moltenvk/README.md
Bill Hollings 2d4de6db68 Fixes to attachment and image clearing to pass CTS tests.
MVKCmdClearAttachments support clearing multiple attachment layers.
MVKCmdClearImage use renderpass clear, and support clearning multiple image layers.
Rename mvkCmdClearImage() to mvkCmdClearColorImage().
MVKDevice add getFormatIsSupported() to allow devices to test for format support.
MVKFramebuffer support multiple layers.
mvk_datatypes.h support both 2D and 3D mipmap calculations and allow
mvkMTLPrimitiveTopologyClassFromVkPrimitiveTopology() in iOS.
Remove support for VK_FORMAT_B10G11R11_UFLOAT_PACK32 & VK_FORMAT_E5B9G9R9_UFLOAT_PACK32
since format components are reversed on Metal.
Move OS extension source files to new OS directory.
Update to latest SPIRV-Cross version.
Update MoltenVK version to 1.0.16.
2018-07-23 20:12:57 -04:00

267 lines
12 KiB
Markdown

<a class="site-logo" href="https://github.com/KhronosGroup/MoltenVK" title="MoltenVK">
<img src="Docs/images/MoltenVK-Logo-Banner.png" alt="MoltenVK" style="width:256px;height:auto">
</a>
MoltenVK
========
Copyright (c) 2014-2018 [The Brenwill Workshop Ltd.](http://www.brenwill.com)
*This document is written in [Markdown](http://en.wikipedia.org/wiki/Markdown) format.
For best results, use a Markdown reader.*
[![Build Status](https://travis-ci.org/KhronosGroup/MoltenVK.svg?branch=master)](https://travis-ci.org/KhronosGroup/MoltenVK)
Table of Contents
-----------------
- [About This Document](#about_this)
- [Introduction](#intro)
- [Installing **MoltenVK**](#install)
- [Building **MoltenVK**](#building)
- [Running the **MoltenVK** Demo Applications](#demos)
- [Using **MoltenVK** in Your Application](#using)
- [**MoltenVK** and *Vulkan* Compliance](#compliance)
- [Contributing to **MoltenVK** Development](#contributing)
<a name="about_this"></a>
About This Document
-------------------
This document describes how to use the **MoltenVK** open-source repository to build a **MoltenVK**
runtime distribution package.
To learn how to integrate the **MoltenVK** runtime into a game or application, see the
[`Docs/MoltenVK_Runtime_UserGuide.md `](Docs/MoltenVK_Runtime_UserGuide.md) document in the `Docs` directory.
If you are just looking for a pre-built **MoltenVK** runtime binary, you can download it as part of the
[*LunarG SDK*](https://vulkan.lunarg.com).
<a name="intro"></a>
Introduction
------------
**MoltenVK** is an implementation of the [*Vulkan 1.0*](https://www.khronos.org/vulkan)
graphics and compute API, that runs on Apple's [*Metal*](https://developer.apple.com/metal)
graphics and compute framework on both *iOS* and *macOS*.
**MoltenVK** allows you to use the *Vulkan* graphics and compute API to develop modern,
cross-platform, high-performance graphical games and applications, and to run them across
many platforms, including both *iOS* and *macOS*.
*Metal* uses a different shading language, the *Metal Shading Language (MSL)*, than
*Vulkan*, which uses *SPIR-V*. **MoltenVK** automatically converts your *SPIR-V* shaders
to their *MSL* equivalents.
To provide *Vulkan* capability to the *iOS* and *macOS* platforms, **MoltenVK** uses *Apple's*
publicly available API's, including *Metal*. **MoltenVK** does **_not_** use any private or
undocumented API calls or features, so your app will be compatible with all standard distribution
channels, including *Apple's App Store*.
**MoltenVK** contains two products:
- **MoltenVK** is an implementation of the [*Vulkan 1.0*](https://www.khronos.org/vulkan)
graphics and compute API.
- **MoltenVKShaderConverter** converts *SPIR-V* shader code to *Metal Shading Language (MSL)*
shader code, and converts *GLSL* shader source code to *SPIR-V* shader code and/or
*Metal Shading Language (MSL)* shader code. The *SPIR-V* converter is included in the
**MoltenVK** runtime to automatically convert *SPIR-V* shaders to their *MSL* equivalents.
In addition, both the *SPIR-V* and *GLSL* converters can be be packaged into a stand-alone
command-line *macOS* tool for converting shaders at development time.
