I am wondering how I would be able to use animated shapes inside a movieclip that would be acting as a mask?
In my Animate CC canvas file I have an instance (stripeMask) that should mask the below instance called mapAnim.
stripeMask contains shapes that are animating in.
So when the function maskIn is called, the playhead should move to the first frame inside the stripeMask clip (the one after frame 0) and animate the mask like so:
function maskIn(){
//maskAnimation to reveal image below
stripeMask.gotoAndPlay(1);
}
I love AnimateCC and it works great, but the need for creating more complex and animated masks is there and it's not easy to achieve unless I am missing something here.
Thanks!
Currently you can only use a Shape as a mask, not a Container or MovieClip.
If you want to do something more complex, you can use something like AlphaMaskFilter, but it has to be cached, and then updated every time the mask OR the content updates:
something.filters = [new createjs.AlphaMaskFilter(stripeMask)];
something cache(0,0,w,h);
// On Change
something.updateCache(); // Re-caches
The source of the AlphaMaskFilter must be an image, so you can either point to a Bitmap image, or a cacheCanvas of a mask clip you have also cached. Note that if the mask changes, the cache has to be updated as well.
This is admittedly not a fantastic solution, and we are working on other options.
Related
I searching an days for this question.
I want to Crop Images like that, in flutter:
GIF Source: https://github.com/ArthurHub/Android-Image-Cropper
The closest lib for this solution is the Image Lib, that lib offers manipulate images and crop, but i want to crop images in UI level like this gif. All libs I found dont offers that.
There is no widget that performs all that for you. However, I believe that it is possible to write that natively in flutter now. I don't have time at this particular moment to do it for you, but I can definitely point you in the right direction.
You're going to need to load the image in such a way that you can either draw it onto a canvas or use a RawImage to draw it rather than using the Image widget directly.
You need to figure out a co-ordinate system relative to the image
You'll need to find a way of drawing the crop indicator - you could do this either by drawing directly on the canvas or possibly using some combination of GestureDetector/Draggable/DropTarget. I'd suggest that sticking to Canvas might be the easiest to start.
Once the user has selected a part of the image, you need to translate the screen co-ordinates to picture co-ordinates.
You then have to create an off-screen canvas to draw the cropped image to. There are various transforms you'll have to do to makes sure the image ends up in the right place.
Once you've made the off-screen crop, you'll have to display the new image.
All of that is quite a lot of work, and probably a lot of finessing to get right.
Here's examples for a couple of the steps you'll need to do, but you'll have to figure out how to put them together.
Loading an image:
var byteData = await rootBundle.load("assets/image.jpg");
Uint8List lst = new Uint8List.view(byteData.buffer);
var codec = await UI.instantiateImageCodec(lst);
var nextFrame = await codec.getNextFrame();
var image = frameInfo.image;
Displaying an image on a canvas:
https://docs.flutter.io/flutter/dart-ui/Canvas/drawImageRect.html
https://docs.flutter.io/flutter/rendering/CustomPainter-class.html
Writing an image to a off-screen canvas:
ui.Image getCroppedImage(Image image, Rect src, Rect dst) {
var pictureRecorder = new ui.PictureRecorder();
Canvas canvas = new Canvas(pictureRecorder);
canvas.drawImageRect(image, src, dst, Paint());
return pictureRecorder.endRecording().toImage(dst.width.floor(), dst.height.floor());
}
You'll probably need to do something like this answer for getting the local coordinates of mouse/touch gestures.
Some advice - I'd start as simple as possible, not thinking about performance to start (i.e. draw everything each paint if needed, etc). Then once you get the basics working you can start thinking of optimization (i.e. using a RawImage, Transform, and Stack for the image and only re-drawing the selector, etc).
If you need any additional help let me know in a comment and I'll do my best to answer. Now that I've been writing about this a bit it does make me slightly curious to try implementing it so I may try at some point, but it probably won't be soon as I'm quite low on time at the moment. Good luck =D
The image_cropper plugin does exactly what you are looking for.
In Monotouch, I need to create a basic animation of an image moving along a path while animating it's image content with a sprite sheet or replacing the content CGImage, everything i try i can't combine both animations. I tried subclassing the CALayer and animate custom properties or combine animations in group nothing seems to work. What's the best way to produce this kind of animation?
To get a smooth animation, you want to think of what CAlayers represent: they are a handle to a texture that live in the GPU space. To get smooth animation you can control a few of their properties, but arbitrary changes like rendering the data again wont work fine.
