Dragging mouse on an image, showing another image underneath - javascript

I'm a beginner with writing code so I'm struggling a bit with this one.
I want to have two images layered on top of each other, and when you use your mouse on it like dragging or painting, the image underneath will show in the places you've traced.
I've been using these as source, but none of them use an image on top and I haven't been able to replace the top layer with an image:
https://rifke.world
https://codepen.io/uargh/pen/eYmoXgJ
I think I'll probably need ctx.globalCompositeOperation="destination-out"; but I'm not too sure how to apply it to an image
Any help would be very appreciated since I've been fighting with this for a while.
Thanks! :)

I do not see anywhere that you are loading a second image, I think you should do something like:
var img2=new Image();
img2.onload=function(){
ctx.drawImage(img2,0,0);
};
img2.src="http://placekitten.com/700/1023";
I tried it here, looks like this achieves what you are trying to do.
Besides, you can use PageX and PageY instead of ClientX and ClientY, so that your code works as expected when page is scrolled.

You'll want a static image and a canvas element, pretty much what the link you included is doing. Here's the code from that site to dig into further how they are updating the canvas element for that effect. https://rifke.world//js/script.js?ver=1.4.
You can draw the image you want on top on the canvas element using the following method https://www.w3schools.com/tags/canvas_drawimage.asp.

Related

How can i draw a part of an image on top of a html page depending on my mouse movement? (with or without canvas)

I want to draw an image on top of my html page depending on my mouse movement.
How can i do that? Is it a better approach to put the image below the rest of the html and scratch the html somehow away, or tu put the image above it and add it partially on top.
I found solutions on the internet with 2 images on top of each other where the top one is erased with canvas, but since i have multiple elements i want to overwrite, i have no idea how to solve it.
Assuming I've interpreted the question correctly, that the requirement is to allow the user to 'scratch away' at the page gradually revealing an image, you could do it either way.
There are libraries that will create a canvas of a page (or part thereof) such as htm2canvas. Using one of these you turn your page into an image, place it over the given image and remove (make transparent) pixels on the top canvas as the mouse moves. The drawback with this approach is that it's possible the conversion of the HTML to canvas isn't totally complete. There may be some aspects for example of CSS that aren't correctly rendered.
To be sure therefore it's probably better to do it the other way round. Lay a blank canvas over the page and copy the image to another canvas with the same dimensions but which is outside the viewport. As the mouse moves over the blank canvas copy the relevant pixels from the offscreen canvas to it.
If you could confirm that I've understood your question correctly I could go into more detail.

Image with a link in a specific point

I need to create a website with this kind of function:
I have an image (like a park area), so in different points of this image I must create a div which will do a hover effect and show a textbox with an image (or maybe a link to it).
My main doubt is that I have no idea how can I get certain points of this image to create a div with this hover effect.
Please check the below URL's. Hope this may helpful
http://www.w3schools.com/tags/tryit.asp?filename=tryhtml_areamap
http://www.howtocreate.co.uk/tutorials/html/imagemaps
http://www.outsharked.com/imagemapster/
you can do with jQuery. Please, firstly look at this link. You can take mouse x and y position on image. Then on x and y position, you can do, what you want.

HTML: Image map areas' responsiveness

I need to use image map in my website, to add different links to each part of image.
But I have problems with its responsiveness. I couldn't change map area's size while resizing window.
Can anyone help me with this? The method is not important, I can use either Js or Css.
Update:
I used http://mattstow.com/experiment/responsive-image-maps/rwd-image-maps.html for responsiveness, but it affects on map area coords. When I reload the page, map coords are all 0, those are being updated only after resizing the window.
Do anyone have this problem too?
Imagemap is a very Old way to create websites I preffer using photoshop image sílice and save as html maybe you should try it ir you will use non dynamic images that way you can fix width and height and a lot more
If you have the image saved as a vector image, you could save it as an SVG and use RaphaelJS. I've only recently picked it up but it is quite easy to use once you get the hang of it.
You can assign links, style and hover events to each node attribute, and Raphael allows you to set the viewBox so that it scales on resize (can't link as rank not high enough - help can easily be found on SO though)
Here are some examples of using RaphaelJS: LINK1 LINK2
And check out jsfiddle.net/AUNwC/294/ for example of each node having a responsive clickable area (resize window to check)

How to enable clicking on layered svg images

My app uses up to 6 svg images layered to create an interactive image. I have found that I cannot mouseclick on any images below the first.
** Edit. Excess code and text removed.
You can make an element insensitive for mouse events by setting the pointer-events attribute to none (see Tinkerbin):
svg > *{opacity:.5}
In essence I cannot do what I want this way. Stacking embedded images results in only the top layer being clickable by the mouse.
An image map works, with some mucking about.
I created a clear image calling it clearOverlay and gave is a usemap value tying it to my image map.
My imagemap I created using a free online app http://www.image-maps.com which took my image allowed me to create my clickable zones and generated the html for me. After cleaning it up and swapping the href values for onclick functions I added the map to my code.
Next problem was getting it to overlay my existing images. I eventually used style="position:relative; top:-300px" forcing it to sit squarely on my image. I'm sure there must be a better way, but at this point that worked for me.
For anyone else doing this don't forget to either place the clearOverlay last in your image list or set the css z-index to higher than everything else to make sure it is sitting on top.
So I now have a stacked svg image, where I can manipulate each svg according to where the user clicks. Its only taken me 5 days! I'm kinda over this coding by yourself lark.
** My image map above will not scale to different sized screens. The next time I try this, I will experiment using a transparent svg with fill zones where I wish to click.

Multiple captions for an image - click on links to see one at a time

What I'm trying to do is something like you see at http://www.nejm.org/doi/full/10.1056/NEJMimc1109704. (Click Play and go to page 5 - the interactive physical exam.) I think they are doing this with Flash, but I'd like to use javascript/jQuery.
Basically there's an image that has multiple captions. The captions have arrows that point to different parts of the image, but that's not essential for me. When you click on different links, different captions appear.
Would I tackle this as an image map? I.e. create a map, and use jQuery to toggle different parts of the map? Is there a plug-in that does that? Google searches aren't helping me - but maybe I don't know what to look for. Any help will be appreciated.
I'm having the same problem and I found imageMapster. Check out
http://www.outsharked.com/imagemapster/default.aspx?demos.html#beatles
I think this is what you want to do. Just this solution today, haven't figured it out yet. Looks promising though. Otherwise check out qTip2
http://craigsworks.com/projects/qtip2/demos/
Maybe some adaptions let you/us do what we wanna do
Good luck! Keep u updated if I figured it out
Why would you need jQuery?
Anyway, put your main image down, and set its position to be fixed where you want it. You could even put it in a nice container div, just make sure all your caption divs are relative to the same parent. Then put fixed position divs of your caption images over it with a higher z-index in your css. Then place your caption images at the appropriate top and left positions until they are correct. Of course, use transparent PNGs.
All you need to do to toggle them is set the element's style.display to "none" or "inherit"

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