In cocos2d for iPhone, how can I turn a selected portion of the screen into a menu item with selector functionality?
Imagine a worldmap with curved borders between different regions. When the player touches one of these regions, there should be a selector / callback for it. Sort of like a standard menu, but without making a label or an image selectable. Instead, what I want is to be able to specify the clickable area manually.
How about making a CCLayer that will contain this custom region? CCLayer already implements the touch delegates, and you could easily start capturing the regions by setting self.isTouchEnabled to true.
Define the areas of your world map manually, ideally as rectangles for polygons you'll need to look up polygon intersection test. Then just use CGRectContainsPoint with all rectangles and the touch point. If the touch is inside a world area, run whatever code needs to run.
Related
I am wondering how can I add a border & background to labels generated via CCLabelBMFont class in cocos2d.
I don't want to use sprites because my labels are generated on the fly and will keep changing and the size of labels are also different.
Also, I want user to touch and move these labels across the screen. When user picks a label it wiggles a bit like in free air. In that case, I wish to keep low complexity and preserve memory and cpu calculations.
Anyone knows best ways to achieve this?
IOS app LetterPress has similar effects.
Create your own class, that will incapsulate creation of complex node.
It will have several layers, for example, the first layer can be simple CCLayerColor of given rect with zOrder -2, the next layer will be your CCLabelBMFont with zOrder -1 and then you can overload draw method to draw border over your control. All that you draw in this method will be drawn with zOrder 0.
Then you can encapsulate any effects in this class. For example, you can rotate it a bit with method pick, etc. Whatever you want.
After I rotate a CCLayer, my boundingBox grows, instead of rotating. Perhaps to be expected.
My issue is, I'm relying on a user touch on this layer. When the layer is rotated as in the figure on the bottom of the attached image, the clickable area increases because I'm calling:
if(CGRectContainsPoint(clickableLayer.boundingBox, touchLocation))
This causes an issue because this bounding box after rotation is covering up other things that are also clickable.
How do I only perform an action if the actual layer is touched? I want something to happen when just the green box is clicked, not the boundingBox of the layer.
Thoughts?
You can use CGMutablePathRef to detect transparent part:
Refer my answer in this thread.
Information about How to create CGPath:Here
For more information, Click Here
This thread got me to my answer: http://www.cocos2d-iphone.org/forum/topic/272336
I am building an editor using C++/Qt which has a click-and-drag feel to it. The behavour is similar to schematic editors (Eagle, KiCAD, etc), Microsoft Visio, or other programs where you drag objects from a toolbar into a central editing area.
My problem is that when the user clicks inside the custom widget I want to be able to select the instance of the box-like object and manipulate it. There will also be lines connecting the boxes together. However, I can't decide on an efficient method for selecting those objects.
I have two main thoughts on how to do the programming for this: The first is that the widget which is drawing the entire editor would simply encapsulate every one of the instances of the box. The other is to have each instance of the box (which is in my Model) carry with it an instance of a QWidget which would handle rendering the box (which would be in my View...but it would end up being strongly attached to the model). As for the lines connecting them, since they don't have a square bounding boxes they will have to be rendered by the containing widget.
So here is the summary of how I see this being done:
The editor widget turns into a container which holds the widgets and the widgets process their own click events. The potential issues here are that I don't know how to make the custom widget turn into a layout which lets click-and-drag functionality.
The editor widget takes care of all the rendering and processes the mouse clicks (the easier way in that I don't have to worry about layout...its just selecting the instances efficiently that I don't know what would be best).
So, now that there is a bit of background, for the 2nd method I plan on having each box-like instance having a bounding rectangle and the lines being represented by 3-4 pixel wide bounding rectangle segments (they are at 90 degree angles). I could iterate through every single box and line, but that seems really inefficient.
The big question: Is there some sort of data structure I can hold rectangles in and link them to widgets (or anything else for that matter) and then give it two coordinates (such as mouse coordinates) and have it spit me out the bounding box or linked object that those coordinates are inside of?
It sounds like your real question is about finding a good way to implement your editor, not the specifics of rectangle intersection performance.
You may be interested in Qt's "Diagram Scene" example project, which demonstrates the QGraphicsScene API. It sounds like a good fit for the scenario you describe. (The full source for the example ships with Qt.)
The best part is that you still don't have to implement hit testing yourself, because the API already provides what you are looking for (e.g., QGraphicsScene::itemAt()).
It's worth noting that internally, QGraphicsScene uses a simple iterative method to perform hit tests. As others have pointed out, this isn't going to be a serious bottleneck unless your scenes have a lot of individual items.
I have to design a GUI using Qt. I would like to draw multiple lines depicting relationships between two objects. It's the same idea as matching a word with a definition by drawing a straight line (which might be a diagonal) between the two.
In my case it is an a label (with image inside of it) that needs to be matched with another label.
So we have something like this - http://dl.dropbox.com/u/46437808/DrawLines.png
And I want to add lines to make it look something like this http://dl.dropbox.com/u/46437808/DrawLines2.png
I need to do this in run time because the relationship will be changing based on different factors.
Thanks!
Do you need interaction or is this just an image that the user needs to see based on other information? If it's just a static image, I would simply draw it onto a QImage and show it. That way you have complete control over how things are drawn. So you can either cache the relationship diagrams you need ahead of time, or just draw them on the fly onto the QImage based on the relationship that needs to be displayed at the time. You can look at Qt's painting example for some ideas on how to accomplish what you need.
If you need interactivity, I would probably go with the Graphics View Framework. This way if you need push buttons, check boxes, etc. for any reason you can use the QGraphicsProxyWidget to get them, or you can just make your own from QGraphicsItem subclasses.
This is related to one of my other questions.
If I am tiling a large image by creating a separate QGraphicsItem (with the raster data as its pixmap), how do I keep track of the QGraphicsItem's position within the scene? Obviously for raster data, it is important to keep all the tiles "touching" to make a continuous image and they also have to be in the right place so the image doesnt look jumbled.
Does each tile have to have positioning methods that move it in relation to it's neighbors on the top/left/bottom/right? This seems kind of clunky. Is there a better way to make them all move together?
In other words, if I pan the scene with scroll bars, or pick up the image and drag/move it around in the scene, I want all the tiles to also move and stay in the right position relative to each other.
What is the best approach for controlling the layout, which tiles need to be rendered (i.e. only the visible ones), and populating the data only once it is needed? Also, once a tile has been rendered, is the data from it ever dropped, and repopulated from the image file, say if it stays out of view for a while, then comes back later if someone pans to that section?
There are (more than) 2 ways of doing this:
Use QGraphicsItemGroup which
handles grouping of your tile items
for you. It moves, selects, updates
it's group members as if they are
one. I've never used it but from the
doc, it seems to work with typical
applications.
Paint the tiles yourself in the
paint() of one custom item. This
gives you total control on how to
place and draw the tiles while the
item truly acts as one item since it
is, well, one item. This is what I
do.