bgfx - Cross-platform rendering library

What is it?

Cross-platform, graphics API agnostic, "Bring Your Own Engine/Framework" style rendering library.

Supported rendering backends:

• Direct3D 9
• Direct3D 11
• OpenGL 2.1
• OpenGL 3.1+
• OpenGL ES 2
• OpenGL ES 3.1
• WebGL 1.0

Supported HMD:

• OculusVR (0.4.2+)

Supported platforms:

• Android (14+, ARM, x86, MIPS)
• asm.js/Emscripten (1.25.0)
• FreeBSD
• iOS
• Linux
• Native Client (PPAPI 37+, ARM, x86, x64, PNaCl)
• OSX (10.9)
• RaspberryPi
• Windows (XP, Vista, 7, 8, 10)
• WinRT (WinPhone 8.0+)

Supported compilers:

• Clang 3.3 and above
• GCC 4.6 and above
• vs2008 and above

Languages:

• C99 API documentation
• C++ API documentation
• C#/VB/F# language API bindings
• D language API bindings
• Go language API bindings

Build status

https://tc27.draster.com/guestAuth/overview.html

Who is using it?

http://airmech.com/ AirMech is a free-to-play futuristic action real-time strategy video game developed and published by Carbon Games.

https://github.com/dariomanesku/cmftStudio cmftStudio - cubemap filtering tool.

https://github.com/taylor001/crown Crown is a general purpose data-driven game engine, written from scratch with a minimalistic and data-oriented design philosophy in mind.

https://github.com/emoon/ProDBG - ProDBG is a new debugger under development that will support a variety of targets and operating systems. Currently it's in very early development and primary focusing on Mac as primary target. This is how it currently looks.

http://www.dogbytegames.com/ Dogbyte Games is an indie mobile developer studio focusing on racing games.

https://github.com/andr3wmac/Torque6 Torque 6 is an MIT licensed 3D engine loosely based on Torque2D. Being neither Torque2D or Torque3D it is the 6th derivative of the original Torque Engine.

https://github.com/cgbystrom/twinkle GPU-accelerated UI framework powered by JavaScript for desktop/mobile apps. Idea is to combine the fast workflow and deployment model of web with the performance of native code and GPU acceleration.

Examples

Most of the examples require shader/texture/mesh data to be loaded. When running examples your current directory should be examples/runtime.

<bgfx_path>/examples/runtime $ ../../.build/<config>/bin/example-00-helloworldDebug

00-helloworld

Initialization and debug text.

01-cubes

Rendering simple static mesh.

02-metaballs

Rendering with transient buffers and embedding shaders.

03-raymarch

Updating shader uniforms.

04-mesh

Loading meshes.

05-instancing

Geometry instancing.

06-bump

Loading textures.

07-callback

Implementing application specific callbacks for taking screen shots, caching OpenGL binary shaders, and video capture.

08-update

Updating textures.

09-hdr

Using multiple views and render targets.

10-font

Use the font system to display text and styled text.

11-fontsdf

Use a single distance field font to render text of various size.

12-lod

Mesh LOD transitions.

13-stencil

Stencil reflections and shadows.

14-shadowvolumes

Shadow volumes.

15-shadowmaps-simple

16-shadowmaps

17-drawstress

60Hz

Draw stress is CPU stress test to show what is the maximimum number of draw calls while maintaining 60Hz frame rate. bgfx currently has default limit of 64K draw calls per frame. You can increase this limit by changing BGFX_CONFIG_MAX_DRAW_CALLS.

