Tag Archives: scale

Let the user zoom on a picture and draw in C#

The example Let the user zoom on a picture in C# allows the user to zoom in on a picture and draw on it. Unfortunately, it doesn’t handle the drawing properly when the image is scaled. It doesn’t scale the … Continue reading

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Use the mouse wheel to scale an image in C#

This example lets you use the mouse wheel to zoom in and out on an image. To use the mouse wheel, the program needs to catch the MouseWheel event. Unfortunately that event isn’t listed in the Form Designer so you … Continue reading

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Drag a map to scroll in C#

This example shows how you can allow a user to drag a map to scroll to hidden parts of it. Scroll bars provide a simple method for allowing the user to view parts of a map that don’t fit on … Continue reading

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Define map hotspots in C#

The example Display a scalable map with hotspots in C# uses a list of hotspots defined by the following code. // The hotspots. private List Hotspots = new List(); … // Prepare the map for first viewing. private void Form1_Load(object … Continue reading

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Display a scalable map with hotspots in C#

Making a scalable map with hotspots is surprisingly easy, although getting the details right is a bit tricky. The program displays a map at several different scales. If the map won’t fit on the form at the current scale, it … Continue reading

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Map drawing coordinates without distortion in C#

The post Easily map drawing coordinates in C# lets you easily map a rectangle in drawing coordinates to a rectangle in device coordinates. Often, however, you’ll want to ensure that the drawing area isn’t distorted. In other words, you don’t … Continue reading

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Easily map drawing coordinates in C#

The example Map points between coordinate systems in C# shows several ways you can map drawing coordinates to screen coordinates. They all work but these sorts of coordinate conversions are really common if you’re doing more advanced graphics so I … Continue reading

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Draw round circles in scaled coordinate systems in C#

In other posts I explain how you can use transformations to draw objects in a coordinate system other than the one provided “natively” by a PictureBox, Bitmap, and other objects that support drawing. Basically a transformation (represented by a Matrix … Continue reading

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Let the user zoom on a picture in C#

Important: This example does not handle new drawings correctly if you have scaled the image. Read this one to learn how it works and then see the new post Let the user zoom on a picture and draw in C#. … Continue reading

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Map points between coordinate systems in C#

This example shows how you can easily map points between different coordinate systems. The Graphics object provides transformations that let you scale, translate, rotate, skew, and otherwise transform graphics as you draw them. One important use of these transformations is … Continue reading

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