I am doing some math projects that require a lot of vector line art--that is a line drawn between to points with a circle at the start point and an arrow at the end point. A call to Math.atan2() keeps the arrow aligned. I call this class DrawVectorLineArt() and it creates instances of 2 other custom classes DrawArrow() and DrawCircle().
So far so good--DrawVectorLineArt() draws just what I need. Now I need to animate the vector art.
So in a function onEnterFrame I want to update the postion of arrow and circle, the objects created by DrawArrow() and DrawCircle(), respectively. I also need to clear and redraw the line drawn between them. At this point I am not sure how to proceed in an OOP framework. Do I need to create methods of my custorm class DrawVectorLineArt() to update the position of arrow and circle and subsequently clear and redraw the connecting line?
Any advice or links appreciated. Thanks!
"Do I need to create methods of my custorm class DrawVectorLineArt() to update the position of arrow and circle and subsequently clear and redraw the connecting line?"
Yes.
The arrow and the circle are very members of DrawVectorLineArt, and going by its name and choice of members, so should the line (if it's implemented through actual data). DrawVectorLineArt should contain and implement the whole animation between the circle, arrow, and line. As such, if the animation's supposed to be able to change after creation, the same instance of DrawVectorLineArt should be able to take any two legitimate points supplied to it (or that it becomes aware of internally, depending on what you're doing), reposition the three components, and turn the arrow and line appropriately, within its own code.
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I have several images in my scene, I managed to make the zoom and pan work but the problem is, All of the images are zooming in at the same time. The scripts are place on each gameobject. I used gameobject for the images.
You need apply a filter so you just appli the transformations to one game object, since every one of them are GameObjects I recommend use raycast to sellect an object and then activate his Zoom.cs script just for this object.
I sugest to use just one Zoom.cs in the scene instead of every object having his own copy, then change your function to work with one game object as a paremeter and, when you touch your game object then that object will be the one to suffer the transformation.
If you doesn't want to implement a raycast or change your function at all, then you could set all the images inside a matrix, or use an index system, the central image, or the index you designed, will be the one to suffer the transformations. so you can scroll betwen your gaery and be sure that just the image that you designate in your matrix/index will be the choosen one. The trouble here is that you need to fully control the scroll animation so no one of the images will be in a wrong place like in between two index.
I have a pygame screen with multiple tree like objects which grows with each update. I also have to draw random circle which appear and disappear with each update.
I am not able to make the circles alone to disappear. If I try to redraw I loose the slowly incrementing tree structure also. Any help
Using sprite groups (http://www.pygame.org/docs/ref/sprite.html#pygame.sprite.Group) you can put all the tree like objects into a sprite group designated for trees. Then at the end of the game loop you could blit the background onto the screen and call "tree_group.draw(screen)" to draw all your tree sprites wherever they may be on the screen. With that in place, you can simply draw a random circle wherever you'd like without worrying about taking corrective measures and trying to fix where the circle was drawn previously. Using sprite groups makes updating in game loops a breeze as well. Just call "tree_group.update(args)" and every object in the group will update with the arguments passed in.
does anybody know/have some idea how to make a mask follow a line? Basically I have a drawing made with 1px line and I need to gradually mask this shape so it actually looks like it is being drawn. The thing is that I cannot just increase the width of the mask (it would simple draw a vertical line in one step which is not desired), it has to be a linear movement along the "guide" line, so the vertical line gets drawn in several steps. Doing this manually will/would be a major pain. This is what I am trying to achieve:
Thanks a lot!
You have to do it manually. Though there are some shortcuts you can take:
Create a Guide layer in Flash Pro.
Copy a vector of your path to this guide layer.
Create a new layer below it, put a circle on that layer at the start of the path and make a classic tween of that circle.
Dock your circle layer under your guide layer and at the last frame of your tween move the circle to the end of the path. This will make the circle go along the path.
Follow the animation and manually fill the covered parts.
Put your guide, circle animation and following animation into a MovieClip and put it above your to be masked symbol and make its layer a mask.
