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Posted 1 Jul 2008

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C# Avionic Instrument Controls

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4.91/5 (70 votes)
17 Jul 2008CPOL2 min read
The aim of this C# project is to purpose six aircraft cockpit instruments usable in forms as any other C# controls.
Image 1


The aim of this C# project is to purpose six aircraft cockpit instruments usable in forms as any other C# controls and to define a generic instrument class in order to design any kind of dashboard instruments.


The controls are built with bitmaps which are rotated, translated or scaled before to be displayed. The basic methods for rotate, translate and scale images are defined in the mother class. Each control then uses its dedicated parameters (related to a physical signification) in order to manipulates the images.

Aircraft Instruments

  • Air speed indicator: airspeed (kts)
  • Attitude Indicator: pitch (deg), roll (deg)
  • Altimeter: altitude (ft)
  • Turn Coordinator: turn rate (deg/min)
  • Vertical speed indicator: vertical speed (ft/min)
  • Heading indicator: heading (deg)

Details of the Key Functions

This section explains in detail the implementation of the basic functions defined in the InstrumentControl class.

Rotate Image


The rotation of the image is divided in two main parts:

First, the rotation of the PaintEventArgs coordinate system around the upper left corner of the drawing area.

Second, the drawing of the image corrected by translation offset in order to display the image as if it has turned around a user defined point.


Let’s see step by step:

Step 0: Initial situation.


Step 1: Rotate the PaintEventArgs coordinate system around the left upper corner of the paint area.


Corresponding code sample:

// Rotate image support
pe.Graphics.RotateTransform((float)(alpha * 180 / Math.PI));

Step 2: Draw the image and apply the translation correction.


Corresponding code sample:

// Display image
pe.Graphics.DrawImage(img, (ptImg.X + deltaX) * scaleFactor, (ptImg.Y + deltaY) * 
	scaleFactor, img.Width * scaleFactor, img.Height * scaleFactor);

Step 3 (Final step): Put the PainEventArgs coordinate system as found.


Corresponding code sample:

// Put image support as found
pe.Graphics.RotateTransform((float)(-alpha * 180 / Math.PI));

The key point in those operations is the calculation of the translation correction coefficients.

The next figure explains the geometrics considerations:


G0 is the user defined rotation center
G1 is the G0 position after the step 1.

The aim of this section is to identify the G1G0 translation and apply the corresponding offset in order to draw the rotation point as if it has not moved.

Then we work with the geometrics definitions:

a. AvionicsControlDemo_RotationCalcs1.JPG
b. AvionicsControlDemo_RotationCalcs2.JPG
c. AvionicsControlDemo_RotationCalcs3.JPG
d. AvionicsControlDemo_RotationCalcs4.JPG

As a result, the offset coefficients are:


The corresponding code sample is as follows:

// Computed offset
deltaX = (float)(d * (Math.Cos(alpha - beta) - Math.Cos(alpha)* 
	Math.Cos(alpha + beta) - Math.Sin(alpha) * Math.Sin(alpha+ beta)));
deltaY = (float)(d * (Math.Sin(beta - alpha) + Math.Sin(alpha)* 
	Math.Cos(alpha + beta) - Math.Cos(alpha) * Math.Sin(alpha + beta)));


  • "pe": The paint area event where the image will be displayed
  • "img": The image to display
  • "alpha": The angle of rotation in radian
  • "ptImg": The location of the left upper corner of the image to display in the paint area in nominal situation
  • "ptRot": The location of the rotation point in the paint area
  • "scaleFactor": Multiplication factor on the display image



This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

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Comments and Discussions

QuestionNice controls Pin
bone krusher17-Oct-21 19:55
Memberbone krusher17-Oct-21 19:55 
QuestionI got an error when try to add it to my project.. Pin
Member 1312901818-Oct-17 5:45
MemberMember 1312901818-Oct-17 5:45 
AnswerRe: I got an error when try to add it to my project.. Pin
Member 140462382-Apr-19 23:48
MemberMember 140462382-Apr-19 23:48 
QuestionExcellent Pin
Pablo Odysseus8-Jun-16 3:34
MemberPablo Odysseus8-Jun-16 3:34 
AnswerRe: Excellent Pin
Member 140462382-Apr-19 23:51
MemberMember 140462382-Apr-19 23:51 
Questioni love you my bro Pin
armanfx28-Mar-16 5:49
Memberarmanfx28-Mar-16 5:49 
QuestionHow d I add this toolbox to my project? there is no .dll file. Pin
Member 118586067-Jan-16 3:54
MemberMember 118586067-Jan-16 3:54 
QuestionUpgraded altimeter Pin
Redgum20-Nov-14 10:58
professionalRedgum20-Nov-14 10:58 
Question!Need Help in Creating a VB.NET Avionics Intsrument Control Pin
schematicsman7-Jan-14 1:30
Memberschematicsman7-Jan-14 1:30 
QuestionHow to use these controls for an existing project PinPopular
Member 1016504020-Jul-13 11:15
MemberMember 1016504020-Jul-13 11:15 
QuestionHow to add these controls to my project? Pin
Haytham.Breaka18-Apr-13 15:34
MemberHaytham.Breaka18-Apr-13 15:34 
GeneralVery very nice Code Project sample... Pin
Destiny77718-Sep-12 8:35
MemberDestiny77718-Sep-12 8:35 
GeneralRe: Very very nice Code Project sample... Pin
Member 140462382-Apr-19 23:57
MemberMember 140462382-Apr-19 23:57 
QuestionAide Pin
bbjodel27-Jun-12 5:53
Memberbbjodel27-Jun-12 5:53 
QuestionVery nice controls Pin
Mike Hankey15-Apr-12 0:30
professionalMike Hankey15-Apr-12 0:30 
QuestionImport to VB.Net Pin
JTmetoo28-Aug-11 9:06
MemberJTmetoo28-Aug-11 9:06 
QuestionGreat Job Pin
Lamar Seifuddin29-Jul-11 21:36
MemberLamar Seifuddin29-Jul-11 21:36 
GeneralRe: Great Job Pin
Destiny77718-Sep-12 8:42
MemberDestiny77718-Sep-12 8:42 
QuestionC# avionic controls Pin
JPC0624020-Jun-11 3:31
MemberJPC0624020-Jun-11 3:31 
Generalthank you Pin
yardloun4-Apr-11 4:56
Memberyardloun4-Apr-11 4:56 
GeneralMy vote of 5 Pin
YEBM Knight8-Feb-11 3:14
MemberYEBM Knight8-Feb-11 3:14 
GeneralGreat work - I am using these with the AR Drone Pin
shobley17-Oct-10 6:52
Membershobley17-Oct-10 6:52 
GeneralRe: Great work - I am using these with the AR Drone Pin
Destiny77718-Sep-12 8:43
MemberDestiny77718-Sep-12 8:43 
Generali love the control I hope Pin
Jayson Ragasa16-May-10 2:23
MemberJayson Ragasa16-May-10 2:23 
GeneralWell done. Pin
Serhat20-Apr-10 20:47
MemberSerhat20-Apr-10 20:47 

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