CPU	Renderer	GPU	Arch/Compiler/OS	Dim	Calls
i7-4770K 4.2	GL2.1	2xGTX780	x64/VS2013/Win 8.1	51	132651
i7-4770K 4.2	DX11	2xGTX780	x64/VS2013/Win 8.1	50	125000
i7-4790K 4.0	GL2.1	GTX970	x64/VS2015/Win 10	47	103823
i7-4790K 4.0	DX11	GTX970	x64/VS2015/Win 10	45	91125
i7-4790K 4.0	DX9	GTX970	x64/VS2013/Win 10	40	64000
i5-3570 3.8	NV 331.49	GTX560Ti	x64/GCC/Linux	40	64000+
i7-920 2.66	GL2.1	GTX650Ti	x64/VS2008/Win 7	38	54872
i7-920 2.66	GL2.1	GTX650Ti	x86/VS2008/Win 7	38	54872
i7-4790K 4.0	DX11	R7 240	x64/VS2015/Win 10	36	46656
i7-920 2.66	NV 331.113	GTX650Ti	x64/GCC/Linux	34	39304
i7-4790K 4.0	DX9	R7 240	x64/VS2015/Win 10	32	32768
i7-920 2.66	DX9	GTX650Ti	x64/GCC/Win 7	32	32768
i7-920 2.66	DX9	GTX650Ti	x64/VS2008/Win 7	32	32768
i7-920 2.66	DX9	GTX650Ti	x86/GCC/Win 7	30	27000
i7-920 2.66	DX9	GTX650Ti	x86/VS2008/Win 7	30	27000
i5-4250U 1.3	GL2.1	HD5000	x64/Clang/OSX 10.9	28	21852
Q8200 2.33	NV 319.32	GTX260	x64/GCC/Linux	27	19683
i7-2600K 3.4	DX9	AMD6800	x64/VS2012/Win 7	27	19683
i7-2600K 3.4	GL2.1	AMD6800	x64/VS2012/Win 7	26	17576
i7-4770R 3.2	Mesa 10.0.1	HD5200	x64/GCC/SteamOS	25	15625
i7-920 2.66	DX9-Wine	GTX650Ti	x64/GCC/Linux	24	13824
i7-4750HQ 2.0	Mesa 10.0.1	HD5200	x64/GCC/Linux	22	10648
i7-4750HQ 2.0	Mesa 10.1.3	HD5200	x64/GCC/Linux	21	9261
i7-920 2.66	ES2-ANGLE	GTX650Ti	x86/VS2008/Win 7	21	9261
Q8200 2.33	Gallium 0.4	AMD5770	x64/GCC/Linux	21	9261
i5-4250U 1.3	ES2	HD5000	JIT/Clang/PNaCl 31	21	9261
i5-4250U 1.3	ES2	HD5000	x86/GCC/NaCl 31	20	8000
Q8200 2.33	Gallium 0.4	GTX260	x64/GCC/Linux	19	6859
i5-2450M 2.5	Mesa 10.2.0	HD3000	x64/GCC/Linux	19	6859
i7-920 2.66	ES2-PowerVR	GTX650Ti	x86/VS2008/Win 7	18	5832
i7-920 2.66	FF27-GL	GTX650Ti	JIT/Clang/W7-asm.js	17	4913
i7-4750HQ 2.0	Mesa 8.0.5	LLVMPIPE	x64/GCC/Linux	16	4096
i7-920 2.66	ES2-Qualcomm	GTX650Ti	x86/VS2008/Win 7	15	3375
i7-920 2.66	ES2	GTX650Ti	x64/GCC/NaCl 31	15	3375
i7-920 2.66	ES2	GTX650Ti	JIT/Clang/PNaCl 31	15	3375
Q8200 2.33	NV 319.32	GTX260	x64/GCC/NaCl 31	15	3375
Q8200 2.33	NV 319.32	GTX260	x64/GCC/PNaCl 31	15	3375
'12 Nexus 7	ES2	Tegra3	ARM/GCC/Android	15	3375
i5-4250U 1.3	ES2-FF27	HD5000	JIT/Clang/OSX-asm.js	15	3375
i5-4250U 1.3	Chrome33	HD5000	JIT/Clang/OSX-asm.js	15	3375
iPad mini 2	ES2	PVR G6430	ARM64/Clang/iOS7	15	3375
i7-920 2.66	Chrome33	GTX650Ti	JIT/Clang/W7-asm.js	14	2744
i7-920 2.66	FF27-ANGLE	GTX650Ti	JIT/Clang/W7-asm.js	12	2744
'13 Nexus 10	ES2	Mali T604	ARM/GCC/Android	13	2197
iPhone 5	ES2	PVR SGX543	ARM/Clang/iOS7	13	2197
'13 Nexus 7	ES2	S4 Pro	ARM/GCC/Android	12	1728
iPad 2	ES2	PVR SGX543	ARM/Clang/iOS6	12	1728
Xperia Z	ES2	Adreno320	ARM/GCC/Android	11	1331
iPod 4	ES2	PVR SGX535	ARM/Clang/iOS6	7	343
i7-920 2.66	ES2-Mali	GTX650Ti	x86/VS2008/Windows7	6	216
RaspberryPi	ES2	VC IV	ARM/GCC/Raspbian	6	216

