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High performance plot control in WPF

I am doing some work for which I need to develop a control, it should be a simple graph that shows several points and two edges.
My problem is that I need to show up to 16k points, with an update rate of 30 Hz. Has anyone done something similar?, and has any advice?.
For example whether to inherit from FrameworkElement or Control (ItemsControl in this case). If the control inherits from FrameworkElememt it may have a better performance drawing the points in the OnRender method but I would miss the Templating feature that comes from inheriting from Control.
Or does there exist another control that can do this out there?
Thanks in advance for your time.

I ended up using InteropBitmap, it is the fatest bitmap rendering class from WPF.
It allows you to map the image that you want to paint (in memory) and then reder it as a Image. This was perfect as i needed to plot points on the screen.
I got great performance (almost 50Hz for 20k points), i also use PLINQ to update the points in memory.
check this article for more details...

Try and read about ZoomableCanvas. I believe it can solve your problem. You can render all the points as small rectangles/ellipses inside the ZoomableCanvas.

Any way to snap animated TranslateTransform to pixel grid?

Is there any way to snap animated TranslateTransform to pixel grid?
There is a very bad jittering, when moving text using animation. I guess it's because of subpixel positioning. I need to avoid this jittering. Suggest possible ways.

It sounds like you want TextOptions.TextHintingMode="Animated" in your XAML. See http://msdn.microsoft.com/en-us/library/system.windows.media.textoptions.texthintingmode(v=VS.95).aspx for more details.

Dave Relyea posted an article on how to implement a pixel snapping control in Silverlight. This is a control which listens to the LayoutUpdated event to perform pixel snapping on child elements. Perhaps this is what you're looking for; hopefully without too much modification :)

Why won't you render thit text to WritableBitmap like this:
WriteableBitmap wb = new WriteableBitmap(textToTranslate, null);
Then place this bitmap into Image and translate image instead?

What are you trying to do exactly? Do pixel snapping using drag'n'drop? If so, you just could call the method that does the translate if the coordinate is a multiple of a certain number.
A small example of what you are trying to do would also be helpful.

C# Load Bitmap into PictureBox - slow and blocks UI .. any alternatives?

I am loading 640x480 Bitmaps into a picture box one after the other. When I do that my UI gets blocked. For example, if I was typing something in a text box which is on the same form where my picture box is, I would not be able to see the key that pressed right away, because the bitmap loading makes the UI very slow ..
How would one handle that ? is there any way around it ?
Any sample code would be great.
Thanks

A Picturebox is actually a fairly 'heavy' control in what it provides; it may not be the appropriate thing to use here. You might consider a much simpler container control, or drawing on the surface of the form itself.
If you want to consider BackgroundWorker or any other threaded technique here, keep in mind that the drawing itself must happen on the UI thread; there's no way around that.
If the loading of the images from disk is the source of the latency, you might consider loading the images into an in-memory bitmap on another thread, then signaling somehow to indicate that a new item is ready to be drawn. You would then invalidate the drawing surface, and add the new item as appropriate.
Also; if you are doing any scaling to the images, doing this in the background thread would be appropriate - that way, the drawing code itself only needs to draw an unscaled rect; Using the GDI+ DrawUnscaled functionality to copy a bitmap to an area of the exact same size is actually quite fast.
To get into anything more specific, like actual code, I would want to see code for how you are doing it now. I'm not even sure you are 'drawing' the images in the first place, rather than simply setting Picture/Image properties.

Use background worker so the gui is not freezed (async invoke the image display).
http://www.dreamincode.net/forums/topic/112547-using-the-backgroundworker-in-c%23/
Your second request is a bit more tricky, I guess short answer would be not to rely on gdi+ if that's what you are doing be cause it's known to be slow. How exactly do you load the image into the imagebox?

Overlaying a 'dot' on to an image on click

I am trying to write a simple program that lets me overlay a dot on top of an image when the image is clicked. I can save the X and Y data back to my database but then I will want to be able to call that information back at a later date and overlay the dots again via code unlike the first time when the user had to click the image.
I got as far as capturing the X and Y of the click no problem but I am having trouble finding examples specifically for what I am trying to do. All of the examples online seem to be for saving the image with the added graphic but I do not need to do that as it will be the same image every time.
Once I can do this, I also need to work out a way that I can detect what area of the image has been clicked. The areas I need to mark out vary in shape and size so I need to try and work out a way to 'map' these areas and then cross reference with the co-ordinates of the users click (I assume that I may need to do some clever geometry stuff for that?)
If anyone has any suggestions of what subjects/classes/methods etc. to research for either of my queries, I would very grateful.
Thanks in advance

You can use the System.Drawing namespace to achieve this.
Create a control and override OnPaint and OnPaintBackground. Store your clicks in a List
In OnPaintBackground, draw the image using DrawImageUnscaled using the graphics object which is passed to you as a parameter.
In OnPaint, loop through your points array and call graphics.FillElipse or similar to draw a little dot.
Because this isnt a retained mode graphics system, you need to keep drawing these items so this may not suit a large number of dots. In that case, you can create an in memory bitmap and get a graphics drawing object using graphics.FromImage.

C# Custom Button

I'm attempting to write a custom button user control. I have run into a challenge when drawing the image.
Is there a simple way to draw the image accounting for the ImageAlign and TextImageRelation? (Kind of like StringFormat makes text aligning a breeze)
Or do I have to do all the aligning logic and stuff manually?
Thanks

What functionality are you trying to achieve? Perhaps it should instead inherit from the Button class (asssuming WinForms), and override appropiate methods. Depending on what you need to do, you will propably get much of the lower levels of functionality in the button for free, if you do this.
To get back to your question; No, if you need to draw stuff yourself, there is no magic easy way to determine where the individual pixels should go :-) One great helper in doing this, that you should be aware of, is the Graphics.DrawString method. It lets you measure the dimensions of a given text string when drawn on the control with the selected font and size.

I do not know of anything that does this stuff for you, but be aware of the ControlPaint class as that has a bunch of handy utility methods for painting controls.