I'm not having much success trying to convert a simple G.D.I.+ effect to use the new system. I have followed @BoltBait 's tutorial (Many thanks) but still have many basic questions. I will keep these questions in this one thread which may be of use for others learning the new system. Hopefully they have relatively easy answers (well, the first three) and the new system will become clearer to me in time. If there is already a reference of simple code snippets for common uses, please direct me to it. Many thanks in advance. 1. How to get the Primary and Secondary colors? Previously: ColorBgra PC = (ColorBgra)EnvironmentParameters.PrimaryColor; ----------------------- 2. How to get pixel values from the src surface? Previously: ColorBgra srcColor = src.GetBilinearSampleWrapped(Xcoord, Ycoord);//or clamped etc. Do I need to somehow lock and import the src surface? ???? What does that look like as code please? (straight over my head 😀). ------------------------ 3. The correct new way to change the destination background colour or image? Previously I would use something like: dst.CopySurface(src, rect.Location, rect);// quickly copies Src to Dst if (TransparentBackground){ColorBgra klear = ColorBgra.Transparent; dst.Clear(rect, klear);} ----------------------- 4. Can GpuDrawingEffects be added to a BitmapEffect and does this need to done in a separate method? ... say you wanted to mess with the colour of the Src pixel by pixel then 'draw' something on top using Direct2D. If so how is this done. ----------------------- 5. Single-threaded effects; Previously 'OnSetRenderInfo' could be used for single threaded calculations to set 'global' variables, which could then be used in 'Render'. Is this approach still possible and if not how should this be done? ---------------------- 6. From @BoltBait's tutorial I can draw ellipses and fill them with a SolidColorBrush but cannot fathom the values needed in the RadialGradientBrush. Actually a more advanced tutorial on using paths and various types of brushes could be very useful! The MS tutorials seem to assume a much deeper knowledge of C# and C++ than I have and I'm not sure how relevant they are within a Pdn effect. Eg. https://learn.microsoft.com/en-us/windows/win32/direct2d/how-to-create-a-radial-gradient-brush The quotes are Rick's from E.E.R.'s Box Outlining thread. ( I don't even know how to use quotes from different threads in this forum! 🙄)

This looks very convertible to a GpuDrawingEffect. Some notes on the conversion: EnvironmentParameters is now just Environment. To get the primary/secondary color, use Environment.PrimaryColor/SecondaryColor. The way this works will be slightly different in 5.1 but it will be the same property (your existing plugin DLL won't break, but you'll need to make changes if you recompile). The OnDraw() method is called once. You won't have to worry about the "roi" or any of that. Your drawing commands will be recorded into something called a command list, and then PDN will do the work to render it into each tile that gets rendered. Worth noting is that a command list is a type of image in Direct2D. Other types of images include bitmaps and effects. So think of an image as an abstraction for something that has a bounding rectangle and which produces pixels within that rectangle. So any time you see a parameter or property of type IDeviceImage, think of terms of bitmap, effect, and command list. You can create your own command lists. I'm not seeing a need for it in this particular effect though. Pens do not exist in Direct2D, but brushes do. A pen is basically just a brush, a stroke width, and a stroke style all in one object. Most of the drawing commands, e.g. DrawRectangle(), will take a brush, stroke width, and stroke style. A stroke style is created with the IDirect2DFactory::CreateStrokeStyle() method. The only thing I see that I don't have in the new system is GetBilinearSampleWrapped(). For now, just access the pixels with the RegionPtr indexer and use % to wrap around. I can provide this method's code and you can copy+paste it, or if it's a popular enough request I can find a way to provide something built-in. You can still access the source layer as a regular CPU-side bitmap. First, use Environment.GetSourceBitmapBgra32() which returns an IEffectInputBitmap<ColorBgra32> Next, call the Lock method to get an IBitmapLock<ColorBgra32> From the lock object, use AsRegionPtr() to get a RegionPtr<ColorBgra32>. This gives faster, simpler access to the bitmap's contents. Like this: using IEffectInputBitmap<ColorBgra32> sourceBitmap = Environment.GetSourceBitmapBgra32(); using IBitmapLock<ColorBgra32> sourceLock = sourceBitmap.Lock(new RectInt32(0, 0, Environment.Document.Size)); RegionPtr<ColorBgra32> sourceRegion = sourceLock.AsRegionPtr(); ... ColorBgra32 color = sourceRegion[x, y]; However, note that if you're using ColorBgra32, the colors will not be linearized by default. So, probably better to use ColorRgba128Float instead of ColorBgra32 in the code above. There are still some growing pains here -- the underlying systems are stable, but our "culture" and our code samples are still migrating. You can use deviceContext.Clear(). It can be called without a color, which will clear as transparent. Or you can do something like, deviceContext.Clear(LinearColors.Red) or any ColorRgba128Float of your choosing. ColorRgba128Float takes the R, G, B, A as floats that should be in the range [0, 1]. You can also create a ColorBgra32 and there's an implicit cast to ColorRgba128Float. So ColorRgba128Float c = ColorBgra32.FromBgra(128, 128, 255, 255) would auto-convert to [ 0.502, 0.502, 1.0, 1.0 ] Note that in your effect you will be working in linear gamma space. Previously you'd have been in companded (sRGB) gamma space. This becomes very important when pulling colors off of a color wheel control, or when reading the source bitmap. This will make more sense in PDN 5.1, as the color management facilities are fully baked. For now, @BoltBait has a lot of examples he can show where he's converting between ColorBgra32, SrgbColorA, LinearColorA, and ColorRgba128Float. Anyway that's enough for now, see how far you get and then ask more questions ...