To test browsers in 60Hz mode following changes were made:

• Firefox 27 about:config adjustments: webgl.prefer-native-gl true (on Windows), and layout.frame_rate 500.
• Chrome 33 command line option: --disable-gpu-vsync.

30Hz (test for browsers)

By default browsers are using vsync, and don't have option to turn it off programatically.

CPU	Renderer	GPU	Arch/Compiler/OS	Dim	Calls
i7-920 2.66	GL2.1	GTX650Ti	x64/VS2008/Win7	38	64000+
i5-4250U 1.3	GL2.1	HD5000	x64/Clang/OSX 10.9	36	46656
i5-4250U 1.3	Chrome34	HD5000	JIT/Clang/OSX-PNaCl 31	28	21952
i5-4250U 1.3	Chrome33	HD5000	JIT/Clang/OSX-PNaCl 31	27	19683
i5-4250U 1.3	FF28	HD5000	JIT/Clang/OSX-asm.js	25	15625
i5-4250U 1.3	FF36	HD5000	JIT/Clang/OSX-asm.js	25	15625
i5-4250U 1.3	Chrome41	HD5000	x64/GCC/OSX-NaCl 41	24	13824
i5-4250U 1.3	FF37	HD5000	JIT/Clang/OSX-asm.js	23	12167
i5-4250U 1.3	FF27	HD5000	JIT/Clang/OSX-asm.js	20	8000
i7-920 2.66	Chrome33	GTX650Ti	JIT/Clang/W7-PNaCl 31	20	8000
i7-920 2.66	Chrome34	GTX650Ti	JIT/Clang/W7-asm.js	18	5832
i7-920 2.66	Chrome33	GTX650Ti	JIT/Clang/W7-asm.js	18	5832
i7-920 2.66	FF28	GTX650Ti	JIT/Clang/W7-asm.js	18	5832
i7-920 2.66	FF27	GTX650Ti	JIT/Clang/W7-asm.js	18	5832
i5-4250U 1.3	Safari7	HD5000	JIT/Clang/OSX-asm.js	15	3375

• JavaScript+WebGL port

18-ibl

Image based lighting.

19-oit

Weighted, Blended Order-Independent Transparency

20-nanovg

NanoVG is small antialiased vector graphics rendering library.

21-deferred

MRT rendering and deferred shading.

22-windows

Rendering into multiple windows.

23-vectordisplay

Rendering lines as oldschool vectors.

24-nbody

N-body simulation with compute shaders using buffers.

25-c99

Initialization and debug text with C99 API.

Dependencies

https://github.com/bkaradzic/bx

Building

Steps bellow are for default build system inside bgfx repository. There is alterative way to build bgfx and examples with fips.

Binary builds (for Windows and Linux) are also available here.

Getting source

git clone git://github.com/bkaradzic/bx.git
git clone git://github.com/bkaradzic/bgfx.git

Quick start (Windows with Visual Studio)

Enter bgfx directory:

cd bgfx

Generate Visual Studio 2013 project files:

..\bx\tools\bin\windows\genie vs2013

Open bgfx solution in Visual Studio 2013:

start .build\projects\vs2013\bgfx.sln

Generating project files for all targets

cd bgfx
make

After calling make, .build/projects/* directory will be generated. All intermediate files generated by compiler will be inside .build directory structure. Deleting .build directory at any time is safe.

