kc3-lang/angle

Diff

  • Show log

    Commit

  • Hash : abc8f277
    Author : Ian Elliott
    Date : 2019-12-19T10:47:31 

    Vulkan: Disallow multisampling with a sample count of 1

GLES uses a sample count of 0 to indicate non-multisampling, and a
sample count of 1 or greater to indicate multisampling.  While the
Vulkan specification seems to support multisampling with a sample count
of 1, the following spec language effectively disallows it (even when
the underlying Vulkan driver supports it):

    If the image was created with VkImageCreateInfo::samples equal to
    VK_SAMPLE_COUNT_1_BIT, the instruction must have MS = 0.

The following GLES 3.1 dEQP tests use shaders that look for the sample
position, with a sample count of 1:

    dEQP-GLES31.functional.texture.multisample.samples_1.*

For Vulkan drivers that fully support multisampling with a sample count
of 1, these tests pass, but get Vulkan validation errors because of the
above spec language.

This was discussed in the Khronos-private issue tracker (see:
https://gitlab.khronos.org/vulkan/vulkan/issues/1925).  The Vulkan
working group wondered if ANGLE could live with not supporting a sample
count of 1 (but upgrading such requests to the next-largest supported
sample count, per the GLES specification).  This change implements that
approach.

Bug: angleproject:4197
Bug: angleproject:4212
Change-Id: I009ba47b48efe5af464011c7c15022fc01f45e76
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1974842
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>
Commit-Queue: Ian Elliott <ianelliott@google.com>

  • Properties

  • Git HTTP https://git.kmx.io/kc3-lang/angle.git
    Git SSH git@git.kmx.io:kc3-lang/angle.git
    Public access ? public
    Description

    A conformant OpenGL ES implementation for Windows, Mac, Linux, iOS and Android.

    Homepage

    Github
    Users
    		 kc3_lang_org thodg_w www_kmx_io thodg_l thodg thodg_m
    Tags

  • README.md

  • ANGLE - Almost Native Graphics Layer Engine

    The goal of ANGLE is to allow users of multiple operating systems to seamlessly run WebGL and other OpenGL ES content by translating OpenGL ES API calls to one of the hardware-supported APIs available for that platform. ANGLE currently provides translation from OpenGL ES 2.0 and 3.0 to desktop OpenGL, OpenGL ES, Direct3D 9, and Direct3D 11. Support for translation from OpenGL ES to Vulkan is underway, and future plans include compute shader support (ES 3.1) and MacOS support.

    Level of OpenGL ES support via backing renderers

    Direct3D 9 Direct3D 11 Desktop GL GL ES Vulkan Metal
    OpenGL ES 2.0 complete complete complete complete complete in progress
    OpenGL ES 3.0 complete complete complete in progress
    OpenGL ES 3.1 in progress complete complete in progress
    OpenGL ES 3.2 planned planned planned

    Platform support via backing renderers

    Direct3D 9 Direct3D 11 Desktop GL GL ES Vulkan Metal
    Windows complete complete complete complete complete
    Linux complete complete
    Mac OS X complete in progress
    iOS planned
    Chrome OS complete planned
    Android complete complete
    Fuchsia in progress

    ANGLE v1.0.772 was certified compliant by passing the ES 2.0.3 conformance tests in October 2011. ANGLE also provides an implementation of the EGL 1.4 specification.

    ANGLE is used as the default WebGL backend for both Google Chrome and Mozilla Firefox on Windows platforms. Chrome uses ANGLE for all graphics rendering on Windows, including the accelerated Canvas2D implementation and the Native Client sandbox environment.

    Portions of the ANGLE shader compiler are used as a shader validator and translator by WebGL implementations across multiple platforms. It is used on Mac OS X, Linux, and in mobile variants of the browsers. Having one shader validator helps to ensure that a consistent set of GLSL ES shaders are accepted across browsers and platforms. The shader translator can be used to translate shaders to other shading languages, and to optionally apply shader modifications to work around bugs or quirks in the native graphics drivers. The translator targets Desktop GLSL, Direct3D HLSL, and even ESSL for native GLES2 platforms.

    Sources

    ANGLE repository is hosted by Chromium project and can be browsed online or cloned with

    git clone https://chromium.googlesource.com/angle/angle

    Building

    View the Dev setup instructions.

    Contributing

kmx.io     mail     discord kmxgit v0.4.0