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Dynamical rectangle plot c# wpf

I want to create a plot that dynamically displays active elements as rectangles. I have achieved a first version that is actually ok using OxyPlot.Annotations.RectangleAnnotation which I add to myPlotModel.Annotations, you can see it in the image hereafter:
Example of wanted display
The thing is that after a while, the amount of drawn rectangles make the update not smooth as I update the shown timewindow (which is set to 15 seconds). I have already set a maximum of drawn elements that suffice to cover the displayed window (i.e. the rectangles get removed as they are too far in the past), but the rendering is still jerky. I draw the rectangles by allocating them to an equal fraction of the Y-axis, that is the third one from the top gets:
rowNumber= 3.0
minimumY = maximalY - maximalY / totalElements * rowNumber
maximumY = maximalY - maximalY / totalElements * (rowNumber + 1.0)
And the Y-axis is hidden.
My question:
Is there a smarter way of creating such a display that would be less computationally heavy, and therefore allow a smoother update? I do not have to stick to OxyPlot, it is simply the easiest way that I found to obtain what I wanted.
Thanks for your answers!

Technically, the answer to your question is "Yes".
There are a number of ways to do this.
You could have a vertical itemscontrol that had an itemscontrol in it's template. That could have a canvas as it's itemspresenter and you could bind canvas.top and canvas.left to properties in it's content. Template each into a rectangle and bind height and width.
And of course do something about the scale on the bottom and the column of activity labels or whatever you want to call them there.
Unless you're using an absolutely ancient machine, that'd just fly.
It's quite a lot of work but it would probably be quicker to write that than to search through a load of alternative packages and decide which was optimal.

How to move a rectangle that's used as a Meter bar in unity

I want to make a vertical meter for values between 2 ranges.
so what i tried so far, was to make a frame, and under it put a mask, and under that a rectangle.
with the idea, of lowering/increasing the rectangle Y position to make it seems to move.
rect.position = new Vector3(rect.position.x, (rect.position.y - rect.sizeDelta.y));
so i did that, to first lower by it's height, so the bar will seem empty.
but it doesn't work right, the position depends on the screen size, and the rect Y end up way lower then exactly his height.
so, tl;dr, i want a bar that i can give a value between 0-100 and it will fill it according to that.
and i might have gone wrong about it.
so, any suggestions would be appreciated.
edit:
Add picture to show what i want the bar to look like:

Well i feel kinda dumb
I didn't realize how customizable the Slider control is.
I removed it's handle, unchecked interactble and removed it's background, and now i can give it a value between 0-100 and it works exactly as i wanted.
thanks Mathias Siig Nørregaard for referencing me to the video link that opened my eyes.

c# Draw Image (Scaled) to Graphics, does not interpolate correctly. Fixes?

I have an image that is 1px wide, and some height. I need to draw this image across the entire width of the control on it's OnPaint event. I get it to draw, however not correctly. It seems like when it stretches it, it doesn't actually fill all the pixels. As if the interpolation is off. Is there a way to say "stop being smart, just draw it already"? I see no InterpolationMode.Off or .None in the options for the graphics object.
I can confirm I actually drawing the full width by using an image of width X where X is the same width as the control. Then when it draws, it covers the full area as normal. However this control is resized all the time, and to save memory and all that jazz using 1px wide images is quite normal in the web world. This is for a desktop C# application though. Any ideas on how to fix this?

Ok I figured out the magic keywords:
g.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.Half;
This coupled with setting the Interpolation Mode to NearestNeighbour allows for a full block to be drawn.
Without setting the Interpolation mode, you get weird blending (expected).
Without setting the PixelOffsetMode, the nearest neighbour algorithm has no neighbour to compare to on a blank paint and therefore only draws half the image, for half the width. Setting it to offset half, moves everything over by -0.5px, and allows this algorithm to work for block textures.

InterpolationMode.NearestNeighbor is what you want to use in this case.

c# GDI+ rendering problem

Not sure if anyone else has seen this, but I am rendering a custom control that has zoom functionality. Lets say for simplicity sake that I am just drawing one rectangle with border width = 1 in the viewable area of the control. When I alter the zoom (graphics.ScaleTransform()) the rectangle's borders take on different sizes (sometimes the same, mostly different). This makes my control look ugly when the user zooms in or out. I'm sure it's something really simple but i'm struggling to fix it. Any help appreciated!
thanks,
Thornza

Yes, the pen width gets scaled as well. Create a pen with a Width = 0. That will always be one pixel wide, regardless of the ScaleTransform.

How do I draw double height text using Graphics.DrawString?

I am trying to emulate a POS printer with System.Drawing and one of the functions I need is to draw text at double height. Any idea how I can do this using .Net's Graphics class?
Do I need to draw the text twice as large and condense it or draw normal size and then stretch? Both seem like messy options but is there an alternative?

Look at the transformation matrix on the Graphics object - you can control horizontal and vertical scaling independently.

Use a ScaleTransform and only scale up the y.