I have created a react app Which is very similar to office whiteboard. I would like to generate a thumbnail or card preview of each whiteboard and wondering how to go about it.
My initial thought was to just create a card component and render the shapes to that the same way I do for the real whiteboard. However, the points for each shape will be outside the stage and I can't think of how I can scale it down.
Any ideas?
Take a look at the official canvas thumbnail demo from Konva.
You can use a similar approach with react-konva.
Create a special component for the preview.
I think this approach will work better and probably more performant (depending on your app). You just need to create another Stage and draw all objects into it. It will be better if you can draw simplified versions of the shape, because the drawing is much smaller, so not all details are visible.
You will have to calculate your own scale ratio.
Use image preview
Instead of making a full components tree for the whiteboard, you can just export the main stage into an image and show it. You have to do reexport from time to time.
Related
I'd like to create a context menu looking similar to this one:
I read suggestions on the web that QWidget::setMask() should be used to create a shape. But how can it fit the variable number of items then? Moreover, the same menu item may take more or less screen space on different machines.
Another question is how to create a shadow around this custom shape? As far as I understand, the mask allows to crop the widget, but not to make it semi-transparent.
I don’t found an easy way to do that! But here goes a way!
Instead of using the Qt mask API, I've used a frame-less widget with transparency enabled!
To draw the shadow, I've used radial gradient!
You can change the size of the menu before opening it, however you can’t resize it after opened (for example resize with mouse).
It’s quite easy add or remove widgets, just respect the layout margin to not draw outside the bounds destined to widgets. To simplify your life I created an inherited class of QPushButton with colors you can easily customize with style sheet.
See the result:
You can browse the source
Hope that helps!
I am trying to implement a tool into my application. the tool would allow the user to plot a triangle meshes using the mouse. I have looked everywhere for a way to do this, tutorials, examples, etc and have not been successful. I have seen the FXyz library but that does not really simulate What I am trying to accomplish. The goal of the program looks as follows:
Use Case Sequence:
The user adds a png image to the 3D scene or drags it into the 3D scene using the mouse.
Once the image is being displayed the user would then be able to plot a mesh around the image.
Once the user has finished plotting the mesh. There would have to be a way to add the image being overlayed by the mesh as a texture to the mesh. The image should look the same after being added as a texture. Is this too hard or beyond the scope of what can be achieve in JavaFX?
Theoretically It would then be possible to drag the vertices of the mesh at draggable points and successfully applying transformations to the texture. Would this be possible?
Images showing what I am trying to achieve
As you can see maybe after plotting the mesh the points connecting the vertices can be dragged in order to manipulate or transform the shape of the mesh. If the mesh has a texture over it. would the image then also transform ?
Would this be possible with the TriangleMesh class that JavaFX has which by the way there is very little out there which explains how to use it and how the points, face points and texture points work. Very confusing =(.
Target End Result
My question is would the type of manipulation shown in the image above be possible in JavaFX? Can this sort of functionality be achieved using the TriangleMesh class or other similar class in JavaFX ? As you can see what I am trying to achieve is really image manipulation I would appreciate knowing if there is another better way to do this.
I unfortunately do not have any code I can share. I just cant seem to produce any regarding this task. I am not asking to be given code or for someone to solve the problem for me. I just want to see examples be guided into the right direction on how to do this and to know if it is even possible or should I just give up on it!
If you have read this far Thank you so much for your time I really appreciate it.
I have read your question till the end :-) In contrast to many people here you are at least providing a clear description of what you want to achieve. According to my own experience I would say that what you want to do is easily possible with JavaFX and the MeshView is the way to go here.
You can use your image as the texture for this mesh and you can distort the image by manipulating the vertices of this mesh. I have implemented part of your functionality myself for a project so I know that it works.
I want to develop an image editing application in Flex 4. My initial requirement is to draw various shapes like Line, Rectablge, Triangle, Circle, Star etc in appication. I want to facilitate user to draw shapes using rubber banding like professional applications do.
All shapes would be vector and should look smooth in an size. So, can't use bitmap and scale them.
What are better methods to achieve this?
if you don't want to start from scratch with the basic shapes, there is this framework called degrafa: http://www.degrafa.org/
they have plenty of parametric shapes & curves and advanced features to organize them together.
Make shape editor with some control points. Control points are draggable sprites (circles or squares as you like). When control point is moved, editor must be updated - it may be resize or move action. On resize, draw your vector shape according to new size. The easiest way to make sprite draggable is startDrag() function - you can also set limits there (to stay in editor area or to disable negative sizes).
I have done such editors based on Sprites, added into Flex application with rawChildren.addChild, but you can try to use Canvases instead of Sprites if you wish.
I'm creating a web app in ASP.NET like this one:
http://www.zazzle.com/cr/design/pt-mug
I know how to do everything except wrapping an image around an object.
It would be a simple task to do if I would only have to stack an image on
top of the other, if they were flat, but if it is a round object, as this mug
is, it's kinda tricky.
My first guess was to create some sort of algorithm for GDI+ that would
simulate "wrapping" image around an object (actualy it wouldn't be an 3d object,
it would just be a screenshot of it).
I figured it would be to raw approach and it would result in very bad quality,
if I could ever make it work.
So, my second guess was to implement somekind of 3d renderer to whom I would
give an image map for some object, it would render me that image onto an object
and in real time return me rendered image. Is that posible?
Is there any other way? Where do I start?
If you are willing to try a commercial product, my company makes a raster processing SDK for .NET called DotImage. If you try it, take a look at PolygonTransform. You supply a polygon as a list of points, and the class warps the image to fit inside the polygon. If you need sample code for it, let me know.
It might be some sort of OpenGL 3D rendering, but an image could easily be morphed in a purely 2D way for this effect. Horizontally, it would need to be squished where it goes off the side of the cup. Each column of pixels needs to be shifted vertically by varying amounts depending on which column - such that a horizontal line the image would become like a "U" shape. With the right parameters, such a morph could mimic the proper 3D shape. Lighting effects could be applied to, by brightening/darkening the image a bit in the right places.
I have a Flex component with a background image. The image is sharp in the beginning, but is jagged whenever I scale the component using scaleX and scaleY. How would I make the image anti-alias so that, it it's scaled to 0.75, the lines are smooth, not jaggedy?
Here is the image
Here is the scaled version
And the unscaled (good) one
If you load the image with an Image component, you can cast the content property of the component to a Bitmap and then set smoothing to true. Unfortunately, the image component doesn't provide this functionality out of the box. However, it's rather easy to hack in.
Here is a tutorial to show you how to create such a component:
http://www.adobe.com/cfusion/communityengine/index.cfm?event=showdetails&productId=2&postId=4001
However, if this is set using the backgroundImage style of a component, you just might be out of luck unless you override updateDisplayList and perform the drawing of the bitmap yourself by using Graphics.beginBitmapFill (which does provide smoothing support).
Why smoothing of images doesn't have better support (such as different interpolation methods) in Flex (and subsequently, Flash) boggles my mind. At least pixel bender filters will help a bit by letting us implement such filters ourselves.
If the dimensions of your Bitmap are both either n^2 or n^8, then the Flash player will automatically use a technique called mip-mapping that will dramatically improve the look (and performance) of scaled bitmap images.