[android-developers] Re: how to create irregular polygon and handle events within its boundary
Processing a click in side a polygon can be difficult task. There is another solution based on a bitmap where each clickable shape has its own color. I have described it in another thread, named "Overlay to make parts of image clickable" Let me know if something is not clear. On Dec 27, 11:51 am, Achie wrote: > How can we create polygons with shapes other than the normal regular > rectangle/circle etc? I need to create a image with boundaries and let > users click within the image. Then I need to highlight the image. > > I also need to highlight the image only when the user clicks within > the boundaries of the shape. > How can I do this in android? > > Thank you. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Re: how to create irregular polygon and handle events within its boundary
Vectoring parts of a photographic image is going to be more difficult than the example I lnked. I think you'l have to zoom the vertices in the polygon yourself, but you might try using some drawing transformation methods - you may have to dig deeper into OpenGL. Now that you've given more problem details, maybe polygons isn't the only approach. Are you trying to map the touch coordinates to a certain shade in the man's arm, or to a particlar part of the arm? In the latter case, it might work out to just use points for the center of each part (bicep, tricep, elbow, etc.) and use an algorithm based on the distances of the centers to the touch point. This may involve additional geometry skills, such as dividing an area into regions based on such centroids. However, sometimes looking at a problem from a different perwspective leads to a better solution. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: how to create irregular polygon and handle events within its boundary
That is very helpful, I will start looking into getting a verices list for my images. Is it possible to extend this so that I can use my own images Instead of using some fixed color in the shape? [eg I have an image of man's arm and it has shades in it. So can I use it as the object that is being displayed?] And is it also possible to zoom in/out if I take this approach or do i have to consider doing something else? I am asking this since I am assuming that the vertices that I obtain will limit me use some standard px sizes in my Layout. Thanks again Frank. On Dec 27, 3:04 pm, Frank Weiss wrote: > I suppose it seemed simple for me since I'm done it with AWT before. > Basically, you build up a Polygon object with vertices. You pass it to the > Graphics.draw method to display it (or not if you want an invisible hit test > layer over the image). You intercept click or touch events and use the > Polygon's inside() or contains() method to do the hit test. > > Depending on the complexity and display size of the image, you may run into > some hit test accuracy issues due to the touch UI. > > If you have the original artwork in Adobe Illustrator, you ought to be able > to get a vertex list therefrom. If not, google for a raster-to-vector tool > of your choice, for > example:http://freegeographytools.com/2007/converting-raster-area-images-into... -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
Re: [android-developers] Re: how to create irregular polygon and handle events within its boundary
I suppose it seemed simple for me since I'm done it with AWT before. Basically, you build up a Polygon object with vertices. You pass it to the Graphics.draw method to display it (or not if you want an invisible hit test layer over the image). You intercept click or touch events and use the Polygon's inside() or contains() method to do the hit test. Depending on the complexity and display size of the image, you may run into some hit test accuracy issues due to the touch UI. If you have the original artwork in Adobe Illustrator, you ought to be able to get a vertex list therefrom. If not, google for a raster-to-vector tool of your choice, for example: http://freegeographytools.com/2007/converting-raster-area-images-into-polygon-shapefiles -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: how to create irregular polygon and handle events within its boundary
> OK, so how hard was it to google android polygon? hmm its harder than just assuming that I did not do the same. I have been looking around for that since a couple of days. May be I am searching with the wrong terms. Still thank you for the reply. The results does not pull up what I am looking for. But your suggestion did show me something helpful I can use later. [ie to detect if a point lies inside a polygon] No I do not have a Vertices list. I have an image that has the shape. It is a human body with parts[head, arms, legs etc]. That is why I was looking for some hint of where I might have to start looking. I need to somehow convert this into a vertices list or was actually wondering if android has any builtin classes that I can take advantage of. Thanks. On Dec 27, 2:08 pm, Frank Weiss wrote: > OK, so how hard was it to google android polygon? > > The tougher question may be do you already have the polygon as a vertex list > or do you just have an image that has a polygon? -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
