Is it possible to move the background image in app inventor?
I'm trying to use the call canvas background pixel color block to get the color of different parts of the background. If I can't move the background image, can I use math blocks to change the x and y parts of the call canvas background pixel color block to a variable?
Important Note
I am referring to the image sprite, under the drawings and animations tab.
An image will have coordinates once you put it inside of a canvas. In order to move it, create 2 sliders with 2 balls and 2 narrow canvases that are (seemingly) equal to the ball's diameter. (Place underneath the image, make sure the image isn't too big)
Go into blocks and place the "when dragged" command, and hook up the change in the ball's x/y to the change of the images x/y. (Assuming you know how to make the ball move while you drag it, also very simplistic). This will make the image's movement equal to the ball's movement (1:1 ratio) Depending on how much you want the image to move, your'e going to have to implement a ratio.
When you drag the ball(s), the image should move with it.
Related
I have a container UIView that contains many columns/subviews.
I want to create a color fill animation on the container UIView, left to right as demonstrated on the image below, so it gradually changes the colors of only the subviews.
How to achieve this?
Im guessing i would have to create a mask and move it over this container UIView?
But then how to achieve that the mask only applies to the subviews?
EDIT:
this is a progress indicator for a playing audio file, so it needs to indicate the current time position precisely.
Also i must be able to have the shapes in different sizes as they represent audio waves
I would do it the opposite to the way you describe it. I would draw your audio wave shapes as a mask, thus revealing whatever is behind them. It is then trivial to position / animate a colored rectangle rightwards behind the mask to indicate the progress through the music:
In other words, the color is not an overlay but an underlay.
I am using fabric.js for html 5 interactive canvas app. If the object scales larger than the canvas, the controls go invisible outside canvas. How to make it visible outside the canvas or is there a way to style those controllers in css.
So, in fabricjs controls are rendered on the canvas, so having controls outside canvas it is not possible.
You can still obtain the effect in this way, this is just a trace.
Make canvas big as 100% of window, or anyway very bigger than drawing area.
Then you can clip the drawing canvas with a rectangle.
If you need borders to define the drawing area you can still put an overlay image as fabricjs allow you.
If you need to have controls near the drawing canvas you will have to position them OVER the non drawing part of the canvas.
This will give you some additional tasks:
When you create some object you have to be sure that they go in the drawing area. If you consider position of objects, you have to consider that a translation has to be applied, because you have absolute position while user will position the object watching a fake top left corner of a drawing area and not the top left corner of the canvas.
The best thing you can do is make a larger canvas, but limit the drawing area to a limited part, like a margin. Not easy because after that you always need to consider the margin when making other calculations, but it is possible.
I was creating an effects library for a PhotoBooth App. I have created effects like Black/White, Vintage, Sepia, Retro etc. etc.
I wanted to create a few effects now in which I wanted to have a Dark Border at the edges which kind of form a frame for the image .. something like this -> Example Effect
How can I do this using Pixel Bender and Flash ?
The effect you are describing is called vignetting. It is basically just darkening the pixels with some weight that changes depending on distance from the center of the image. In image editing it corresponds to overlaying the image with black color and applying a circular or elliptic mask to it, for example:
(source: johnhpanos.com)
You can do this by several methods depending on how you operate with image and its pixels. For example by multiplying the pixels by a weight coefficient that is smaller when closer to the center and bigger when farther away from it. The distance can be calculated from the difference between pixel coordinates.
If have an image which is 1024x1250 and a canvas element that is 600x800, I can draw the image to the canvas centered such that the canvas is essentially a smaller view port of the larger image. I then want to allow that center point to move, thus creating the illusion that the viewport is viewing a different portion of the image.
Right now I've done this in sort of a hokey way where I redraw the portion of the image I want to see to the canvas, but I get this feeling that this isnt optimal. Is there a way to render the whole image to the canvas and then somehow "transform" my current center point so this view shift happens behind the scenes hopefully in some native layer?
You can add transformations to the context before drawing any image (rotation, scaling, translation...). What you need is the function context.translate(x,y).
Then, you only need to draw your image at (0,0)
For example, to display the bottom right portion of your image:
ctx.translate (-424, -450);
ctx.drawImage (image, 0, 0);
You can check this link https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Canvas_tutorial/Transformations to see a lot of examples on context transformation.
I am a complete novice when coming to using Flash but I am looking to create an animation similar to the line into text animation at:
http://www.louisebradley.co.uk/fl/
where instead of running from the top of the screen I want the line to effectively stretch across my homepage horizontally.
I have created an animated gif that does the job but it takes a long time to stretch across 974 pixels in width, and if the frames are reduced it takes away any smoothing effect. I did this in photoshop by simply creating 20 or so frames, each increasing the size of the line by 60 pixels until the full page is covered.
Would I be better off creating the effect in Flash? And if so, where on earth do I start!! Would tweening do this, and how I would I implement it?
Thanks in advance for any help!
I am assuming you are talking about the line to the left of the main navigation? If this is the case, this is being done using a mask that is tweened. You can simply draw out the shape you want "wiped" across the screen and than on the layer above it, draw a box over the shape to be animated. Right click the layer the box is on and select "mask". You can now tween the mask to move from right to left over the shape you drew and it will appear to wipe over. Just remember, whatever the mask is currently over, is what will show through from the layer that is masked. Think of the mask as a window. This can be completely done without actionscript and only using the timeline.