Prerequisites for Android

Download AndroidNDK from:
https://developer.android.com/tools/sdk/ndk/index.html

setx ANDROID_NDK_ROOT <path to AndroidNDK directory>
setx ANDROID_NDK_ARM <path to AndroidNDK directory>\toolchains\arm-linux-androideabi-4.7\prebuilt\windows-x86_64
setx ANDROID_NDK_MIPS <path to AndroidNDK directory>\toolchains\mipsel-linux-android-4.7\prebuilt\windows-x86_64
setx ANDROID_NDK_X86 <path to AndroidNDK directory>\toolchains\x86-4.7\prebuilt\windows-x86_64

Prerequisites for Linux

sudo apt-get install libgl1-mesa-dev

Prerequisites for Native Client

Download Native Client SDK from:
https://developers.google.com/native-client/sdk/download

setx NACL_SDK_ROOT <path to Native Client SDK directory>

Prerequisites for Windows

Windows users download GnuWin32 utilities from:
http://gnuwin32.sourceforge.net/packages/make.htm
http://gnuwin32.sourceforge.net/packages/coreutils.htm
http://gnuwin32.sourceforge.net/packages/libiconv.htm
http://gnuwin32.sourceforge.net/packages/libintl.htm

When building on Windows, you have to set DXSDK_DIR environment variable to point to DirectX SDK directory.

setx DXSDK_DIR <path to DirectX SDK directory>

If you're building with Visual Studio 2008, you'll need TR1 support from:
Visual C++ 2008 Feature Pack Release

If you're building with MinGW/TDM compiler on Windows make DirectX SDK directory link to directory without spaces in the path.

mklink /D c:\dxsdk <path to DirectX SDK directory>
setx DXSDK_DIR c:\dxsdk

Apply this patch to DXSDK from June 2010 to be able to use it with MinGW/TDM.

Building

Visual Studio 2008 command line:

make vs2008-release64

Visual Studio 2008 IDE:

start .build/projects/vs2008/bgfx.sln

Xcode 5 IDE:

open .build/projects/xcode4/bgfx.xcworkspace

Due to inability to set working directory for an Xcode project from premake configuration file, it has to be set manually for each example project:

1. Open "Edit scheme..." dialog for a given project.
2. Select "Run" settings.
3. Check "Use custom working directory" and enter following path: ${PROJECT_DIR}/../../../examples/runtime.

Linux 64-bit:

make linux-release64

WinRT / Windows Phone 8.1:

../bx/tools/bin/windows/genie --vs=winphone81 vs2013

Build the resulting solution and deploy to device. Note that shaders will need to be compiled with the appropriate target profile for your platform.

Other platforms:

make <configuration>

Configuration is <platform>-<debug/release>[32/64]. For example:

linux-release32, nacl-debug64, nacl-arm-debug, pnacl-release, 
android-release, etc.

Amalgamated build

For ease of integration to other build system bgfx library can be built with single .cpp file. It's only necessary to build src/amalgamated.cpp inside different build system.

OculusVR integration

OculusVR support is currently experimental, and only DX11 is tested. To build with OculusVR HMD support enabled you must set OVR_DIR enviroment variable:

set OVR_DIR=<path to OculusSDK>

And generate project files with --with-ovr option:

genie --with-ovr vs2012

In LibOVR/Include create trampoline headers OVR_D3D.h and OVR_GL.h.

OVR_D3D.h should contain:

#include "../Src/OVR_CAPI_D3D.h"

OVR_GL.h should contain:

#include "../Src/OVR_CAPI_GL.h"

Internals

bgfx is using sort-based draw call bucketing. This means that submission order doesn't necessarily match the rendering order, but on the low-level they will be sorted and ordered correctly. On the high level this allows more optimal way of submitting draw calls for all passes at one place, and on the low-level this allows better optimization of rendering order. This sometimes creates undesired results usually for GUI rendering, where draw order should usually match submit order. bgfx provides way to enable sequential rendering for these cases (see bgfx::setViewSeq).

Internally all low-level rendering draw calls are issued inside single function Context::rendererSubmit. This function exist inside each renderer backend implementation.

More detailed description of sort-based draw call bucketing can be found at:
Order your graphics draw calls around!

Customization

By default each platform has sane default values. For example on Windows default renderer is DirectX9, and on Linux it is OpenGL 2.1. On Windows platform all rendering backends are available. For OpenGL ES on desktop you can find more information at:- OpenGL ES 2.0 and EGL on desktop

If you're targeting specific mobile hardware, you can find GLES support in their official SDKs: Adreno SDK, Mali SDK, PowerVR SDK.

All configuration settings are located inside src/config.h.

