free-transform | Free Transform Tool Utility

by skmail JavaScript Version: Current License: MIT

X-Ray Key Features Code Snippets Community Discussions(2)Vulnerabilities Install Support

kandi X-RAY | free-transform Summary

free-transform is a JavaScript library. free-transform has no bugs, it has no vulnerabilities, it has a Permissive License and it has low support. You can download it from GitHub.

A set of functions to calculate boundries element resizing, translating, rotating and styles object extraction.

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Support

free-transform has a low active ecosystem.

It has 20 star(s) with 10 fork(s). There are 3 watchers for this library.

It had no major release in the last 6 months.

There are 3 open issues and 0 have been closed. There are 6 open pull requests and 0 closed requests.

It has a neutral sentiment in the developer community.

The latest version of free-transform is current.

Quality

free-transform has 0 bugs and 0 code smells.

Security

free-transform has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.

free-transform code analysis shows 0 unresolved vulnerabilities.

There are 0 security hotspots that need review.

License

free-transform is licensed under the MIT License. This license is Permissive.

Permissive licenses have the least restrictions, and you can use them in most projects.

Reuse

free-transform releases are not available. You will need to build from source code and install.

Installation instructions, examples and code snippets are available.

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free-transform Key Features

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free-transform Examples and Code Snippets

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Community Discussions

Trending Discussions on free-transform

Get mouse coordinates when the mouse is over a disabled element?

How to paint / deform a QImage in 2D?

QUESTION

Get mouse coordinates when the mouse is over a disabled element?

Asked 2019-Aug-22 at 12:14

When using a global mousemove event attached to the window object, the mouse coordinates are not available when the mouse moves over a disabled element. Disabled elements do not fire any events, presenting a problem.

Part of my application includes a free-transform tool which allows elements to be rotated, scaled, resized and dragged around the viewport (drag & drop). The flow of my app is broken if the mouse is moved over a disabled element while freely transforming an object, because suddenly the mouse coordinates are not available to my objects until the mouse leaves the element, giving a choppy / laggy feel and a poor user experience.

I've tried the readonly attribute instead. However, this is not a viable solution as it is only supported by two elements (input and textarea) source: https://www.w3.org/TR/html4/interact/forms.html#h-17.12 and has different behaviour.

Here's a Fiddle showing the choppy / laggy behaviour: https://jsfiddle.net/rmw9anLs/2/

I understand the element itself doesn't fire any events, but I'm not attaching any events to the disabled element. I would expect the window.mousemove event to fire regardless and don't understand why a disabled element on the page would interrupt a global event listener.

Aside from implementing a custom disabled feature using JavaScript, is there a way to get the mouse coordinates without having to account for the mouse being on top of disabled elements?

...

ANSWER

Answered 2019-Aug-22 at 12:14

You cannot, hence the disabled attribute has no effect, other than making your HTML invalid.

To stop the mouse event working, attach an event handler to the element using event.preventDefault() on it, check for a data-disabled attribute on the element in your existing click handlers or use pointer-events: none in a CSS class which you toggle on/off as needed. Also be aware that pointer-events is not well supported in IE <11

E.g: https://jsfiddle.net/x4nLu0a5/

Source https://stackoverflow.com/questions/57608908

QUESTION

How to paint / deform a QImage in 2D?

Asked 2019-Jul-12 at 06:40

I have a code that manipulates and renders a QImage onto a QWidget. Manipulation includes typical homogeneous transformations as well as clipping, applying a color-transfer function, etc.

Now I have to deform the image onto a four-vertices polygon (a quad), not necessarily a rectangle. To be clear, I'm not talking about clipping the image, but deforming it.

I know how to do it using OpenGL (a textured quad), but I wonder if it is possible to do it without switching to OpenGL.

Does Qt have any 2D-like textured polygon or any other way to deform a QImage, like the free-transformation tool in PhotoShop?

...

ANSWER

Answered 2019-Jul-12 at 06:40

QPainter::transform() is indeed the solution as I already recommended in my comment. I was not fully sure about this but QPainter::transform() even covers drawn images deforming the original image rectangle respectively. (Otherwise, I had applied the transformation to the QImage itself.)

However, while making a small sample I realized that's only half of the story.

A small Qt sample application was done ASAP but I struggled to find a way to setup the transformation properly.

By the way I had to realize that translate(), scale(), and shear() are at best good for a 3 point deformation. A 4 point deformation may introduce perspective distortion as well. Hence, project() may be needed also. Feeling, that I had reached the border of my personal math capabilities I googled how other guys have solved that and found

OpenCV getPerspectiveTransform()
Calculates a perspective transform from four pairs of the corresponding points.

That sounded promising. Having a look into the (not so long) implementation of cv::getPerspectiveTransform(), I realized that they made a linear equation and used a solver to yield the respective transformation.

So, I did another search on google and found an IMHO straight-forward implementation by Martin Thoma Solving linear equations with Gaussian elimination. (I somehow remember that I must have heard about Gaussian elimination in my math lessons but that's decades ago, and I never have needed this in daily business since then.)

So, this is what I did for a solver (applying minor stylistic changes to the original code of Martin Thoma) – solveLin.h:

Source https://stackoverflow.com/questions/56952305

Community Discussions, Code Snippets contain sources that include Stack Exchange Network

Vulnerabilities

No vulnerabilities reported

Install free-transform

You can download it from GitHub.

Support

For any new features, suggestions and bugs create an issue on GitHub. If you have any questions check and ask questions on community page Stack Overflow .

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