Tag Archives: geometry

Use a custom dash pattern with WPF and XAML in C#

My post Render dashed lines in a WPF program using C# explains how a WPF program can use C# code to render lines with a custom dash pattern onto a bitmap. This post shows how to use a custom dash … Continue reading

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Draw text on a circle in C#

This example uses some of the techniques described in the post Measure character positions when drawing long strings in C# to draw text on a circle. The previous post explains how to determine where the characters in a string will … Continue reading

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Calculate where a line segment and an ellipse intersect in C#

Finding the intersection between a line segment and an ellipse requires a lot of mathematics. It’s not particularly hard mathematics, but if you’d rather skip it, you can use the following links to jump to the other parts of this … Continue reading

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Generate random polygons in C#

I needed a method for generating random polygons for a graphics program and the following code shows the result. // Make random polygons inside the bounding rectangle. private static Random rand = new Random(); public static PointF[] MakeRandomPolygon( int num_vertices, … Continue reading

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Make silly eyes that track the mouse without flicker in C#

The example Make silly eyes that track the mouse in C# shows how to make eyes track the mouse position, but if you look closely as that program runs you will see a noticeable flicker. The solution is quite simple: … Continue reading

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Make silly eyes that track the mouse in C#

This example uses a Timer named tmrTick to track the mouse. Its Tick event handler, which is shown in the following code, updates the eyes. // The previous mouse location. private Point OldMousePos = new Point(-1, -1); // See if … Continue reading

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Make a 3D globe in WPF and C#

This example shows how you can draw a 3D globe. More generally it shows how you can make a three-dimensional textured sphere in WPF. The example Draw smooth spheres using WPF and C# shows how to make smooth colored spheres. … Continue reading

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Draw an interesting pattern of circles in C#

This program simply draws an interesting arrangement of circles. I wrote it because a C# Helper post was mentioned on this Factal [sic] Patterns & Art page. This program uses the following code to draw the circles and connecting lines. … Continue reading

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Circumscribe three tangent circles in C#

The first step in the example Draw an Apollonian gasket in C# is to circumscribe three circles that all meet tangentially with a larger circle as shown in this example. In the previous example I glossed over how the program … Continue reading

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Find the shortest distance between a point and a line segment in C#

This example treats the segment as parameterized vector where the parameter t varies from 0 to 1. It finds the value of t that minimizes the distance from the point to the line. If t is between 0.0 and 1.0, … Continue reading

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