One way: Use your ArrayList to draw the current curve as it is being drawn, but Use a BufferedImage to draw your completed curves You would do this on mouseReleased and would draw the current curve to the BufferedImage using the current color. You’ll also need to re-initialize your ArrayList of points after drawing to … Read more
I posted two solutions for a similar requirement here Basically you have two options. 1- Get a graphics object for the desktop and start drawing to it. The problem is if you need to start clearing what you have previously drawn etc. Point pt = Cursor.Position; // Get the mouse cursor in screen coordinates using … Read more
As simple as I can get it. You’ll have to prepend context.beginPath() and append context.stroke() yourself: ctx = document.getElementById(“c”).getContext(“2d”); ctx.beginPath(); canvas_arrow(ctx, 10, 30, 200, 150); canvas_arrow(ctx, 100, 200, 400, 50); canvas_arrow(ctx, 200, 30, 10, 150); canvas_arrow(ctx, 400, 200, 100, 50); ctx.stroke(); function canvas_arrow(context, fromx, fromy, tox, toy) { var headlen = 10; // length of … Read more
There are a few issues: You are using control points that are midpoints between the two points, resulting in line segments. You probably want to choose control points that smooth the curve. See http://spin.atomicobject.com/2014/05/28/ios-interpolating-points/. Here is a Swift 3 implementation of a simple smoothing algorithm, as well as Swift renditions of the above Hermite and … Read more
For a “cleaner solution” and in order to keep using the base Panel, you could simply use Reflection to implement the double buffering, by adding this code to the form that holds the panels in which you want to draw in typeof(Panel).InvokeMember(“DoubleBuffered”, BindingFlags.SetProperty | BindingFlags.Instance | BindingFlags.NonPublic, null, DrawingPanel, new object[] { true }); Where … Read more
Start with the first bitmap by putting it into an Image object Bitmap bitmap = (Bitmap)Image.FromFile(file); Save the bitmap to memory as tiff MemoryStream byteStream = new MemoryStream(); bitmap.Save(byteStream, ImageFormat.Tiff); Put Tiff into another Image object Image tiff = Image.FromStream(byteStream) Prepare encoders: var encoderInfo = ImageCodecInfo.GetImageEncoders().First(i => i.MimeType == “image/tiff”); EncoderParameters encoderParams = new EncoderParameters(2); … Read more
Google has open sourced its excellent PDF rendering engine – PDFium – that it wrote with Foxit Software. There is a C# nuget package called PdfiumViewer which gives a C# wrapper around PDFium and allows PDFs to be displayed and printed. I have used it and was very impressed with the quality of the rendering. … Read more
The way to do it is to create a DrawAction class which holds all the data needed for the things you want to draw: The Point data, the Pen or Brush etc. Then you create and manage a List<DrawAction> drawActions and then you have a choice: You either do all the drawing ‘live’ in the … Read more
I can’t believe no one has answered this yet! A rare occurrence on SO! 1 The question doesn’t quite make sense to me. But I’ll give it a stab. If you’re asking about direct drawing to a canvas (polygons, shading, text etc…) vs. loading a bitmap and blitting it onto the canvas that would depend … Read more
To hit test shapes you don’t need linear algebra. You can create GraphicsPath for your shapes and then using GraphicsPath.IsVisible method or GraphicsPath.IsOutlineVisible method perform hit-testing. To check if a point is in the area of your path, for example a filled shape, use IsVisible. To hit-test for lines or curves or empty shapes, you … Read more