<a name="install"></a>
Installing **MoltenVK**
-----------------------
To install **MoltenVK**, clone this `MoltenVK` repository, and then run the
`fetchDependencies` script to retrieve and build several external
open-source libraries on which **MoltenVK** relies:
1. Ensure you have `cmake` and `python3` installed:
brew install cmake
brew install python
For faster dependency builds, you can also optionally install `ninja`:
brew install ninja
2. Clone the `MoltenVK` repository:
git clone https://github.com/KhronosGroup/MoltenVK.git
3. Retrieve and build the external libraries:
cd MoltenVK
./fetchDependencies
For more information about the external open-source libraries used by **MoltenVK**,
see the [`ExternalRevisions/README.md`](ExternalRevisions/README.md) document.
<a name="building"></a>
Building **MoltenVK**
-------------------
At development time, **MoltenVK** references advanced OS frameworks during building.
- *Xcode 9* or above is required to build and link **MoltenVK** projects.
Once built, **MoltenVK** can be run on *iOS* or *macOS* devices that support *Metal*.
- **MoltenVK** requires at least *macOS 10.11* or *iOS 9*.
- Information on *macOS* devices that are compatible with *Metal* can be found in
[this article](http://www.idownloadblog.com/2015/06/22/how-to-find-mac-el-capitan-metal-compatible).
- Information on compatible *iOS* devices that are compatible with *Metal* can be found in
[this article](https://developer.apple.com/library/content/documentation/DeviceInformation/Reference/iOSDeviceCompatibility/HardwareGPUInformation/HardwareGPUInformation.html).
>***Note:*** To support `IOSurfaces` on *iOS*, **MoltenVK**, and any app that uses **MoltenVK**,
must be built with a minimum **iOS Deployment Target** (aka `IPHONEOS_DEPLOYMENT_TARGET `) build
setting of `iOS 11.0` or greater.
The `MoltenVKPackaging.xcodeproj` *Xcode* project contains targets and schemes to build
and package the entire **MoltenVK** runtime distribution package, or to build individual
**MoltenVK** or **MoltenVKShaderConverter** components.
To build a **MoltenVK** runtime distribution package, suitable for testing and integrating into an app,
open `MoltenVKPackaging.xcodeproj` in *Xcode*, and use one of the following *Xcode Schemes*:
- **MoltenVK (Release)** - build the entire **MoltenVK** runtime distribution package using the
*Release* configuration.
- **MoltenVK (Debug)** - build the entire **MoltenVK** runtime distribution package using the
*Debug* configuration.
Each of these`MoltenVKPackaging.xcodeproj` *Xcode* project *Schemes* puts the resulting packages in the
`Package` directory, creating it if necessary. This directory contains separate `Release` and `Debug`
directories, holding the most recent **Release** and **Debug** builds, respectively.
A separate `Latest` directory links to the most recent build, regardless of whether it was a **Release**
or **Debug** build. Effectively, the `Package/Latest` directory points to whichever of the `Package/Release`
or `Package/Debug` directories was most recently updated.
With this packaging structure, you can follow the [instructions below](#using) to link your application
to the **MoltenVK** frameworks in the `Package/Latest` directory, to provide the flexibility to test your
app with either a **Debug** build, or a higher-performance **Release** build.
### Building from the Command Line
If you prefer to build **MoltenVK** from the command line, or to include the activity in a larger build script,
you can do so using the following command from within the `MoltenVK` repository:
xcodebuild -project MoltenVKPackaging.xcodeproj -scheme "MoltenVK (Release)" build
or
xcodebuild -project MoltenVKPackaging.xcodeproj -scheme "MoltenVK (Debug)" build
<a name="demos"></a>
Running the **MoltenVK** Demo Applications
------------------------------------------
Once you have compiled and built the **MoltenVK** runtime distribution package from this **MoltenVK** repository,
as described in the [Building **MoltenVK**](#building) section, you can explore how **MoltenVK** provides *Vulkan*
support on *iOS* and *macOS* by investigating and running the demo applications that are included in **MoltenVK**.
The **MoltenVK** demo apps are located in the `Demos` folder. Each demo app is available as an *Xcode* project.