What you should do is put all of your images in the sprite sheet, and then animate the ContentsRect property of the CALayer.
i have a scrollview which contains a pdfpage rendered with CATiledLayer, i want to draw stuff onto the pdf page so i created a overlay layer, i need the graphic to look vectorized so i decided to use CATiledlayer for the overlay layer. Only problem is that it is very slow to draw (I'm using beizerpath to draw), then i tried to optimize it by creating the overlay layer with the visible height and width when zooming in and out, so i don't need to create the overlay for the whole content bound. But still no luck , i want to try CALayer but the draw path just becomes blurry and pixelated, so i'm not sure how i can improve on this. I also tried drawinrect but for some reason it doesn't seem to work.
I suggest not using bezierpath to draw annotations since it requires you to redraw the whole path every time the pen moves. It would be better if you draw only the current line segment using CGContextAddQuadCurveToPoint.
At touchMoved, get the current point and 2 prev points
Using those points, get the area where the line should be drawn
draw at that area in drawRect using setNeedsDisplayAtRect
inside drawRect, go to the end of your path and add your new line using CGContextAddQuadCurveToPoint
I'd like to take an image and use it as a mask for a view on which I add numerous image views. I know of the quartz CGContextClipToMask() call but what would be the best way to approach this? Can I override the drawRect method of a container view, call CGContextClipToMask() within it, and then expect its subviews to adhere to that clipping region? It doesn't seem to work.
Do I need to instead add some blocking mask image over top?
Instead of subclassing or overriding drawing functions, I chose to overlay the images with an image that had transparency in the viewable portion. i.e., if my 'surface' was an image of a parchment, and I aimed to draw a bunch of images on it. I would have the parchment image, then a container UIView for any images to be put on that parchment, then a masking image over top of that which was the original parchment image but with the parchment itself converted instead to full transparency, while the surrounding area is left exactly as the background the parchment is on (then all other UI widgets over top of that).
This seems a viable solution in all cases except if one were to need some image to visually animate around and behind the parchment (not my case).
What i need is a bit difficult to explain. Let's try...
I need to write a text in my app, and that text will gradually change color from left to right.
I think i could say it's a similar effect to what you see in a karaoke screen.
For instance. I draw a text line, in blue color, and gradually, using a timer, the color from left to right changes to red. But i don't want it to change letter by letter, but gradually. That would require that at some moment, the same letter can have a part in red and a part in blue.
I've been reading about core drawing, and maybe it's the solution, but i really don't know how to start. I was thinking about using a background layer and in top of it draw a transparent text (only with border), but i am not very sure how to do it.
any ideas would be appreciated.
You can probably do the job with a CGLayer.
Best of all you should be able to use your existing code to draw the characters (or anything else) in to the CGLayer.
Here's some rough code:
// first, make a CGLayer...
CGLayerRef yourDrawingPad =
CGLayerCreateWithContext(UIGraphicsGetCurrentContext(),etc..
CGContextRef yourRef = CGLayerGetContext(yourDrawingPad);
// now, draw to yourRef .. draw your various typography (or anything)
// use your current drawing code.
// all done drawing, now make an image mask...
UIGraphicsBeginImageContext(CGLayerGetSize(yourDrawingPad));
CGContextRef temp = UIGraphicsGetCurrentContext();
CGContextDrawLayerAtPoint(temp, CGPointZero, yourDrawingPad);
CGImageRef anAlphaMask = CGBitmapContextCreateImage(temp);
UIGraphicsEndImageContext();
You now have a nice mask you can use:
CGContextSaveGState(UIGraphicsGetCurrentContext()) ...
CGContextClipToMask(UIGraphicsGetCurrentContext(), self.frame, anAlphaMask);
So just mask it in to an image of a gradient, or whatever works.
(Conceivably: perhaps you will have to construct a bitmap image offscreen, and then use that as the mask?)
Footnote: Don't forget it is very likely you will have to paint upside down! Fortunately that is simple to deal with. Where it says "now, draw to yourRef" before drawing save your state and add the two lines of code:
CGContextTranslateCTM(refForMask, 0, self.frame.size.height);
CGContextScaleCTM(refForMask, 1.0, -1.0);
Hope it helps
I have an idea of how this could be done, but it is kind of complex. You could create an NSBezierPath and add the glyphs for each character. Then, set that as the clip and draw a NSGradient. Then you would just have to change the offset of the colors in the NSGradient to move the color along.