I am using Silverlight (4) to create an application in (VS 2010). I utilized the ArcGIS API’s for Silverlight to generate the following scenario:
I buffered a polyline to a variable distance.
I then retrieve all but only those polygons that are overlapped by the buffer.
I then intersect the overlapped portions to separate them.
Attaining the separated overlapped portions, I was about to utilize the Area and perimeter service to retrieve the areas of the portions, but realized that this last step would be in the wind.
I have no problem coding the above scenario except; I now realize that step 4 would not be very useful at this point, since I have no way of sharing data between the separated overlapped portions to the original polygons. Imagine if you will; before I separated the overlapped portions from the polygons, they had data tied to them; such as valuationNumber and volume, but after the separation due to the intersection service, the separated portions seems blank with no data. My goal is to have a list highlighting the valuationNumber, volume, and the area of the separated portion.
Something like:
Valuation:
12345678
Volume:
1234/123
Area of Separation (M):
12
Any, and I mean any help would be appreciated.
[copied and pasted my comments from above due to laziness]
Well then, I would suppose I created a work around, I wonder if there is a right way out there though. Anyhow, I did the following: I created a Dictionary Object and populated it with the Attribute values of the original polygon just as they are created. Then, just as the overlapped portions are being created I assigned the attribute values from my Dictionary. So, now the values match up, and all binding works just fine. But hey, if anyone know a better way; I'm all eyes.
In fact, to make matters seem a bit better, I made an improvement on the work around. I create a class with the fields I wanted to be in both original and separated portions. Then added this class as the value parameter of my dictionary object I spoke of earlier, then followed the same procedure. Now I have all the fields being mapped to in XAML working nicely (for now).
Related
Is there a way to change the clutter perspective for a given container or widget?
The clutter perspective controls how all the clutter actors on the screen are displayed when rotated, translated, scaled, etc.
What I would really like to do is to change the perspective's origin from the center of the screen to another coordinate.
I have messed with a few of the stage methods. However, I haven't had much luck understanding some of the results, and often I hit some stability issues.
I know there are transformation matrices that do all the logic under the hood, and there are documented ways to change the transform matrices. Honestly, I haven't researched much further and just though I would ask for guidance before spending a lot of time on it.
Which leads me to another question regarding the matrices and transformations. Can one of these matrices be used to skew an actor? Or deform it into a trapezoid, etc? And any idea how to get started on that, ie. what a skew matrix would look like?
Finally, does anyone know why the clip path was deprecated? It seems that would have worked for what I ultimately want to do: draw irregular shaped 2d objects on the screen If I can implement an answer to question 2, then I guess a clip box with a transformation can be used here.
1, I do not know if (or how) one might change the Clutter stage's focal point.
2 A skew or shear transformation matrix is easy enough to construct, and can be implemented in the GJS Clutter functions Clutter.Actor.set_transform(T) and Clutter.Actor.set_child_transform(T) where T is a Clutter.Matrix .
This does present another problem, however, for the current codebase; and this leads to another question. (I guess I should post it somewhere else). But, when a transform is set on a clutter actor (or its children), the rest of the actor's properties are ignored. This has the added effect that the Tweener library cannot be used for animation of these properties.
3 Finally, one can use Cairo to draw irregular shaped objects and paths on a Clutter actor, however, the reactive area for the actor (ie. mouse-enter and -leave events) will still be for the entire actor, not defined by the Cairo path.
I'm performing some geographical computations in a grid with squares (i.e. regions). I'm using Delphi, but the logic could probably be applied to C++ too. Let me first explain what I want to do.
The following image is a portion of my grid, which is represented by a two-dimensional array Square that denotes the centre point in each square, and the "movement through the layers":
The green square has an X and Y coordinate of 2, so that is Square[2,2]. The actual coordinates are stored in Square[2,2].Latitude and Square[2,2].Longitude as wel as extra information in e.g. Square[2,2].Info that I use for computations.
Now comes the purpose: I need to do some computations on the surrounding areas. How many of the surrounding areas can be called "neighbours", depends on how many "layers" I have defined. In the image above, I used two of these "layers". That means that when starting from the green cell, I go around it once (blue arrows) and then again in the second layer (red arrows).
Now comes the problem: if I would have started in Square[1,1] (green square) instead of Square[2,2] as in the image below, the second layer (in red) would try to access data on the left side and at the bottom that does not exist (i.e. in the "-1" column and row). See the image below. This problem occurs at all borders of course.
I probably can make exceptions with IF-statements for every scenario, but I was wondering if there are common programming "tricks" that can handle such situations where you try to access data does not exist.
For example, I imagine it would be very handy if I can follow the pattern of the arrows depicted in the first image to access all the neighbouring squares every single time, even if there are non-existing squares. So, looking at the first image, after Square[3,0] you'd go to something like Square[3,-1] etc. and then eventually come back into the "feasible" zone in Square[0,3].
To visit neighborhood, you can use some kind of BFS (breadth-first search).
But for sparse structure (like the last picture shows) it is worth to use some data structure to organize cells in a good way. Perhaps kd-tree is suitable - you add all existing cells in the tree and make range search around given cell to get other cells in its vicinity.
Also look at another spatial data structures (see list at the bottom of kd-tree page).
I'm looking at some new options for displaying a percentage value as a fill in a custom shape. Consider the effect to be similar to a "progress thermometer" in a traditional dashboard UI sense.
Considerations
Goal - a graphic element showing a percentage value for a custom report.
Format - Either a full graphic (or infographic) itself, or part of a PDF via Photoshop/InDesign or even iBooks (as an excuse to use it).