To review and run the included demo apps, open the `Demos/Demos.xcworkspace` workspace in *Xcode*.
Please read the [`Demos/README.md`](Demos/README.md) document for a description of each demo app, and instructions
on running the demo apps. Several of the demo apps allow you to explore a variety of *Vulkan* features by modifying
*Xcode* build settings. Additional demos can be downloaded and built from external repositories, as described in the
[`Demos/README.md`](Demos/README.md) document
<a name="using"></a>
Using **MoltenVK** in Your Application
--------------------------------------
Once you have compiled and built the **MoltenVK** runtime distribution package from this **MoltenVK** repository,
as described in the [Building **MoltenVK**](#building) section, follow the instructions in the Installation
section of the [`Docs/MoltenVK_Runtime_UserGuide.md`](Docs/MoltenVK_Runtime_UserGuide.md#install) document in the
`Docs` directory, to link the **MoltenVK** frameworks and libraries to your application.
The runtime distribution package in the `Package/Latest` directory is a stand-alone package, and you can copy
the contents of that directory out of this **MoltenVK** repository into your own application building environment.
<a name="compliance"></a>
**MoltenVK** and *Vulkan* Compliance
------------------------------------
**MoltenVK** is designed to be a *Vulkan 1.0* driver that runs on *macOS* and *iOS* platforms by mapping *Vulkan*
capability to native *Metal* capability.
The fundamental design and development goal of **MoltenVK** is to provide this capability in a way that
is both maximally compliant with the *Vulkan 1.0* specification, and maximally performant.
Such compliance and performance is inherently affected by the capability available through *Metal*, as the
native driver on *macOS* and *iOS* platforms. *Vulkan* compliance may fall into one of the following categories:
- Direct mapping between *Vulkan* capabilities and *Metal* capabilities. Within **MoltenVK**, almost all capability
is the result of this type of direct mapping.
- Synthesized compliance through alternate implementation. A very small amount of capability is provided using
this mechanism, such as via an extra render or compute shader stage.
- Non-compliance. This appears where the capabilities of *Vulkan* and *Metal* are sufficiently different, that
there is no practical, or reasonably performant, mechanism to implement a *Vulkan* capability in *Metal*.
Because of design differences between *Vulkan* and *Metal*, a very small amount of capability falls into this
category, and at present **MoltenVK** is **_not_** fully compliant with the *Vulkan* specification. A list of
known limitations is documented in the [`Docs/MoltenVK_Runtime_UserGuide.md`](Docs/MoltenVK_Runtime_UserGuide.md#limitations)
document in the `Docs` directory.
The **MoltenVK** development team welcomes you to [post Issues](https://github.com/KhronosGroup/MoltenVK/issues)
of non-compliance, and engage in discussions about how compliance can be improved, and non-compliant features can
be implemented or worked around.
**MoltenVK** is a key component of the [*Khronos Vulkan Portability Initiative*](https://www.khronos.org/vulkan/portability-initiative),
whose intention is to provide specifications, resources, and tools to allow developers to understand and design
their *Vulkan* apps for maximum cross-platform compatibility and portability, including on platforms, such as
*macOS* and *iOS*, where a native *Vulkan* driver is not available.
<a name="contributing"></a>
Contributing to **MoltenVK** Development
----------------------------------------
As a public open-source project, **MoltenVK** benefits from code contributions from a wide range of developers,
and we encourage you to get involved and contribute code to this **MoltenVK** repository.
To contribute your code, submit a [Pull Request](https://github.com/KhronosGroup/MoltenVK/pulls)
to this repository. The first time you do this, you will be asked to agree to the **MoltenVK**
[Contributor License Agreement](https://cla-assistant.io/KhronosGroup/MoltenVK).
### Licensing
**MoltenVK** is licensed under the Apache 2.0 license. All new source code files should include a
copyright header at the top, containing your authorship copyright and the Apache 2.0 licensing stub.
You may copy the text from an existing source code file as a template.
The Apache 2.0 license guarantees that code in the **MoltenVK** repository is free of Intellectual Property
encumbrances. In submitting code to this repository, you are agreeing that the code is free of any Intellectual
Property claims.
### Code Formatting
When contributing code, please honour the code formatting style found in existing **MoltenVK** source code.
In future, this will formally be enforced using `clang-format`.