/*
This file is part of Magnum.
Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019,
2020, 2021, 2022, 2023 Vladimír Vondruš <mosra@centrum.cz>
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
*/
namespace Magnum {
/** @page platforms-gl OpenGL and OpenGL ES platforms
@brief Information common for all platforms that support OpenGL and OpenGL ES
@tableofcontents
@m_keyword{ANGLE OpenGL compatibility layer,,}
@m_footernavigation
@todoc desktop gles
@section platforms-gl-best-practices OpenGL best practices
Various links gathered around the web:
- [Performance tuning applications for Intel Graphics for Linux and Chrome OS](http://software.intel.com/sites/default/files/Performance-tuning-applications-for-Intel-GEN-Graphics-for-Linux-and-Google-Chrome-OS.pdf) [PDF]
- [PowerVR Performance Recommendations](https://github.com/burningsun/pecker_framework/blob/master/参考资料/PowerVR.Performance%20Recommendations.pdf?raw=true) [PDF]
- [ATI Radeon HD 2000 programming guide](http://developer.amd.com/wordpress/media/2012/10/ATI_Radeon_HD_2000_programming_guide.pdf) [PDF]
@section platforms-gl-es OpenGL ES
@subsection platforms-gl-es-best-practices OpenGL ES best practices
Various links gathered around the web:
- [Writing Portable OpenGL ES 2.0](https://www.khronos.org/assets/uploads/developers/library/2011-siggraph-mobile/Writing-Portable-OpenGL-ES-2.0_Aug-11.pdf) [PDF]
- [Optimize OpenGL ES 2.0 Performance for Tegra](http://docs.nvidia.com/tegra/index.html#GLES2_Perf_Main.html)
- [Qualcomm Adreno Best Practices](https://developer.qualcomm.com/sites/default/files/docs/adreno-gpu/snapdragon-game-toolkit/gdg/gpu/best_practices.html)
@subsection platforms-gl-es-differences Differences to desktop GL
- Rendering to RGB textures doesn't work on many platforms, either due to
alignment issues or other factors. For example it is not possible to render
to @ref GL::TextureFormat::RGB8 on iOS (but it works elsewhere); rendering
to @ref GL::TextureFormat::RGB32F is not possible even on NVidia. Use RGBA
formats instead.
- While on desktop GL it's often permitted to upload a RGB image to a texture
with RGBA internal format, on mobile devices usually nothing happens. Be
sure to match the component count.
- Rendering to 16- and 32-bit float textures is only possible with OpenGL ES
3.2 or with the @gl_extension{EXT,color_buffer_half_float} and
@gl_extension{EXT,color_buffer_float} extensions. You can work around that
issue by rendering to 32-bit unsigned integer textures and using the
@glsl floatBitsToUInt() @ce GLSL function instead.
- Linear filtering on 32-bit float textures is only possible with
@gl_extension{OES,texture_float_linear} (it's not even on ES 3.2 yet). You can
work around that issue by using half-float texture formats or doing the
interpolation manually in a shader.
@subsection platforms-gl-es-angle ANGLE OpenGL ES translation layer
[ANGLE](https://github.com/google/angle) is a layer that translates OpenGL ES
code to D3D, desktop GL, Vulkan or Metal, originally created for web browsers
to provide better WebGL experience without relying on buggy OpenGL drivers on
Windows or abandoned OpenGL drivers on Apple platforms. See
@ref platforms-macos-gl-angle and @ref platforms-windows-gl-angle for further
information.
Related links:
- [Getting Good Performance From ANGLE](https://github.com/microsoft/angle/wiki/Getting-Good-Performance-From-ANGLE)
- [WebGL Insights --- ANGLE](https://books.google.cz/books?id=6crECQAAQBAJ&lpg=PP1&pg=PA3&redir_esc=y#v=onepage&q&f=true)
*/
}
