slang.git/examples/model-viewer/shaders.slang, branch master

Improve documentation and example formatting consistency (#4299)

2024-06-07T15:47:17+00:00

* Improve doc and example consistency Improve consistency of formatting in example shaders and remove trailing spaces in documentation files. Fix minor typos.

Update gfx back-ends to handle static specialization (#1826)

2021-04-29T22:27:24+00:00

* Update gfx back-ends to handle static specialization The main goal here is to make the D3D11, D3D12 and Vulkan back-ends support static specialization of interface types in the case where the data for the type won't "fit" in the pre-allocated space for existential values. This includes all cases where the concrete type being specialized to has resources/samplers/etc., as well as any cases where its ordinary/uniform data exceeds the space available. (Note that the CPU and CUDA targets don't need this work since they can (in theory) support arbitrary-size data in the fixed-size existential payload by using pointer indirection. Actually supporting indirection in those cases should be a distinct change) The Slang compiler already performs layout for programs that have this kind of data that doesn't "fit," and it lays them out using an idea of "pending" type layouts. Basically, a type that contains some amount of specialized interface-type fields will produce both a "primary" type layout that just covers the data for the unspecialized case, as well as "pending" type layout that describes the layout for all the extra data needed by specialization. When laying out a `ConstantBuffer` or `ParameterBlocK` ("CB" or "PB"), the front-end will try to place as much of that "pending" data into the layout of the buffer/block itself as is possible. That means that both CBs and PBs will be able to allocate trailing bytes for any ordinary data in the "pending" layout. PBs will be able to allocate any trailing resources/samplers into their layout, but for CBs they will spill out to be part of the pending layout for the buffer itself. In order for the back-ends to properly handle pending data, they need to *either* assume the exact layout rules used by the front-end and try to reproduce them (e.g., by iterating over binding ranges and sub-objects in the exact same order that front-end layout would enumerate them), *or* they need to respect the reflection information produced by the front-end. This change takes the latter approach, trying to make only minimal assumptions about the layout rules being used. This choice is motivated by wanting to decouple the `gfx` implementation from the compiler front-end, especially insofar as this work has made me question whether the current layout rules are the best ones possible. A common theme across all the implementations is to have a fixed-size type that can represent "binding offsets" for the chosen back-end. The offset type has fields that depend on the API-specific way bindings are indexed; e.g., for D3D11 it has offsets for CBV, SRV, UAV, and sampler bindings. This fixed-size offset type can be filled in based on Slang reflecton information, and then used to compute derived offsets with just a few add operations. The simple offset type for each API is then extended to produce an offset type that includes both the offsets for "primary" data and also the offsets for "pending" data. Most logic that traffics in offsets doesn't have to know about this more complicated representation. Making consistent use of these offsets required that I pretty much rewrite the logic that actually applies shader objects to the API state. Doing so might be lowering the efficiency of the system in the near term, but the increase in clarity was important for getting the work done, and it seems like it will also be important if/when we start trying to perform special-case optimizations around root and entry-point parameter setting. While there are many API-specific differences, we can identify a repeated pattern where many steps, whether applying parameters to the pipeline stage or constructing signatures / layouts, can be broken down into three main operations on `ShaderObject`s or their layouts: * `*AsValue()` is the core operation, and is the one used for the `ExistentialValue` case most of the time. It ignores the ordinary data in the object, and instead processes all nested binding ranges (for resources/smaplers) and sub-objects. * `*AsConstantBuffer()` handles the `ConstntBuffer` case, by dealing with the implicit buffer for ordinary data (if it is needed) and then delegates to the `*AsValue()` case. * `*AsParameterBlock()` handles the `ParameterBlock` case, by allocating/preparing/etc. any descriptor tables/sets that would be required for the current object/layout and then delegating to `*AsConstantBuffer()` to do the rest The idea is that by having the parameter block case delegate to the constant buffer case, which delegates to the value/existential case, we can streamline a lot of the logic so that it doesn't seem quite as full of special cases. Note: When preparing this pull request I spent a reasonable amount of time trying to clean up the D3D11 and Vulkan implementations, so they are probably the easiest to read and understand when it comes to the new code. Doing the cleanup work also helped to work out some weird corner case bugs/issues. In contrast, the D3D12 path hasn't had as much attention given to cleanliness and comments, so it really needs some attention down the line to get things into a state that is easier to understand. * fixup: remove debugging code spotted in review

Various fixes to make `model-viewer` example almost working. (#1801)

2021-04-20T20:17:29+00:00

* Fixing `PseudoPtr` legalization and `gfx` lifetime issues. * Fixing `model-viewer` example. This change contains various fixes to bring `model-viewer` example to fully functional. These fixes include: 1. Add `spReflectionTypeLayout_getSubObjectRangeSpaceOffset` function to return the space index for a sub object referenced through a `ParameterBlock` binding. 2. Make sure `D3D12Device` specifies column major matrix order creating a Slang session. 3. Fix `platform::Window::close()` and `platform::Application::quit()`. 4. Fix memory leak during `model-viewer''s model loading. 5. Fix command buffer recording in `model-viewer`. With these changes, model viewer can now produce an image with a gray cube. The lighting is still incorrect becuase the `gfx` shader object implementation still does not handle "pending layout" resulting from global existential parameters. * Fix d3d12 root signature creation. * Use row-major matrix layout in model-viewer

Update `model-viewer` example and fixing compiler bugs. (#1795)

2021-04-16T17:34:26+00:00

Refactor `gfx` to surface `CommandBuffer` interface. (#1735)

