The pixel-shader stage (PS) enables rich shading techniques such as per-pixel lighting and post-processing. A pixel shader is a program that combines constant variables, texture data, interpolated per-vertex values, and other data to produce per-pixel outputs. The rasterizer stage invokes a pixel shader once for each pixel covered by a primitive, however, it is possible to specify a NULL shader to avoid running a shader.
When multisampling a texture, a pixel shader is invoked once per-covered pixel while a depth/stencil test occurs for each covered multisample. Samples that pass the depth/stencil test are updated with the pixel shader output color.
The pixel shader intrinsic functions produce or use derivatives of quantities with respect to screen space x and y. The most common use for derivatives is to compute level-of-detail calculations for texture sampling and in the case of anisotropic filtering, selecting samples along the axis of anisotropy. Typically, a hardware implementation runs a pixel shader on multiple pixels (for example a 2x2 grid) simultaneously, so that derivatives of quantities computed in the pixel shader can be reasonably approximated as deltas of the values at the same point of execution in adjacent pixels.
Pixel shader input data includes vertex attributes (that can be interpolated with or without perspective correction) or can be treated as per-primitive constants. Pixel shader inputs are interpolated from the vertex attributes of the primitive being rasterized, based on the interpolation mode declared. If a primitive gets clipped before rasterization, the interpolation mode is honored during the clipping process as well.
Vertex attributes are interpolated (or evaluated) at pixel shader center locations. Pixel shader attribute interpolation modes are declared in an input register declaration, on a per-element basis in either an argument or an input structure. Attributes can be interpolated linearly, or with centroid sampling. Centroid evaluation is relevant only during multisampling to cover cases where a pixel is covered by a primitive but a pixel center may not be; centroid evaluation occurs as close as possible to the (non-covered) pixel center.
Inputs may also be declared with a system-value semantic, which marks a parameter that is consumed by other pipeline stages. For instance, a pixel position should be marked with the SV_Position semantic. The IA stage can produce one scalar for a pixel shader (using SV_PrimitiveID); the rasterizer stage can also generate one scalar for a pixel shader (using SV_IsFrontFace).
A pixel shader can output up to 8, 32-bit, 4-component colors, or no color if the pixel is discarded. Pixel shader output register components must be declared before they can be used; each register is allowed a distinct output-write mask.
Use the depth-write-enable state (in the output-merger stage) to control whether depth data gets written to a depth buffer (or use the discard instruction to discard data for that pixel). A pixel shader can also output an optional 32-bit, 1-component, floating-point, depth value for depth testing (using the SV_Depth semantic). The depth value is output in the oDepth register, and replaces the interpolated depth value for depth testing (assuming depth testing is enabled). There is no way to dynamically change between using fixed-function depth or shader oDepth.
Explore some of the sample code hosted on the Windows Terminal repo, including Pixel Shader .hlsl samples, an EchoCon ConPTY sample Win32 pseudo console, a GUIConsole sample WPF console targeting .NET, a MiniTerm sample using basic PTY API calls, and a ReadConsoleInputStream demo for monitoring of console events while streaming character input.
Windows Terminal allows users to provide a pixel shader, applied to the terminal by adding the experimental.pixelShaderPath property to a profile in your settings.json file. Pixel shaders are written in a language called HLSL, a C-like language with some restrictions.
GUIConsole.ConPTY: a .NET Standard 2.0 library that handles the creation of the console and enables pseudoconsole behavior. The Terminal.cs file contains the publicly visible pieces that the WPF application will interact with. Terminal.cs exposes two things that allow reading from, and writing to, the console:
Demonstration of asynchronous monitoring of console events (like mouse, menu, focus, buffer/viewport resize) while simultaneously streaming the character input view from the console. A particularly useful feature when working with VT100 streams and ConPTY.
I have an old class library project that was building fine in a previous version of Visual Studio (2017 IIRC). The project contains an HLSL-based pixel shader that generates a radial color picker. I have just ported it to VS2022 and it is no longer building telling me that it cannot find a build task. Here is the error message:
The ShaderBuildTask MsBuild task assembly that one can see used and talked about in various places on the Internet is dated more than 10 years ago and was written in C++ for an x86 processor. It also depends on files that may not be there or cannot be loaded easily today (DirectX9, etc.).