Every BGFX_CONFIG_* setting can be changed by passing defines thru compiler switches. For example setting preprocessor define BGFX_CONFIG_RENDERER_OPENGL=1 will change backend renderer to OpenGL 2.1. on Windows. Since rendering APIs are platform specific, this obviously won't work nor make sense in all cases. Certain platforms have only single choice, for example the Native Client works only with OpenGL ES 2.0 renderer, using anything other than that will result in build errors.

Debugging and Profiling

RenderDoc

Loading of RenderDoc is integrated in bgfx when using DX11 or OpenGL renderer. You can drop in renderdoc.dll from RenderDoc distribution into working directory, and it will be automatically loaded during bgfx initialization. This allows frame capture at any time by pressing F11.

Download: RenderDoc

IntelGPA

Right click Intel GPA Monitor tray icon, choose preferences, check "Auto-detect launched applications" option. Find InjectionList.txt in GPA directory and add examples-* to the list.

Download: IntelGPA

Other debuggers:

Name	OS	DX9	DX11	GL	GLES	Source
APITrace	Linux/OSX/Win	x	x	x	x	x
CodeXL	Linux/Win			x
Dissector	Win	x				x
IntelGPA	Linux/OSX/Win	x	x		x
Nsight	Win	x	x	x
PerfHUD	Win	x	x
RenderDoc	Win		x	x		x
vogl	Linux			x		x

Download:
APITrace
CodeXL
Dissector
Nsight
PerfHUD
vogl

SDL, GLFW, etc.

It is possible to use bgfx with SDL, GLFW and similar cross platform windowing libraries. The main requirement is that windowing library provides access to native window handle that's used to create Direct3D device or OpenGL context.

Using bgfx with SDL example:

#include <SDL.h>
#include <bgfxplatform.h> // it must be included after SDL to enable SDL
                          // integration code path.

#include <bgfx.h>
...

int main(...
{
    SDL_window* window = SDL_CreateWindow(...
    bgfx::sdlSetWindow(window);

    ...
    bgfx::init();

NOTE You can use --with-sdl when runnning GENie to enable SDL2 integration with examples:

genie --with-sdl vs2012

NOTE --with-glfw is also available, but it's just simple stub to be used to test GLFW integration API.

NOTE Special care is necessary to make custom windowing to work with multithreaded renderer. Each platform has rules about where renderer can be and how multithreading interacts with context/device. To disable multithreaded render use BGFX_CONFIG_MULTITHREDED=0 preprocessor define.

Tools

Shader Compiler (shaderc)

bgfx cross-platform shader language is based on GLSL syntax. It's uses ANSI C preprocessor to transform GLSL like language syntax into HLSL. This technique has certain drawbacks, but overall it's simple and allows quick authoring of cross-platform shaders.

Some differences between bgfx's shaderc flavor of GLSL and regular GLSL:

• No bool/int uniforms, all uniforms must be float.
• Attributes and varyings can be accessed only from main() function.
• Must use SAMPLER2D/3D/CUBE/etc. macros instead of sampler2D/3D/Cube/etc. tokens.
• Must use vec2/3/4_splat(<value>) instead of vec2/3/4(<value>).
• Must use mul(x, y) when multiplying vectors and matrices.
• Must use varying.def.sc to define input/output semantic and precission instead of using attribute/in and varying/in/out.
• $input/$output tokens must appear at the begining of shader.

For more info see shader helper macros.

Texture Compiler (texturec)

This tool doesn't currently exist. To produce DDS, KTX or PVR textures use:

.dds - nVidia Texture Tools - DDS Utilities
.ktx - Mali GPU Texture Compression Tool
.pvr - PowerVR Insider SDK

Geometry Compiler (geometryc)

Converts Wavefront .obj mesh file to format optimal for using with bgfx.

Todo

• Blit between textures.
• Occlusion queries.
• Fullscreen mode.
• ETC2, PVRTC1/2 decoding fallback for targets that don't support it natively.
• shaderc as library for runtime shader building.
• texturec tool with support for all supported texture formats.
• Multiple vertex streams support.
• Animated mesh example.
• Direct3D 12 renderer backend.
• Metal renderer backend.
• Vulkan renderer backend.

