I have a video playing of lines being drawn on the screen. Is it possible to create a pixel shader (for WPF) that turns newly colored pixels a certain color for N milliseconds?
That way, there can be some indication to the user to movement on the screen when the lines don't move often and the user isn't always looking at the screen.
You can use DirectShow. Its written in unmanaged code, so you need to use this wrapper DirectShow.NET in order to use it in your C# application which is running in managed environment (samples are included, even with EVR which stands for Enhanced video Renderer which means MUCH better video quality). And when you will be passing a control handle to wrapper method for setting the video output, you need a WinForms control, because only from them you can get your desired control handle. That WinForms control you can then host in your WPF application using the WindowsFormsHost control provided for such situations when you need to use some WinForms control(s) in a WPF application. Its just theory, so i dont know if its an ultimate solution for you.
BTW: The whole idea is based on fact, that DirectShow is just some query constructed from separated filters. Renderer is a filter (EVR, VMR-7, VMR-9). Sound player is a filter. And they are connected through their pins. Its like a diagram. Electronic schema or something like that. And you can put for example Grey scale filter in there. And voila, video output will be greyscale. There is a bunch of tutorials for that. And completed simple filters as well. Unfortunately, filters must be written in C++:(
PS: I never said its gonna be easy:D
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The app I'm writing involves buttons that have a slight noise filter texture, which can be any size. For a standard button I'd simply use resizableImageWithCapInsets: but due to the texture, this causes unusual artefacts to appear on the resulting button.
A solution I have in mind, is to use the Core Image monochrome filter combined with the random noise filter to add the noise texture to a plain image. In theory this works, and in practice this has been shown to work (One example here) but these are all in cases where the button size is known at the point of invoking the CI code.
What I'm looking to do, is use the appearance proxies, so across the app I can simply set the style of UIBarButtonItems for instance.
Is there a way I can apply these CI filters to the buttons through the appearance proxies or isn't this possible? Would something like a category on UIImage to add noise work? I'm not entirely sure at which point the appearance proxy would actually invoke that code.
Any help is appreciated
OK So I finally solved it but found out some stuff on the way.
It seems you can create a category on UIImage and use that in the appearance proxy. I created a category to add noise, and it seemed to partly work, but I couldn't get it looking how I wanted as it wasn't quite rendering properly, but in the process of coding this discovered another method
resizableImageWithCapInsets:resizingMode:
Because the texture I was dealing with was simply noise, it could be tiled, so rather than the image now being stretched, the centre of the image is instead tiled which gives me the appearance I needed :)
I am not a real designer and I would like to know if anyone have an idea how can I build the following visual :
The idea is to get 2 rings where inside I will draw secific number of pie represented as "Interactive shape or button". Base on the number of shape, they should cover the whole circle.
In addition to that, I need to be able to interact with each pie shape, and inside and oustide edge of those shape should be a perfect arc based on the circle diameter.
As I am not a perfect designer, how can I represent this visual ?
I was thinking of using a custom panel but then how to draw each panel shape in order that they gets perfect inside and ouside arc and offer interactivity with each of them ?
Thanks for your help
I would appreciate samples as well
Theres actually a Silverlight tutorial on making something exactly like this.
If you didnt want to use that, you could always do it in javascript. Here's an example using Rapheal js
I would recommend looking into WPF Geometry and how you can create custom controls (such as the Circular Gauge Custom Control over on CodeProject) using said Geometry.
I've never created a control quite like what your suggesting, but I would image you would define some form of area that can contain children and style it so that it forms the circular shape you want. Then, adding interactive regions should be as simple as adding controls to standard containers.
Here's a link to a "generic radial panel that can be used to host any items" which subclasses Panel.
we want to make application like silverlight showcase Mapview
where we can search by different category on left hand side panel or people can select country or region on map. can anyone suggest some sample or guidelines to implement this?
Thanks
Given the complexity and obvious expense, I would be really impressed if anything like that was released as a sample (Microsoft are you listening?). It requires a lot of data to drive it.
I have been involved in creating a Xaml World map from scratch (below) and that alone took nearly a day for a stylised polygon version (no fine detail)....
Quoting myself: "You import a map as a background image and use the pen tool to dot-to-dot trace around the country. Combine all those path segments into a single path. Then create a separate poly-path for each state (close them to allow for a fill)."
Once you create them you can name the individual country polygons and connect up mouse logic to make them all glow on mouse over or change colour on press etc.
Basically all the other stuff on that screen are user controls and custom controls. Work out the behaviour you want and create controls to suit your own needs.
Given a WPF Application running full screen, a fair amount of controls some of which will animate from off screen to center. I was wondering if there are any special ways to save on the amount of time required to optimize an application for different screen resolutions?
For example, using Blend I've setup some text, which is originally off screen to scroll into view. Now in design mode the start positions are static. If resolution changes the start positions will obviously not be correct.
So I guess to correct this, during app startup. I need to
Check resolution
Move the text box to the desired start location
Adjust the storyboard as required, so the frames all have correct co-ordinates depending on the res of the screen.
I don't mind doing all of this, but if there is an easier way please share!
Thanks
In WPF layout of controls should be made in such way, that when size of window or content changes, controls automaticaly resize/reposition themselves to reflect this change.
This is highly affected how your layout is made, especialy by using specific panels, that do layout of their child elements.
This is also made obvious by using device-independent units for sizes, margins and sometimes positions of controls. And also allows different kind of zooming and scaling of whole UI without any need to redesign the whole thing.
If you are trying to position your controls absolutely, either by using Canvas panel or margins, your are doing it totaly wrong.
In WPF, scene is measured in abstract units, not pixels, and controls are freely scaled. There should be no problems to center something, or what?
I'm working on SEM image processing application, written in WPF. I have an image display control, derived from Canvas, which displays image & overlays using DrawingVisuals (one for each "layer"). It also implements Zoom & Pan using scale & translate transform, applied on DrawingVisuals.
When I zoom in the image to see individual pixels, they are displayed smooth, evidently using bilinear filtering to stretch the bitmap (no surprise, as WPF is rendered through Direct3D). However, for my use case, I would rather see individual pixels as sharp boxes, as usual in any image editor like Photoshop. That's why user of my app zooms the image -> to be able to operate on pixel level.
Is there such option in WPF (other than manually stretching the bitmap before displaying it)? I was not able to find anything.
thanks in advance,
Zbynek Vrastil
Czech Republic
Finally found an answer, with some help from Experts Exchange. Class RenderOptions defines attached property BitmapScalingMode, which can be set to NearestNeighbor. So,
RenderOptions.SetBitmapScalingMode(imageDisplay, BitmapScalingMode.NearestNeighbor);
does the trick.
Zbynek Vrastil
Hate to put a dampener on things, but if NearestNeighbor works like GDI+, then this will give you a limited success. As you increase magnification in areas of high contrast you might not get the desired results. In GDI+ you find blacks becoming blue, and whites becoming red - again I stress in areas of high contrast! If this isn't the case in WPF, think yourself lucky!
Perhaps a WCF developer could confirm that?
I've found that there are more options to consider, but I can only speak for the GDI+ Graphics class, which might be useful to someone.
Graphics graph = e.Graphics;
graph.InterpolationMode = InterpolationMode.NearestNeighbor;
graph.CompositingQuality = CompositingQuality.AssumeLinear;
graph.SmoothingMode = SmoothingMode.None;
This works for me. I think the SmoothingMode is the trick. Hope this helps someone else out there.