This assembly contains only one task wich is PixelShaderCompile. Its role is to take .fx files ("effect files") from a project (BTW not necessarily a C# project), compile them as .ps files (using the D3DXCompileShader function or similar) and add them to the project as resources.
This work can be replaced by the Windows SDK's Effect Compiler tool (fxc.exe) and the MsBuild Exec task. For example this task will compile all .fx files in the project as .ps file, just like PixelShaderCompile does:
Am I right with the assumption, that on Windows the .fx will compile for HLSL and on Linux/Mac for GLSL? I noticed, that the MonoGame.ContentPipeline compiles with DX_9 but when I do start the .exe it compiles with OpenGL. (Because I target .netcore3.0, instead of .NET4.whatever)
The tree gets drawn always at the same position, kinda ignoring the ViewMatrix. However, without the effect the ViewMatrix kicks in and the tree gets drawn in relation to the Cameras ViewMatrix. Why is that?
So i altered it really quick to demonstrate moving everything via a world matrix
Or by adding to the vertice positions directly in the shader. It does some stuff to clip in the pixel shader to
It has two shaders the Game2_Alterposition class ( look to the update method ) and the similarly named altered position shader is the one to look at ( the vertex shader ).
If you want to see something that is useful and done on a shader just under that idea. This basically demonstrates scrolling textures in place while also alphablending and shading a texture against a second masking texture that makes a cool effect.
Maybe this might help to get a better idea of what spritebatch is doing.
In this post i bypass spritebatch altogether to just draw with quads.
but the effect is just like you would see with spritebatch,
It is not always possible for PIX to successfully take a GPU capture if a game is calling Direct3D 12 in invalid ways. We make a best effort to be robust even in the case of incorrect usage patterns, but this is inevitably sometimes a case of garbage in, garbage out. If you are having difficulty taking GPU captures, try using the D3D12 Debug Layer and GPU-Based Validation to find and fix any bad API calls.
Windows GPU captures are not in general portable across different GPU hardware and driver versions. In most cases a capture taken on one machine will play back correctly on other similar GPUs from the same hardware family, and captures of some games may even work across GPUs from entirely different manufacturers, but it is also possible that something as trivial as a driver upgrade could break compatibility with older captures. We can only guarantee playback will succeed when the GPU and driver are exactly the same, so PIX will warn before starting analysis if there is not a perfect match. Proceed past this at your own risk!
PIX has limited support for multiple GPUs. It will always play back GPU captures on a single adapter, regardless of how many adapters the application used. PIX allows you to select the playback adapter from a drop-down in the PIX toolbar. PIX will attempt to auto-select the playback adapter if the application used only one adapter.
When you first load a GPU capture, data is loaded and parsed but the API calls are not yet actually played back on your GPU. Not all parts of PIX are fully functional while in this state. To enable complete functionality you must start analysis, which instructs PIX to create a Direct3D 12 device and play back the capture in the various ways necessary to extract information. The analysis Start button is found in the PIX toolbar:
The event list can be filtered, optionally using regular expressions. By default it only shows events that resulted in actual rendering work for the GPU hardware, as opposed to simply preparing state for use by later operations. To include non-GPU events, click the button labelled !G.
More information about each event, such as the full set of API call parameters, is available in the Event Details view. This is not included in the default PIX layout, but can be accessed via the Views button in the upper right corner of the main PIX window.
The Collect Timing Data button (top right of the Events view) instructs PIX to replay the captured API calls a number of times, measuring how long each operation takes to execute on the GPU. Results from more than one replay are averaged to reduce measurement noise.
Because GPUs are massively parallel and deeply pipelined, it is common for more than one piece of work to be executing at the same time, and for adjacent operations to overlap. PIX measures time in two different ways that can offer insight into the parallel execution model of the hardware:
The Timeline view displays one or more lanes showing the timing of each GPU operation. There is a separate lane containing EOP Duration data for each queue (graphics, compute, or copy) used by the game, plus a single lane showing Execution Duration data (where available) combined across all the queues.
b1e95dc632