Here's an example I made for you if I wasn't clear enough: http://db.tt/kvaaYaLA
Note that this method is only useful if you need a static animation, not for a dynamic one.
I have this small project HERE. Right now it barely does anything but make the character move.
I move the character by using <s:Move>. Now as you can see on the link to my project page, it moves to where you point the mouse and click. I want to be able to stop the character from moving if it hits another object or in this case, the "tree". Is there a script in AS3 that will let me detect collisions or controls that are overlapping each other?
If my question is a bit lacking information, please comment back here and I'll update it with more details as you need.
Please and thank you!
All DisplayObjects have a a method called hitTestObject(obj:DisplayObject) that tests when one object overlaps another. You can read about it in the Tree class, DisplayObject class, or any class that extends DisplayObject.
Im looking for an easy to use method of assigning drag behavior to multiple objects (images, shapes etc) in canvas. Does anyone have a good way or know of any libraries for dragging objects around? Thanks
Creating your own mouse events takes a little work - ideally you should either create or use some kind of mini-library. I'm thinking of creating something like this in the near future. Anyway, I created a drag and drop demo on jsFiddle showing how to drag images - you can view it here.
You can create draggable images like this:
var myImage = new DragImage(sourcePath, x, y);
Let me know if you have any questions about this. Hope it helps.
EDIT
There was a bug when dragging multiple images. Here is a new version.
Another thing you might want to check out is easeljs it sort of in the style of AS3... mouseEvents dragging etc...
The HTML Canvas—unlike SVG or HTML—uses a non-retained (or immediate) graphics API. This means that when you draw something (like an image) to the canvas no knowledge of that thing remains. The only thing left is pixels on the canvas, blended with all the previous pixels. You can't really drag a subset of pixels; for one thing, the pixels that were 'under' them are gone. What you would have to do is:
Track the mousedown event and see if it's in the 'right' location for dragging. (You'll have to keep track of what images/objects are where and perform mouse hit detection.)
As the user drags the mouse, redraw the entire canvas from scratch, drawing the image in a new location each time based on the offset between the current mouse location and the initial mousedown location.
Some alternatives that I might suggest:
SVG
Pure HTML
Multiple layered canvases, and drag one transparent canvas over another.
The HTML Canvas is good for a lot of things. User interaction with "elements" that appear to be distinct (but are not) is not one of those things.
Update: Here are some examples showing dragging on the canvas:
http://developer.yahoo.com/yui/examples/dragdrop/dd-region.html
http://www.redsquirrel.com/dave/work/interactivecanvas/
http://langexplr.blogspot.com/2008/11/using-canvas-html-element.html
None of these have created a separate library for tracking your shapes for you, however.
KineticJS is one such Javascript Library that u can use exclusively for animations
Heres the Link html5canvastutorials
Canvas and jCanvas
You're definitely gonna want to check out jCanvas. It's a super clean wrapper for Canvas, which kicks open a lot of doors without adding code complexity. It makes things like this a breeze.
For example, here's a little sandbox of something close to what you're after, with dragging and redrawing built right in:
Drawing an Arrow Between Two Elements.
I ventured down the road of doing everything with DIVs and jQuery but it always fell short on interactivity and quality.
Hope that helps others, like me.
JP
As you create new objects whether they are windows, cards, shapes or images to be draggable, you can store them in an array of "objects currently not selected". When you click on them or select them or start dragging them you can remove them from the array of "objects not selected". This way you can control what can move in the event of a particular mousedown event or mousemove event by checking if it isn't selected. If it is selected it will not be in the "not selected" array and you can move the mouse pointer over other shapes while dragging shapes without them becoming dragged.
Creating arrays of objects you would like to drag also helps with hierarchy. Canvas draws the pixels belonging to the foremost object last. So if the objects are in an array you simply switch their instance as in element in the array say from objectArray[20] to objectArray[4] as you iterate through the array and draw the objects stored in the array elements you can change whether other objects are seen on top or behind other objects.