema4D, then start working around with Verold.com & PlayCanvas.com
C4D is just my personal favorite because if it's easy integration with AE. You will find that with exporting your 3D models, Textures, Mesh's, anything to Three.JS (or any game engine period) that it is Blender that is the most widely supported. As of writing this, their are 2 separate C4D workflows to ThreeJS. Both are tedious, not always going to work, and actually just unnecessary. PlayCanvas was also a bit of a let down. Verold, however is an EXCELLENT browser based 3D editor in which you can import a variety of files (even FBX with Baked animations!) and when you are satisfied you can export into a standalone client or an iframe. The standalone client is superb. It is a bit glitchy, so have patience. You shouldn't get comfortable with it any way. Go back to your roots.
3.) iPhone app development, Android app dev (to an impressive extent), Web Sites, Web Apps, and more all function in a way that an application need only be made using JavaScript, HTML/5 and CSS/3. Once this is understood, and the truth hits you as to how much control you may not have known you had, then the day becomes good indeed. Learn the code. With a million untested and horrible "GUI's" out there that claim to do what you want, avoid the useless search. Learn the code. You can never go wrong at that point.
4.)What code do I need to learn?
JavaScript is the most essential. More on that in a moment. Seriously dive into creating apps of any kind with ThreeJS. Mr. Doob (co-creator of the library) has an EXCELLENT, well-documented website with tons of examples, tuts, and source code for you to dive into. Chrome Experiments is your next awesome option to see how people are really taking this kind of development to a new level. In the process of learning ThreeJS, you'll become more proficient with JavaScript. You will also start to play with things you maybe never had to, like JSON, or XML files for packaging data. You'll also learn how simple it is to implement Three.JS as a WebGL render, or even fallbacks to Canvas and even CSS3D if and when possible.
Before going on, I will make a caveat. I believe that once Unity 3D drops ThreeJS fro pro and free users, we will see much much more 3D in the web. In that case, it can't hurt to Download the software and play around a bit. It also serves an an excellent visual editor. There are exporters from Unity 3D to ThreeJS, but again they are still pre alpha stage.
2D or not 2D. that is the question
After getting a little dirty with 3D I moved into drawing in the 2D realm using the canvas. Flash still seems like a viable tool, but again, it's all about the code. Learn how to do it and you may find Flash is actually costing you time. I found 2D more difficult than 3D because the nature of 2D has yet to radically change, at least in my lifetime. You'll need to start learning Spritesheet creation tutorials. Nothing incredible hard if you know where to look. Use A photoshop, or an equivalent application. Create as many "movement" frames that if were put together in a GIF would be enough to seamlessly loop the sprite. OR render a master image out and cut around the elements naturally distinct pats. Ex: You want to make the guy you have standing on a street corner you created, stays. Cut that character up in as many separate PNG files as you believe you need. The second method is all about using the same sprite sheet we brought in the first try. The first scenario meant writing CSS selector and have javascript written for the regular user would become increasingly difficult.
First solution: Using CSS and Javascript to plot "frames" meticulously put together in the sprite sheet. This really can become a pain if not done correctly all the way through.
Second solution: We lose the frame by frame effect if we need it, but our overall 2D animations will look incredible. Also, building in this way creates more efficient games when implementing physics engines and setting up collision detectors. We will still use the same sprite sheet, however we only need to choose the frames we really actually need. The idea is to use dynamic tweening between frames that are called together via Javascript. In the end you have a fully animated Sprite, but could have done so with just one frame. Ex: You have a Stickman you want to show walking in a straight line. Solution one would jump frame by frame, creating a mild chop, to illustrate an animated walk. In solution 2, we take the Stick man and chop his dynamic bits apart so we can call them through JavaScript, then build our sprite from JavaScript directly. To create the walking effect, we cut apart stickmans legs and have those separate in the sprite sheet from the rest of his body (unless you need to animate another body part as well). We map out where the coordinates are for each piece of stickman. Free software like DarkFunctionEditor is one of many programs that will instantly take care of generating for you a reliable sprite sheet, printing out the coordinates of your sprite sheet after you bake it. With this knowledge, head into JavaScript and call in your variables that you wish to associate to the pieces of Stick Man and their corresponding coordinates. Then use Javascript to "build" all the pieces together. The walking animation is accomplished by the Tween we talked about earlier. Each leg essentially runs on a beautifully fluid path you set in JavaScript. No chop. Very easy to customize and control. If you want to make it even easier for yourself, try using one of the many libraries for Sprite animation. My favorite at the moment being CreateJS.
If you are looking to include collision detection or create particle systems then you will need a physics engine. For 2D I am torn between 2 at the moment. Right now I would put PhysicsJS over KineticJS. Both are fantastic. I believe PhysicsJS integrates with CaccoonJS and other mobile scripts easier.
My last words of advice are=, after reading this, understand you will be working will JavaScript. You will have a bit of jQuery to make it easy, but you will encounter things that are difficult on the way. My HUGE recommendation is to move into learning how to build using NodeJS. It's an Asynchronous Javascript Server-side and client-side development space. The documentation is wonderful. Your first stop should be learing about npm, and bower. Then understand how to effectively implement Grunt into the workflow. Try out NodeJS assets like Yeoman to give you "boilerplate" Node setups from which to start with. After you start understanding NodeJS mechanics and feel comfortable with setting up your initial package.json, you'll find that all this JavaScript will almost feel like it's writing itself after a certain point.
And that's all you need to know to get into 2D and 3D design and development. My initial question could have been answered using say a 3D rendered fullscreen. However my final conclusion came in a different method entirely.
After learning about 2D sprites and framing, then noticing the encoding process of gifs. I had the idea to try and create PNG Sprite Animations. Not PNG Gifs, per say. But rather creating a 2D scene and using a PNG sequence that I would then animate via JavaScript. I found a few great libraries on Github, both for my idea and cool ideas for GIF manipulation.
My final choices was with the Github Repo "jquery.animateSprite" Instead of mulling through sprite sheets, you take your individual PNG's and this library gives you an incredible amount of control in how you can store variables for later use, but also the animations you can pull off in general. For a full screen, responsive background that works on any device (and can even be animated to sound....) I'd recommend this technique. It works much like a flip book animation works, except much much more effectively.
I hope this helps someone along the way. If you have a question on anything I have mentioned here, or know of an area that needs further detail, then by all means please let me know.
-Cheers