Contact

@bkaradzic

Project page
https://github.com/bkaradzic/bgfx

3rd Party Libraries

All required 3rd party libraries are included in bgfx repository in 3rdparty/ directory.

Blendish (MIT)

Blendish - Blender 2.5 UI based theming functions for NanoVG.

https://bitbucket.org/duangle/oui-blendish

edtaa3 (MIT)

Contour Rendering by Distance Fields

https://github.com/OpenGLInsights/OpenGLInsightsCode/tree/master/Chapter%2012%202D%20Shape%20Rendering%20by%20Distance%20Fields

fcpp (BSD)

Frexx C preprocessor

https://github.com/bagder/fcpp

Forsyth Triangle Order Optimizer (Public Domain)

http://gameangst.com/?p=9

FreeType

http://www.freetype.org/

glsl-optimizer (MIT)

GLSL optimizer based on Mesa's GLSL compiler. Used in Unity for mobile shader optimization.

https://github.com/aras-p/glsl-optimizer

NanoVG (ZLIB)

NanoVG is small antialiased vector graphics rendering library.

https://github.com/memononen/nanovg

ImGui (MIT)

Bloat-free Immediate Mode Graphical User interface for C++ with minimal dependencies.

https://github.com/ocornut/imgui

SDF (MIT)

Sweep-and-update Euclidean distance transform of an antialised image for contour texturing.

https://github.com/memononen/SDF

stb (Public Domain)

http://nothings.org

Vertex Cache Optimised Index Buffer Compression (BSD)

https://github.com/ConorStokes/IndexBufferCompression

Assets

Bunny
Stanford University Computer Graphics Laboratory

Uffizi
Light Probe Image Gallery

Wells
Bernhard Vogl Light probes

Pisa, Ennis, Grace
High-Resolution Light Probe Image Gallery

Droid Sans Font
http://www.fontsquirrel.com/license/Droid-Sans

Bleeding Cowboys Font
http://www.dafont.com/bleeding-cowboys.font

Cheap Fire Font
http://www.dafont.com/cheap-fire.font

Five Minutes Font
http://www.fonts2u.com/fiveminutes.font

Mias Scribblings Font
http://www.dafont.com/mias-scribblings.font

Ruritania Font
http://www.dafont.com/ruritania.font

Signika Font
http://fontfabric.com/signika-font/

Visitor Font
http://www.dafont.com/visitor.font

Special-Elite Font
http://www.fontspace.com/astigmatic-one-eye-typographic-institute/special-elite

FontAwesome Font
http://fontawesome.io/

Sherlock Holmes text
http://www.gutenberg.org/ebooks/1661

Tree Pack 1
http://www.turbosquid.com/3d-models/free-obj-mode-tree-pack/506851

Getting involved

Everyone is welcome to contribute to bgfx by submitting bug reports, testing on different platforms, writing examples, improving documentation, profiling and optimizing, etc.

When contributing to the bgfx project you must agree to the BSD 2-clause licensing terms.

Contributors

Garett Bass (@gtbass) - OSX port.
Jeremie Roy (@jeremieroy) - Font system and examples.
Miloš Tošić (@milostosic) - 12-lod example.
Dario Manesku (@dariomanesku) - 13-stencil, 14-shadowvolumes, 15-shadowmaps-simple, 16-shadowmaps, 18-ibl
James Gray (@james4k) - Go language API bindings.
Guillaume Piolat (@p0nce) - D language API bindings.
Mike Popoloski (@MikePopoloski) - C#/VB/F# language API bindings, WinRT/WinPhone support.
Kai Jourdan (@questor) - 23-vectordisplay example
Stanlo Slasinski (@stanlo) - 24-nbody example
Daniel Collin (@emoon) - Port of Ocornut's ImGui to bgfx.
Andre Weissflog (@floooh) - Alternative build system fips.
Andrew Johnson (@ajohnson23) - TeamCity build.

License (BSD 2-clause)

Copyright 2010-2015 Branimir Karadzic. All rights reserved.

https://github.com/bkaradzic/bgfx

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

   1. Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.

   2. Redistributions in binary form must reproduce the above copyright notice,
      this list of conditions and the following disclaimer in the documentation
      and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
EVENT SHALL COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.