Usage - I'd like the process to be programmatic, for re-use. It needs to be accurate, and I'd like the solution to be somewhat object oriented to apply to other datasets and graphical containers. This rules out hand-drawn charting.
Source data - currently a pivot table in Excel, but I can work with any other host as required.
Shape - is a custom vector shape that will originate from Illustrator/Inkscape. final format as best fits resolution and rendering of the report. I would also be interested in any other generative shape ideas (such as java/javascript).
Fill - I'd like to be able to represent the fill as both an actual percentage of total area (true up), and as a percentage of the vertical scale. I'd imagine this flexibility would also help reuse of the method as a fill value against selected object variables (height, area, whatever).
I know I'm being slightly vague in the programming languages or hosts side of things, but this gives me an opportunity to break out of the usual analytic toolchain and scope out some innovative or new solutions. I'm specifically interested in open source solutions, but I'm very keen to review other current methods you might suggest.
This might be a little open ended for you, but d3.js is very powerful. There might be some useful templates on the site, or you can build your own from the library.
If you limit yourself to shapes where the percentage can be easily converted into a new shape by varying one of the dimensions, then the display part can be covered by creating a second shape based on the first one, and filling in 100% of the second shape.
This obviously works best with simple shapes like squares, rectangles, circles, etc, where it is simple to convert "50% of the area" or "75% of the height" into manipulation of vector nodes.
However, things gets significantly more difficult if you want to support genuinely arbitrary custom shapes. One way to handle that would be to break up a complex "progress bar" into "progress pieces" (e.g. a thermometer bulb that represents 10% of total progress, then a simple bar for the remaining 90%).
As has been mentioned, D3 seems like it would meet your needs - here are some simple examples of what I think you are asking:
Changing the fill color of a distinct shape: http://jsfiddle.net/jsl6906/YCMb8/
Changing the 'fill amount' of a simple shape: http://jsfiddle.net/jsl6906/YCMb8/1/
I've just created my first WPF application (3 calculators inside 3 different tabs).
The entire application has been built using widths/margins/paddings as static values, since I originally didn't know that dynamic values can be used by just putting an asterix after the value.
The client has come back to me though and has asked me to increase the size of the app, that includes form fields, tabs, font-sizes, grids etc...
What would be the easiest (and/or quickest) way to do this? I'd hate to go value by value resizing every single element since there are quite a few.
I can provide code but there is lots of it and I'm not sure of how much help it would be.
Appreciate your help,
Marko
Put it all in one ViewBox, play with viewbox size to change the app size
Write an XSLT transform to take your XAML as input and spit out appropriate modified XAML, which you put back in your app.
Although there seem to be very few up to date references for OpenGL 3.x itself, the actual low level manipulation of OpenGL is relatively straight forward. However I am having serious trouble trying to even conceptualise how one would manipulate VBOs in order to render a dynamic world.
Obviously the immediate mode ways of old are non applicable, but from there where do I go? Do I write some kind of scene structure and then convert that to a set of vertices and stream that to the VBO, how would I store translation data? If so how would that look code wise?
Basically really unsure how to continue.
If your entire world is truly dynamic, you can use the GL_STREAM_DRAW_ARB usage flag and reset the data on each frame. Don't bother manipulating it, just try to stream as efficient as possible.
However, I assume that you have a scene that consists of multiple rigid objects that move relative to each other. In this case, use one VBO for each object and specify the GL_STATIC_DRAW_ARB usage flag. You can then set the modelview transform for each instance of an object and render them using one draw call per instance.
A rule of thumb (on the PC) is to issue not more than one draw call per MHz of your CPU. This is a crude estimate, but there's some truth to it. Don't worry about putting multiple independent objects into a single VBO or other performance tricks if you stay below this limit.
Short answer:
Use glMapBufferRange and only update the subrange that needs modification.
Long answer:
The trick is to map the already existing buffer with glMapBufferRange, and then only map the range you need. Given these assumptions:
Your geometry uses per-vertex animation morphing
The vertex count for models is constant during animation.
Then you can use glMapBufferRange to update only the changing parts, and leave the rest of the data alone. Full uploads using glBufferData are slow as a turtle, because they delete the old memory store and allocates a new one. That's in addition to uploading the new data. glMapBufferRange only lets you read/write existing data, it does no allocation or deallocation.
However, if you use skeleton animation, rather pass vertex transformations as 4x4 matrices per-vertex to the vertex shader, and do the calculations there. Per-vertex data is of course specified with glVertexAttribPointer.
Also, remember that you can read texture data in the vertex shader, and that OpenGL 3.1 introduced some new instance draw calls; glDrawArraysInstanced and glDrawElementsInstanced. Those combined can be used for instance-specific lookups. I.e you can do instance draw calls with the same geometry data bound, but send positions or whatever per-vertex data you need as textures or texture-arrays. This can save you from mixing and matching different vertex array data sets.
Imagine if you want to render 100 instances of the same model, but with different positions or color schemes. Or even texture maps.
Using VBOs doesn't mean you have to render your entire scene with only single draw call. You can still issue multiple draw calls, and set up different transformation matrices along the way.
For example, if you're using a scenegraph, each model in the scenegraph can correspond to a single draw call. In such a case, the easiest way to use VBOs is creating a separate VBO for each model.
As an optimization, you might be able to combine several models into a single VBO, then pass in non-zero offsets when making your draw calls; this plucks out the correct model from the VBO. It's also desirable to combine multiple draw calls into a single draw call, but that's not possible if they need to have independent transforms. (Actually it is possible in certain situations if you use instancing or vertex blending, but I suggest getting the basics out of the way first.)