Browser render engines: which strategy would be best for a huge image background

I have a project I'm planning which based on kind of an 'interactive world' style experience where the browsers viewport moves around to show many different graphic environments, it must all be fluid and no page-to-page breaks. The project is in js/html5/css3
The problem this poses is that the entire 'world' will be perhaps 8-15,000 px squared (it also rotates, and has various png alpha overlays on top of it)
I was going to run some tests but there are so many ways to approach this and I'm looking for the most fluid one. My knowledge of the internal workings of browser render engines isn't great so I thought I'd ask around.
I cant use the 'tiling' approach which google map uses as it's not fluid enough (too blocky) also when rotating around it's going to create headaches do the math-transforms to work out which tiles to load at what angles so here are the 2 choices I have boiled it down to:
(1) The "Huge" image approach
The benefit of this is that once it's loaded everything is easy, the downside is that it's going to be huge and I cannot show an incremental preloader as the image queue will essentially be 2 images (overlay and huge img)
(2) Image segments
The benefit is that I can show a preloader with an image queue at 10% increments (10x images)
Question:
is the 2nd approach going to have a more painful overhead on the browser's rendering engine due to there being 9 separate sets of calculations being done or do browser engines simply see them as one painted area once it's initially rendered and then update it as a whole? Or each time the dom is changed (rotated etc), the browser has to run the same transform/repaint process 9 times?
Thanks very much.

LOTS of tests later: result: Use a big image, seems to be less for the browser to deal with.

animated board game for web - not Flash - what is possible?

What is the best cross-browser way to get a flat mouse coordinate input data and simple callback for mouse events for my rectangular game area on my web page, even when it has loads of larger and smaller images and text string overlaid haphazard onto it?
And what is the best way to insert or remove a text string or semi-transparent image overlay at an arbitrary location (and Z order, specified relative to existing objects) in a board game rectangle with cross-browser DHTML?
And how can I stop the user selecting part or all of my montage of images (I just want them to interact with it as if it was Flash), and can I stop the right click menus coming up in IE, FF etc?
I want to do this without Flash because I want something that will work both on desktops and on iPhone and potentially other mobile platforms too.
I appreciate there are serious limitations (eg less image scaling capabilities, not vector, no rotation capability) to what I can do if I'm not using Flash but I'm very interested to know what capabilities are available.
Are there perhaps any frameworks available to make it easier than coding from scratch?
Would J/Query be a good match for some of the requirements? What else do I need?

I would recommend Google Web Toolkit. It lets you program in Java, which gives you all the type-safety and nice IDE functionality that Java entails, but compiles to Javascript so that you can just run it in a browser. It also does a ton of optimization and supports tons of features.

jQuery is excellent at doing this. I used jQuery's UI and Ajax functionality to implement the frontend for a game of chess.
I made it a little easier by creating an 8-by-8 table with unique div names for each tile, so Javascript can access them by getting the elements by id. If you can't create something like that, you do have the option of placing elements anywhere on the page (either absolute or relative to a given element). You can also easily change the z-index, including when the use is dragging a piece or when they have dropped it.
As far as disable right click and item selection goes, that's something that I didn't figure out how to do. You might want to take a look at some other Ajax games like Grand Strategy, which are much more polished than my experiment and may have figured out how to do this.

There are two main APIs for working with arbitrary drawing and positioning on the web, Canvas and SVG.
Take a look at Chrome Canvas Experiments and the Raphael Javascript toolkit to see some examples and Javascript abstractions.

The key is element.style.position = 'absolute'. To illustrate just what's possible here's how far I've managed to push javascript (and from scratch at that!):
http://slebetman.110mb.com/tank3.html - RTS in DOM! Click on units/squads then click somewhere else to tell them where to go. You can control both sides.