2021-03-05T00:25:58+00:00

* Refactor `gfx` to surface `CommandBuffer` interface. * Fixes. * Fix code review issues, and make vulkan runnable on devices without VK_EXT_extended_dynamic_states. * Update solution files * Move out-of-date examples to examples/experimental Co-authored-by: Yong He

Add callable shader support for Vulkan ray tracing (#718)

2018-11-12T17:57:46+00:00

* Add callable shader support for Vulkan ray tracing This change extends the previous work to update Vulkan ray tracing support for the finished `GL_NV_ray_tracing` spec. One of the features missing in the experimental extension that was added to the final spec is "callable shaders," which allow ray tracing shaders to call other shaders as general-purpose subroutines. Most of the implementation work here mirrors what was done for the `TraceRay()` function to map it to `traceNV()`. We map the generic `CallShader

` function to the non-generic `executeCallableNV`, with a payload identifier that indicates a specific global variable of type `P` (the global variable being generated from a `static` local in `CallShader`). A new modifier is added to identify the payload structure, and the parameter binding/layout logic introduces a new resource kind for callable-shader payload data (where previously the logic had assumed ray and callable payloads should use the same resource kind). Two test shaders are included: one for the callable shader (`callable.slang`) and one for a ray generation shader that calls it (`callable-caller.slang`). Just for kicks, the payload data type is defined in a shared file so that we can be sure the two agree (trying to emulate what might be good practice, and ensure that ray tracing support works together with other Slang mechanisms). * Typo fix: assocaited->associated One instance was found in review, but I went ahead and fixed a bunch since I seem to make this typo a lot. * Typo fix: defintiion->definition

Improve model-viewer support for lights (#626)

2018-08-11T05:21:44+00:00

* Improve model-viewer support for lights The main visible change here is that the model-viewer example supports multiple light sources, with a basic UI for adding new light sources to the scene, and for manipulating the ones that are there. Along the way I also refactored the `IMaterial` decomposition to be a bit less naive, while still only including a completely naive Blinn-Phong implementation. I also went ahead and spruced up the `cube.obj` file so that it has multiple materials, although it is still a completely uninteresting asset. * Fixup: Windows SDK version

Major overhaul of Renderer abstraction, to support a new example (#624)

2018-08-03T15:39:28+00:00

The original goal here was to bring up a second example program: `model-viewer`. While the existing `hello-world` example is enough to get somebody up to speed with the basics of the Slang API (as a drop-in replacement for `D3DCompile` or similar), it doesn't really show any of the big-picture stuff that Slang is meant to enable. There wasn't any use of D3D12/Vulkan descriptor tables/sets, and there wasn't any use of interfaces, generics, or `ParameterBlock`s in the shader code. The `model-viewer` example addresses these issues. Its shader code involves generics, interfaces, and multiple `ParameterBlock`s, and the host-side code demonstrates a few key things for working with Slang: * There is an application-level abstraction for parameter blocks, that combines the graphics-API descriptor set object with Slang type information * There is a shader cache layer used to look up an appropriate variant of a rendering effect by using parameter block types to "plug in" global type variables * There is a clear separation between the phases of compilation: a first phase that does semantic checking and enables reflection-based allocation of graphics API objects, followed by one or more code generation passes for specialized kernels. This example is certainly not perfect, and it will need to be revamped more going forward. In particular: * The output picture is ugly as sin. We need a plan for how to get this to load better content, perhaps even popping up an error message to note that the required input data isn't present in the basic repository. * The shader code is too simplistic. There isn't any real material variety, and the `IMaterial` abstraction is completely wrong. * The use of parameter blocks is facile because there are no resource parameters right now. Fixing that will likely expose issues around interfacing with Slang's reflection API. * The whole example exposes the issue that Slang's current APIs aren't really designed for the benefit of two-phase compilation (since our many client application has been stuck on one-phase compilation). * Global type parameters are actually a Bad Idea that we only did for compatibility with existing codebases. We should not be showing them off in an example of the Right Way to use Slang, but the language support for type parameters on entry points is still not complete. Of course, the majority of the changes here are *not* inside the example applications, and instead involve a major overhaul of the `Renderer` abstraction that is used for both tests and examples. The main thrust of the change is to make the abstraction layer be closer to the D3D12/Vulkan model than to a D3D11-style model. This is important for the `model-viewer` example, since it aspires to show how Slang can be incorporated into a renderer that targets a modern API. The most important bit is actually the use of descriptor sets and "pipeline layouts" a la Vulkan, since without these Slang's `ParameterBlock` abstraction won't make a lot of sense. Implementation of the abstraction for the various APIs has very much been on an as-needed basis. The current implementation is just enough for the two examples to work, plus enough to get all the tests to pass in both debug and release builds on Windows. A big missing feature in the API abstraction right now is memory lifetime management. The code had been trending toward something D3D11-like where a constant buffer could be mapped per-frame with the implementation doing behind-the-scenes allocation for targets like D3D12/Vulkan. I'd like to shift more toward a model of just exposing "transient" allocations that are only valid for one frame, because these are more representation of how an efficient renderer for next-generation APIs will work. That transition isn't actually complete, though, so there are problems with the existing examples where `hello-world` is actually scribbling into memory that the GPU might still be using, while `model-viewer` is doing full-on heavy-weight allocations on a per-frame basis with no real concern for the performance implications. All together, there are a lot of things here that need more work, but this branch has been way too long-lived already, and so I'd like to get this checked in as long as all the tests pass.